Ning, Su; Yong-Jie, Xu
2016-12-13
Relevant projects carried out within the Yangtze River economic belt on the impact of schistosomiasis epidemic and transmission are important issues for "ecological priority" in the process of implementing the strategy. The key problems of schistosomiasis epidemic risk, epidemic happening repeatedly, difficulty of rehabilitating Oncomelania hupensis snail control and schistosomiasis prevention forest, lag of evaluation system and platform construction, lack of basic research, et al. were analyzed in the Yangtze River economic belt taking "ecological priority" as the basis in this paper. Then corresponding countermeasures to these challenges were put forward so as to provide the reference for the national forestry schistosomiasis control programs, which include: execution of the comprehensive prevention and control strategy, scheming of the new round of forestry schistosomiasis control programs, strengthening schistosomiasis prevention and control, promoting productivity in existing forestry to consolidate and improve the achievements of previous forestry schistosomiasis control programs, and promoting the intensity of technological innovation to improve the technological level of forestry schistosomiasis control programs.
Sokolow, Susanne H.; Wood, Chelsea L.; Jones, Isabel J.; Lopez, Melina; Lafferty, Kevin D.; Kuris, Armand M.; Rickards, Chloe; De Leo, Giulio A.
2016-01-01
Background Despite control efforts, human schistosomiasis remains prevalent throughout Africa, Asia, and South America. The global schistosomiasis burden has changed little since the new anthelmintic drug, praziquantel, promised widespread control. Methodology We evaluated large-scale schistosomiasis control attempts over the past century and across the globe by identifying factors that predict control program success: snail control (e.g., molluscicides or biological control), mass drug administrations (MDA) with praziquantel, or a combined strategy using both. For data, we compiled historical information on control tactics and their quantitative outcomes for all 83 countries and territories in which: (i) schistosomiasis was allegedly endemic during the 20th century, and (ii) schistosomiasis remains endemic, or (iii) schistosomiasis has been "eliminated," or is "no longer endemic," or transmission has been interrupted. Principal Findings Widespread snail control reduced prevalence by 92 ± 5% (N = 19) vs. 37 ± 7% (N = 29) for programs using little or no snail control. In addition, ecological, economic, and political factors contributed to schistosomiasis elimination. For instance, snail control was most common and widespread in wealthier countries and when control began earlier in the 20th century. Conclusions/Significance Snail control has been the most effective way to reduce schistosomiasis prevalence. Despite evidence that snail control leads to long-term disease reduction and elimination, most current schistosomiasis control efforts emphasize MDA using praziquantel over snail control. Combining drug-based control programs with affordable snail control seems the best strategy for eliminating schistosomiasis. PMID:27441556
Sokolow, Susanne H; Wood, Chelsea L; Jones, Isabel J; Swartz, Scott J; Lopez, Melina; Hsieh, Michael H; Lafferty, Kevin D; Kuris, Armand M; Rickards, Chloe; De Leo, Giulio A
2016-07-01
Despite control efforts, human schistosomiasis remains prevalent throughout Africa, Asia, and South America. The global schistosomiasis burden has changed little since the new anthelmintic drug, praziquantel, promised widespread control. We evaluated large-scale schistosomiasis control attempts over the past century and across the globe by identifying factors that predict control program success: snail control (e.g., molluscicides or biological control), mass drug administrations (MDA) with praziquantel, or a combined strategy using both. For data, we compiled historical information on control tactics and their quantitative outcomes for all 83 countries and territories in which: (i) schistosomiasis was allegedly endemic during the 20th century, and (ii) schistosomiasis remains endemic, or (iii) schistosomiasis has been "eliminated," or is "no longer endemic," or transmission has been interrupted. Widespread snail control reduced prevalence by 92 ± 5% (N = 19) vs. 37 ± 7% (N = 29) for programs using little or no snail control. In addition, ecological, economic, and political factors contributed to schistosomiasis elimination. For instance, snail control was most common and widespread in wealthier countries and when control began earlier in the 20th century. Snail control has been the most effective way to reduce schistosomiasis prevalence. Despite evidence that snail control leads to long-term disease reduction and elimination, most current schistosomiasis control efforts emphasize MDA using praziquantel over snail control. Combining drug-based control programs with affordable snail control seems the best strategy for eliminating schistosomiasis.
Yu, Qing; Zhao, Geng-Ming; Hong, Xian-Lin; Lutz, Eric A; Guo, Jia-Gang
2013-11-28
Schistosomiasis japonica remains a significant public-health problem in China. This study evaluated cost-effectiveness of a comprehensive schistosomiasis control program (2003-2006). The comprehensive control program was implemented in Zhangjia and Jianwu (cases); while standard interventions continued in Koutou and Xiajia (controls). Incurred costs were documented and the schistosomiasis comprehensive impact index (SCI) and cost-effectiveness ratio (Comprehensive Control Program Cost/SCI) were applied. In 2003, prevalence of Schistosoma japonicum infection was 11.3% (Zhangjia), 6.7% (Jianwu), 6.5% (Koutou), and 8.0% (Xiajia). In 2006, the comprehensive control program in Zhangjia and Jianwu reduced infection to 1.6% and 0.6%, respectively; while Koutou and Xiajia had a schistosomiasis prevalence of 3.2% and 13.0%, respectively. The year-by-year SCIs in Zhangjia were 0.28, 105.25, and 47.58, with an overall increase in cost-effectiveness ratio of 374.9%-544.8%. The SCIs in Jianwu were 16.21, 52.95, and 149.58, with increase in cost-effectiveness of 226.7%-1,149.4%. Investment in Koutou and Xiajia remained static (US$10,000 unit cost). The comprehensive control program implemented in the two case villages reduced median prevalence of schistosomiasis 8.5-fold. Further, the cost effectiveness ratio demonstrated that the comprehensive control program was 170% (Zhangjia) and 922.7% (Jianwu) more cost-effective. This work clearly shows the improvements in both cost and disease prevention effectiveness that a comprehensive control program-approach has on schistosomiasis infection prevalence.
Yu, Qing; Zhao, Geng-Ming; Hong, Xian-Lin; Lutz, Eric A.; Guo, Jia-Gang
2013-01-01
Schistosomiasis japonica remains a significant public-health problem in China. This study evaluated cost-effectiveness of a comprehensive schistosomiasis control program (2003–2006). The comprehensive control program was implemented in Zhangjia and Jianwu (cases); while standard interventions continued in Koutou and Xiajia (controls). Incurred costs were documented and the schistosomiasis comprehensive impact index (SCI) and cost-effectiveness ratio (Comprehensive Control Program Cost/SCI) were applied. In 2003, prevalence of Schistosoma japonicum infection was 11.3% (Zhangjia), 6.7% (Jianwu), 6.5% (Koutou), and 8.0% (Xiajia). In 2006, the comprehensive control program in Zhangjia and Jianwu reduced infection to 1.6% and 0.6%, respectively; while Koutou and Xiajia had a schistosomiasis prevalence of 3.2% and 13.0%, respectively. The year-by-year SCIs in Zhangjia were 0.28, 105.25, and 47.58, with an overall increase in cost-effectiveness ratio of 374.9%–544.8%. The SCIs in Jianwu were 16.21, 52.95, and 149.58, with increase in cost-effectiveness of 226.7%–1,149.4%. Investment in Koutou and Xiajia remained static (US$10,000 unit cost). The comprehensive control program implemented in the two case villages reduced median prevalence of schistosomiasis 8.5-fold. Further, the cost effectiveness ratio demonstrated that the comprehensive control program was 170% (Zhangjia) and 922.7% (Jianwu) more cost-effective. This work clearly shows the improvements in both cost and disease prevention effectiveness that a comprehensive control program-approach has on schistosomiasis infection prevalence. PMID:24287861
Jiao-Jiao, Lin
2016-10-20
Although great success has been achieved in schistosomiasis control, schistosomiasis japonica remains a publichealth concern in China. Schistosoma japonicum is found to naturally infect over 40 mammalian animals. The implementation of the integrated schistosomiasis control strategy emphasizing infectious source control since 2004, which integrates replacement of bovines with machines, breeding domestic animals in fences, building safe pastures and chemotherapy of infected bovines, results in a clear-cut reduction in the prevalence of S. japonicum infection in both humans and bovines, as well as the areas of infected snail habitats, and the national schistosomiasis control program is moving from transmission control towards transmission interruption and elimination. It has been found that goat is highly susceptible to S. japonicum infection, and previous epidemiological data have shown a high prevalence of infection in goat. However, the role of goat in the transmission of schistosomiasis japonica has not been paid much attention, and there are few systematic surveys to evaluate the role of goat in schistosomiasis transmission in China to date. Professor Liang Yousheng's group investigated S. japonicum development and reproduction (egglaying) in goat body, environmental contamination by goat feces, and the effect of temperature and humidity on the survival of S. japonicum eggs in goat feces. Their findings further demonstrate the role of goat in the transmission of schistosomiasis japonica. In addition, they proposed, based on their findings and previous reports, that the management of goat should be integrated into the national schistosomiasis control program in China, since goat is virtually one of the major infectious sources of schistosomiasis japonica in China. Moreover, this group improved the fecal hatching test and optimized the parasitological technique for diagnosis of S. japonicum infection in goats. These innovative studies fill in the gaps of goat schitsosomiasis japonica research in China, and the research outcomes will enrich the currently implemented integrated schistosomiasis control strategy emphasizing infectious source control, and are believed to play a critical role in schistosomiasis elimination in China. Since schistosomiasis seriously affects goat husbandry development and local famer income, and goat has become a major infectious source of schistosomiasis japonica in China, the control of goat schistosomiaiss will facilitate the progress towards the elimination of schistosomiasis in China, and the following research priorities are suggested: (1) to emphasize the control of goat schistosomiasis, and to integrate the comprehensive management of goat into the national schistosomiasis control program in China; and (2) to develop new techniques, products and interventions for the control of goat schistosomiasis.
Sokolow, Susanne H.; Wood, Chelsea L.; Jones, Isabel J.; Swartz, Scott J.; Lopez, Melina; Hsieh, Michael H.; Lafferty, Kevin D.; Kuris, Armand M.; Rickards, Chloe; De Leo, Giulio A.
2016-01-01
Snail control has been the most effective way to reduce schistosomiasis prevalence. Despite evidence that snail control leads to long-term disease reduction and elimination, most current schistosomiasis control efforts emphasize MDA using praziquantel over snail control. Combining drug-based control programs with affordable snail control seems the best strategy for eliminating schistosomiasis.
[Implementation of precision control to achieve the goal of schistosomiasis elimination in China].
Zhou, Xiao-nong
2016-02-01
The integrated strategy for schistosomiasis control with focus on infectious source control, which has been implemented since 2004, accelerated the progress towards schistosomiasis control in China, and achieved transmission control of the disease across the country by the end of 2015, which achieved the overall objective of the Mid- and Long-term National Plan for Prevention and Control of Schistosomiasis (2004-2015) on schedule. Then, the goal of schistosomiasis elimination by 2025 was proposed in China in 2014. To achieve this new goal on schedule, we have to address the key issues, and implement precision control measures with more precise identification of control targets, so that we are able to completely eradicate the potential factors leading to resurgence of schistosomiasis transmission and enable the achievement of schistosomiasis elimination on schedule. Precision schistosomiasis control, a theoretical innovation of precision medicine in schistosomiasis control, will provide new insights into schistosomiasis control based on the conception of precision medicine. This paper describes the definition, interventions and the role of precision schistosomiasis control in the elimination of schistosomiasis in China, and demonstrates that sustainable improvement of professionals and integrated control capability at grass-root level is a prerequisite to the implementation of schistosomiasis control, precision schistosomiasis control is a key to the further implementation of the integrated strategy for schistosomiasis control with focus on infectious source control, and precision schistosomiasis control is a guarantee of curing schistosomiasis patients and implementing schistosomiasis control program and interventions.
Song, Langui; Wu, Xiaoying; Zhang, Beibei; Liu, Jiahua; Ning, An; Wu, Zhongdao
2017-11-01
The prevalence and intensity of schistosomiasis has dropped dramatically in China due to an effective integrated control program. However, advanced schistosomiasis is becoming a key challenge on the road to elimination. The aims of this study were to compare the disease condition between advanced cases under the general assistance program (GAP) and free treatment program (FTP) and to determine whether the FTP should be popularized to provide an objective reference for policymakers in China's advanced schistosomiasis control program. One hundred and ninety-four patients with schistosomiasis japonica who were enrolled in the GAP or FTP participated in this study. Little significant difference was observed in the potential confounders, including general characteristics, comorbidities, and lifestyle, indicating a similar effect on the pathology of liver damage caused by schistosome infection. There was no apparent difference in the incidence of common clinical symptoms. Furthermore, no significant difference was observed in the ultrasound findings, implying that the GAP and FTP groups shared a similar degree of liver lesion. With the exception of the abnormal rates of aspartate aminotransferase (AST), alkaline phosphatase (ALP), and hyaluronic acid (HA), the other serological indicators were comparable between the groups. Overall, the FTP is not a better option for controlling advanced schistosomiasis in China. It is important to reveal the precise mechanism underlying the pathogenesis of advanced schistosomiasis so that specific approaches to treating and preventing the development of advanced schistosomiasis can be developed and schistosomiasis can be eliminated in China.
An Epidemiological Trend of Urogenital Schistosomiasis in Ethiopia
Chala, Bayissa; Torben, Workineh
2018-01-01
Schistosomiasis is a major public health problem in Ethiopia. Currently, the prevalence of the disease can possibly be heightened due to man-made ecological transformations particularly related to the recent development programs involving irrigation and construction of dams. The expansion of some of the water resource development projects has been cited enhancing the upsurge of urogenital schistosomiasis mainly in the lower altitude areas of the country. In connection to the extensive initiation of development projects in low altitude areas of the country, simultaneous and adequate attentions have never been given to address a pre-assessment of health impacts of the development programs prior to launching the projects. Helpful appraisals focusing on evaluation of epidemiology of urogenital schistosomiasis in Ethiopia have not been explored. Therefore, the current review attempts to trace an overall picture of the epidemiological status of urogenital schistosomiasis in the country; the past and existing trends of urogenital schistosomiasis surveys and control programs of the country are reviewed. Essential recommendations are highlighted for possible inputs in future control design strategies of national control program of schistosomiasis. PMID:29556490
Mo, Annie X; Agosti, Jan M; Walson, Judd L; Hall, B Fenton; Gordon, Lance
2014-01-01
In March 2013, the National Institute of Allergy and Infectious Diseases and the Bill and Melinda Gates Foundation co-sponsored a meeting entitled "Schistosomiasis Elimination Strategy and Potential Role of a Vaccine in Achieving Global Health Goals" to discuss the potential role of schistosomiasis vaccines and other tools in the context of schistosomiasis control and elimination strategies. It was concluded that although schistosomiasis elimination in some focal areas may be achievable through current mass drug administration programs, global control and elimination will face several significant scientific and operational challenges, and will require an integrated approach with other, additional interventions. These challenges include vector (snail) control; environmental modification; water, sanitation, and hygiene; and other future innovative tools such as vaccines. Defining a clear product development plan that reflects a vaccine strategy as complementary to the existing control programs to combat different forms of schistosomiasis will be important to develop a vaccine effectively.
Maseko, Thokozani S B; Mkhonta, Nkosazana R; Masuku, Sakhile K S; Dlamini, Sabelo V; Fan, Chia-Kwung
2018-02-01
Schistosomiasis, a worldwide concern, has received attention in Swaziland through control programs such as deworming programs, education programs, and school health programs; however, these programs neglect the importance of monitoring and evaluation strategies such as assessing children's knowledge, attitudes and practices (KAPs) and the prevalence of the disease. Children are a high-risk group because of their water contact practices, and need to be informed about schistosomiasis to influence their attitudes and practices. Social and cultural factors are involved in schistosomiasis control because they instill myths and misconceptions about the disease. As a result, children in the community may be comfortable with bad practices. This study aimed to assess the KAPs of schoolchildren on schistosomiasis, and to identify practices that support or hinder the progress of schistosomiasis control. In 2014, a descriptive quantitative cross-sectional survey was conducted through questionnaires among Siphofaneni primary schools, an area hit by schistosomiasis in the Lowveld of Swaziland. A logistic regression model was applied to analyze the data. Moderate knowledge, good attitudes, and fairly good practices were observed in the children. However, practices of certain children were risky and they still had some misconceptions. Knowledge was correlated with practice and with predictors of good and bad practices such as male sex, always urinating in water, and always using river water for domestic practices. This study suggests that empowering children with knowledge and attempting to modify their water contact, and improved human waste disposal practices are necessary for schistosomiasis control. Copyright © 2016. Published by Elsevier B.V.
Critical analysis of molluscicide application in schistosomiasis control programs in Brazil.
Coelho, Pmz; Caldeira, R L
2016-07-04
In Brazil, Biomphalaria glabrata, B. tenagophila, and B. straminea are naturally infected by the trematode Schistosoma mansoni, the causative agent of schistosomiasis. Despite decades of governmental efforts through official control programs, schistosomiasis remains an important public health problem in the country: thousands of people are infected with the trematode each year and millions live in endemic areas. The World Health Organization recommends using a combination of molluscicide (niclosamide) and mass chemotherapy to control the transmission of schistosomiasis, with this treatment successfully reducing the morbidity of the disease. In the past, niclosamide has been used in official schistosomiasis control programs in Brazil. However, as B. glabrata recolonizes even after molluscicide application, the use of molluscicides has gradually decreased in the country until they were discontinued in 2002, mainly due to the rising global pressure to preserve the environment and the difficulties of obtaining licenses from the Brazilian Ministry of Environment to use toxic substances in aquatic ecosystems. Therefore, the discovery of new molluscicides, which could be more selective to Biomphalaria species and less harmful to the aquatic ecosystem, is necessary. In addition, political efforts to sensitize funders to provide grants for this field of research are required. In this context, this article aims to make a critical analysis of molluscicide application in schistosomiasis control programs in Brazil.
Mo, Annie X.; Agosti, Jan M.; Walson, Judd L.; Hall, B. Fenton; Gordon, Lance
2014-01-01
In March 2013, the National Institute of Allergy and Infectious Diseases and the Bill and Melinda Gates Foundation co-sponsored a meeting entitled “Schistosomiasis Elimination Strategy and Potential Role of a Vaccine in Achieving Global Health Goals” to discuss the potential role of schistosomiasis vaccines and other tools in the context of schistosomiasis control and elimination strategies. It was concluded that although schistosomiasis elimination in some focal areas may be achievable through current mass drug administration programs, global control and elimination will face several significant scientific and operational challenges, and will require an integrated approach with other, additional interventions. These challenges include vector (snail) control; environmental modification; water, sanitation, and hygiene; and other future innovative tools such as vaccines. Defining a clear product development plan that reflects a vaccine strategy as complementary to the existing control programs to combat different forms of schistosomiasis will be important to develop a vaccine effectively. PMID:24402703
Wang, Xiaoli; Wang, Wei; Wang, Peng
2017-02-01
Schistosomiasis is a neglected tropical parasitic disease of great public health significance worldwide. Currently, mass drug administration with praziquantel remains the major strategy for global schistosomiasis control programs. Since 2005, an integrated strategy with emphasis on infectious source control was implemented for the control of schistosomiasis japonica, a major public health concern in China, and pilot studies have demonstrated that such a strategy is effective to reduce the prevalence of Schistosoma japonicum infection in both humans and bovines. However, there is little knowledge on the long-term effectiveness of this integrated strategy for controlling schistosomiasis japonica. The aim of this study was to evaluate the long-term effectiveness of the integrated strategy for schistosomiasis control following the 10-year implementation, based on the data from the national schistosomiasis control program released by the Ministry of Health, People's Republic of China. In 2014, there were 5 counties in which the transmission of schistosomiasis japonica had not been interrupted, which reduced by 95.2% as compared to that in 2005 (105 counties). The number of schistosomiasis patients and acute cases reduced by 85.5 and 99.7% in 2014 (115,614 cases and 2 cases) as compared to that in 2005 (798,762 cases and 564 cases), and the number of bovines and S. japonicum-infected bovines reduced by 47.9 and 98% in 2014 (919,579 bovines and 666 infected bovines) as compared to that in 2005 (1,764,472 bovines and 33,736 infected bovines), respectively. During the 10-year implementation of the integrated strategy, however, there was a minor fluctuation in the area of Oncomelania hupensis snail habitats, and there was only a 5.6% reduction in the area of snail habitats in 2014 relative to in 2005. The results of the current study demonstrate that the 10-year implementation of the integrated strategy with emphasis on infectious source has greatly reduced schistosomiasis-related morbidity in humans and bovines. It is concluded that the new integrated strategy has remarkable long-term effectiveness on the transmission of schistosomiasis japonica in China, which facilitates the shift of the national schistosomiasis control program from transmission control to transmission interruption and elimination. However, such a strategy seems to have little effect on the shrinking of areas of snail habitats.
Can mass drug administration lead to the sustainable control of schistosomiasis?
Ross, Allen G P; Olveda, Remigio M; Chy, Delia; Olveda, David U; Li, Yuesheng; Harn, Donald A; Gray, Darren J; McManus, Donald P; Tallo, Veronica; Chau, Thao N P; Williams, Gail M
2015-01-15
In the Philippines, the current national control strategy for schistosomiasis is annual mass drug administration (MDA) with 40 mg/kg of praziquantel in all schistosomiasis-endemic villages with a prevalence ≥10%. A cross-sectional survey of schistosomiasis was conducted in 2012 on 18 221 individuals residing in 22 schistosomiasis-endemic villages in the province of Northern Samar. The prevalence of schistosomiasis, intensity of Schistosoma infection, and morbidity of disease were assessed. Despite an active schistosomiasis-control program in Northern Samar for >30 years, which included a MDA campaign in the last 5 years, the mean prevalence of schistosomiasis among 10 435 evaluated subjects was 27.1% (95% confidence interval [CI], 26.3%-28.0%), and the geometric mean intensity of infection among 2832 evaluated subjects was 17.2 eggs per gram of feces (95% CI, 16.4-18.1). Ultrasonography revealed high levels of schistosomiasis-induced morbidity in the schistosomiasis-endemic communities. Left lobe liver enlargement (≥70 mm) was evident in 89.3% of subjects. Twenty-five percent of the study population had grade II/III liver parenchyma fibrosis, and 13.3% had splenomegaly (≥100 mm). MDA on its own was insufficient to control the prevalence of schistosomiasis, intensity of Schistosoma infection, or morbidity of the disease. Alternative control measures will be needed to complement the existing national MDA program. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
Schistosomiasis Sustained Control Program in Ethnic Groups Around Ninefescha (Eastern Senegal).
N'Diaye, Monique; Dioukhane, Elhadji M; Ndao, Babacar; Diedhiou, Kemo; Diawara, Lamine; Talla, Idrissa; Vernet, Charlotte; Bessin, François; Barbier, Dominique; Dewavrin, Patrick; Klotz, Francis; Georges, Pierre
2016-09-07
Schistosomiasis is the second most significant parasitic disease in children in several African countries. For this purpose, the "Programme National de Lutte contre les Bilharzioses" (PNLB) was developed in partnership with the World Health Organization (WHO) to control this disease in Senegal. However, geographic isolation of Bedik ethnic groups challenged implementation of the key elements of the schistosomiasis program in eastern Senegal, and therefore, a hospital was established in Ninefescha to improve access to health care as well as laboratory support for this population. The program we have implemented from 2008 in partnership with the PNLB/WHO involved campaigns to 1) evaluate schistosomiasis prevalence in children of 53 villages around Ninefescha hospital, 2) perform a mass drug administration following the protocol established by the PNLB in school-aged children, 3) monitor annual prevalence, 4) implement health education campaigns, and 5) oversee the building of latrines. This campaign led to a drop in schistosomiasis prevalence but highlighted that sustainable schistosomiasis control by praziquantel treatment, awareness of the use of latrines, and inhabitants' voluntary commitment to the program are crucial to improve Schistosoma elimination. Moreover, this study revealed that preschool-aged children, for whom praziquantel was not recommended until 2014 in Senegal, constituted a significant reservoir for the parasite. © The American Society of Tropical Medicine and Hygiene.
Hu, Yi; Li, Si; Xia, Congcong; Chen, Yue; Lynn, Henry; Zhang, Tiejun; Xiong, Chenglong; Chen, Gengxin; He, Zonggui; Zhang, Zhijie
2017-01-01
Schistosomiasis remains a major public health problem in eastern China, particularly along the Yangtze River Basin. The latest national schistosomiasis control program (NSCP) was implemented in 2005 with the main goal of reducing the rate of infection to less than 5% by 2008 and 1% by 2015. To assess the progress, we applied a Bayesian spatio-temporal model to describe dynamics of schistosomiasis in Guichi, Anhui Province, China, using annual parasitological and environmental data collected within 41 sample villages for the period 2005-2011. Predictive maps of schistosomiasis showed that the disease prevalence remains constant and low. Results of uncertainty analysis, in the form of probability contour maps (PCMs), indicated that the first goal of "infection rate less than 5% by 2008" was fully achieved in the study area. More longitudinal data for schistosomiasis are needed for the assessment of the second goal of "infection rate less than 1% by 2015". Compared with the traditional way of mapping uncertainty (e.g., variance or mean-square error), our PCMs provide more realistic information for schistosomiasis control. Copyright © 2016 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.
Early lessons from schistosomiasis mass drug administration programs
Secor, W. Evan
2015-01-01
Mass drug administration using praziquantel is the backbone of the current strategy for the control of schistosomiasis. As the theoretical plans have moved into practical application, certain challenges with this approach have surfaced, and it is likely that annual mass drug administration alone may not be sufficient to achieve program goals. However, mass drug administration is still the only available intervention that can be readily used in the wide variety of settings where schistosomiasis is endemic. The task then becomes how to improve this approach and identify what adjuncts to mass drug administration are effective, as programs move from morbidity control to elimination goals. Other aspects worthy of consideration include how best to employ new diagnostic tools to more easily identify where treatment is needed, and new formulations of praziquantel to extend the availability of treatment to all age groups. The aim of this review is to highlight both areas of challenge and of opportunity to improve the public health impact of schistosomiasis control programs. PMID:26937275
Li, Hongjun; Wang, Wei
2017-03-07
Schistosomiasis is a snail-transmitted infectious disease affecting over 200 million people worldwide. Snail control has been recognized as an effective approach to interrupt the transmission of schistosomiasis, since the geographic distribution of this neglected tropical disease is determined by the presence of the intermediate host snails. In a recent Scoping Review published in Infectious Diseases of Poverty, Coelho and Caldeira performed a critical review of using molluscicides in the national schistosomiasis control programs in Brazil. They also described some chemical and plant-derived molluscicides used in China. In addition to the molluscicides described by Coelho and Caldeira, a large number of chemicals, plant extracts and microorganisms have been screened and tested for molluscicidal actions against Oncomelania hupensis, the intermediate host of Schistosoma japonicum in China. Here, we presented the currently commercial molluscicides available in China, including 26% suspension concentrate of metaldehyde and niclosamide (MNSC), 25% suspension concentrate of niclosamide ethanolamine salt (SCNE), 50% niclosamide ethanolamine salt wettable powder (WPN), 4% niclosamide ethanolamine salt dustable powder (NESP), 5% niclosamide ethanolamine salt granule (NESG) and the plant-derived molluscicide "Luowei". These molluscicides have been proved to be active against O. hupensis in both laboratory and endemic fields, playing an important role in the national schistosomiasis control program of China. Currently, China is transferring its successful experiences on schistosomiasis control to African countries. The introduction of Chinese commercial molluscicides to Africa, with adaptation to local conditions, may facilitate the progress towards the elimination of schisosomiasis in Africa.
Zhang, Zhijie; Zhu, Rong; Ward, Michael P; Xu, Wanghong; Zhang, Lijuan; Guo, Jiagang; Zhao, Fei; Jiang, Qingwu
2012-01-01
The World Bank Loan Project (WBLP) for controlling schistosomiasis in China was implemented during 1992-2001. Its short-term impact has been assessed from non-spatial perspective, but its long-term impact remains unclear and a spatial evaluation has not previously been conducted. Here we compared the spatial distribution of schistosomiasis risk using national datasets in the lake and marshland regions from 1999-2001 and 2007-2008 to evaluate the long-term impact of WBLP strategy on China's schistosomiasis burden. A hierarchical Poisson regression model was developed in a Bayesian framework with spatially correlated and uncorrelated heterogeneities at the county-level, modeled using a conditional autoregressive prior structure and a spatially unstructured Gaussian distribution, respectively. There were two important findings from this study. The WBLP strategy was found to have a good short-term impact on schistosomiasis control, but its long-term impact was not ideal. It has successfully reduced the morbidity of schistosomiasis to a low level, but can not contribute further to China's schistosomiasis control because of the current low endemic level. A second finding is that the WBLP strategy could not effectively compress the spatial distribution of schistosomiasis risk. To achieve further reductions in schistosomiasis-affected areas, and for sustainable control, focusing on the intermediate host snail should become the next step to interrupt schistosomiasis transmission within the two most affected regions surrounding the Dongting and Poyang Lakes. Furthermore, in the lower reaches of the Yangtze River, the WBLP's morbidity control strategy may need to continue for some time until snails in the upriver provinces have been well controlled. It is difficult to further reduce morbidity due to schistosomiasis using a chemotherapy-based control strategy in the lake and marshland regions of China because of the current low endemic levels of infection. The future control strategy for schistosomiasis should instead focus on a snail-based integrated control strategy to maintain the program achievements and sustainably reduce the burden of schistosomiasis in China.
Advances in the Diagnosis of Human Schistosomiasis
Weerakoon, Kosala G. A. D.; Gobert, Geoffrey N.; Cai, Pengfei
2015-01-01
SUMMARY Schistosomiasis is a major neglected tropical disease that afflicts more than 240 million people, including many children and young adults, in the tropics and subtropics. The disease is characterized by chronic infections with significant residual morbidity and is of considerable public health importance, with substantial socioeconomic impacts on impoverished communities. Morbidity reduction and eventual elimination through integrated intervention measures are the focuses of current schistosomiasis control programs. Precise diagnosis of schistosome infections, in both mammalian and snail intermediate hosts, will play a pivotal role in achieving these goals. Nevertheless, despite extensive efforts over several decades, the search for sensitive and specific diagnostics for schistosomiasis is ongoing. Here we review the area, paying attention to earlier approaches but emphasizing recent developments in the search for new diagnostics for schistosomiasis with practical applications in the research laboratory, the clinic, and the field. Careful and rigorous validation of these assays and their cost-effectiveness will be needed, however, prior to their adoption in support of policy decisions for national public health programs aimed at the control and elimination of schistosomiasis. PMID:26224883
Hawkins, Kenneth R; Cantera, Jason L; Storey, Helen L; Leader, Brandon T; de Los Santos, Tala
2016-12-01
Global efforts to address schistosomiasis and soil-transmitted helminthiases (STH) include deworming programs for school-aged children that are made possible by large-scale drug donations. Decisions on these mass drug administration (MDA) programs currently rely on microscopic examination of clinical specimens to determine the presence of parasite eggs. However, microscopy-based methods are not sensitive to the low-intensity infections that characterize populations that have undergone MDA. Thus, there has been increasing recognition within the schistosomiasis and STH communities of the need for improved diagnostic tools to support late-stage control program decisions, such as when to stop or reduce MDA. Failure to adequately address the need for new diagnostics could jeopardize achievement of the 2020 London Declaration goals. In this report, we assess diagnostic needs and landscape potential solutions and determine appropriate strategies to improve diagnostic testing to support control and elimination programs. Based upon literature reviews and previous input from experts in the schistosomiasis and STH communities, we prioritized two diagnostic use cases for further exploration: to inform MDA-stopping decisions and post-MDA surveillance. To this end, PATH has refined target product profiles (TPPs) for schistosomiasis and STH diagnostics that are applicable to these use cases. We evaluated the limitations of current diagnostic methods with regards to these use cases and identified candidate biomarkers and diagnostics with potential application as new tools. Based on this analysis, there is a need to develop antigen-detecting rapid diagnostic tests (RDTs) with simplified, field-deployable sample preparation for schistosomiasis. Additionally, there is a need for diagnostic tests that are more sensitive than the current methods for STH, which may include either a field-deployable molecular test or a simple, low-cost, rapid antigen-detecting test.
Sm-p80-Based Schistosomiasis Vaccine: Preparation for Human Clinical Trials.
Siddiqui, Afzal A; Siddiqui, Sabrina Z
2017-03-01
Mass antiparasitic drug administration programs and other control strategies have made important contributions in reducing the global prevalence of helminths. Schistosomiasis, however, continues to spread to new geographic areas. The advent of a viable vaccine and its deployment, coupled with existing control efforts, is expected to make significant headway towards sustained schistosomiasis control. In 2016, Science ranked the schistosomiasis vaccine as one of the top 10 vaccines that needs to be urgently developed. A vaccine that is effective against geographically distinct forms of intestinal/hepatic and urinary disease is essential to make a meaningful impact in global reduction of the disease burden. In this opinion article, we focus on salient features of schistosomiasis vaccines in different phases of the clinical development pipeline and highlight the Sm-p80-based vaccine which is now being prepared for human clinical trials. Copyright © 2016 Elsevier Ltd. All rights reserved.
Central-provincial relations for anti-schistosomiasis policy in china.
Fan, Ka-Wai
2012-01-01
This paper discusses central-local relations for healthcare policy in China from a principal-agent perspective, based on schistosomiasis control. In order to control the disease, the central government produced the Outline of the Mid-Long-Term National Plan for Schistosomiasis Prevention and Control (2004-2015) in 2004. By discussing the implementation of the National Outline at the provincial level, the author uses principal-agent theory to examine conflict and coordination between the central and provincial governments. The documents were collected from the Internet. Although the central and provincial governments all want to eliminate schistosomiasis, allocating funding among them creates conflict and forms an obstacle to achieving the goal. This paper extensively discusses the topics related to central-provincial relation and schistosomiasis control program. Further case study on a single province may be needed to intensify the discussion from a micro perspective. The conflict between central and provincial relations needs to be resolved in order to implement the national policy.
Central-Provincial Relations for Anti-Schistosomiasis Policy in China
FAN, Ka-wai
2012-01-01
This paper discusses central-local relations for healthcare policy in China from a principal-agent perspective, based on schistosomiasis control. In order to control the disease, the central government produced the Outline of the Mid-Long-Term National Plan for Schistosomiasis Prevention and Control (2004–2015) in 2004. By discussing the implementation of the National Outline at the provincial level, the author uses principal-agent theory to examine conflict and coordination between the central and provincial governments. The documents were collected from the Internet. Although the central and provincial governments all want to eliminate schistosomiasis, allocating funding among them creates conflict and forms an obstacle to achieving the goal. This paper extensively discusses the topics related to central-provincial relation and schistosomiasis control program. Further case study on a single province may be needed to intensify the discussion from a micro perspective. The conflict between central and provincial relations needs to be resolved in order to implement the national policy. PMID:23113188
McManus, Donald P.; Raso, Giovanna; Utzinger, Jürg; Xiao, Shui-Yuan; Yu, Dong-Bao; Zhao, Zheng-Yuan; Li, Yue-Sheng
2013-01-01
Background Access to health care is a major requirement in improving health and fostering socioeconomic development. In the People's Republic of China (P.R. China), considerable changes have occurred in the social, economic, and health systems with a shift from a centrally planned to a socialist market economy. This brought about great benefits and new challenges, particularly for vertical disease control programs, including schistosomiasis. We explored systemic barriers in access to equitable and effective control of schistosomiasis. Methodology Between August 2002 and February 2003, 66 interviews with staff from anti-schistosomiasis control stations and six focus group discussions with health personnel were conducted in the Dongting Lake area, Hunan Province. Additionally, 79 patients with advanced schistosomiasis japonica were interviewed. The health access livelihood framework was utilized to examine availability, accessibility, affordability, adequacy, and acceptability of schistosomiasis-related health care. Principal Findings We found sufficient availability of infrastructure and human resources at most control stations. Many patients with advanced schistosomiasis resided in non-endemic or moderately endemic areas, however, with poor accessibility to disease-specific knowledge and specialized health services. Moreover, none of the patients interviewed had any form of health insurance, resulting in high out-of-pocket expenditure or unaffordable care. Reports on the adequacy and acceptability of care were mixed. Conclusions/Significance There is a need to strengthen health awareness and schistosomiasis surveillance in post-transmission control settings, as well as to reduce diagnostic and treatment costs. Further studies are needed to gain a multi-layered, in-depth understanding of remaining barriers, so that the ultimate goal of schistosomiasis elimination in P.R. China can be reached. PMID:23936580
Efficacy of new low-cost filtration device for recovering Schistosoma haematobium eggs from urine.
Gyorkos, T W; Ramsan, M; Foum, A; Khamis, I S
2001-07-01
A new, inexpensive filtration device for the diagnosis of urinary schistosomiasis was tested against the commonly used Millipore device. The experimental protocol was performed with 25 urine samples known to be positive for Schistosoma haematobium. The results suggest that the new device is as effective as the Millipore device for the diagnosis of urinary schistosomiasis. Its low cost will be attractive to schistosomiasis control programs.
Ethiopia Schistosomiasis and Soil-Transmitted Helminthes Control Programme: Progress and Prospects.
Negussu, Nebiyu; Mengistu, Birhan; Kebede, Biruck; Deribe, Kebede; Ejigu, Ephrem; Tadesse, Gemechu; Mekete, Kalkidan; Sileshi, Mesfin
2017-01-01
Schistosomiasis and soil-transmitted helminthes are among seventeen WHO prioritized neglected tropical diseases that infect humans. These parasitic infections can be treated using single-dose and safe drugs. Ethiopia successfully mapped the distribution of these infections nationwide. According to the mapping there are an estimated 37.3 million people living in schistosomiasis endemic areas, and 79 million in schistosomiasis and soil-transmitted helminthes endemic areas. The Federal Ministry of Health successfully scaled up Schistosomiasis and schistosomiasis and soil-transmitted helminthes intervention in endemic areas and treated over 19 million individuals in 2015. The Ministry of Health has made a huge effort to establish neglected tropical diseases, including schistosomiasis and soil-transmitted helminthes program in the health system which helped to map majority of the woredas and initiate nationwide intervention. The National control programme is designed to achieve elimination for those diseases as a major public health problem by 2020 and aim to attain transmission break by 2025. The programme focuses on reaching those school-aged children who are not attending school, integration between neglected tropical diseases programme, and further collaboration with the WASH actors.
Olveda, David U; McManus, Donald P; Ross, Allen G P
2016-12-01
Preventive chemotherapy is advocated for the global control and elimination of schistosomiasis. Despite the well known short-term benefits of treating patients for schistosomiasis, the impact of mass drug administration (MDA) campaigns to control the disease in the long term remains unresolved. Many studies have advocated the success of MDA programs in order to attract donor funds for elimination efforts but such successes are often short-lived given the drug does not alter the life cycle of the organism or prevent reinfection. Within a matter of months to years after halting treatment, the prevalence, intensity of infection and morbidity of disease return to baseline levels. Other mitigating factors contribute to the failings of MDA campaigns namely: poverty, poor drug coverage, poor drug compliance, and, in the case of Asiatic schistosomiasis, zoonotic transmission. Genetic and innate and acquired immunologic mechanisms complicate the epidemiologic picture of schistosomiasis globally, and may contribute indirectly to MDA shortcomings. The possibility of drug resistance is an ever present concern because of the sole reliance on one drug, praziquantel. Preventive chemotherapy is advocated for the global control and elimination of schistosomiasis. The short-term benefits of MDA campaigns are well documented but the long-term benefits are questionable.
Pulmonary arterial hypertension in schistosomiasis.
Gavilanes, Francisca; Fernandes, Caio J C; Souza, Rogerio
2016-09-01
Schistosomiasis is one of the most prevalent parasitic diseases in the world, being present in more than 70 countries. Pulmonary hypertension is one of the several chronic complications of schistosomiasis; particularly in developing countries, schistosomiasis-associated pulmonary arterial hypertension might represent one of the most prevalent causes of pulmonary arterial hypertension. New epidemiological data reinforce the importance of schistosomiasis in the context of pulmonary hypertension; furthermore, the inflammatory components of the pathophysiology of pulmonary hypertension associated with schistosomiasis have been recently explored, opening the perspective of new targets to be explored. Clinical and hemodynamic features of this particular complication of schistosomiasis, and the role of targeted therapies in this setting, have been better described in recent years. The importance of schistosomiasis-associated pulmonary hypertension is now recognized with better knowledge about its pathophysiology and management. Nevertheless, there is a need for better understanding the predisposal factors (genetic, environmental and so on) for the development of pulmonary hypertension in schistosomiasis as a way to prevent it from occurring. Furthermore, better control programs to decrease disease transmission are still missing, ensuring that we will have to face this devastating complication of schistosomiasis for a long future.
Efficacy of New Low-Cost Filtration Device for Recovering Schistosoma haematobium Eggs from Urine
Gyorkos, Theresa W.; Ramsan, Mahdi; Foum, Ali; Khamis, Iddi Simba
2001-01-01
A new, inexpensive filtration device for the diagnosis of urinary schistosomiasis was tested against the commonly used Millipore device. The experimental protocol was performed with 25 urine samples known to be positive for Schistosoma haematobium. The results suggest that the new device is as effective as the Millipore device for the diagnosis of urinary schistosomiasis. Its low cost will be attractive to schistosomiasis control programs. PMID:11427595
Martin, G. T.; Yoon, S. S.; Mott, K. E.
1991-01-01
Schistosomiasis, a group of parasitic diseases caused by Schistosoma parasites, is associated with water resources development and affects more than 200 million people in 76 countries. Depending on the species of parasite involved, disease of the liver, spleen, gastrointestinal or urinary tract, or kidneys may result. A computer-assisted teaching package has been developed by WHO for use in the training of public health workers involved in schistosomiasis control. The package consists of the software, ZOOM, and a schistosomiasis information file, Dr Schisto, and uses hypermedia technology to link pictures and text. ZOOM runs on the IBM-PC and IBM-compatible computers, is user-friendly, requires a minimal hardware configuration, and can interact with the user in English, French, Spanish or Portuguese. The information files for ZOOM can be created or modified by the instructor using a word processor, and thus can be designed to suit the need of students. No programming knowledge is required to create the stacks. PMID:1786618
Wang, Shi-ping; He, Xin; Zhou, Yun-fei
2015-12-01
Schistosomiasis is a type of zoonotic parasitosis that severely impairs human health. Rapid detection of infection sources is a key to the control of schistosomiasis. With the effective control of schistosomiasis in China, the detection techniques for infection sources have also been developed. The rate and the intensity of infection among humans and livestocks have been significantly decreased in China, as the control program has entered the transmission control stage in most of the endemic areas. Under this situation, the traditional etiological diagnosing techniques and common immunological methods can not afford rapid detection of infection sources of schistosomiasis. Instead, we are calling for detection methods with higher sensitivity, specificity and stability while being less time-consuming, more convenient and less costing. In recent years, many improved or novel detection methods have been applied for the epidemiological surveillance of schistosomiasis, such as the automatic scanning microscopic image acquisition system, PCR-ELISA, immunosensors, loop-mediated isothermal amplification, etc. The development of new monitoring techniques can facilitate rapid detection of schistosome infection sources in endemic areas.
Africa: Schistosomiasis in Africa and the Role of Environmental Education.
ERIC Educational Resources Information Center
Stapp, William B.
1985-01-01
Illustrates problems involved in controlling a public health disease (schistosomiasis) which is interwoven into a country's religious, economic, political, educational, and social systems. The strong relationship between the disease and development of irrigation systems is pointed out. A successful education and integrative program is described.…
Jia-Sheng, Wang; Jin-You, Lu; Feng-Yang, Min; Kong-Xian, Zhu
2017-04-27
The spread of schistosomiasis seriously threaten the health of people and hinder the economic and social development in China. The water conservancy combined with schistosomiasis prevention and control effectively controlled the spread of schistosomiasis by controlling the spread of Oncomelania hupensis , the only intermediate host of Schistosoma japonicum . This paper reviews the evolution of the strategy of schistosomiasis prevention and control in China and points out the historical role of water conservancy combined with schistosomiasis prevention and control. Furthermore, this article analyzes the problems and challenges of water conservancy combined with schistosomiasis prevention and control in the new period. In response to the challenges, the new strategy of water conservancy combined with schistosomiasis prevention and control is put forward, including: developing the research of the new strategy of water conservancy combined with schistosomiasis prevention and control, enhancing the research of water conservancy technology combined with schistosomiasis prevention and control, improving the efficiency and applicability of water conservancy projects combined with schistosomiasis prevention and control, strengthening the guidance of water conservancy technology combined with schistosomiasis prevention and control, and perfecting the evaluation system.
McManus, Donald P.; Gray, Darren J.; Ross, Allen G.; Williams, Gail M.; He, Hong-Bin; Li, Yue-Sheng
2011-01-01
Schistosomiasis is a chronic and debilitating parasitic disease that has often been neglected because it is a disease of poverty, affecting poor rural communities in the developing world. This is not the case in the People's Republic of China (PRC), where the disease, caused by Schistosoma japonicum, has long captured the attention of the Chinese authorities who have, over the past 50–60 years, undertaken remarkably successful control programs that have substantially reduced the schistosomiasis disease burden. The Dongting Lake region in Hunan province is one of the major schistosome-endemic areas in the PRC due to its vast marshland habitats for the Oncomelania snail intermediate hosts of S. japonicum. Along with social, demographic, and other environmental factors, the recent completion and closure of the Three Gorges dam will most likely increase the range of these snail habitats, with the potential for re-emergence of schistosomiasis and increased transmission in Hunan and other schistosome-endemic provinces being a particular concern. In this paper, we review the history and the current status of schistosomiasis control in the Dongting Lake region. We explore the epidemiological factors contributing to S. japonicum transmission there, and summarise some of the key research findings from studies undertaken on schistosomiasis in Hunan province over the past 10 years. The impact of this research on current and future approaches for sustainable integrated control of schistosomiasis in this and other endemic areas in the PRC is emphasised. PMID:21912706
Burnim, Michael; Ivy, Julianne A; King, Charles H
2017-10-01
The mainstay of current schistosomiasis control programs is mass preventive chemotherapy of school-aged children with praziquantel. This treatment is delivered through school-based, community-based, or combined school- and community-based systems. Attaining very high coverage rates for children is essential in mass schistosomiasis treatment programs, as is ensuring that there are no persistently untreated subpopulations, a potential challenge for school-based programs in areas with low school enrollment. This review sought to compare the different treatment delivery methods based both on their coverage of school-aged children overall and on their coverage specifically of non-enrolled children. In addition, qualitative community or programmatic factors associated with high or low coverage rates were identified, with suggestions for overall coverage improvement. This review was registered prospectively with PROSPERO (CRD 42015017656). Five hundred forty-nine publication of potential relevance were identified through database searches, reference lists, and personal communications. Eligible studies included those published before October 2015, written in English or French, containing quantitative or qualitative data about coverage rates for MDA of school-aged children with praziquantel. Among the 22 selected studies, combined community- and school-based programs achieved the highest median coverage rates (89%), followed by community-based programs (72%). School-based programs had both the lowest median coverage of children overall (49%) and the lowest coverage of the non-enrolled subpopulation of children. Qualitatively, major factors affecting program success included fear of side effects, inadequate education about schistosomiasis, lack of incentives for drug distributors, and inequitable distribution to minority groups. This review provides an evidence-based framework for the development of future schistosomiasis control programs. Based on our results, a combined community and school-based delivery system should maximize coverage for both in- and out-of-school children, especially when combined with interventions such as snacks for treated children, educational campaigns, incentives for drug distributors, and active inclusion of marginalized groups. ClinicalTrials.gov CRD42015017656.
Assessment of morbidity due to Schistosoma japonicum infection in China
2014-01-01
This paper presents a historical assessment of morbidity due to the Schistosoma japonicum infection in China. Due to the socio-economic situation, which did not allow for a control program to be implemented until the early 1950s, morbidity was serious and mortality was high before this. Based on a few investigations and published papers, it can be said that the disease caused millions of deaths, and destroyed numerous families and villages. Since the 1950s, there has been a national control program, intensive control and prevention work has been carried out, and consequently the disease is being controlled. At present, both the prevalence and the morbidity of the disease have been decreasing substantially. The morbidity of the three phases of the disease is outlined in this paper. Comparatively higher morbidity is seen in the acute and advanced phases of the disease. The four major forms of advanced schistosomiasis i.e., ascites, megalosplenia, dwarfism, and colonic tumoroid proliferation, are outlined with their characteristic clinical presentations; their proportions are different during various periods of the national control program. Ectopic schistosomiasis and the relationship between the S. japonicum infection and colorectal cancer are also discussed. Post-transmission schistosomiasis is briefly discussed (which can happen even if the disease reaches the criteria of elimination, and the infection and transmission have stopped, but yet it still develops). The problem of mammalian reservoir hosts of S. japonicum makes the epidemiology and control of schistosomiasis in China even more complicated and arduous, and the control progress in animal reservoirs is briefly presented. PMID:24529186
Knowledge, attitudes and practices on Schistosomiasis in sub-Saharan Africa: a systematic review.
Sacolo, Hlengiwe; Chimbari, Moses; Kalinda, Chester
2018-01-18
Schistosomiasis remains a global health problem with an estimated 250 million people in 78 countries infected, of whom 85% live in Sub-Saharan Africa. Preventive chemotherapy remains the key public health strategy to combat schistosomiasis worldwide. Recently the WHO emphasized on the use of integrative approaches in the control and elimination of schistosomiasis. However, a detailed understanding of sociocultural factors that may influence the uptake of the intended health activities and services is vital. Thus, our study sought to understand the knowledge, attitudes, perceptions, beliefs and practices about schistosomiasis in various communities in Sub-Saharan Africa. A systematic search of literature for the period 2006-2016 was done on Medline, PubMed, CINAHL, Psych info and Google Scholar using the following key words "Schistosomiasis, S. mansoni, S. haematobium, knowledge, attitudes, perceptions, beliefs and practices in Sub-Saharan Africa" in combination with Bolean operators (OR, AND). In this context, we reviewed studies conducted among school children, community members and caregivers of preschool children. Thematic analysis was utilised for the overall synthesis of the selected studies. This was done after reading the articles in depth. Themes were identified and examined for similarities, differences and contradictions. Gaps in schistosomiasis related knowledge and sociocultural barriers towards the uptake of preventive and treatment services among communities in Sub-Saharan Africa were identified. In addition to limited knowledge and negative attitudes, risky water related practices among community members, school children and caregivers of preschool children were identified as key factors promoting transmission of the disease. The study concluded that a comprehensive health education programme using contextual and standardised training tools may improve peoples' knowledge, attitudes and practices in relation to schistosomiasis prevention and control. Findings also highlight the significance of including caregivers in the planning and implementation schistosomiasis control programs targeting pre-school children.
2016-01-01
Background In 2012 the World Health Assembly adopted resolution WHA65.21 on elimination of schistosomiasis, calling for increased investment in schistosomiasis control and support for countries to initiate elimination programs. This study aims to analyze prevalence and intensity of Schistosoma mansoni infection in children in Latin America and the Caribbean countries and territories (LAC), at the second administrative level or lower. Methodology A systematic review of schistosomiasis prevalence and intensity of infection was conducted by searching at PubMed, LILACS and EMBASE. Experts on the topic were informally consulted and institutional web pages were reviewed (PAHO/WHO, Ministries of Health). Only SCH infection among children was registered because it can be a ‘proxi-indicator’ of recent transmission by the time the study is conducted. Principal Findings One hundred thirty two full-text articles met the inclusion criteria and provided 1,242 prevalence and 199 intensity of infection data points. Most of them were from Brazil (69.7%). Only Brazil published studies after 2001, showing several 'hot spots' with high prevalence. Brazil, Venezuela, Suriname and Saint Lucia need to update the epidemiological status of schistosomiasis to re-design their national programs and target the elimination of Schistosoma mansoni transmission by 2020. In Antigua and Barbuda, Dominican Republic, Guadeloupe, Martinique, Montserrat and Puerto Rico schistosomiasis transmission may be interrupted. However the compilation of an elimination dossier and follow-up surveys, per WHO recommendations, are needed to verify that status. Hence, the burden of subtle SCH chronic infection may be still present and even high in countries that may have eliminated transmission. Heterogeneity in the methodologies used for monitoring and evaluating the progress of the schistosomiasis programs was found, making cross-national and chronological comparisons difficult. Conclusions There is a need for updating the schistosomiasis status in the historically endemic countries and territories in LAC to address the required public health interventions for control and elimination programs or to verify the elimination of transmission of Schistosoma mansoni. Improved reporting and standardization of the monitoring and evaluation methodologies used are recommended, while using available WHO guidelines. Meeting a regional elimination goal will require additional and improved epidemiological data by age group and sex. PMID:27007193
Zoni, Ana Clara; Catalá, Laura; Ault, Steven K
2016-03-01
In 2012 the World Health Assembly adopted resolution WHA65.21 on elimination of schistosomiasis, calling for increased investment in schistosomiasis control and support for countries to initiate elimination programs. This study aims to analyze prevalence and intensity of Schistosoma mansoni infection in children in Latin America and the Caribbean countries and territories (LAC), at the second administrative level or lower. A systematic review of schistosomiasis prevalence and intensity of infection was conducted by searching at PubMed, LILACS and EMBASE. Experts on the topic were informally consulted and institutional web pages were reviewed (PAHO/WHO, Ministries of Health). Only SCH infection among children was registered because it can be a 'proxi-indicator' of recent transmission by the time the study is conducted. One hundred thirty two full-text articles met the inclusion criteria and provided 1,242 prevalence and 199 intensity of infection data points. Most of them were from Brazil (69.7%). Only Brazil published studies after 2001, showing several 'hot spots' with high prevalence. Brazil, Venezuela, Suriname and Saint Lucia need to update the epidemiological status of schistosomiasis to re-design their national programs and target the elimination of Schistosoma mansoni transmission by 2020. In Antigua and Barbuda, Dominican Republic, Guadeloupe, Martinique, Montserrat and Puerto Rico schistosomiasis transmission may be interrupted. However the compilation of an elimination dossier and follow-up surveys, per WHO recommendations, are needed to verify that status. Hence, the burden of subtle SCH chronic infection may be still present and even high in countries that may have eliminated transmission. Heterogeneity in the methodologies used for monitoring and evaluating the progress of the schistosomiasis programs was found, making cross-national and chronological comparisons difficult. There is a need for updating the schistosomiasis status in the historically endemic countries and territories in LAC to address the required public health interventions for control and elimination programs or to verify the elimination of transmission of Schistosoma mansoni. Improved reporting and standardization of the monitoring and evaluation methodologies used are recommended, while using available WHO guidelines. Meeting a regional elimination goal will require additional and improved epidemiological data by age group and sex.
Omedo, Martin; Ogutu, Michael; Awiti, Alphonce; Musuva, Rosemary; Muchiri, Geoffrey; Montgomery, Susan P; Secor, W Evan; Mwinzi, Pauline
2014-11-01
Compliance with mass drug administration (MDA) can be affected by rumors and mistrust about the drug. Communication campaigns are an effective way to influence attitudes and health behaviors in diverse public health contexts, but there is very little documentation about experiences using health communications in schistosomiasis control programs. A qualitative study was conducted with community health workers (CHWs) as informants to explore the effect of a health communication campaign on their experiences during subsequent praziquantel MDA for schistosomiasis. Discussions were audio-recorded, transcribed verbatim, translated into English where applicable, and analyzed thematically using ATLAS.ti software. According to the CHWs, exposure to mass media messages improved awareness of the MDA, which in turn, led to better treatment compliance. Our findings suggest that communication campaigns influence health behaviors and create awareness of schistosomiasis control interventions, which may ultimately improve praziquantel MDA. © The American Society of Tropical Medicine and Hygiene.
Reduction Patterns of Acute Schistosomiasis in the People's Republic of China
Abe, Eniola Michael; Yang, Kun; Bergquist, Robert; Qian, Ying-Jun; Zhang, Li-Juan; Xu, Zhi-Min; Xu, Jing; Guo, Jia-Gang; Xiao, Ning; Zhou, Xiao-Nong
2014-01-01
Background Despite significant, steady progress in schistosomiasis control in the People's Republic of China over the past 50 years, available data suggest that the disease has re-emerged with several outbreaks of acute infections in the early new century. In response, a new integrated strategy was introduced. Methods This retrospective study was conducted between Jan 2005 and Dec 2012, to explore the effectiveness of a new integrated control strategy that was implemented by the national control program since 2004. Results A total of 1,047 acute cases were recorded between 2005 and 2012, with an annual reduction in prevalence of 97.7%. The proportion of imported cases of schistosomiasis was higher in 2011 and 2012. Nine clusters of acute infections were detected by spatio-temporal analysis between June and November, indicating that the high risk areas located in the lake and marshland regions. Conclusion This study shows that the new integrated strategy has played a key role in reducing the morbidity of schistosomiasis in the People's Republic of China. PMID:24810958
Abnormal liver function in different patients with Schistosoma japonicum.
Ning, An; Wu, Xiaoying; Li, Hongyu; Liang, Jinyi; Gao, Zulu; Shen, Jia; Liu, Zhen; Xu, Jun; Hu, Fei; Wu, Feng; Ji, Pengyu; Wu, Zhongdao; Sun, Xi
2015-01-01
Schistosomiasis japonica, caused by Schistosoma japonicum, is still a serious public health problem in China. It is important for schistosomiasis control to prevent from infection and advanced patients. Recent years, however, the form of the prevalence of schistosomiasis japonica in China was changed these days. Paying attention to the quality of life of these patients already infected with S. japonicum becomes a new objective to schistosomiasis control program. Although most of the chronic infections with S. japonicum will finally appear as liver fibrosis symptoms, it is still unknown liver function abnormalities in patients with severe forms of schistosomiasis, and there is also no evidence whether S. japonicum infection will directly cause damage to liver cells. Thus, this study investigated 494 patients diagnosed with S. japonicum (87.7%) and 69 healthy subjects from a endemic areas belonging to Jiangxi Province of China and aimed to evaluate the liver function abnormalities in patients with severe forms of schistosomiasis and possible associations with coinfection with HBV. The results showed that the hepatic metabolism situation significantly changed in patients infected with S. japonicum; meanwhile, the abnormal rates of ALT and AST in patients with schistosomiasis were significantly higher than that in the control group, which confirmed that patients infected with S. japonicum not only had damaged liver function but also the hepatic cells were directly influenced. And the coinfection of CHB and schistosomiasis japonica can be a risk factor for more serious outcomes in patients from endemic areas. These results give us the advice that in the further treatment of patients infected with S. japonicum, especially these coinfections, we should better give the routine liver-protection treatment in advance.
Burnim, Michael; Ivy, Julianne A.
2017-01-01
Background The mainstay of current schistosomiasis control programs is mass preventive chemotherapy of school-aged children with praziquantel. This treatment is delivered through school-based, community-based, or combined school- and community-based systems. Attaining very high coverage rates for children is essential in mass schistosomiasis treatment programs, as is ensuring that there are no persistently untreated subpopulations, a potential challenge for school-based programs in areas with low school enrollment. This review sought to compare the different treatment delivery methods based both on their coverage of school-aged children overall and on their coverage specifically of non-enrolled children. In addition, qualitative community or programmatic factors associated with high or low coverage rates were identified, with suggestions for overall coverage improvement. Methodology/Principal findings This review was registered prospectively with PROSPERO (CRD 42015017656). Five hundred forty-nine publication of potential relevance were identified through database searches, reference lists, and personal communications. Eligible studies included those published before October 2015, written in English or French, containing quantitative or qualitative data about coverage rates for MDA of school-aged children with praziquantel. Among the 22 selected studies, combined community- and school-based programs achieved the highest median coverage rates (89%), followed by community-based programs (72%). School-based programs had both the lowest median coverage of children overall (49%) and the lowest coverage of the non-enrolled subpopulation of children. Qualitatively, major factors affecting program success included fear of side effects, inadequate education about schistosomiasis, lack of incentives for drug distributors, and inequitable distribution to minority groups. Conclusions/Significance This review provides an evidence-based framework for the development of future schistosomiasis control programs. Based on our results, a combined community and school-based delivery system should maximize coverage for both in- and out-of-school children, especially when combined with interventions such as snacks for treated children, educational campaigns, incentives for drug distributors, and active inclusion of marginalized groups. Trial registration ClinicalTrials.gov CRD42015017656 PMID:29077723
[Strategy and effect of schistosomiasis emergency control after earthquake in Lushan County].
Wang, Chao-Fu; Wang, Cheng-Xiang; Mou, Li-Rong; Zhong, Bo; Liu, Yang; Wu, Zi-Song; Xu, Liang; Meng, Xian-Hong; Yang, Zong-Cai; Cheng, Yong; Zhu, Jin-Hua; Zhou, Qi-Fu
2014-10-01
To evaluate the effects of measures on the schistosomiasis control after the earth quake in Lushan County, so as to provide the experiences for post-disaster schistosomiasis control. The measures taken in schistosomiasis control after the earth quake were reviewed in Lushan County in 2013, and the epidemic situation of schistosomiasis was investigated and the results were analyzed. The schistosomiasis control in floating population and the control of Oncomelania hupensis snails were enhanced, and no schistosome infections were found in both human and livestock. No infected snails and infested water were found. The measures of schistosomiasis control after the disaster are effective in Lushan County, and the goal to prevent major plague after the earth quake is achieved.
Zhu, H; Yap, P; Utzinger, J; Jia, T-W; Li, S-Z; Huang, X-B; Cai, S-X
2016-01-01
Schistosomiasis remains a public health problem in many developing countries around the world. After the founding of The People's Republic of China, from 1949 till date, all levels of government, from central to local, have been attaching great importance to schistosomiasis control in The People's Republic of China. With considerable policy support and resources mobilization, the national schistosomiasis control programmes have been implemented during the past 65years. Here, we summarize the successful experience of schistosomiasis control during the process. Recommendations for the future management of the Chinese national schistosomiasis elimination programme are put forward after considering the remaining challenges, shortcomings and lessons learnt from 65years of schistosomiasis control drives in The People's Republic of China. They will help to sustain past achievements, foster the attainment of the ultimate goal of schistosomiasis elimination for the country and provide reference for schistosomiasis control programme in other countries. Copyright © 2016 Elsevier Ltd. All rights reserved.
The WHO Collaborating Centre for Research and Control of Schistosomiasis at Niamey, Niger.
Chippaux, J P; Boulanger, D; Brémond, P; Campagne, G; Véra, C; Sellin, B
1997-01-01
The Centre de Recherche sur les Méningites et les Schistosomes (CERMES) is a research institute depending on the Organisation de Coordination et de Coopération pour la lutte contre les Grandes Endémies--a West African Organization for Public Health--devoted to the studies on schistosomiasis and meningitis. The staff includes 32 persons with 11 scientists and one financial officer. The activities of the CERMES involving schistosomiasis concern three research units: (a) ecology of human and animal schistosomiasis transmission; the CERMES defined the different patterns of schistosomiasis transmission in Niger (involving African dry savana); in this field, we have shown, (i) the existence of important variability in conditions of transmission of S. haematobium and, (ii) natural hybridization between parasitic species of the ruminants (S. bovis and S. curassoni) and genetic interaction between human and animal parasites; (b) definition of morbidity indicators usable for rapid assessment methods, for appraisal of the severity of the disease and for the evaluation of the efficiency of control methods; we have established the correlation between ultrasonographic data and some cheap and simple field indicators; (c) immune response and protective immunity induced by recombinant glutathion S-transferase (Sm28, Sb28 and Sh28) in homologous and heterologous animal models including goats, sheep and non human primates (Erythrocebus patas). In Niger, we participate in all control programs against schistosomiasis to define control strategies, to supervise operations and to participate in their evaluation with external experts. International collaborations constitute a frame including four laboratories in Africa and six laboratories in developed countries (Europe and USA).
Hu, Yi; Xiong, Chenglong; Zhang, Zhijie; Luo, Can; Cohen, Ted; Gao, Jie; Zhang, Lijuan; Jiang, Qingwu
2014-01-03
We compared changes in the spatial clustering of schistosomiasis in Southwest China at the conclusion of and six years following the end of the World Bank Loan Project (WBLP), the control strategy of which was focused on the large-scale use of chemotherapy. Parasitological data were obtained through standardized surveys conducted in 1999-2001 and again in 2007-2008. Two alternate spatial cluster methods were used to identify spatial clusters of cases: Anselin's Local Moran's I test and Kulldorff's spatial scan statistic. Substantial reductions in the burden of schistosomiasis were found after the end of the WBLP, but the spatial extent of schistosomiasis was not reduced across the study area. Spatial clusters continued to occur in three regions: Chengdu Plain, Yangtze River Valley, and Lancang River Valley during the two periods, and regularly involved five counties. These findings suggest that despite impressive reductions in burden, the hilly and mountainous regions of Southwest China remain at risk of schistosome re-emergence. Our results help to highlight specific locations where integrated control programs can focus to speed the elimination of schistosomiasis in China.
Luo, Zhi-Hong; Li, Sheng-Ming; Zhou, Xiao-Nong; Yi, Ping; Ren, Guang-Hui; Franziska, Bieri; Zhao, Zheng-Yuan; Hou, Xun-Ya; Ren, Mao-Yuan; Li, Yi-Yi; Dong, Ru-Lan; Zeng, Jin-Yuan; She, Shu-Ping
2013-02-01
To clarify the role of socio-economy and management in the sustainable schistosomiasis-control in Taoyuan County, an endemic area in hilly region, Hunan Province, China. From 1996 to 2011, the data of socio-economy, the management of schistosomiasis control organizations, environment, and the changes in schistosomiasis prevalence were collected in Taoyuan County where schistosomiasis transmission had been controlled since 2008. A sampling survey of schistosomiasis prevalence of human and bovine was performed in 2011 to verify the current status of schistosomiasis transmission. All the data were analyzed statistically to evaluate the role of socio-economy and management in the sustainable schistosomiasis control. During the period from 1998 to 2012, the socio-economy including the residents' productive mode and daily life in Taoyuan County improved dramatically, but the recurrence risk of schistosomiasis endemic still existed due to the retuning of out-going workers and the migrating population. Moreover, the introduction of exotic species of plants and animals may increase the risk. The low running cost of schistosomiasis control organization as well as the efficient and adequate resource allocation in the county was in line with the national requirement to strengthen the rural grass-roots public health system. The harmonious development of socio-economy and the scientific and efficient health system in Taoyuan County are the key factors for the sustainable transmission control of schistosomiasis.
Kanamura, H Y; Dias, L C; da Silva, R M; Glasser, C M; Patucci, R M; Vellosa, S A; Antunes, J L
1998-01-01
The diagnostic potential of circulating IgM and IgA antibodies against Schistosoma mansoni gut-associated antigens detected by the immunofluorescence test (IFT) on adult worm paraffin sections was evaluated comparatively to the fecal parasitological method, for epidemiological purposes in low endemic areas for schistosomiasis. Blood samples were collected on filter paper from two groups of schoolchildren living in two different localities of the municipality of Itariri (São Paulo, Brazil) with different histories and prevalences of schistosomiasis. The parasitological and serological data were compared to those obtained for another group of schoolchildren from a non-endemic area for schistosomiasis. The results showed poor sensitivity of the parasitological method in detecting individuals with low worm burden and indicate the potential of the serological method as an important tool to be incorporated into schistosomiasis control and vigilance programs for determining the real situation of schistosomiasis in low endemic areas.
Shi, L; Li, W; Wu, F; Zhang, J-F; Yang, K; Zhou, X-N
2016-01-01
Schistosomiasis was one of the most serious parasitic diseases in The People's Republic of China, and the endemic region was classified into three types according to the epidemiological characteristics and living conditions of the intermediate host. After more than 60years of efforts, schistosomiasis control programme has made great strides in waterway-network regions. We analyse the epidemic changes of schistosomiasis and its control progress through the schistosomiasis regions' documents and investigation data to evaluate the efficacy of the schistosomiasis control strategies in the waterway-network-type endemic region, which provides the basis for refinement of efforts, as well as summary of the Chinese schistosomiasis control experience in the waterway-network areas. Copyright © 2016 Elsevier Ltd. All rights reserved.
Barbosa, Constança Simões; de Souza Gomes, Elainne Christine; Campos, Julyana Viegas; de Oliveira, Fernando José Moreira; da Silva Mesquita, Millena Carla; de Oliveira, Emilia Carolle Azevedo; Domingues, Ana Lucia Coutinho
2016-12-01
Current scientific information reported that due to successive treatments of schistosomiasis cases in endemic areas of Brazil in the last 30 years, there has been a decrease in severe clinical form (hepatosplenic) and mortality from upper gastrointestinal bleeding due to this disease. Against this information, literature data show that the state of Pernambuco presents significant percentage of deaths and hospitalizations due to schistosomiasis, and occurrence of severe clinical forms as schistosomiasis myeloradiculopathy and persistence of localities with high parasite loads. This scenario justified this research which seeking to update the morbidity and mortality of schistosomiasis in Pernambuco. To conduct a temporal analysis on the evolution of deaths, hospital admissions and severe forms of Manson's schistosomiasis over the last 16 years in Pernambuco, Brazil. It was performed a gathering secondary data on schistosomiasis, from healthcare information systems and from the records of Hospital das Clínicas, Federal University of Pernambuco (HC-UFPE), covering the period from 1999 to 2014. From 1999 to 2013 were registred 2578 deaths due to schistosomiasis and between 2008 and 2014 were recorded 473 hospitalizations for this disease. Among 1999-2014 were identified 1943 cases of schistosomiasis treated at the Hospital das Clínicas of Pernambuco. Among these cases, 72.6% (n. 1411) of the individuals presented the hepatosplenic clinical form (HE), 60.8% (n. 858) were at the age group 30-59 years (adults) and 58% were female. Among the HE cases, 4.6% (n. 58) had ascites, 43.2% (n. 556) had upper gastrointestinal bleeding and 39.1% (n. 489) had collateral circulation. The pattern of fibrosis in the liver E/EC (advanced fibrosis) and F/FC (very advanced fibrosis) occurred in 65.5% (n. 793) of cases. Between 1999-2014 the evolution curve of severe clinical forms of schistosomiasis remained stable, showing a tendency to decline from 2012. When compared to other states of Brazil, Pernambuco shows high numbers of deaths and hospital admissions due to schistosomiasis. The actions of the Schistosomiasis Control Program (PCE) have been developed in a disintegrated, disjointed and discontinuous way, which may explain the magnitude of deaths, hospitalizations and severe forms of the disease in Pernambuco, showing a lack of control and the maintenance of severe frame morbidity of schistosomiasis in this state. Copyright © 2016 Elsevier B.V. All rights reserved.
Ying, Zhao-yu; Tan, Xiao-dong; Huang, Ya-dong; Jiang, Bao-jie
2014-08-01
To evaluate the levels of the Chinese literature published by the schistosomiasis control institutions of 17 municipal cities of Hubei Province. The related literature published from 2008 to 2012 was searched from the databases of CNKI, VIP and Wanfang and then screened by the exclusion criteria. NoteExpress and Excel softwares were applied to collect the literature and carry out the bibliometric analysis. A total of 168 papers were included and the schistosomiasis control institutes of Jingzhou City and Wuhan City had the highest amount. The literature was mainly published in Chinese Journal of Schistosomiasis Control and Journal of Public Health and Preventive Medicine. The comprehensive influence indexes of the schistosomiasis control institutes of Jingzhou, Wuhan and Qianjiang cities were higher. The schistosomiasis control institutes of Jingzhou City had an extensive content of literature while Wuhan was mainly focused on epidemiology, case report and Oncomelania hupensis snail control. The research of schistosomiasis in each municipal city has an extensive content and the research capacity of the schistosomiasis control institute of Jingzhou City is relatively outstanding.
Schistosomiasis in the People's Republic of China: Prospects and Challenges for the 21st Century
Ross, Allen G. P.; Sleigh, Adrian C.; Li, Yuesheng; Davis, George M.; Williams, Gail M.; Jiang, Zheng; Feng, Zheng; McManus, Donald P.
2001-01-01
Schistosomiasis japonica is a serious communicable disease and a major disease risk for more than 30 million people living in the tropical and subtropical zones of China. Infection remains a major public health concern despite 45 years of intensive control efforts. It is estimated that 865,000 people and 100,250 bovines are today infected in the provinces where the disease is endemic, and its transmission continues. Unlike the other schistosome species known to infect humans, the oriental schistosome, Schistosoma japonicum, is a true zoonotic organism, with a range of mammalian reservoirs, making control efforts extremely difficult. Clinical features of schistosomiasis range from fever, headache, and lethargy to severe fibro-obstructive pathology leading to portal hypertension, ascites, and hepatosplenomegaly, which can cause premature death. Infected children are stunted and have cognitive defects impairing memory and learning ability. Current control programs are heavily based on community chemotherapy with a single dose of the drug praziquantel, but vaccines (for use in bovines and humans) in combination with other control strategies are needed to make elimination of the disease possible. In this article, we provide an overview of the biology, epidemiology, clinical features, and prospects for control of oriental schistosomiasis in the People's Republic of China. PMID:11292639
Santos, Allan Dantas Dos; Lima, Ana Caroline Rodrigues; Santos, Márcio Bezerra; Alves, José Antônio Barreto; Góes, Marco Aurélio de Oliveira; Nunes, Marco Antônio Prado; Sá, Sidney Lourdes César Souza; Araújo, Karina Conceição Gomes Machado de
2016-01-01
Schistosomiasis is a parasitic infectious disease with a worldwide prevalence. The objective of this work is to identify risk areas for schistosomiasis mansoni transmission in the State of Sergipe, Brazil, during the period from 2005 to 2014. We conducted an epidemiological study with secondary data from the Information System Control Program of Schistosomiasis [Sistema de Informação do Programa de Controle da Esquistossomose (SISPCE)]. Temporal trends were analyzed to obtain the annual percentage change (APC) in the rates of annual prevalence. In addition to the description of general indicators of the disease, the spatial analysis was descriptive, by means of the estimator of intensity kernel, and showed spatial dependence by indicators of global Moran (I) and Local Index of Spatial Association (LISA). Thematic maps of spatial distribution were made, identifying priority intervention areas in need of healthcare. There were 78,663 cases of schistosomiasis, with an average of 8.7% positivity recorded; 79.8% of the cases were treated, and Sergipe showed a decreasing positive trend (APC: -2.78). There was the presence of spatial autocorrelation and a significant global Moran index (I = 0.19; p-value = 0.03). We identified clusters of high-risk areas, mainly located in the northeast and southcentral of the state, which each had equally high infection rates. There was a decreasing positive trend of schistosomiasis in Sergipe. Spatial analysis identified the geographic distribution of risk and allowed the definition of priority areas for the maintenance and intensification of control interventions.
Xiao, Han; Peng, Minjin; Yan, Hong; Gao, Mengting; Li, Jingjing; Yu, Bin; Wu, Hanbo; Li, Shiyue
2016-01-01
Further advancement in schistosomiasis prevention requires new tools to assess protective motivation, and promote innovative intervention program. This study aimed to develop and evaluate an instrument developed based on the Protection Motivation Theory (PMT) to predict protective behavior intention against schistosomiasis among adolescents in China. We developed the Schistosomiasis PMT Scale based on two appraisal pathways of protective motivation- threat appraisal pathway and coping appraisal pathway. Data from a large sample of middle school students ( n = 2238, 51 % male, mean age 13.13 ± 1.10) recruited in Hubei, China was used to evaluated the validity and reliability of the scale. The final scale contains 18 items with seven sub-constructs. Cronbach's Alpha coefficients for the entire instrument was 0.76, and for the seven sub-constructs of severity, vulnerability, intrinsic reward, extrinsic reward, response efficacy, self-efficacy and response cost was 0.56, 0.82, 0.75, 0.80, 0.90, 0.72 and 0.70, respectively. The construct validity analysis revealed that the one level 7 sub-constructs model fitted data well (GFI = 0.98, CFI = 0.98, RMSEA = 0.03, Chi-sq/df = 3.90, p < 0.001). Predictive validity showed that both the PMT instrument score and the 7 sub-construct scores were significantly correlated with the intention engaged in protective behavior against schistosomiasis ( p < 0.05). This study provides a reliable and valid tool to measure protective motivation in schistosomiasis prevention control. Further studies are needed to develop more effective intervention programs for schistosomiasis prevention.
Wei, Hua; Fei, Yang; Guo-Hua, Peng
2017-01-16
To improve the management level of patients' information of schistosomiasis control stations in Nanchang City, the B/S three-layer architecture and ASP+SQL technology were applied to formulate the WEB-based management system of chronic schistosomiasis patients' information, so as to achieve the information sharing of chronic schistosomiasis among schistosomiasis control stations.
Zhu, Rong; Xu, Jing
2014-04-01
The imported schistosomiasis cases in the Chinese literature and reports from the infectious disease monitoring information system from 1979 to 2013 were collected and compiled. Totally 365 cases were reported to be infected with outside schistosomiasis, including 239 cases of schistosomiasis haematobia (74.0%) and 71 cases of schistosomiasis mansoni (22.0%), and 42 foreigners (11.5%) and 323 Chinese (88.5%). The infection areas involved 15 countries and regions in Africa. Totally 74.92% of patients worked in the construction or geological prospecting in the wild field. According to the analysis of these cases, we found that the management system of prevention and control of imported schistosomiasis cases was not perfect including the high missing re-port rate, high misdiagnosis rate, and no standard diagnostic criteria. We suggest that all the levels of CDC or health administrative authorities should adopt the following relevant control measures to strengthen the imported schistosomiasis prevention and control in order to reduce the damage to the public health and the risk of the spread of African schistosomiasis in China: (1) to establish and perfect the imported schistosomiasis monitoring and control system in China; (2) to integrate the dynamic information platform of labor export and establish the comprehensive prevention and control management system of infectious diseases; (3) to standardize the diagnosis and treatment of oversea imported schistosomiasis; (4) to strengthen the research on the transmission risk of imported schistosomiasis in the territory of China.
Zhao-Hui, Zheng; Jun, Qin; Li, Chen; Hong, Zhu; Li, Tang; Zu-Wu, Tu; Ming-Xing, Zeng; Qian, Sun; Shun-Xiang, Cai
2016-10-09
To analyze the construction and operation status of management system of laboratories of schistosomiasis control institutions in Hubei Province, so as to provide the reference for the standardized detection and management of schistosomiasis laboratories. According to the laboratory standard of schistosomiasis at provincial, municipal and county levels, the management system construction and operation status of 60 schistosomiasis control institutions was assessed by the acceptance examination method from 2013 to 2015. The management system was already occupied over all the laboratories of schistosomiasis control institutions and was officially running. There were 588 non-conformities and the inconsistency rate was 19.60%. The non-conformity rate of the management system of laboratory quality control was 38.10% (224 cases) and the non-conformity rate of requirements of instrument and equipment was 23.81% (140 cases). The management system has played an important role in the standardized management of schistosomiasis laboratories.
Guo-Hua, Peng; Zhu-Hua, Hu; Wei, Hua; Ke, Qian; Xiao-Gang, Li; Zhi-Shu, Zhang; Zhi-Gang, Chen; Xiao-Wu, Feng
2017-06-26
To understand the present situation of the chronic schistosomiasis patients' knowledge, attitude and practice on schistosomiasis control in Nanchang City. The knowledge, attitude and values on schistosomiasis control of 523 chronic schistosomiasis patients in Nanchang County, Jinxian County and Xinjian District in the Poyang Lake District were investigated with questionnaires. And the accuracy rates of the knowledge, attitude and practice among the patient groups of different counties, genders, age groups, occupations and educational levels were analyzed. The accuracy rates of the knowledge, attitude and practice of patients on schistosomiasis control were 95.76%, 82.80%, and 81.73% in Nanchang County; 91.37%, 93.32%, and 76.48% in Jinxian County; 88.25%, 67.56%, and 49.40% in Xinjian District. In the accuracy rates of knowledge, attitude and practice, the differences among the three counties (districts) were statistically significant ( χ 2 = 57.511-301.378, all P < 0.05) . The accuracy rates of chronic schistosomiasis patients' attitude and practice on schistosomiasis control in Nanchang City remain low. Therefore, the intensity of attitude and practice intervention should be strengthened in the Poyang Lake District in order to enhance the self-protection awareness of the patients.
Huan, Liu; Ai-Xia, Wang; Yuan-Zhen, Li; Ming-Ming, Zhou
2017-02-22
To investigate the status of knowledge, attitude and behavior of schistosomiasis control of rural residents in Wanjiang River region after a flood, so as to provide the reference for targeted health education. The multistage sampling was applied to select the respondents in rural residents in Wanjiang River region, and the self-designed questionnaire was used to investigate the current situation of knowledge, attitude and behavior of schistosomiasis prevention and control of the rural residents. The total awareness rate of knowledge about the prevention and control of schistosomiasis was 47.92%. The age, education, family income, relatives and friends with medical background, and health education significantly influenced the awareness rate ( χ 2 = 12.76, 89.19, 18.19, 50.83 and 92.60 respectively, all P < 0.05). The accuracy rates of attitude and behavior in schistosomiasis control were 62.89% and 52.37% respectively. The awareness rate of knowledge about the prevention and control of schistosomiasis, and the accuracy rates of attitude and behavior in schistosomiasis control of the rural residents in Wanjiang River region are all inefficient, and therefore, the targeted health education should be strengthened to decrease the risk of schistosomiasis transmission.
Enhancing Schistosomiasis Control Strategy for Zimbabwe: Building on Past Experiences
Chimbari, Moses J.
2012-01-01
Schistosoma haematobium and Schistosoma mansoni are prevalent in Zimbabwe to levels that make schistosomiasis a public health problem. Following three national surveys to map the disease prevalence, a national policy on control of schistosomiasis and soil transmitted helminths is being developed. This paper reviews the experiences that Zimbabwe has in the area of schistosomiasis control with a view to influence policy. A case study approach to highlight key experiences and outcomes was adopted. The benefits derived from intersectoral collaboration that led to the development of a model irrigation scheme that incorporates schistosomiasis control measures are highlighted. Similarly, the benefits of using plant molluscicides and fish and duck biological agents (Sargochromis codringtonii and Cairina moschata) are highlighted. Emphasis was also placed on the importance of utilizing locally developed water and sanitation technologies and the critical human resource base in the area of schistosomiasis developed over years. After synthesis of the case studies presented, it was concluded that while there is a need to follow the WHO recommended guidelines for schistosomiasis control it is important to develop a control strategy that is informed by work already done in the country. The importance of having a policy and local guidelines for schistosomiasis control is emphasized. PMID:22655171
Mwai, J; Njenga, S; Barasa, M
2016-08-18
Schistosomiasis remains a major public health problem in Kenya. Inadequate knowledge, attitudes and practices (KAP) on causative factors are some of the critical factors for the increased prevalence. The study assessed KAP on the control and prevention of schistosomiasis infection in Mwea division, Kirinyaga County-Kenya. Four hundred and sixty five house-hold heads were enrolled in this study by use of simple random sampling technique. The study employed an analytical descriptive cross sectional design utilizing both quantitative and qualitative data collection methods. A pretested structured questionnaire, Focus Group Discusions (FGDs) and Key Informant Interviews (KII) guides were used for data collection. Descriptive statistics and Chi square tests and Fisher's exact tests were computed where applicable. Data from the FGDs and KIIs were analyzed using NUID.IST NUIRO.6 software. Significant associations between knowledge and demographic factors i.e. age (p = 0.011), education level (p = 0.046), were reported. Handwashing after visiting the toilet (p = 0.001), having a toilet facility at home (p = 0.014); raring animals at home (p = 0.031), households being affected by floods (p = 0.005) and frequency of visits to the paddies (p = 0.037) had a significant association with respondents practices and schistosomiasis infection. Further significance was reported on households being affected by floods during the rainy season (p < 0.001), sources of water in a household (p < 0.047) and having a temporary water body in the area (p = 0.024) with increase in schistosomiasis infection. Results revealed that respondents practices were not significantly associated with gender (p = 0.060), marital status (p = 0.71), wearing of protective gear (p = 0.142) and working on the paddies (p = 0.144). This study reveals that knowledge about the cause, transmission, symptoms and prevention of schistosomiasis among the Mwea population was inadequate, and that this could be a challenging obstacle to the elimination of schistosomiasis in these communities. Due to various dominant risk factors, different control strategies should be designed. Therefore, there is a need for integrated control programme to have a lasting impact on transmission of schistosomiasis infection. Control programs like mass drug administration need to go beyond anti-helminthic treatment and that there is a need of a more comprehensive approach including access to clean water, sanitation and hygiene. School and community-based health education is also imperative among these communities to significantly reduce the transmission and morbidity from schistosomiasis.
Technique for controlling spread of limnotic oncomelania
NASA Astrophysics Data System (ADS)
Li, Damei; Wang, Xiangsan; Lai, Yonggen
2003-09-01
Schistosomiasis is a parasitic disease mostly found in areas along the Changjiang River of China. The disease is spread solely through an intermediary named oncomelania, so its spread of schistosomiasis can be controlled by properly designing water intakes which prevent oncomelania from entering farming land or residential areas. This paper reports a successful design process and a new oncomelania-free intake device. The design of the new intake is based on a sound research program in which extensive experimental studies were carried out to gain knowledge of oncomelania eco-hydraulic behavior and detailed flow field information through CFD simulation.
Rong-Zhi, Li; Yang, Liu; Hui, Zhang; Yi, Zhang; Bo, Zhong; Jian-Jun, Wu; Chun-Xia, Yang
2017-09-28
To explore the effectiveness of comprehensive schistosomiasis control interventions based on urban-rural integration system construction to carry out the schistosomiasis control in hilly schistosomiasis endemic areas, so as to offer a new mode to consolidate the achievements of schistosomiasis control in the new situation. Shouan Town and Changqiu Township in Pujiang County in hilly schistosomiasis endemic regions were selected as demonstration areas. The comprehensive schistosomiasis control interventions based on urban-rural integration system construction were implemented, including the land consolidation, centralized residence and so on. The effectiveness the interventions was evaluated. In Shouan Town and Changqiu Township, the transformed environments with Oncomelania hupensis snail habitats were 1 330.61 hm 2 and 1 456.84 hm 2 , the areas with snails decreased from 94.31 hm 2 and 83.00 hm 2 in 2000 to both 0 in 2015, the positive rates of serological tests for schistosomiasis decreased from 11.8% and 7.53% in 2000 to 1.01% and 1.86% in 2015, and the positive rates of parasitological tests decreased from 0.18% and 0.15% in 2000 to both 0 in 2015 respectively. The numbers of cattle decreased from 358 and 368 in 2000 to 4 and 6 in 2015 respectively. In 2000, the schistosome infection rates of cattle were 3.63% and 6.51% in Shouan Town and Changqiu Township respectively, and from 2004, no infected cattle were found. The comprehensive schistosomiasis control interventions based on urban-rural integration system construction can decrease the schistosome infection rate and area with snails effectively, providing a new mode for schistosomiasis elimination.
Evolution of the National Schistosomiasis Control Programmes in The People's Republic of China.
Xu, J; Steinman, P; Maybe, D; Zhou, X-N; Lv, S; Li, S-Z; Peeling, R
2016-01-01
Schistosomiasis japonica is caused by the parasitic trematode Schistosoma japonicum. It is endemic in The People's Republic of China and has significant impact on human health and socioeconomic development in certain regions. Over the last six decades, the national control programmes evolved in remarkable ways and brought schistosomiasis japonica largely under control. We describe the history and evolution of schistosomiasis control in The People's Republic of China, with an emphasis on shifts in control strategies that evolved with new insights into the biology of the parasite and its intermediate hosts, and the epidemiology of the disease in the country. We also highlight the achievements in controlling the disease in different socioecological settings, and identify persisting challenges to fully eliminate schistosomiasis japonica from the country. To reach the goal of schistosomiasis elimination, further integration of interventions, multisector collaboration, sensitive and effective surveillance are needed to strengthen. Copyright © 2016 Elsevier Ltd. All rights reserved.
Liwanag, Harvy Joy; Uy, Jhanna; Bataller, Ramil; Gatchalian, Janis Ruth; De La Calzada, Betty; Uy, Justine Alessandra; Dayrit, Manuel
2017-10-01
Neglected tropical diseases (NTDs) continue to be a public health problem in the Philippines. We assessed the association of soil-transmitted helminthiasis (STH) and schistosomiasis with selected health-related and socioeconomic variables in four villages in Leyte, Philippines. Stool specimens from 418 adults and 533 of their children from 209 families were examined through the Kato-Katz technique. STH and schistosomiasis were present in 64.6% and 12.5%, respectively, of study participants. Analysis through the generalized linear mixed model revealed a number of associations between infection in parents and their children. Findings indicate that years of disease prevention and control efforts in these areas have been unable to bring down prevalence in children and their parents. Eliminating NTDs as public health problems will require a systems thinking approach beyond implementation of vertical control programs alone. © The Author [2017]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com
Jia, Xu; Xue-Xiang, Wan; Lin, Chen; Bo, Zhong; Yi, Zhang
2016-10-13
To study the effectiveness of comprehensive control measures based on systematic ecological system construction to interrupt the transmission of schistosomiasis in hilly endemic regions in Sichuan Province, so as to provide the evidence for adjustment of schistosomiasis prevention and control strategies. A high endemic area of schistosomiasis, Panao Township of Dongpo District in Meishan City, was selected as a demonstration area. The comprehensive measures for schistosomiasis control with focus on systematic ecological management were implemented, and the income of residents, indexes of schistosomiasis control effect and so on were investigated before and after the intervention and the results were compared. The project based on systematic ecological system construction started in 2009 and 317.351 million Yuan was put into the construction. The construction included economic forest plant base (1 866.68 hm 2 , 72.66% of the total farmland areas), ecological protection gardens (585.35 hm 2 ) and so on. Totally 97.04% of historical areas with Oncomelania hupensis snails were comprehensively improved. In 2015, the peasants´ pure income per capita increased 4 938 Yuan, with the average annual growth rate of 14.69%. All the farm cattle were replaced by the machine. The benefit rate of water improvement was increased by 52.84% and the coverage rate of harmless toilets increased by 18.30%. The positive rate of serological tests for schistosomiasis decreased from 7.69% to 3.50%, and the positive rate of parasitological tests decreased from 1.18% to 0. The area with snails was decreased from 23.33 hm 2 to 0. The awareness rate of schistosomiasis control knowledge and correct behavior rate of the residents increased from 85.50% and 82.60% to 95.70% and 93.90% respectively. The comprehensive schistosomiasis control measures based on systematic ecological management are conform to the currently actual schistosomiasis prevention and control work in hilly endemic regions, and have good ecological economic benefit and schistosomiasis control effectiveness, which provide an effectively new model of prevention and control for advancing process, consolidating the effect, finally realizing goal of interruption and elimination of schistosomiasis in hilly endemic regions.
Qian, Yi-Li; Wang, Wei; Hong, Qing-Biao; Liang, You-Sheng
2014-12-01
To evaluate the outcomes of implementation of integrated schistosomiasis control strategy with emphasis on infectious source control using a bibliometric method. The literature pertaining to integrated schistosomiasis control strategy with emphasis on infectious source control was retrieved from CNKI, Wanfangdata, VIP, PubMed, Web of Science, BIOSIS and Google Scholar, and a bibliometric analysis of literature captured was performed. During the period from January 1, 2004 through September 30, 2014, a total of 94 publications regarding integrated schistosomiasis control strategy with emphasis on infectious source control were captured, including 78 Chinese articles (82.98%) and 16 English papers (17.02%). The Chinese literature was published in 21 national journals, and Chinese Journal of Schistosomiasis Control had the largest number of publications, consisting of 37.23% of total publications; 16 English papers were published in 12 international journals, and PLoS Neglected Tropical Diseases had the largest number of publications (3 publications). There were 37 affiliations publishing these 94 articles, and National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (16 publications), Anhui Institute of Schistosomiasis Control (12 publications) and Hunan Institute of Schistosomiasis Control (9 publications) ranked top three affiliations in number of publications. A total of 157 persons were co-authored in these 94 publications, and Wang, Zhou and Zhang ranked top 3 authors in number of publications. The integrated schistosomiasis control strategy with emphasis on infectious source control has been widely implemented in China, and the achievements obtained from the implementation of this strategy should be summarized and transmitted internationally.
Lin, Dan-Dan; Zeng, Xiao-Jun; Chen, Hong-Gen; Hong, Xian-Lin; Tao, Bo; Li, Yi-Feng; Xiong, Ji-Jie; Zhou, Xiao-Nong
2009-08-01
To evaluate the cost-effectiveness and cost-benefit on the integrated schistosomiasis control strategies with emphasis on infection source, and provide scientific basis for the improvement of schistosomiasis control strategy. Aiguo and Xinhe villages in Jinxian County were selected as intervention group where the new comprehensive strategy was implemented, while Ximiao and Zuxi villages in Xinzi County served as control where routine control program was implemented. New strategy of interventions included removing cattle from snail-infested grasslands and providing farmers with farm machinery, improving sanitation by supplying tap water and building lavatories and methane gas tanks, and implementing an intensive health education program. Routine interventions were carried out in the control villages including diagnosis and treatment for human and cattle, health education, and focal mollusciciding. Data were collected from retrospective investigation and field survey for the analysis and comparison of cost-effectiveness and cost-benefit between intervention and control groups. The control effect of the intervention group was better than that of the control. The cost for 1% decrease of infection rate per 100 people, 100 cattle, and 100 snails in intervention group was 480.01, 6 851.24, and 683.63 Yuan, respectively, which were about 2.70, 4.37 and 20.25 times as those in the control respectively. The total cost/benefit ratio (BCR) was lower than 1 (0.94 in intervention group and 0.08 in the control). But the total benefit of intervention group was higher than that of the control from 2005 to 2008. The forecasting analysis indicated that the total BCR in intervention group would be 1.13 at the 4th year and all cost could be recalled. Sensitivity analysis revealed that the BCR in intervention group changed in the range around 1.0 and that of the control ranged blow 0.5. The cost-benefit of intervention group was evidently higher than that of the control. The integrated control strategy focusing on infection source control brings about triplex benefits in schistosomiasis control, social development (and ecological protection) and economic efficacy, and shows better effects and benefits than the conventional control strategy.
Diagnosing schistosomiasis: where are we?
Gomes, Luciana Inácia; Enk, Martin Johannes; Rabello, Ana
2014-01-01
In light of the World Health Organization's initiative to extend schistosomiasis morbidity and mortality control programs by including a disease elimination strategy in low endemic settings, this paper reviews diagnostic tools described during the last decades and provide an overview of ongoing efforts in making an efficient diagnostic tool available worldwide. A literature search on PubMed using the search criteria schistosomiasis and diagnosis within the period from 1978 to 2013 was carried out. Articles with abstract in English and that used laboratory techniques specifically developed for the detection of schistosomiasis in humans were included. Publications were categorized according to the methodology applied (parasitological, immunological, or molecular) and stage of development (in house development, limited field, or large scale field testing). The initial research generated 4,535 publications, of which only 643 met the inclusion criteria. The vast majority (537) of the publications focused on immunological techniques; 81 focused on parasitological diagnosis, and 25 focused on molecular diagnostic methods. Regarding the stage of development, 307 papers referred to in-house development, 202 referred to limited field tests, and 134 referred to large scale field testing. The data obtained show that promising new diagnostic tools, especially for Schistosoma antigen and deoxyribonucleic acid (DNA) detection, which are characterized by high sensitivity and specificity, are being developed. In combination with international funding initiatives these tools may result in a significant step forward in successful disease elimination and surveillance, which is to make efficient tests accessible and its large use self-sustainable for control programs in endemic countries.
[Study on the change of semantic perspective of schistosomiasis control in China].
Zhou, Li-ying; Liu, Si-yuan; Li, Yu-ye; Deng, Yao; Yang, Kun
2015-12-01
To analyze the evolution process, discourse and semantic meaning of schistosomiasis prevention and control, so as to provide suggestions for control work. The official documents and mainstream media reports of schistosomiasis prevention and control were selected at different periods as discourse samples, and the deep social reasons behind the strategy change and the semantic meaning of the utterance were analyzed at different periods. The discourse of schistosomiasis prevention and control experienced the evolution of the political discourse, pluralistic discourse and public discourse, and the semantic connotations showed the authority conflict semantic features, and then transferred to semantic cooperation. The prevention and control of schistosomiasis have different semantic meanings at different periods, and the prevention and control work should correspond to a social practice, seek truth from facts, correctly understand the actual situation, and then establish the effective control policy.
[Evaluation standards and application for photography of schistosomiasis control theme].
Chun-Li, Cao; Qing-Biao, Hong; Jing-Ping, Guo; Fang, Liu; Tian-Ping, Wang; Jian-Bin, Liu; Lin, Chen; Hao, Wang; You-Sheng, Liang; Jia-Gang, Guo
2018-02-26
To set up and apply the evaluation standards for photography of schistosomiasis control theme, so as to offer the scientific advice for enriching the health information carrier of schistosomiasis control. Through the literature review and expert consultation, the evaluation standard for photography of schistosomiasis control theme was formulated. The themes were divided into 4 projects, such as new construction, natural scenery, working scene, and control achievements. The evaluation criteria of the theme photography were divided into the theme (60%), photographic composition (15%), focus exposure (15%), and color saturation (10%) . A total of 495 pictures (sets) from 59 units with 77 authors were collected from schistosomiasis epidemic areas national wide. After the first-step screening and second-step evaluation, the prizes of 3 themes of control achievements and new construction, working scene, and natural scenery were selected, such as 6 pictures of first prize, 12 pictures of second prize, 18 pictures of third prize, and 20 pictures of honorable prize. The evaluation standards of theme photography should be taken into the consideration of the technical elements of photography and the work specification of schistosomiasis prevention and control. In order to improve the ability of records for propaganda purpose of schistosomiasis control and better play a role of guiding correct propaganda, the training and guidance of photography of professionals should be carried out.
Zhang, S-Q; Sun, C-S; Wang, M; Lin, D-D; Zhou, X-N; Wang, T-P
2016-01-01
Schistosomiasis is one of neglected tropical diseases in the world. The People's Republic of China has made great achievements in schistosomiasis control through integrated interventions. Although the morbidity and mortality have been reduced to the lowest level in all three endemic regions, namely lake and marshland regions, hilly and mountainous regions and plains with waterway networks regions, the endemic status in lake and marshland region is still that of implementing the interventions in the higher endemicity areas towards elimination of schistosomiasis transmission. This review explores and analyses the endemic characteristics, control measures and its effectiveness in the course of schistosomiasis control programme, in order to provide more theoretical information and experiences for development of appropriate strategies leading to schistosomiasis elimination in the next stage in the country. Copyright © 2016 Elsevier Ltd. All rights reserved.
Xu, Jia; Chen, Lin; Zhang, Yi; Wu, Jian-Jun; Wan, Xue-Xiang; Zhu, Rong; Xu, Hui-Rong; Liu, Qing; Huang, Liang; Wu, Zi-Song; Lu, Long-Ting; Zhong, Bo
2013-12-01
To analyze the main obstacles existing in the implementation of integrated schistosomiasis prevention and control strategies with emphasis on infection source in hilly endemic regions, and to find out the current priority issues in schistosomiasis prevention and control, so as to provide the evidence for further solutions. Two typical hilly schistosomiasis endemic regions in Sichuan Province, including Pujiang County of Chengdu City and Dongpo District of Meishan City, were selected as research areas. A framework of obstacle factors in the implementation of integrated schistosomiasis prevention and control strategies with emphasis on infectious source in hilly endemic regions was built by literature review, and the management and technical personnel who worked on schistosomiasis prevention and control in eight different industries (health, agriculture, forestry and so on) and five levels (provincial, city, county, township and village levels) were investigated by questionnaires in the way of nominal group. One hundred and fifty-three management and technical personnel in different industries and different levels were investigated. The questionnaire recovery rate (experts' positive coefficient) was 100%. The results showed that the first four problems needing to be concerned in the implementation of integrated schistosomiasis prevention and control strategies with emphasis on infection source were eliminating Oncomelania hupensis snails by projects, health education, examination and treatment for schistosomiasis persons, and harmless treatment of night-soil and safe water supply. The focuses of two counties in the implementation of integrated strategy measures were different. The harmless treatment of night-soil and safe water supply was the most important measure in Pujiang County, while the elimination of snails by projects was the most in Dong-po District. As the differences in the situation of epidemic areas and the existed condition of the prevention and treatment progress, the comprehensive schistosomiasis control measures should be adjusted according to the local conditions in the implementation of integrated schistosomiasis prevention and control strategies with emphasis on infection source.
Tang, Qi-Qiang; Zhao, An; Zhu, Jing; Zhang, Gang-Gang
2011-02-01
To understand the status of health education on schistosomiasis for residents in susceptible zone and provide a reasonable basis for related study. A questionnaire survey on knowledge, attitude about schistosomiasis of the residents was conducted. Status of education on schistosomiasis of susceptible areas for the residents in general is not optimistic, the frequency of contacting with infected water was high, the demographic characteristics were also significant: (1) The passing rate for the villagers' schistosomiasis knowledge was too low, only 39.6%, the difference between awareness rates of schistosomiasis knowledge among villagers with different educational levels was significant (P < 0.05); (2) The overall level of correct attitude for schistosomiasis control was poor, only 37.7% of the villagers with a good attitude, the differences among villagers with different ages and occupations were significant (both P values < 0.05); (3) 73.5% of the villagers had ever contacted with infected water, and different groups contacted with infected water in different ways, 67.5% of men contacting for bathing, fishing, 63.7% of women contacting for washing clothes. Health education for schistosomiasis control in susceptible zones should be strengthened, the reasons for differences in cognitive level about schistosomiasis control among the villagers with different demographic characteristics and the better models for educational interventions for different villagers need to be explored.
Utzinger, Jürg; N'goran, Eliézer K; Caffrey, Conor R; Keiser, Jennifer
2011-09-01
Compared to malaria, tuberculosis and HIV/AIDS, schistosomiasis remains a truly neglected tropical disease. Schistosomiasis, perhaps more than any other disease, is entrenched in prevailing social-ecological systems, since transmission is governed by human behaviour (e.g. open defecation and patterns of unprotected surface water contacts) and ecological features (e.g. living in close proximity to suitable freshwater bodies in which intermediate host snails proliferate). Moreover, schistosomiasis is intimately linked with poverty and the disease has spread to previously non-endemic areas as a result of demographic, ecological and engineering transformations. Importantly though, thanks to increased advocacy there is growing awareness, financial and technical support to control and eventually eliminate schistosomiasis as a public health problem at local, regional and global scales. The purpose of this review is to highlight recent progress made in innovation, validation and application of new tools and strategies for research and integrated control of schistosomiasis. First, we explain that schistosomiasis is deeply embedded in social-ecological systems and explore linkages with poverty. We then summarize and challenge global statistics, risk maps and burden estimates of human schistosomiasis. Discovery and development research pertaining to novel diagnostics and drugs forms the centrepiece of our review. We discuss unresolved issues and emerging opportunities for integrated and sustainable control of schistosomiasis and conclude with a series of research needs. Copyright © 2010 Elsevier B.V. All rights reserved.
Person, Bobbie; Ali, Said M.; A’Kadir, Faiza M.; Ali, Jamal N.; Mohammed, Ulfat A.; Mohammed, Khalfan A.; Rollinson, David; Knopp, Stefanie
2016-01-01
Background On the Zanzibar islands, United Republic of Tanzania, elimination of urogenital schistosomiasis is strived for in the coming years. This qualitative study aimed to better understand community knowledge, perceptions, and practices associated with schistosomiasis among school-aged children on Unguja and Pemba islands, in order to inform the development of behavior change interventions contributing to eliminate urogenital schistosomiasis. Methodology In 2011, we conducted 35 children’s discussion groups, 41 in-depth interviews with parents and teachers, and 5 focus group discussions with community members in Zanzibar. Using a modified-grounded theory approach, we transcribed and coded the narrative data followed by thematic analysis of the emergent themes. Principal Findings Urogenital schistosomiasis is a common experience among children in Zanzibar and typically considered a boys’ disease. Children engage in multiple high-risk behaviors for acquiring schistosomiasis because of poor knowledge on disease transmission, lack of understanding on severity of disease-associated consequences, and lack of alternative options for water related activities of daily living and recreational play. Local primary school teachers had little to no training about the disease and no teaching tools or materials for students. Conclusions/Significance Conducting activities in open natural freshwater contaminated by S. haematobium larvae compromises the health of school-aged children in Zanzibar. The perception of urogenital schistosomiasis as a minor illness rather than a serious threat to a child’s well-being contributes to the spread of disease. Understanding community perceptions of disease along with the barriers and facilitators to risk reduction behaviors among children can inform health promotion activities, campaigns, and programs for the prevention, control, and elimination of urogenital schistosomiasis in Zanzibar. PMID:27399310
Li, Zhongwu; Nie, Xiaodong; Zhang, Yan; Huang, Jinquan; Huang, Bin; Zeng, Guangming
2016-01-01
Schistosomiasis is a severe public health problem in the Dongting Lake region, and its distribution, prevalence, and intensity of infection are particularly sensitive to environmental changes. In this study, the human and bovine schistosomiasis variations in the Dongting Lake region were studied from 1996 to 2010, and the relationships between schistosomiasis and water level were examined. Furthermore, based on these results, the potential effects of the Three Gorges Dam (TGD) on schistosomiasis were investigated. Results showed an increase in human schistosomiasis and in the scope of seriously affected regions, along with a decrease in bovine schistosomiasis. Human schistosomiasis was negatively correlated with water level during wet season (from May to October), particularly the average water level in October. This finding indicated that the decreasing water level may be highly related to the increasing of human schistosomiasis in the Dongting Lake region. Based on this result and the variation of schistosomiasis before and after the construction and operation of TGD, the impoundment of the Three Gorges reservoir is believed to decrease the water level and increase the contact between people and schistosomiasis. Therefore, the TGD, which is operated by regulating water and scheduling water operations, is not good for the control of human schistosomiasis in the Dongting Lake region. Although the extent of the influence of the TGD on schistosomiasis remains unclear, the influence of the TGD on preventing and controlling schistosomiasis should not be ignored.
Phillips, Anna E; Gazzinelli-Guimarães, Pedro H; Aurelio, Herminio O; Dhanani, Neerav; Ferro, Josefo; Nala, Rassul; Deol, Arminder; Fenwick, Alan
2018-01-10
The results presented here are part of a five-year cluster-randomised intervention trial that was implemented to understand how best to gain and sustain control of schistosomiasis through different preventive chemotherapy strategies. This paper presents baseline data that were collected in ten districts of Cabo Delgado province, northern Mozambique, before treatment. A cross-sectional study of 19,039 individuals was sampled from 144 villages from May to September 2011. In each village prevalence and intensity of S. haematobium were investigated in 100 children first-year students (aged 5-8 years), 100 school children aged 9-12 years (from classes 2 to 7) and 50 adults (20-55 years). Prevalence and intensity of S. haematobium infection were evaluated microscopically by two filtrations, each of 10 ml, from a single urine specimen. Given that individual and community perceptions of schistosomiasis influence control efforts, community knowledge and environmental risk factors were collected using a face-to-face interview. Data were entered onto mobile phones using EpiCollect. Data summary was made using descriptive statistics. Chi-square and logistic regression were used to determine the association between dependent and independent variables. The overall prevalence of urogenital schistosomiasis was 60.4% with an arithmetic mean intensity of infection of 55.8 eggs/10 ml of urine. Heavy infections were detected in 17.7%, of which 235 individuals (6.97%) had an egg count of 1000 eggs/10 ml or more. There was a significantly higher likelihood of males being infected than females across all ages (62% vs 58%; P < 0.0005). Adolescents aged 9-12 years had a higher prevalence (66.6%) and mean infection intensity (71.9 eggs/10 ml) than first-year students (63.1%; 58.2 eggs/10 ml). This is the first study in Mozambique looking at infection rates among adults. Although children had higher levels of infection, it was found here that adults had a high average prevalence and intensity of infection (44.5%; 23.9 eggs/10 ml). Awareness of schistosomiasis was relatively high (68.6%); however, correct knowledge of how schistosomiasis is acquired was low (23.2%) among those who had heard of the disease. Schistosomiasis risk behaviour such as washing (91.3%) and bathing (86.7%) in open water sources likely to be infested with host snails was high. Urogenital schistosomiasis is widespread in Cabo Delgado. In addition, poor community knowledge about the causes of schistosomiasis and how to prevent it increases the significant public health challenge for the national control program. This was the first study in Mozambique that examined infection levels among adults, where results showed that S. haematobium infection was also extremely high. Given that this controlled trial aims to understand the impact of different combinations of schistosomiasis control through treatment of communities, schools, and treatment holidays over a five-year period, these findings highlight the importance of examining the impact of different treatment approaches also in adults. The trials have been registered with the International Standard Randomised Controlled Trial registry under ISRCT 14117624 Mozambique (14 December 2015).
Cao, Z-G; Zhao, Y-E; Lee Willingham, A; Wang, T-P
2016-01-01
Schistosomiasis japonica, an endemic, zoonotic tropical parasitic disease caused by Schistosoma japonicum, remains an important public health concern in The People's Republic of China. Unlike other species of Schistosoma, over 40 species of wild and domestic animals can act as reservoir hosts of S. japonicum, which increases the difficulty for the control of this tropical disease. It is widely recognized that domestic animals, particularly water buffaloes and cattle, play an important role in the transmission of S. japonicum. Hence, since the 1950s when The People's Republic of China commenced fight against the disease, the control of animal schistosomiasis has been carried out almost synchronously with that of human schistosomiasis, such that great strides have been made over the past six decades. In this chapter, we review the history and current status of schistosomiasis control in domestic animals in The People's Republic of China. We thoroughly analyse the prevalence of domestic animal schistosomiasis at different stages of schistosomiasis control and the role of different species of domestic animals in transmission of the disease, summarize the control strategies and assess their effectiveness. Furthermore, the challenges ahead are discussed and recommendations for future direction are provided. Copyright © 2016 Elsevier Ltd. All rights reserved.
Enhancing collaboration between China and African countries for schistosomiasis control.
Xu, Jing; Yu, Qing; Tchuenté, Louis-Albert Tchuem; Bergquist, Robert; Sacko, Moussa; Utzinger, Jürg; Lin, Dan-Dan; Yang, Kun; Zhang, Li-Juan; Wang, Qiang; Li, Shi-Zhu; Guo, Jia-Gang; Zhou, Xiao-Nong
2016-03-01
Schistosomiasis remains an important public health issue, with a large number of cases reported across sub-Saharan Africa, and parts of Asia and Latin America. China was once highly endemic, but has made substantial progress and is moving towards elimination of schistosomiasis. Meanwhile, despite long-term, repeated, school-based chemotherapy in many African countries, more than 90% of all schistosomiasis cases are concentrated in Africa, and hence, this continent constitutes the key challenge for schistosomiasis control. Opportunities and issues for international collaboration in the fight against schistosomiasis are outlined with a focus on China's experiences, including the role of public health authorities and intersectoral collaboration, use of new and effective snail control approaches and diagnostic tools adapted to the specific stage of control, as well as the strengthening of risk mapping and surveillance-response mechanisms. Training courses targeting African governmental officials and professionals, coupled with field visits of African scientists and control programme managers to China, and vice versa, are considered important for improved schistosomiasis control and elimination. The crucial question remains whether the Chinese experience can be translated and applied in African countries to improve the effectiveness of health interventions and scale-up. Copyright © 2016 World Health Organization. Published by Elsevier Ltd/Inc/BV. All rights reserved. Published by Elsevier Ltd.. All rights reserved.
Wang, X-Y; He, J; Yang, K; Liang, S
2016-01-01
Schistosomiasis, as the important parasitic disease, has caused serious threats to human health globally. The People's Republic of China has acquired significant achievements based on large-scale interventions and innovational technology. The spatial technology was introduced in 1980s and widely used in the study and control of schistosomiasis in The People's Republic of China. This chapter reviews the progress and application of spatial technology in schistosomiasis control by analysing the spatiotemporal pattern of and the impact of ecological changes on schistosomiasis transmission, which have provided the information to design and select the control strategy, and assisted the establishment of the monitoring and early warning system in The People's Republic of China, especially in the marshland and mountainous regions. Copyright © 2016 Elsevier Ltd. All rights reserved.
Chen, Zhe; Rao, Xian-long; Li, Yi-feng; Gu, Xiao-nan; Xu, Mei-xin; Lin, Dan-dan
2015-12-01
To evaluate the effect of schistosomiasis control strategy with emphasis on infection source control in the Yongxiu County promotion zone of Poyang Lake region. The Wucheng Township of Yongxiu County was selected as the observation site, and the effect of the comprehensive control strategy was evaluated by using the method of field surveys combined with retrospective investigations. In 2010, there were 17 persons whose stool tests for schistosome infection were positive, and the number of calculated schistosomiasis patients was 2,331. The infection rate of cattle was 4.5%, and the area with infected Oncomelania hupensis snails was 10.00 hm². In 2011, the comprehensive control strategy was carried out, and in 2012, there were no cattle in the promotion zone. In 2013 and 2014, there were no schistosomiasis patients with positive stool tests. In 2014, no schistosome infected snails were found. The control strategy with emphasis on infection source control effectively controls the transmission of schistosomiasis in Yongxiu County promotion zone.
Quantifying Quality of Life and Disability of Patients with Advanced Schistosomiasis Japonica
Jia, Tie-Wu; Utzinger, Jürg; Deng, Yao; Yang, Kun; Li, Yi-Yi; Zhu, Jin-Huan; King, Charles H.; Zhou, Xiao-Nong
2011-01-01
Background The Chinese government lists advanced schistosomiasis as a leading healthcare priority due to its serious health and economic impacts, yet it has not been included in the estimates of schistosomiasis burden in the Global Burden of Disease (GBD) study. Therefore, the quality of life and disability weight (DW) for the advanced cases of schistosomiasis japonica have to be taken into account in the re-estimation of burden of disease due to schistosomiasis. Methodology/Principal Findings A patient-based quality-of-life evaluation was performed for advanced schistosomiasis japonica. Suspected or officially registered advanced cases in a Schistosoma japonicum-hyperendemic county of the People's Republic of China (P.R. China) were screened using a short questionnaire and physical examination. Disability and morbidity were assessed in confirmed cases, using the European quality of life questionnaire with an additional cognitive dimension (known as the “EQ-5D plus”), ultrasonography, and laboratory testing. The age-specific DW of advanced schistosomiasis japonica was estimated based on patients' self-rated health scores on the visual analogue scale of the questionnaire. The relationships between health status, morbidity and DW were explored using multivariate regression models. Of 506 candidates, 215 cases were confirmed as advanced schistosomiasis japonica and evaluated. Most of the patients reported impairments in at least one health dimension, such as pain or discomfort (90.7%), usual activities (87.9%), and anxiety or depression (80.9%). The overall DW was 0.447, and age-specific DWs ranged from 0.378 among individuals aged 30–44 years to 0.510 among the elderly aged ≥60 years. DWs are positively associated with loss of work capacity, psychological abnormality, ascites, and active hepatitis B virus, while splenectomy and high albumin were protective factors for quality of life. Conclusions/Significance These patient-preference disability estimates could provide updated data for a revision of the GBD, as well as for evidence-based decision-making in P.R. China's national schistosomiasis control program. PMID:21358814
[Investigation on schistosomiasis cognitive levels of people from Chaohu area].
Liu, Huan; Sha, Jian-jun; Huang, Hao; Cao, Zhi-guo; Zhao, Jin-hong; Li, Chao-pin
2015-12-01
To investigate the cognitive levels of people from Chaohu area, Anhui Province about the prevention and control knowledge of schistosomiasis before the water transfer project operation, so as to provide the reference for formulating the health education intervention. A schistosomiasis questionnaire survey was conducted among the students, fishermen, boat people and villagers from Chaohu selected by the random cluster sampling from May to October, 2014. A total of 1 140 questionnaires were issued with the actual recovery of 1 096 copies and 1 032 valid questionnaires. The awareness rate of prevention and control knowledge of schistosomiasis was from 11.72% to 71.71%. The highest awareness rate was in the "know schistosomiasis", however the lowest awareness rate was in the "know the intermediate host of schistosomiasis". Catching fish or shrimp in river or lake was the main way of contacting water in production activities (39.05%), and swimming or playing in river or lake was the main way of contacting water in life activities (63.18%). The prevention and control knowledge of schistosomiasis by teaching was at a rate of 41.47% on average, and the main way was anti-schistosomiasis professionals going to countryside to do health education (49.53%). That the feces directly discharged into water accounted for 91.14% in fishman and boatman. It is necessary for people from Chaohu to carry out various forms of health education of schistosomiasis prevention and control before the water transfer project operation.
Price, Amy; Verma, Arpana; Welfare, William
2015-04-01
An estimated 129 million people are infected with urogenital schistosomiasis in sub-Saharan Africa. Current control recommendations endorse mass administration of praziquantel. Health education is an important component of effective schistosomiasis prevention and control, but there has been limited research on its effectiveness. This paper reviews the effectiveness of health education as an intervention in the prevention and control of urogenital schistosomiasis in sub-Saharan Africa. The outcomes of interest were prevalence, incidence or transmission of schistosomiasis, behaviour change associated with infection, or changes in knowledge of the disease. The findings from this review suggest that health education has a beneficial impact on knowledge and understanding of schistosomiasis within the target groups. However, further research is needed due to the poor quality of the included studies. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Zhang, Li-juan; Zhu, Rong; Xu, Jing; Li, Shi-zhu
2015-06-01
To understand the knowledge level on schistosomiasis prevention and treatment among professionals of schistosomiasis endemic counties in Hunan and Hubei provinces, so as to provide the basis for the ability construction of schistosomiasis control institution. The theoretical test was applied to investigate the mastering situation on schistosomiasis prevention and control among professionals of 12 selected schistosomiasis endemic counties in Hunan and Hubei provinces, and the results were analyzed statistically. Ninety-six professionals were surveyed. The average score was 66.94 ± 11.53, in the range of 34-91, and the pass rate was 75.00%. The scoring rates of the knowledge points of the test and treatment of schistosomiasis, snail survey and killing as well as basic knowledge and laws and regulations about schistosome were 68.69%, 70.54% and 73.19%, respectively. On the knowledge points of the test and treatment of schistosomiasis and basic knowledge and laws and regulations about schistosome, the differences among different education backgrounds were significant (F = 3.337, 4.793, both P < 0.05), and the scores were higher in professionals with higher diploma. In the scores, there were no statistical differences between or among different genders, age groups, professional titles or specialties (all P > 0.05). The overall knowledge level on schistosomiasis prevention and treatment of the professionals from 12 schistosomiasis endemic counties in Hunan and Hubei provinces is low. Therefore, the learning of relative knowledge should be strengthened.
Mao, Yuan-Hua; Li, Dong; Ning, An; Qiu, Ling; Xiong, Ji-Jie
2011-04-01
To develop the information management system for advanced schistosomiasis chemotherapy and assistance in Jiangxi Province. Based on Access 2003, the system was programmed by Visual Basic 6.0 and packaged by Setup Factory 8.0. In the system, advanced schistosomiasis data were able to be input, printed, indexed, and statistically analyzed. The system could be operated and maintained easily and timely. The information management system for advanced schistosomiasis chemotherapy and assistance in Jiangxi Province is successfully developed.
Liu, Han-cheng; Zhong, Chen-hui; Liao, Si-qi; He, Hui
2014-08-01
To investigate the current situation of management of institutions of schistosomiasis prevention and control in Hubei Province, so as to explore the probable competency building standards for these institutions at the county and township levels. By using a combination of quantitative and qualitative methods, the institutions of schistosomiasis prevention and control at county and township levels were investigated for the institutional setup, staffing and fulfillment functions since the reform of 2004. Among 63 schistosomiasis endemic counties (cities, districts) of Hubei Province, there were 26 independent schistosomiasis control institutions (41.27%), there were 24 institutions which were incorporated into CDC (38.10%), and there were no institutions in 13 counties (20.63%). Among 518 endemic towns, there were 299 institutions (57.72%). The total staffing size were 1 932, but there were 1 586 (82.09%) people actually working in the post, and therefore there were 346 (17.91%) empty positions. The average rates of carrying out the six functions were 91.48%-71.19%, but only 19.23% of the institutions participated in the comprehensive schistosomiasis control management project and its effect assessment. According to the management model for schistosomiasis control institutions under the current institutional mechanisms, we need a rigorous industry standard to constrain, guide and standardize the management and capacity-building of the institutions in different historical periods.
[Schistosomiasis status of staff in Hydrology Bureau of Yangtze Water Resources Committee in 2013].
Fu, Jun; Leng, Cheng-mei; Tang, Min; Yao, Wei-gang
2014-08-01
To understand the status of schistosomiasis of staff in the Hydrology Bureau of Yangtze Water Resources Committee and the Oncomelania hupensis snail condition of their work areas in 2013, so as to provide the evidences for the schistosomiasis control in the industry. The physical examination data about schistosomiasis of the staff from 2006 to 2013 were collected and analyzed to understand the schistosomiasis prevalence condition of the staff and the changes of their liver parenchyma. Meanwhile, the snail status in the work areas was surveyed. There were 1,393 staff involved in the physical examinations of schistosomiasis in 2003, 197 of them were schistosomiasis patients, the prevalence rate was 14.14%, and no new acute schistosomiasis case occurred. The cases whose liver parenchyma were classified as Grade 0, I , II , III occupied 28.9%, 67.0%, 3.05% and 1.02%, respectively. A total of 24 work areas were involved in the snail survey, and 71 snails were captured. Among the whole snails captured, 39 were living snails, but no schistosome infected snails were found. The prevalence rate of schistosomiasis in staff of the Hydrology Bureau of Yangtze Water Resources Committee is relatively high, so the schistosomiasis surveillance as well as the snail survey and control still should be carried out consistently.
[Qualitative research of self-management behavior in patients with advanced schistosomiasis].
Wang, Jian-ping; Wang, Xing-ju; Bao, Hui-hong; Zhang, Hong; Xu, Zheng-rong
2013-10-01
To explore the self-management behavior of patients with advanced schistosomiasis, so as to provide the evidence for improving clinical nursing. A total of 18 patients with advanced schistosomiasis were interviewed in depth by using a semi structured interview method. The results were analyzed with Miles and Huberman content analysis method. Most of the patients with advanced schistosomiasis had self-management control behavior and were cooperated with medical assistance because of their seriously illness. Based on data analysis, the symptom management, follow-up management, a healthy lifestyle, medication awareness, and emotional management were obtained. The patients with advanced schistosomiasis have self management control behavior. Health care workers should promote the patients, their families and social people to participate in the self-management behavior of advanced schistosomiasis patients.
Zhou, Xiao-Rong; Huang, Shui-Sheng; Gong, Xin-Guo; Cen, Li-Ping; Zhang, Cong; Zhu, Hong; Yang, Jun-Jing; Chen, Li
2012-04-01
To construct a performance evaluation and management system on advanced schistosomiasis medical treatment, and analyze and evaluate the work of the advanced schistosomiasis medical treatment over the years. By applying the database management technique and C++ programming technique, we inputted the information of the advanced schistosomiasis cases into the system, and comprehensively evaluated the work of the advanced schistosomiasis medical treatment through the cost-effect analysis, cost-effectiveness analysis, and cost-benefit analysis. We made a set of software formula about cost-effect analysis, cost-effectiveness analysis, and cost-benefit analysis. This system had many features such as clear building, easy to operate, friendly surface, convenient information input and information search. It could benefit the performance evaluation of the province's advanced schistosomiasis medical treatment work. This system can satisfy the current needs of advanced schistosomiasis medical treatment work and can be easy to be widely used.
Chen, Xinguang; Yu, Bin; Gao, Mengting; Yan, Hong; Okafor, Chukwuemeka N.
2014-01-01
Background Among millions of people who suffer from schistosomiasis in China, adolescents are at increased risk to be infected. However, there is a lack of theory-guided behavioral prevention intervention programs to protect these adolescents. This study attempted to apply the Protection Motivation Theory (PMT) in predicting intentions to engage in protective behaviors against schistosomiasis infection. Methods The participants were selected using the stratified cluster sampling method. Survey data were collected using anonymous self-reported questionnaire. The advanced structural equation modeling (SEM) method was utilized to assess the complex relationship among schistosomiasis knowledge, previous risk exposure and protective measures in predicting intentions to engage in protective behavior through the PMT constructs. Principal Findings Approximately 70% of participants reported they were always aware of schistosomiasis before exposure to water with endemic schistosomiasis, 6% of the participants reported frequency of weekly or monthly prior exposure to snail-conditioned water. 74% of participants reported having always engaged in protective behaviors in the past three months. Approximately 7% were unlikely or very unlikely to avoid contact with snail-conditioned water, and to use protective behaviors before exposure. Results from SEM analysis indicated that both schistosomiasis knowledge and prior exposure to schistosomiasis were indirectly related to behavior intentions through intrinsic rewards and self-efficacy; prior protective behaviors were indirectly related to behavior intentions through severity, intrinsic rewards and self-efficacy, while awareness had an indirect relationship with behavior intentions through self-efficacy. Among the seven PMT constructs, severity, intrinsic rewards and self-efficacy were significantly associated with behavior intentions. Conclusions The PMT can be used to predict the intention to engage in protective behaviors against schistosomiasis. Schistosomiasis intervention programs should focus on the severity, intrinsic rewards and self-efficacy of protection motivation, and also increase the awareness of infection, and enrich the contents of schistosomiasis education. PMID:25329829
Xiao, Han; Li, Shiyue; Chen, Xinguang; Yu, Bin; Gao, Mengting; Yan, Hong; Okafor, Chukwuemeka N
2014-10-01
Among millions of people who suffer from schistosomiasis in China, adolescents are at increased risk to be infected. However, there is a lack of theory-guided behavioral prevention intervention programs to protect these adolescents. This study attempted to apply the Protection Motivation Theory (PMT) in predicting intentions to engage in protective behaviors against schistosomiasis infection. The participants were selected using the stratified cluster sampling method. Survey data were collected using anonymous self-reported questionnaire. The advanced structural equation modeling (SEM) method was utilized to assess the complex relationship among schistosomiasis knowledge, previous risk exposure and protective measures in predicting intentions to engage in protective behavior through the PMT constructs. Approximately 70% of participants reported they were always aware of schistosomiasis before exposure to water with endemic schistosomiasis, 6% of the participants reported frequency of weekly or monthly prior exposure to snail-conditioned water. 74% of participants reported having always engaged in protective behaviors in the past three months. Approximately 7% were unlikely or very unlikely to avoid contact with snail-conditioned water, and to use protective behaviors before exposure. Results from SEM analysis indicated that both schistosomiasis knowledge and prior exposure to schistosomiasis were indirectly related to behavior intentions through intrinsic rewards and self-efficacy; prior protective behaviors were indirectly related to behavior intentions through severity, intrinsic rewards and self-efficacy, while awareness had an indirect relationship with behavior intentions through self-efficacy. Among the seven PMT constructs, severity, intrinsic rewards and self-efficacy were significantly associated with behavior intentions. The PMT can be used to predict the intention to engage in protective behaviors against schistosomiasis. Schistosomiasis intervention programs should focus on the severity, intrinsic rewards and self-efficacy of protection motivation, and also increase the awareness of infection, and enrich the contents of schistosomiasis education.
Mwanga, Joseph R; Kaatano, Godfrey M; Siza, Julius E; Chang, Su Young; Ko, Yunsuk; Kullaya, Cyril M; Nsabo, Jackson; Eom, Keeseon S; Yong, Tai-Soon; Chai, Jong-Yil; Min, Duk-Young; Rim, Han-Jong; Changalucha, John M
2015-10-01
Schistosomiasis and intestinal worm infections are widespread diseases of public health importance in Tanzania. A study on perceptions and practices related to schistosomiasis and intestinal worm infections was undertaken among a community population of Kome Island in Sengerema District, north-western Tanzania, where intestinal schistosomiasis and intestinal worm infections are endemic. Schistosomiasis and intestinal worm-related perceptions and practices were assessed before and 3 years after implementation of a participatory hygiene and sanitation transformation (PHAST) intervention as a control measure. Data were obtained from baseline and post-intervention knowledge, attitudes, and practices (KAP) questionnaire surveys conducted twice in 2009 and 2012 among 82 individuals aged ≥15 years. We found significant increases in respondents' knowledge of the cause, transmission, symptoms, health consequences, and prevention of schistosomiasis and intestinal worm infections after PHAST intervention. The increase in respondents' knowledge on almost all aspects of the said infections was translated into actions to control schistosomiasis and intestinal worm infections. This has not been achieved by chance, but due to well-designed and locally-adapted PHAST intervention. We conclude that despite criticisms, PHAST approach is still useful in empowering communities to control water, sanitation, and hygiene related infectious diseases such as schistosomiasis and intestinal worm infections.
[Filariasis control: entry point for other helminthiasis control programs?].
Boussinesq, M
2006-08-01
Filariasis control programs are based on a decentralized drug distribution strategy known as "community-directed". This strategy could also be applied to the control of schistosomiasis and intestinal nematode infections. Integration of these control programs could be highly cost-effective. However, as a prerequisite for integration, it would be necessary to identify zones where these helminthic infections co-exist, specify the population categories that should receive each medication (ivermectin, albendazole, mebendazole, and praziquantel), check that combined administration of these drugs is safe and ensure that an integrated program would have no detrimental effect on the health care system and on the efficacy of ongoing programs.
Quantitative assessment of the impact of partially protective anti-schistosomiasis vaccines
Ndeffo Mbah, Martial; Galvani, Alison
2017-01-01
Background Mass drug administration (MDA) of praziquantel has been the intervention of choice against schistosomiasis but with limited success in interrupting the transmission. The development of anti-Schistosoma vaccines is underway. Our objective is to quantify the population-level impact of anti-Schistosoma vaccines when administered alone and in combination with mass drug administration (MDA) and determine factors in vaccine design and public health implementation that optimize vaccination role in schistosomiasis control and elimination. Methods and findings We developed a deterministic compartmental model simulation of schistosomiasis transmission in a high-risk Kenyan community, including stratification by age, parasite burden, and vaccination status. The modeled schistosomiasis vaccines differed in terms of vaccine duration of protection (durability) and three biological efficacies. These are vaccine susceptibility effect (SE) of reducing person’s susceptibility to Schistosoma acquisition, vaccine mortality effect (ME) of reducing established worm burden and vaccine fecundity effect (FE) of reducing egg release by mature worms. We quantified the population-level impact of vaccination over two decades under diverse vaccination schemes (childhood vs. mass campaigns), with different age-targeting scenarios, different risk settings, and with combined intervention with MDA. We also assessed the sensitivity of our predictions to uncertainties in model parameters. Over two decades, our base case vaccine with 80% SE, FE, and ME efficacies, 10 years’ durability, provided by mass vaccination every 10 years, reduced host prevalence, mean intensity, incidence, and patent snail prevalence to 31%, 20 eggs/10-ml sample/person, 0.87 worm/person-year, and 0.74%, from endemic-state values of 71%, 152, 3.3, and 0.98%, respectively. Lower impact was found when coverage did not encompass all potential contaminators, and childhood-only vaccination schemes showed delayed and lower impact. In lower prevalence settings, the base case vaccine generated a proportionately smaller impact. A substantially larger vaccine program effect was generated when MDA + mass vaccination was provided every 5 years, which could be achieved by an MDA-only program only if drug was offered annually. Vaccine impact on schistosomiasis transmission was sensitive to a number of parameters including vaccine efficacies, human contact rates with water, human density, patent snails’ rate of patency and lifespan, and force of infection to snails. Conclusions To be successful a vaccine-based control strategy will need a moderately to highly effective formulation combined with early vaccination of potential contaminators and aggressive coverage in repeated rounds of mass vaccination. Compared to MDA-only program, vaccination combined with MDA accelerates and prolongs the impact by reducing the acquisition of new worms and reducing egg release from residual worms. PMID:28410369
Quantitative assessment of the impact of partially protective anti-schistosomiasis vaccines.
Alsallaq, Ramzi A; Gurarie, David; Ndeffo Mbah, Martial; Galvani, Alison; King, Charles
2017-04-01
Mass drug administration (MDA) of praziquantel has been the intervention of choice against schistosomiasis but with limited success in interrupting the transmission. The development of anti-Schistosoma vaccines is underway. Our objective is to quantify the population-level impact of anti-Schistosoma vaccines when administered alone and in combination with mass drug administration (MDA) and determine factors in vaccine design and public health implementation that optimize vaccination role in schistosomiasis control and elimination. We developed a deterministic compartmental model simulation of schistosomiasis transmission in a high-risk Kenyan community, including stratification by age, parasite burden, and vaccination status. The modeled schistosomiasis vaccines differed in terms of vaccine duration of protection (durability) and three biological efficacies. These are vaccine susceptibility effect (SE) of reducing person's susceptibility to Schistosoma acquisition, vaccine mortality effect (ME) of reducing established worm burden and vaccine fecundity effect (FE) of reducing egg release by mature worms. We quantified the population-level impact of vaccination over two decades under diverse vaccination schemes (childhood vs. mass campaigns), with different age-targeting scenarios, different risk settings, and with combined intervention with MDA. We also assessed the sensitivity of our predictions to uncertainties in model parameters. Over two decades, our base case vaccine with 80% SE, FE, and ME efficacies, 10 years' durability, provided by mass vaccination every 10 years, reduced host prevalence, mean intensity, incidence, and patent snail prevalence to 31%, 20 eggs/10-ml sample/person, 0.87 worm/person-year, and 0.74%, from endemic-state values of 71%, 152, 3.3, and 0.98%, respectively. Lower impact was found when coverage did not encompass all potential contaminators, and childhood-only vaccination schemes showed delayed and lower impact. In lower prevalence settings, the base case vaccine generated a proportionately smaller impact. A substantially larger vaccine program effect was generated when MDA + mass vaccination was provided every 5 years, which could be achieved by an MDA-only program only if drug was offered annually. Vaccine impact on schistosomiasis transmission was sensitive to a number of parameters including vaccine efficacies, human contact rates with water, human density, patent snails' rate of patency and lifespan, and force of infection to snails. To be successful a vaccine-based control strategy will need a moderately to highly effective formulation combined with early vaccination of potential contaminators and aggressive coverage in repeated rounds of mass vaccination. Compared to MDA-only program, vaccination combined with MDA accelerates and prolongs the impact by reducing the acquisition of new worms and reducing egg release from residual worms.
Massara, Cristiano Lara; Schall, Virgínia Torres
2004-01-01
The experience described here is part of an extensive program that aims to stimulate schools to develop health integrated projects from theme generators, i.e., themes that have a meaning for the community. It was developed in Jaboticatubas, a town in the metropolitan region of Belo Horizonte, capital of the state of Minas Gerais, Brazil, and the focus was schistosomiasis. The selection was based on the expressive and historical prevalence of this disease in the county, which has been known as the "capital of schistosomiasis", in a national press release since the 1960's. Schistosomiasis is also a theme pointed out by teachers as requiring more information and methodologies to work with their students, most of them living in areas of high risk of transmission. In addition, during the last years, this disease has been transmitted silently through an increasing rural tourism in that region, requiring integrated and effective control actions. The developed strategy included four schools, whose teachers, students, and families took part in the process. It emphasizes in a critical pedagogy approach, which focuses on health issues as themes that may mobilize the school community and awake the population to a work which integrates environment, health, and citizenship. The results demonstrate that teachers and students not only acquired new knowledge and methodological skills, but also gained confidence in their ability to improve their health conditions. Thus, the project promotes a critical education that can result a more permanent effect on the control of schistosomiasis as well as other benefits for the schools and for the population.
[Basic reproduction rate and its application in schistosomiasis].
Yang, Guo-Jing
2013-02-01
A key parameter in the transmission dynamics of schistosomiasis, namely basic reproduction rate (R0) is introduced in this paper, as well as its epidemiological significance, formulas in mathematical models of schistosomiasis transmission dynamics, and its application in the evaluation of schistosomiasis control measures. It suggests that the studies on transmission thresholds such as R0 are of important theoretical guiding significance to the establishment of a schistosomiasis elimination standard in China.
China-Africa and China-Asia Collaboration on Schistosomiasis Control: A SWOT Analysis.
Xu, J; Bergquist, R; Qian, Y-J; Wang, Q; Yu, Q; Peeling, R; Croft, S; Guo, J-G; Zhou, X-N
2016-01-01
Schistosomiasis, a disease caused by a trematode, parasitic worm, is a worldwide public health problem. In spite of great progress with regard to morbidity control, even elimination of this infection in recent decades, there are still challenges to overcome in sub-Saharan Africa and endemic areas in Southeast Asia. Regarded as one of the most successful countries with respect to schistosomiasis control, The People's Republic of China has accumulated considerable experience and learnt important lessons in various local settings that could benefit schistosomiasis control in other endemic countries. Based on an analysis of conceived strengths, weaknesses, opportunities and threats (SWOT) of potential collaborative activities with regard to schistosomiasis in Africa and Asia, this article addresses the importance of collaborative efforts and explores the priorities that would be expected to facilitate the transfer of Chinese experience to low- and middle-income countries in Africa and Asia. Copyright © 2016 Elsevier Ltd. All rights reserved.
Xiao-Nong, Zhou; Shi-Zhu, Li; Qing-Biao, Hong; Kun, Yang; Shan, Lü; Jing, Xu
2018-02-26
This paper reviews the huge promotion of Chairman Mao Zedong's two poems entitled "Farewell to the God of Plague" which were published 60 years ago, and the great achievements of the national schistosomiasis control programme in China. The publication of the two poems promotes the establishment of the mechanism for the national schistosomiasis control programme in China, and in addition, the schistosomiasis control spirit of the people from Yujiang County is still the source of power for the promotion of transferring the schistosomiasis control to elimination stage in China. Now, that we commemorate the 60th anniversary of publishing Chairman Mao Zedong's two poems entitled "Farewell to the God of Plague" means we remain the true to our original aspiration to serve the people forever, which is also to promote the progress of schistosomiasis elimination in China according to the law, the scientific principle, and local conditions, so as to contribute our efforts for realizing the healthy China's dream.
Optimal control analysis of malaria-schistosomiasis co-infection dynamics.
Okosun, Kazeem Oare; Smith, Robert
2017-04-01
This paper presents a mathematical model for malaria--schistosomiasis co-infection in order to investigate their synergistic relationship in the presence of treatment. We first analyse the single infection steady states, then investigate the existence and stability of equilibria and then calculate the basic reproduction numbers. Both the single-infection models and the co-infection model exhibit backward bifurcations. We carrying out a sensitivity analysis of the co-infection model and show that schistosomiasis infection may not be associated with an increased risk of malaria. Conversely, malaria infection may be associated with an increased risk of schistosomiasis. Furthermore, we found that effective treatment and prevention of schistosomiasis infection would also assist in the effective control and eradication of malaria. Finally, we apply Pontryagin's Maximum Principle to the model in order to determine optimal strategies for control of both diseases.
Knight, Matty; Ittiprasert, Wannaporn; Arican-Goktas, Halime D; Bridger, Joanna M
2016-06-01
Blood flukes are the causative agent of schistosomiasis - a major neglected tropical disease that remains endemic in numerous countries of the tropics and sub-tropics. During the past decade, a concerted effort has been made to control the spread of schistosomiasis, using a drug intervention program aimed at curtailing transmission. These efforts notwithstanding, schistosomiasis has re-emerged in southern Europe, raising concerns that global warming could contribute to the spread of this disease to higher latitude countries where transmission presently does not take place. Vaccines against schistosomiasis are not currently available and reducing transmission by drug intervention programs alone does not prevent reinfection in treated populations. These challenges have spurred awareness that new interventions to control schistosomiasis are needed, especially since the World Health Organization hopes to eradicate the disease by 2025. For one of the major species of human schistosomes, Schistosoma mansoni, the causative agent of hepatointestinal schistosomiasis in Africa and the Western Hemisphere, freshwater snails of the genus Biomphalaria serve as the obligate intermediate host of this parasite. To determine mechanisms that underlie parasitism by S. mansoni of Biomphalaria glabrata, which might be manipulated to block the development of intramolluscan larval stages of the parasite, we focused effort on the impact of schistosome infection on the epigenome of the snail. Results to date reveal a complex relationship, manifested by the ability of the schistosome to manipulate the snail genome, including the expression of specific genes. Notably, the parasite subverts the stress response of the host to ensure productive parasitism. Indeed, in isolates of B. glabrata native to central and South America, susceptible to infection with S. mansoni, the heat shock protein 70 (Bg-HSP70) gene of this snail is rapidly relocated in the nucleus and transcribed to express HSP70. Concurrently, hypomethylation of the CpG sites, within the Bg-HSP70 intergenic DNA region, proceeds by conveying epigenetic and spatio-epigenetic mechanisms in temporal concordance. It is notable that this is only the second example reported where a pathogen has been shown to control host cell spatio-epigenetics for its own advantage. Nonetheless, the remarkable mechanisms through which genes become activated i.e. DNA and chromatin remodeling and relocation to a nuclear compartment conducive to gene expression may represent novel intervention targets. Copyright © 2016 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.
Rassi, Christian; Kajungu, Dan; Martin, Sandrine; Arroz, Jorge; Tallant, Jamie; Zegers de Beyl, Celine; Counihan, Helen; Newell, James N; Phillips, Anna; Whitton, Jane; Muloliwa, Artur Manuel; Graham, Kirstie
2016-03-01
Schistosomiasis is a parasitic disease which affects almost 300 million people worldwide each year. It is highly endemic in Mozambique. Prevention and control of schistosomiasis relies mainly on mass drug administration (MDA), as well as adoption of basic sanitation practices. Individual and community perceptions of schistosomiasis are likely to have a significant effect on prevention and control efforts. In order to establish a baseline to evaluate a community engagement intervention with a focus on schistosomiasis, a survey to determine knowledge, attitudes and practices relating to the disease was conducted. A representative cross-sectional household survey was carried out in four districts of Nampula province, Mozambique. Interviews were conducted in a total of 791 households, using a structured questionnaire. While awareness of schistosomiasis was high (91%), correct knowledge of how it is acquired (18%), transmitted (26%) and prevented (13%) was low among those who had heard of the disease. Misconceptions, such as the belief that schistosomiasis is transmitted through sexual contact (27%), were common. Only about a third of those who were aware of the disease stated that they practiced a protective behaviour and only a minority of those (39%) reported an effective behaviour. Despite several rounds of MDA for schistosomiasis in the recent past, only a small minority of households with children reported that at least one of them had received a drug to treat the disease (9%). Poor knowledge of the causes of schistosomiasis and how to prevent it, coupled with persisting misconceptions, continue to pose barriers to effective disease prevention and control. To achieve high levels of uptake of MDA and adoption of protective behaviours, it will be essential to engage individuals and communities, improving their understanding of the causes and symptoms of schistosomiasis, recommended prevention mechanisms and the rationale behind MDA.
Le, Aiping; Zhang, Lunli; Liu, Wei; Li, Xiaopeng; Ren, Jianwei; Ning, An
2017-02-01
A structural equation model was used for verification with chronic schistosomiasis to investigate the coagulation-anticoagulation system imbalance and to deduce the mechanism of D-dimer (D-D) level elevation in patients with advanced schistosome hepatic disease. We detected the plasma levels of tissue-type fiber plasminogen activator (tPA), urokinase type plasminogen activator (uPA), plasmin-antiplasmin complex (PAP), plasminogen (PLG), antithrombin (AT), plasminogen activator inhibitor 1 (PAI1), D-D, factor VIII: C (FVIII:C), antithrombin-III (AT-III), PLG, protein S (PS), and protein C (PC) in the healthy people as control (69), patients with chronic schistosomiasis (150) or advanced chronic schistosomiasis (90). FVIII, PAP, D-D, tPA, and uPA plasma levels were significantly higher in the chronic group than in the control group and were also significantly higher in the advanced group. However, AT-III, PC, PS, AT, PLG, and PAI1 plasma levels in the advanced and chronic groups were significantly lower than those in the control group. With progression of disease in patients with schistosomiasis japonica, a hypercoagulable state is induced by the coagulation-anticoagulation imbalance, eventually leading to patients with high levels of D-D. Furthermore, we established a structural equation model path of a "chronic schistosomiasis disease stage-(coagulation-anticoagulation-fibrinolysis)-D-D." By using analysis of moment structures (AMOS), it was shown that the chronic schistosomiasis stage was positively related to factor VIII and had negative correlation with AT-III; a good positive correlation with PAP, tPA, and uPA; and a good negative correlation with PLG and PAI1. In addition, our results show that the path coefficient of anticoagulation-fibrinolysis system to the chronic stage of schistosomiasis or D-D levels was significantly higher than that of the coagulation system. In conclusion, the coagulation and fibrinolysis imbalance in patients with chronic schistosomiasis, especially with advanced schistosomiasis, is due to the progression of disease stages.
Schistosomiasis among pregnant women in rural communities in Nigeria.
Salawu, Oyetunde T; Odaibo, Alexander B
2013-07-01
To assess the epidemiology of urogenital schistosomiasis among pregnant women in rural communities of southwestern Nigeria. The present cross-sectional epidemiologic survey of urogenital schistosomiasis was conducted during 2010-2011 among pregnant women in Yewa North Local Government, Ogun State, Nigeria. The women were microscopically screened for infection with Schistosoma haematobium. Of 313 volunteer participants, 20.8% tested positive for S. haematobium infection. The prevalence of infection was highest (31.5%) among women aged 20-24years. The infection intensity did not differ significantly between age groups (t=1.848, P=0.71). Primigravidae and women in the first trimester of pregnancy had the highest intensity of infection with 33.1 and 27.7 eggs/10mL of urine, respectively. There was an association between disease prevalence and parasite intensity across the age groups (χ(2)=68.82, P=0.02). The prevalence of S. haematobium was not associated with age or pregnancy trimester (P=0.06), but associations existed between intensity of infection and gravidity (P=0.001). The prevalence of urogenital schistosomiasis among pregnant women in Nigeria was high, with younger women and primigravidae at the greatest risk. These data can be used to develop a schistosomiasis control program among pregnant women in the study area. Copyright © 2013 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.
PARASITES AND POVERTY: THE CASE OF SCHISTOSOMIASIS
King, Charles H.
2009-01-01
Simultaneous and sequential transmission of multiple parasites, and their resultant overlapping chronic infections, are facts of life in many underdeveloped rural areas. These represent significant but often poorly-measured health and economic burdens for affected populations. For example, the chronic inflammatory process associated with long-term schistosomiasis contributes to anaemia and undernutrition, which, in turn, can lead to growth stunting, poor school performance, poor work productivity, and continued poverty. To date, most national and international programs aimed at parasite control have not considered the varied economic and ecological factors underlying multi-parasite transmission, but some are beginning to provide a coordinated approach to control. In addition, interest is emerging in new studies for the re-evaluation and recalibration of the health burden of helminthic parasite infection. Their results should highlight the strong potential of integrated parasite control in efforts for poverty reduction. PMID:19962954
Hepatitis B virus infection among immunocompromised patients in Egypt.
Darwish, M; Shoair, S; Abou-Gamrah, E S; el-Shafie, M S; Helmy, M F
1990-01-01
Several workers reported an increased susceptibility to hepatitis B virus (HBV) in immunosuppressed patients. A study was carried out on 4 groups of supposedly immunocompromised patients for hepatitis B surface antigen (HBsAg), and anti-HBs. The 4 groups of patients were suffering from: Leprosy, Bronchial asthma, Diabetes and hepatosplenic Schistosomiasis. Serum specimens were obtained from 137 patients representing the 4 groups and from a control group of 25 healthy individuals. All sera were tested by ELISA technique for HBsAg and anti-HBs. Results indicated that HBsAg carrier rate was 4% for the control healthy group, 7% for Bronchial asthma, 10% for Diabetes, 24% for Leprosy and 28% for hepatosplenic Schistosomiasis. On the other hand, the anti-HBs was 21% for the control group, 29% for Schistosomiasis, 55% and 58% for Diabetes and Bronchial asthma respectively and 74% for Leprosy. This study shows that immunosuppressed patients particularly those suffering from leprosy and hepatosplenic Schistosomiasis experience higher HBsAg carrier rate than the control group for the endemic hepatitis B (6-7 times higher for leprosy and Schistosomiasis). An important observation was the diminished anti-HBs rate in hepatosplenic Schistosomiasis patients, despite the highest HBsAg carrier rate they exhibited. This may be due to an immunological defect, resulting in an unsatisfactory antibody response and chronic hepatitis B antigenemia. In Egypt, where Schistosomiasis is prevalent (40-50%), the problems caused by hepatitis B infection are increased.
To reduce the global burden of human schistosomiasis, use ‘old fashioned’ snail control
Sokolow, Susanne H.; Wood, Chelsea L.; Jones, Isabel J.; Lafferty, Kevin D.; Kuris, Armand; Hsieh, Michael H.; De Leo, Giulio A.
2018-01-01
Control strategies to reduce human schistosomiasis have evolved from ‘snail picking’ campaigns, a century ago, to modern wide-scale human treatment campaigns, or preventive chemotherapy. Unfortunately, despite the rise in preventive chemotherapy campaigns, just as many people suffer from schistosomiasis today as they did 50 years ago. Snail control can complement preventive chemotherapy by reducing the risk of transmission from snails to humans. Here, we present ideas for modernizing and scaling up snail control, including spatiotemporal targeting, environmental diagnostics, better molluscicides, new technologies (e.g., gene drive), and ‘outside the box’ strategies such as natural enemies, traps, and repellants. We conclude that, to achieve the World Health Assembly’s stated goal to eliminate schistosomiasis, it is time to give snail control another look.
Impact of schistosomiasis on quality of life and productivity of workers.
Kamel, M I; Moustafa, Y A; Foda, N; Khashab, S; Moemen, M; Abo el-Naga, R M
2002-01-01
The effect of schistosomiasis on quality of life (QOL) and productivity of workers was examined. In a textile factory in Alexandria, Egypt, personal, occupational and sociodemographic data were collected from 172 workers with schistosomiasis and 172 workers without schistosomiasis. Several indicators of productivity and the World Health Organization QOL brief were used to determine the impact of schistosomiasis. The disease affected the general, physical and independence, psychological and spiritual, and social domains of QOL. Although the productivity score of workers with schistosomiasis did not differ significantly from the control group, they had significantly lower additional hours of work and lower total incentives/month. A significant relationship was found between severity of schistosomiasis and QOL domains and productivity indicators.
Sokolow, Susanne H.; Huttinger, Elizabeth; Jouanard, Nicolas; Hsieh, Michael H.; Lafferty, Kevin D.; Kuris, Armand M.; Riveau, Gilles; Senghor, Simon; Thiam, Cheikh; D'Diaye, Alassane; Faye, Djibril Sarr; De Leo, Giulio A.
2015-01-01
Eliminating human parasitic disease often requires interrupting complex transmission pathways. Even when drugs to treat people are available, disease control can be difficult if the parasite can persist in nonhuman hosts. Here, we show that restoration of a natural predator of a parasite’s intermediate hosts may enhance drug-based schistosomiasis control. Our study site was the Senegal River Basin, where villagers suffered a massive outbreak and persistent epidemic after the 1986 completion of the Diama Dam. The dam blocked the annual migration of native river prawns (Macrobrachium vollenhoveni) that are voracious predators of the snail intermediate hosts for schistosomiasis. We tested schistosomiasis control by reintroduced river prawns in a before-after-control-impact field experiment that tracked parasitism in snails and people at two matched villages after prawns were stocked at one village’s river access point. The abundance of infected snails was 80% lower at that village, presumably because prawn predation reduced the abundance and average life span of latently infected snails. As expected from a reduction in infected snails, human schistosomiasis prevalence was 18 ± 5% lower and egg burden was 50 ± 8% lower at the prawn-stocking village compared with the control village. In a mathematical model of the system, stocking prawns, coupled with infrequent mass drug treatment, eliminates schistosomiasis from high-transmission sites. We conclude that restoring river prawns could be a novel contribution to controlling, or eliminating, schistosomiasis.
Epidemiology and control of human schistosomiasis in Tanzania
2012-01-01
In Tanzania, the first cases of schistosomiasis were reported in the early 19th century. Since then, various studies have reported prevalences of up to 100% in some areas. However, for many years, there have been no sustainable control programmes and systematic data from observational and control studies are very limited in the public domain. To cover that gap, the present article reviews the epidemiology, malacology, morbidity, and the milestones the country has made in efforts to control schistosomiasis and discusses future control approaches. The available evidence indicates that, both urinary and intestinal schistosomiasis are still highly endemic in Tanzania and cause significant morbidity.Mass drug administration using praziquantel, currently used as a key intervention measure, has not been successful in decreasing prevalence of infection. There is therefore an urgent need to revise the current approach for the successful control of the disease. Clearly, these need to be integrated control measures. PMID:23192005
Chen, Wen; Zhu, Ming-Dong; Yan, Xiao-Lan; Lin, Li-Jun; Zhang, Jian-Feng; Li, Li; Wen, Li-Yong
2011-06-01
To understand and evaluate the quality of feces examination for schistosomiasis in province-level laboratories of Zhejiang Province. With the single-blind method, the stool samples were detected by the stool hatching method and sediment detection method. In the 3 quality control assessments in 2006, 2008 and 2009, most laboratories finished the examinations on time. The accordance rates of detections were 88.9%, 100% and 93.9%, respectively. The province-level laboratories for schistosomiasis feces examination of Zhejiang Province is coming into standardization, and the techniques of schistosomiasis feces examination are optimized gradually.
[Effect of ecological civilized homestead construction on schistosomiasis control].
Tang, Meng; Jia, Tie-Wu; Wu, Zi-Song; Mao, Ping; Chen, Lin; Li, Han-Gang; Zhong, Bo; Qiu, Dong-Chuan; Yao, Qin; Hu, You-Ping
2012-02-01
To evaluate the effect of Ecological Civilized Homestead Construction on schistosomiasis control. The data of ecological civilized homestead construction and schistosomiasis control were collected and analyzed in Meiwan Village, Shuangqiao Town, Danling County, Sichuan Province from 2004 to 2010. Ecological Civilized Homestead Construction was carried out from 2004 to 2010. Totally 454 bio-gas pools were built. All the farmers used well water. The popularized rates of the household bio-gas pool, sanitary toilet, sewage treatment pool reached 100%. The number of cattle was 4, which decreased by 91.30% compared with that in 2004, and all the cattle were fed in captivity. The schistosome infection rates of populations were 0.26% and 0.30% in 2005 and 2008, respectively, and nobody was infected in other years. The infection rate of cattle was 0 from 2004 to 2010. The awareness rate of knowledge about schistosomiasis control achieved 100% in the population over 6 years old. Most of the farmers could use certain protective measures while they were farming. The effect of ecological civilized homestead construction on schistosomiasis control is remarkable.
Kaatano, Godfrey M.; Siza, Julius E.; Mwanga, Joseph R.; Min, Duk-Yong; Yong, Tai-Soon; Chai, Jong-Yil; Ko, Yunsuk; Chang, Su Young; Kullaya, Cyril M.; Rim, Han-Jong; Changalucha, John M.; Eom, Keeseon S.
2015-01-01
Integrated control strategies are important for sustainable control of schistosomiasis and soil-transmitted helminthiasis, despite their challenges for their effective implementation. With the support of Good Neighbors International in collaboration with National Institute of Medical Research, Mwanza, Tanzania, integrated control applying mass drug administration (MDA), health education using PHAST, and improved safe water supply has been implemented on Kome Island over 5 years for controlling schistosomiasis and soil-transmitted helminths (STHs). Baseline surveys for schistosomiasis and STHs was conducted before implementation of any integrated control strategies, followed by 4 cross-sectional follow-up surveys on randomly selected samples of schoolchildren and adults in 10 primary schools and 8 villages, respectively, on Kome islands. Those follow-up surveys were conducted for impact evaluation after introduction of control strategies interventions in the study area. Five rounds of MDA have been implemented from 2009 along with PHAST and improved water supply with pumped wells as other control strategies for complementing MDA. A remarkable steady decline of schistosomiasis and STHs was observed from 2009 to 2012 with significant trends in their prevalence decline, and thereafter infection rate has remained at a low sustainable control. By the third follow-up survey in 2012, Schistosoma mansoni infection prevalence was reduced by 90.5% and hookworm by 93.3% among schoolchildren while in adults the corresponding reduction was 83.2% and 56.9%, respectively. Integrated control strategies have successfully reduced S. mansoni and STH infection status to a lower level. This study further suggests that monitoring and evaluation is a crucial component of any large-scale STH and schistosomiasis intervention. PMID:26537032
Kaatano, Godfrey M; Siza, Julius E; Mwanga, Joseph R; Min, Duk-Yong; Yong, Tai-Soon; Chai, Jong-Yil; Ko, Yunsuk; Chang, Su Young; Kullaya, Cyril M; Rim, Han-Jong; Changalucha, John M; Eom, Keeseon S
2015-10-01
Integrated control strategies are important for sustainable control of schistosomiasis and soil-transmitted helminthiasis, despite their challenges for their effective implementation. With the support of Good Neighbors International in collaboration with National Institute of Medical Research, Mwanza, Tanzania, integrated control applying mass drug administration (MDA), health education using PHAST, and improved safe water supply has been implemented on Kome Island over 5 years for controlling schistosomiasis and soil-transmitted helminths (STHs). Baseline surveys for schistosomiasis and STHs was conducted before implementation of any integrated control strategies, followed by 4 cross-sectional follow-up surveys on randomly selected samples of schoolchildren and adults in 10 primary schools and 8 villages, respectively, on Kome islands. Those follow-up surveys were conducted for impact evaluation after introduction of control strategies interventions in the study area. Five rounds of MDA have been implemented from 2009 along with PHAST and improved water supply with pumped wells as other control strategies for complementing MDA. A remarkable steady decline of schistosomiasis and STHs was observed from 2009 to 2012 with significant trends in their prevalence decline, and thereafter infection rate has remained at a low sustainable control. By the third follow-up survey in 2012, Schistosoma mansoni infection prevalence was reduced by 90.5% and hookworm by 93.3% among schoolchildren while in adults the corresponding reduction was 83.2% and 56.9%, respectively. Integrated control strategies have successfully reduced S. mansoni and STH infection status to a lower level. This study further suggests that monitoring and evaluation is a crucial component of any large-scale STH and schistosomiasis intervention.
Li, Xiao-Song; Li, Fei-Yue; Zhu, Shao-Ping; Zhou, Yi-Biao; Yi, Ping; Luo, Zhi-Hong; Ren, Guang-Hui; Li, Yi-Yi; Tang, Ling; Jiang, Qing-Wu
2013-06-01
To understand the effect of comprehensive schistosomiasis control measures with focus on buffalo and sheep removal in Anxiang City, Dongting Lake area. The data of buffalo and sheep removal, routine schistosomiasis control measures such as disease detection and treatment, Oncomelania snail survey and control, as well as health education were collected and analyzed in Anxiang County, Hunan Province from 2004 to 2012. The schistosome infection rates of people, domestic animals and snails decreased from 11.23%, 17.06% and 1.07% in 2004 when the comprehensive measures had not been implemented to 0.58%, 0 and 0 in 2012, respectively. The average density of infected snails decreased from 0.003 4 snails/0.1 m2 to 0. The comprehensive control measures with focus on buffalo and sheep removal are significantly effective, and can control the transmission of schistosomiasis in marshland and lake regions.
A Hybrid Model for Predicting the Prevalence of Schistosomiasis in Humans of Qianjiang City, China
Wang, Ying; Lu, Zhouqin; Tian, Lihong; Tan, Li; Shi, Yun; Nie, Shaofa; Liu, Li
2014-01-01
Backgrounds/Objective Schistosomiasis is still a major public health problem in China, despite the fact that the government has implemented a series of strategies to prevent and control the spread of the parasitic disease. Advanced warning and reliable forecasting can help policymakers to adjust and implement strategies more effectively, which will lead to the control and elimination of schistosomiasis. Our aim is to explore the application of a hybrid forecasting model to track the trends of the prevalence of schistosomiasis in humans, which provides a methodological basis for predicting and detecting schistosomiasis infection in endemic areas. Methods A hybrid approach combining the autoregressive integrated moving average (ARIMA) model and the nonlinear autoregressive neural network (NARNN) model to forecast the prevalence of schistosomiasis in the future four years. Forecasting performance was compared between the hybrid ARIMA-NARNN model, and the single ARIMA or the single NARNN model. Results The modelling mean square error (MSE), mean absolute error (MAE) and mean absolute percentage error (MAPE) of the ARIMA-NARNN model was 0.1869×10−4, 0.0029, 0.0419 with a corresponding testing error of 0.9375×10−4, 0.0081, 0.9064, respectively. These error values generated with the hybrid model were all lower than those obtained from the single ARIMA or NARNN model. The forecasting values were 0.75%, 0.80%, 0.76% and 0.77% in the future four years, which demonstrated a no-downward trend. Conclusion The hybrid model has high quality prediction accuracy in the prevalence of schistosomiasis, which provides a methodological basis for future schistosomiasis monitoring and control strategies in the study area. It is worth attempting to utilize the hybrid detection scheme in other schistosomiasis-endemic areas including other infectious diseases. PMID:25119882
Stothard, J R; Khamis, A N; Khamis, I S; Neo, C H E; Wei, I; Rollinson, D
2016-09-01
Endeavours to control urogenital schistosomiasis on Unguja Island (Zanzibar) have focused on school-aged children. To assess the impact of an associated health education campaign, the supervised use of the comic-strip medical booklet Juma na Kichocho by Class V pupils attending eighteen primary schools was investigated. A validated knowledge and attitudes questionnaire was completed at baseline and repeated one year later following the regular use of the booklet during the calendar year. A scoring system (ranging from 0.0 to 5.0) measured children's understandings of schistosomiasis and malaria, with the latter being a neutral comparator against specific changes for schistosomiasis. In 2006, the average score from 751 children (328 boys and 423 girls) was 2.39 for schistosomiasis and 3.03 for malaria. One year later, the score was 2.43 for schistosomiasis and 2.70 for malaria from 779 children (351 boys and 428 girls). As might be expected, knowledge and attitudes scores for schistosomiasis increased (+0.05), but not as much as originally hoped, while the score for malaria decreased (-0.33). According to a Kolmogorov-Smirnov test, neither change was statistically significant. Analysis also revealed that 75% of school children misunderstood the importance of reinfection after treatment with praziquantel. These results are disappointing. They demonstrate that it is mistaken to assume that knowledge conveyed in child-friendly booklets will necessarily be interpreted, and acted upon, in the way intended. If long-term sustained behavioural change is to be achieved, health education materials need to engage more closely with local understandings and responses to urogenital schistosomiasis. This, in turn, needs to be part of the development of a more holistic, biosocial approach to the control of schistosomiasis.
Utzinger, J; Xiao, S; Keiser, J; Chen, M; Zheng, J; Tanner, M
2001-12-01
Human schistosomiasis, a chronic and debilitating parasitic disease of the tropics, is ranked second after malaria in terms of public health importance. At present, there is no vaccine available, and chemotherapy is the cornerstone of schistosomiasis control. Praziquantel is the drug of choice. Oxamniquine has become difficult to obtain and metrifonate has recently been withdrawn from the market. Rapid re-infection following treatment and concern about praziquantel resistance called for the search of novel drugs for prevention and cure of schistosomiasis. Significant progress has been made with artemether, the methyl ether of dihydroartemisinin, already widely used for the treatment of malaria. The present article reviews the literature that led to the development of artemether for chemoprophylaxis in schistosomiasis, and it summarises the experiences so far obtained with its use to control schistosomiasis in different endemic settings. Topics covered include an overview of the global burden of schistosomiasis and approaches for its control; the nature and features of artemisinin and related derivatives, initially discovered as antimalarials, other bioactivities, and their recent discovery of antischistosomal properties; a historic account disclosing the antischistosomal activity of artemether; in vivo assessment of drug susceptibility of different developmental stages of schistosome parasites; artemether-induced pathology evidenced by scanning and transmission electron microscopy; the possible mechanism of action; in vivo studies with combination therapy of artemether and praziquantel; results of randomised controlled clinical trials of oral artemether for the prevention of patent infection and morbidity; and, ultimately the translation of this knowledge into public health action in different endemic settings towards a more integrated approach of schistosomiasis control.
Shen, Xue-hui; Sun, Le-ping; Li, Ye-fang; Wang, Lin; Chen, Xiang-ping; Wang, He-sheng; Dai, Jian-rong
2015-10-01
To evaluate the effectiveness of mid- and long-term schistosomiasis control plan and explore the consolidation strategy in marshland endemic regions, so as to provide an effective approach for interrupting and eliminating schistosomiasis in the regions. A prospective field study was designed. Dantu District of Zhenjiang City, a marshland schistosomiasis endemic region, was selected, and the "key village, key environment, and key water regions" comprehensive control strategy was implemented according to the endemic level of schistosomiasis. The morbidity due to schistosomiasis in humans and domestic animals, and Oncomelania hupensis snails were surveyed, and the data of the implementation of control measures were collected. The schistosomiasis morbidity and snail status were compared before and after the implementation of the mid- and long-term plan for schistosomiasis prevention and control, and the changing trends of human, domestic animal and snail infections were plotted. During the implementation of the plan from 2005 to 2014, 16.84 km concrete and bank protection and 9 snail sinks were built, 10 culverts re-built, 3.85 hm2 fences were constructed, 29.5 thousand domestic animals were examined and treated, 170 cattle were eliminated, 4930 hm2 fishing farms were built for snail control, 1 560.00 hM2 land were improved, and 376.00 hm2 forests were built for snail control. In addition, 19,364.80 hm2 snail areas were surveyed, 4694.6 hm2 area received molluscicide, 207.9 thousand of people (person-times) received the examination and treatment, 69.1 thousand of harmless toilets were built, 282.2 thousand health education materials and protection materials were allocated, 958 warning signs were established, and 5435 slogans were pasted or hung. After the implementation of the mid- and long-term plan, the percentages of human, bovine and snail infections appeared decline tendencies year by year, and reduced from 0.08%, 1.28% and 0.13% in 2005 to 0 in 2014, respectively, while the areas with snails and infected snails reduced from 284.34 hm2 and 55.10 hm2 in 2005 to 73.60 hm2 and 0 hm2 in 2014, with reduction rates of 74.12% and 100%, respectively. The infection rate of sheep appeared a fluctuation between 2005 and 2014, with the rate of 1.13% in 2005, 0 in 2007 and 2008, rising in 2009 and then between 0.25% and 0.95% from 2009 to 2012, and reducing to 0 in 2013 and 2014. During the 10-year period, the number of cattle reduced year by year from 2005 to 2010, and slightly increased after 2011, showing an overall stable level, while the number of sheep increased year by year after 2006, peaked in 2010, and appeared a decline tendency since 2011, which was almost consistent with the fluctuation of schistosome infection rate in sheep. The sustainable comprehensive control strategy with the "key village, key environments, and key water regions" is an effective approach for schistosomiasis control in marshland endemic regions. However, the endemic situation of schistosomiasis is extremely easy to repeat. The prevention and control of the impact of sheep and wild animals on schistosomiasis transmission should be strengthened in order to consolidate the schistosomiasis control achievements gained.
[Effect of integrated control of schistosomiasis in Shashi District from 2009 to 2013].
Liu, Jin-Ming; Liao, Xian-Chao
2014-10-01
To evaluate the effect of integrated schistosomiasis control in Shashi District from 2009 to 2013, so as to provide the evidence for the development and adjustment of schistosomiasis control strategies. The data of integrated schistosomiasis control from 2009 to 2013 were collected and analyzed for the epidemic situations of human, livestock and Oncomelania hupensis snails. From 2009 to 2013, the infection rates of human and cattle decreased from 2.24% and 1.92% to 0.63% and 0, with decrease rates of 71.88% and 100%, respectively; the area with snails decreased from 760.40 hm2 to 715.08 hm2, with a decrease rate of 5.69%; the occurrence rate of frames with living snails and the average density of living snails decreased from 26.32% and 0.67 snail/0.1 m2 to 18.30% and 0.53 snail/0.1 mi2, with decrease rates of 30.47% and 20.90%, respectively. No infected living snails were found from 2012 to 2013. The integrated schistosomiasis prevention and control strategies with emphasis on infectious source control could effectively reduce the infection rates of human and cattle as well as the snail situation.
Rassi, Christian; Kajungu, Dan; Martin, Sandrine; Arroz, Jorge; Tallant, Jamie; Zegers de Beyl, Celine; Counihan, Helen; Newell, James N.; Phillips, Anna; Whitton, Jane; Muloliwa, Artur Manuel; Graham, Kirstie
2016-01-01
Background Schistosomiasis is a parasitic disease which affects almost 300 million people worldwide each year. It is highly endemic in Mozambique. Prevention and control of schistosomiasis relies mainly on mass drug administration (MDA), as well as adoption of basic sanitation practices. Individual and community perceptions of schistosomiasis are likely to have a significant effect on prevention and control efforts. In order to establish a baseline to evaluate a community engagement intervention with a focus on schistosomiasis, a survey to determine knowledge, attitudes and practices relating to the disease was conducted. Methodology/Principal Findings A representative cross-sectional household survey was carried out in four districts of Nampula province, Mozambique. Interviews were conducted in a total of 791 households, using a structured questionnaire. While awareness of schistosomiasis was high (91%), correct knowledge of how it is acquired (18%), transmitted (26%) and prevented (13%) was low among those who had heard of the disease. Misconceptions, such as the belief that schistosomiasis is transmitted through sexual contact (27%), were common. Only about a third of those who were aware of the disease stated that they practiced a protective behaviour and only a minority of those (39%) reported an effective behaviour. Despite several rounds of MDA for schistosomiasis in the recent past, only a small minority of households with children reported that at least one of them had received a drug to treat the disease (9%). Conclusion/Significance Poor knowledge of the causes of schistosomiasis and how to prevent it, coupled with persisting misconceptions, continue to pose barriers to effective disease prevention and control. To achieve high levels of uptake of MDA and adoption of protective behaviours, it will be essential to engage individuals and communities, improving their understanding of the causes and symptoms of schistosomiasis, recommended prevention mechanisms and the rationale behind MDA. PMID:26942416
Parasites and poverty: the case of schistosomiasis.
King, Charles H
2010-02-01
Simultaneous and sequential transmission of multiple parasites, and their resultant overlapping chronic infections, are facts of life in many underdeveloped rural areas. These represent significant but often poorly measured health and economic burdens for affected populations. For example, the chronic inflammatory process associated with long-term schistosomiasis contributes to anaemia and undernutrition, which, in turn, can lead to growth stunting, poor school performance, poor work productivity, and continued poverty. To date, most national and international programs aimed at parasite control have not considered the varied economic and ecological factors underlying multi-parasite transmission, but some are beginning to provide a coordinated approach to control. In addition, interest is emerging in new studies for the re-evaluation and recalibration of the health burden of helminthic parasite infection. Their results should highlight the strong potential of integrated parasite control in efforts for poverty reduction. Copyright 2009 Elsevier B.V. All rights reserved.
Omedo, Martin O; Matey, Elizabeth J; Awiti, Alphonce; Ogutu, Michael; Alaii, Jane; Karanja, Diana M S; Montgomery, Susan P; Secor, W Evan; Mwinzi, Pauline N M
2012-12-01
Abstract. The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) includes communitywide treatment in areas with ≥ 25% prevalence of schistosomiasis along the shores of Lake Victoria using community health workers (CHWs). The CHWs are key drivers in community-owned mass drug administration (MDA) intervention programs. We explored their experiences and perceptions after initial MDA participation. Unstructured open-ended group discussions were conducted after completion of MDA activities. Narratives were obtained from CHWs using a digital audio recorder during the group discussion, transcribed verbatim and translated into English where applicable. Thematic decomposition of data was done using ATLAS.t.i. software. From the perspective of the CHWs, factors influencing MDA compliance included drug side effects, food supply stability, and conspiracy theories about the "real" purpose of treatment. The interest of CHWs to serve as community drug distributors stemmed from both intrinsic and extrinsic factors. Feedback from CHWs can promote more effective MDA in rural Kenyan communities.
Xia, Shang; Xue, Jing-Bo; Zhang, Xia; Hu, He-Hua; Abe, Eniola Michael; Rollinson, David; Bergquist, Robert; Zhou, Yibiao; Li, Shi-Zhu; Zhou, Xiao-Nong
2017-04-26
The prevalence of schistosomiasis remains a key public health issue in China. Jiangling County in Hubei Province is a typical lake and marshland endemic area. The pattern analysis of schistosomiasis prevalence in Jiangling County is of significant importance for promoting schistosomiasis surveillance and control in the similar endemic areas. The dataset was constructed based on the annual schistosomiasis surveillance as well the socio-economic data in Jiangling County covering the years from 2009 to 2013. A village clustering method modified from the K-mean algorithm was used to identify different types of endemic villages. For these identified village clusters, a matrix-based predictive model was developed by means of exploring the one-step backward temporal correlation inference algorithm aiming to estimate the predicative correlations of schistosomiasis prevalence among different years. Field sampling of faeces from domestic animals, as an indicator of potential schistosomiasis prevalence, was carried out and the results were used to validate the results of proposed models and methods. The prevalence of schistosomiasis in Jiangling County declined year by year. The total of 198 endemic villages in Jiangling County can be divided into four clusters with reference to the 5 years' occurrences of schistosomiasis in human, cattle and snail populations. For each identified village cluster, a predictive matrix was generated to characterize the relationships of schistosomiasis prevalence with the historic infection level as well as their associated impact factors. Furthermore, the results of sampling faeces from the front field agreed with the results of the identified clusters of endemic villages. The results of village clusters and the predictive matrix can be regard as the basis to conduct targeted measures for schistosomiasis surveillance and control. Furthermore, the proposed models and methods can be modified to investigate the schistosomiasis prevalence in other regions as well as be used for investigating other parasitic diseases.
BROOKER, S.; KABATEREINE, N. B.; GYAPONG, J. O.; STOTHARD, J. R.; UTZINGER, J.
2009-01-01
SUMMARY There is growing interest and commitment to the control of schistosomiasis and other so-called neglected tropical diseases (NTDs). Resources for control are inevitably limited, necessitating assessment methods that can rapidly and accurately identify and map high-risk communities so that interventions can be targeted in a spatially-explicit and cost-effective manner. Here, we review progress made with (i) mapping schistosomiasis across Africa using available epidemiological data and more recently, climate-based risk prediction; (ii) the development and use of morbidity questionnaires for rapid identification of high-risk communities of urinary schistosomiasis; and (iii) innovative sampling-based approaches for intestinal schistosomiasis, using the lot quality assurance sampling technique. Experiences are also presented for the rapid mapping of other NTDs, including onchocerciasis, loiasis and lymphatic filariasis. Future directions for an integrated rapid mapping approach targeting multiple NTDs simultaneously are outlined, including potential challenges in developing an integrated survey tool. The lessons from the mapping of human helminth infections may also be relevant for the rapid mapping of malaria as its control efforts are intensified. PMID:19450373
[Survey of current situation of schistosomiasis health education in Wuxi City].
Meng, Xiao-jun; Gao, Dong-lin; Zhang, Xuan; Lu, Bing
2015-04-01
To understand the current situation of schistosomiasis health education in in Wuxi City where schistosomiasis transmission has been interrupted, so as to provide the evidence for formulating the health education strategies. Face to face interviews and a professional designed questionnaire were used to collect the information of the current schistosomiasis health education and investigate the awareness of schistosomiasis knowledge in primary and middle schools and in communities. The total awareness rate of schistosomiasis knowledge was 87.7% among 873 students and the figure was 83.0% among 693 community residents. The students who studied in the schools with more than 1 class hour of schistosomiasis health education, completed schistosomiasis health education material or teaching plan, and implementing health education through multiple ways had higher knowledge awareness rates compared with the schools without (χ2 = 291.408, 709.622, 13.751, all P <0.001). The residents living in the communities with schistosomiasis health education through broadcast/TV or square propaganda had a higher knowledge awareness rate compared with the communities without (χ2= 90.772, 47.436, all P < 0.001). The awareness rates of schistosomiasis knowledge among both students and community residents in Wuxi City are low. Therefore, the schistosomiasis control health education should be strengthened.
Ejike, Cynthia Uchechukwu; Oluwole, Akinola Stephen; Mogaji, Hammed Oladeji; Adeniran, Adebiyi Abdulhakeem; Alabi, Oladimeji Michael; Ekpo, Uwem Friday
2017-06-28
Schistosomiasis remains a public health problem in many regions of the world, including Nigeria. Current control strategy involves mass drug administration with praziquantel to the endemic population. To complement and sustain on-going preventive chemotherapy, we developed a health educational game named Schisto and Ladders™ and tested its potential for the control of schistosomiasis among schoolchildren living in Imala-Odo, a highly endemic community near Abeokuta, Nigeria. One hundred school children were randomly selected and divided into intervention and control groups through balloting. Their knowledge, attitudes and practices (KAP) concerning schistosomiasis transmission, control and prevention were assessed using structured questionnaires. Schisto and Ladders™ game were given to the intervention group and the popular Snake and Ladders™ game to the control group. Both games were played for 2 months under the supervision of their class teachers. A post-KAP assessment was carried out in both groups, including focus group discussions (FGDs) to investigate knowledge and the impact of the games. Knowledge about urinary schistosomiasis and its transmission significantly improved (P = 0.000) in the intervention group (68.0%) compared to the control group (8.0%). FGDs showed that the frequency of visits to dam water also significantly reduced (P = 0.048) in the intervention group (18.0%) compared to the control group (40.0%). There was a significant increase in knowledge regarding risk behaviours, prevention and control of schistosomiasis among the intervention group, but no new knowledge gained in the control group. This study demonstrates the potential of the health education game Schisto and Ladders™ for teaching basic health education and promoting behavioural changes among schoolchildren in endemic communities.
Schistosomiasis control in China: the impact of a 10-year World Bank Loan Project (1992-2001).
Xianyi, Chen; Liying, Wang; Jiming, Cai; Xiaonong, Zhou; Jiang, Zheng; Jiagang, Guo; Xiaohua, Wu; Engels, D.; Minggang, Chen
2005-01-01
China has been carrying out large-scale schistosomiasis control since the mid-1950s, but in the early 1990s, schistosomiasis was still endemic in eight provinces. A World Bank Loan Project enabled further significant progress to be made during the period 1992-2001. The control strategy was focused on the large-scale use of chemotherapy -- primarily to reinforce morbidity control -- while at the same time acting on transmission with the ultimate goal of interrupting it. Chemotherapy was complemented by health education, chemical control of snails and environmental modification where appropriate. A final evaluation in 2002 showed that infection rates in humans and livestock had decreased by 55% and 50%, respectively. The number of acute infections and of individuals with advanced disease had also significantly decreased. Although snail infection rates continued to fluctuate at a low level, the densities of infected snails had decreased by more than 75% in all endemic areas. The original objectives of the China World Bank Loan Project for schistosomiasis control had all been met. One province, Zhejiang, had already fulfilled the criteria for elimination of schistosomiasis by 1995. The project was therefore a success and has provided China with a sound basis for further control. PMID:15682248
Zhang, L-J; Li, S-Z; Wen, L-Y; Lin, D-D; Abe, E M; Zhu, R; Du, Y; Lv, S; Xu, J; Webster, B L; Rollinson, D; Zhou, X-N
2016-01-01
Schistosoma japonicum is the main schistosome species in The People's Republic of China, causing intestinal schistosomiasis, a debilitating disease of public health importance. The People's Republic of China used to be heavily endemic with schistosomiasis, but great progress has been made through the vigorous efforts of the national control programmes in the last six decades. Presently, efforts are geared towards eliminating schistosomiasis from The People's Republic of China by the end of 2025 through effective schistosomiasis surveillance, an important component in the drive towards schistosomiasis elimination. Therefore, this article explicitly outlines the development and progress made in schistosomiasis surveillance since 1990 with a special focus on the new surveillance system in use. Although the surveillance system has steadily improved over the years, it is faced with many challenges. Hence, more efforts are needed to establish an effective and sensitive evaluation system for the national schistosomiasis elimination programme in The People's Republic of China. Copyright © 2016 Elsevier Ltd. All rights reserved.
Song, Lan-Gui; Wu, Xiao-Ying; Sacko, Moussa; Wu, Zhong-Dao
2016-11-01
Schistosomiasis is a snail-borne disease caused by worms of the genus Schistosoma. Worldwide, human schistosomiasis remains a serious public health problem, threatening ∼800 million people in 78 countries with a loss of 70 million disability-adjusted life years. Schistosoma japonicum is the only human blood fluke that occurs in China. As one of the countries suffering greatly from schistosomiasis, over the past 65 years, China has made great strides in controlling schistosomiasis, blocking the transmission of S. japonicum in five provinces, remarkably reducing transmission intensities in the other seven endemic provinces, and China is currently preparing to move toward the elimination of this disease before 2025. However, while on the road to schistosomiasis elimination, emerging challenges merit attention, including severe advanced cases, increased movements of population and livestock, large-area distribution of intermediate host snails, limitations of new drug developments and no vaccine available, as well as imported schistosomiasis and its potential risk.
Cha, Seungman; Hong, Sung-Tae; Lee, Young-Ha; Lee, Keon Hoon; Cho, Dae Seong; Lee, Jinmoo; Chai, Jong-Yil; Elhag, Mousab Siddig; Khaled, Soheir Gabralla Ahmad; Elnimeiri, Mustafa Khidir Mustafa; Siddig, Nahid Abdelgadeir Ali; Abdelrazig, Hana; Awadelkareem, Sarah; Elshafie, Azza Tag Eldin; Ismail, Hassan Ahmed Hassan Ahmed; Amin, Mutamad
2017-09-12
Schistosomiasis and soil-transmitted helminthiasis (STHs) are target neglected tropical diseases (NTDs) of preventive chemotherapy, but the control and elimination of these diseases have been impeded due to resource constraints. Few reports have described study protocol to draw on when conducting a nationwide survey. We present a detailed methodological description of the integrated mapping of schistosomiasis and STHs on the basis of our experiences, hoping that this protocol can be applied to future surveys in similar settings. In addition to determining the ecological zones requiring mass drug administration interventions, we aim to provide precise estimates of the prevalence of these diseases. A school-based cross-sectional design will be applied for the nationwide survey across Sudan. The survey is designed to cover all districts in every state. We have divided each district into 3 different ecological zones depending on proximity to bodies of water. We will employ a probability-proportional-to-size sampling method for schools and systematic sampling for student selection to provide adequate data regarding the prevalence for schistosomiasis and STHs in Sudan at the state level. A total of 108,660 students will be selected from 1811 schools across Sudan. After the survey is completed, 391 ecological zones will be mapped out. To carry out the survey, 655 staff members were recruited. The feces and urine samples are microscopically examined by the Kato-Katz method and the sediment smears for helminth eggs respectively. For quality control, a minimum of 10% of the slides will be rechecked by the federal supervisors in each state and also 5% of the smears are validated again within one day by independent supervisors. This nationwide mapping is expected to generate important epidemiological information and indicators about schistosomiasis and STHs that will be useful for monitoring and evaluating the control program. The mapping data will also be used for overviewing the status and policy formulation and updates to the control strategies. This paper, which describes a feasible and practical study protocol, is to be shared with the global health community, especially those who are planning to perform nationwide mapping of NTDs by feces or urine sampling.
Ezeamama, Amara E; He, Chun-La; Shen, Ye; Yin, Xiao-Ping; Binder, Sue C; Campbell, Carl H; Rathbun, Stephen; Whalen, Christopher C; N'Goran, Eliézer K; Utzinger, Jürg; Olsen, Annette; Magnussen, Pascal; Kinung'hi, Safari; Fenwick, Alan; Phillips, Anna; Ferro, Josefo; Karanja, Diana M S; Mwinzi, Pauline N M; Montgomery, Susan; Secor, W Evan; Hamidou, Amina; Garba, Amadou; King, Charles H; Colley, Daniel G
2016-05-26
The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) was established in 2008 to answer strategic questions about schistosomiasis control. For programme managers, a high-priority question is: what are the most cost-effective strategies for delivering preventive chemotherapy (PCT) with praziquantel (PZQ)? This paper describes the process SCORE used to transform this question into a harmonized research protocol, the study design for answering this question, the village eligibility assessments and data resulting from the first year of the study. Beginning in 2009, SCORE held a series of meetings to specify empirical questions and design studies related to different schedules of PCT for schistosomiasis control in communities with high (gaining control studies) and moderate (sustaining control studies) prevalence of Schistosoma infection among school-aged children. Seven studies are currently being implemented in five African countries. During the first year, villages were screened for eligibility, and data were collected on prevalence and intensity of infection prior to randomisation and the implementation of different schemes of PZQ intervention strategies. These studies of different treatment schedules with PZQ will provide the most comprehensive data thus far on the optimal frequency and continuity of PCT for schistosomiasis infection and morbidity control. We expect that the study outcomes will provide data for decision-making for country programme managers and a rich resource of information to the schistosomiasis research community. The trials are registered at International Standard Randomised Controlled Trial registry (identifiers: ISRCTN99401114 , ISRCTN14849830 , ISRCTN16755535 , ISRCTN14117624 , ISRCTN95819193 and ISRCTN32045736 ).
Qiang, Zhou; Li-Xin, Wan; De-Rong, Hang; Qi-Hui, You; Jun, You; Yu-Lin, Zhang; Zhao-Feng, Zhu; Yi-Xin, Huang
2017-12-07
To evaluate the effect of the water conservancy schistosomiasis control projects combined with molluscicide to control Oncomelania hupensis snails in the rivers connecting with the Yangtze River. The water conservancy schistosomiasis control projects of Zhujiashan River, Qili River and Gaowang River were chosen as the study objects in Pukou District, Nanjing City. The data review method and field investigation were used to evaluate the effect of the water conservancy schistosomiasis control projects combined with molluscicide to control O. hupensis snails. After the projects of the water level control and concrete slope protection and mollusciciding were implemented, the snails in the project river sections were completely eliminated. The snail diffusion did not happen in the inland irrigation area too. In the outside of the river beach, though the snails still existed, the snail densities plunged below 1.0 snail per 1.0 m 2 . The comprehensive measures of the combination of water level control, concrete slope protection and mollusciciding can effectively control and eliminate the snails, and prevent the snails from spreading.
Christinet, Vanessa; Lazdins-Helds, Janis K; Stothard, J Russell; Reinhard-Rupp, Jutta
2016-06-01
In recent years, control of neglected tropical diseases has been increasingly gaining momentum and interventions against schistosomiasis are being progressively scaled-up through expansion of donated praziquantel and preventive chemotherapy campaigns. However, the public health importance of female genital schistosomiasis is not fully recognised nor its control is adequately addressed. Taking a clinical and anatomopathological perspective, we evaluated the available literature to highlight the importance of female genital schistosomiasis and its connections with two sexually transmitted infections of global importance, Human Immunodeficiency Virus (HIV) and Human Papilloma Virus. Outside the long list of clinical descriptive reports beginning in 1899, there is presently a shocking gap in epidemiological assessment and a significant underestimation of the burden of FGS remains. The scarcity of integrated approaches to address female genital schistosomiasis calls for more concerted action in its detection, treatment and prevention alongside other concomitant women's health issues, otherwise female genital schistosomiasis will remain a neglected gynaecological disease. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
Paediatric and maternal schistosomiasis: shifting the paradigms.
Bustinduy, Amaya L; Stothard, J Russell; Friedman, Jennifer F
2017-09-01
In endemic areas, schistosomiasis causes both overt and subclinical disease in young children and their mothers, as well as in returned travellers. Key recently published literature. An action plan for paediatric schistosomiasis and female genital schistosomiasis (FGS) is needed with expanded access to praziquantel (PZQ) treatment required. Schistosomiasis-related morbidity is underappreciated. Present and future demand for PZQ treatment is bottlenecked, imbalanced and inequitable. Current dosing, treatment algorithms and access plans are suboptimal with treatment stalled during pregnancy. Raised dosing of PZQ (>40 mg/kg) is being explored in young children. Surveillance of female genital schistosomiasis FGS is increasing. Use of PZQ in pregnancy is safe and preventive chemotherapy guidelines are being revised in morbidity- and transmission-control settings. Shifting focus of population-level control to individual-case management. Detection and prevention of FGS within general health services and integration of PZQ treatment for women and children in antenatal clinics. Feasibility studies assessing alternative and expanded access to PZQ treatment to at-risk children and mothers and pregnant women. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com
Sun, Le-Ping; Wang, Wei; Zuo, Yin-Ping; Hong, Qing-Biao; Du, Guang-Lin; Ma, Yu-Cai; Wang, Jian; Yang, Guo-Jing; Zhu, Dao-Jian; Liang, You-Sheng
2017-03-14
Although great success has been achieved, schistosomiasis remains a major public health concern in China, and the remaining core endemic regions are concentrated along the middle and lower reaches of the Yangtze River. In this longitudinal study, we evaluated the effectiveness of a multidisciplinary, integrated approach for schistosomiasis elimination in a historically hyper-endemic region in the lower reaches of the Yangtze River, China over the 10-year period from 2005 through 2014. A three-step roadmap for schistosomiasis elimination was designed in the study site, and multidisciplinary, integrated interventions were implemented by the health, agriculture, water resources development, land and resources, and forestry sectors from 2005 to 2014, including chemotherapy for infected individuals, health education, management of the source of Schistosoma japonicum infection, and intermediate host snail control. The annual number of schistosomiasis patients, S. japonicum infection in humans, bovines and Oncomelania hupensis snails, and water infectivity were observed to assess the effectiveness of the multidisciplinary, integrated approach for the elimination of schistosomiasis. There was a tendency towards a gradual decline in both the number of schistosomiasis cases and the prevalence of S. japonicum human infection across the study period from 2005 through 2014. No S. japonicum human infection was detected since 2012, and no acute infection was seen since 2006. During the study period, no infection was found in bovines, and a 0.03% overall infection rate was observed in O. hupensis snails. Since 2009, no infected snails were identified, and the area of both snail habitats and infected snail habitats appeared a reduction over the study period. Following the 3-year multidisciplinary, integrated control, infection control was achieved, and transmission control was achieved after 6-year implementation, with all infected snails and water infectivity eliminated; in addition, the 10-year implementation resulted in interruption of schistosomiasis transmission in the study site in 2014. The results of the present 10-year longitudinal study demonstrate that the multidisciplinary, integrated approach is effective for the elimination of schistosomiasis as a public health problem in the lower reaches of the Yangtze River, China.
Toor, Jaspreet; Alsallaq, Ramzi; Truscott, James E; Turner, Hugo C; Werkman, Marleen; Gurarie, David; King, Charles H; Anderson, Roy M
2018-06-01
Schistosomiasis remains an endemic parasitic disease affecting millions of people around the world. The World Health Organization (WHO) has set goals of controlling morbidity to be reached by 2020, along with elimination as a public health problem in certain regions by 2025. Mathematical models of parasite transmission and treatment impact have been developed to assist in controlling the morbidity caused by schistosomiasis. These models can inform and guide implementation policy for mass drug administration programs, and help design monitoring and evaluation activities. We use these models to predict whether the guidelines set by the WHO are on track for achieving their 2020 goal for the control of morbidity, specifically for Schistosoma mansoni. We examine whether programmatic adaptations; namely increases in treatment coverage and/or expansion to adult inclusion in treatment, will improve the likelihood of reaching the WHO goals. We find that in low-prevalence settings, the goals are likely to be attainable under current WHO guidelines, but in moderate to high-prevalence settings, the goals are less likely to be achieved unless treatment coverage is increased and expanded to at least 85% for school-aged children and 40% for adults. To improve the likelihood of reaching the WHO goals, programmatic adaptations are required, particularly for moderate- to high-prevalence settings. Furthermore, improvements in adherence to treatment, potential development of candidate vaccines, and enhanced snail control and WASH (water, sanitation, and hygiene) measures will all assist in achieving the goals.
Liu, Han-Cheng; Liao, Si-Qi; Zhong, Chen-Hui; He, Hui
2014-12-01
To understand the human resources of the grassroots institutions of schistosomiasis control and prevention, so as to provide the evidence for formulating the standards of institutional capacity-building. By using the combination of quantitative and qualitative methods, the hierarchy of schistosomiasis control institution workers, structural features of workers, and benefits of workers were investigated and the results were analyzed statistically after the 2004 reform. The constituent ratios of personnel ≤ 30 years old, 30 to 45 years old, and ≥ 45 years old were 6.8%, 64.0% and 29.2% respectively, with an average age of 43.1 years. For education levels, 61.35% of the personnel had secondary or high school levels. At the city level, the structural proportion of the senior professional; medium professional and primary professional titles was 1.4 : 5.6 : 3.0, and at the county level, the proportion was 0.5 : 6.1 : 3.4. There was 14 200 yuan per capita at the township schistosomiasis control institutions. The technology of the personnel in schistosomiasis institutions of Hubei Province is weak, the average age of personnel is old, and the salary is low.
Yang, Gao; Le-Ping, Sun; Yin-Ping, Zuo; Yu-Hui, Xu; Zheng-Qiu, Zhang; Yu-Cai, Ma; Jin-Bin, Gao; Xi-Guang, Zhu; Bo, Zheng; Guo-Jing, Yang; Qing-Biao, Hong; Kun, Yang; You-Sheng, Liang
2011-10-01
To construct the regional joint mechanism for schistosomiasis examination and treatment and the examination protocol among mobile boatmen, so as to provide effective measures for control of mobile infectious sources of schistosomiasis in the Yangtze River basin. According to the characteristics of the cargo frequent mobility of ships with fixed anchor points, the health, maritime and transport sections were jointly cooperated to set up sites for schistosomiasis examination and treatment in ship locks, wharfs and harbors. The infection of schistosomiasis was detected by means of rapid immunological screening and stool examination, and the regional joint mechanism was constructed. The sero-positives were traced for further parasitological examinations and treatment by using the regional joint network for schistosomiasis examination and treatment. The schistosome infections in boatmen were analyzed and compared between different examination and treatment sites and among different navigation coverage. A total of 16 sites for examination and treatment of schistosomiasis, including 5 fixed sites and 11 mobile sites, were set up in 12 townships of 6 districts (counties) of Yangzhou City. During a period between June and August, the examination of schistosomiasis was conducted in 40 sites, and of the 1 225 boatmen from 967 boats detected, 19 cases were sero-positive, with a positive rate of 1.55%. Among the 14 sero-positives examined, no stool positive patients were found. Among the 1 225 boatmen detected, 820 were from fixed sites and 405 from mobile sites, and 4 and 15 cases were found, respectively, with positive rates of 0.49% and 3.70%, respectively, and the sero-positive rate was higher in mobile sites and that in fixed sites. A total of 898 boatmen from the Yangtze River basin and 305 from the local inland rivers were examined, and 3 and 16 sero-positive cases were detected, respectively, with positive rates of 0.33% and 5.25%, respectively, and the sero-positive rate was significantly higher in the boatmen from the local inland rivers than that from the Yangtze River basin. Regional joint mechanism is an effective strategy for examination and treatment of schistosomiasis among mobile boatmen, which provides a new approach to control mobile infectious sources of schistosomiasis in the Yangtze River basin.
Schistosomiasis: The Social Challenge of Controlling a Man-Made Disease
ERIC Educational Resources Information Center
Lemma, Aklilu
1973-01-01
There is an indication of a method for curbing or controlling schistosomiasis or bilharziasis. Modern technological advances in applied pharmacology have not provided a satisfactory remedy but a simple natural product, an endod berry, has been used to control the disease on a self-help basis. (EB)
Praziquantel for Schistosomiasis: Single-Drug Metabolism Revisited, Mode of Action, and Resistance.
Vale, Nuno; Gouveia, Maria João; Rinaldi, Gabriel; Brindley, Paul J; Gärtner, Fátima; Correia da Costa, José M
2017-05-01
Schistosomiasis, a major neglected tropical disease, affects more than 250 million people worldwide. Treatment of schistosomiasis has relied on the anthelmintic drug praziquantel (PZQ) for more than a generation. PZQ is the drug of choice for the treatment of schistosomiasis; it is effective against all major forms of schistosomiasis, although it is less active against juvenile than mature parasites. A pyrazino-isoquinoline derivative, PZQ is not considered to be toxic and generally causes few or transient, mild side effects. Increasingly, mass drug administration targeting populations in sub-Saharan Africa where schistosomiasis is endemic has led to the appearance of reduced efficacy of PZQ, which portends the selection of drug-resistant forms of these pathogens. The synthesis of improved derivatives of PZQ is attracting attention, e.g., in the (i) synthesis of drug analogues, (ii) rational design of pharmacophores, and (iii) discovery of new compounds from large-scale screening programs. This article reviews reports from the 1970s to the present on the metabolism and mechanism of action of PZQ and its derivatives against schistosomes. Copyright © 2017 American Society for Microbiology.
Human plasma lipid modulation in schistosomiasis mansoni depends on apolipoprotein E polymorphism.
Martins da Fonseca, Caíque Silveira; Pimenta Filho, Adenor Almeida; dos Santos, Bianka Santana; da Silva, César Augusto; Domingues, Ana Lúcia Coutinho; Owen, James Stuart; Lima, Vera Lúcia de Menezes
2014-01-01
Schistosomiasis mansoni is a parasitic liver disease, which causes several metabolic disturbances. Here, we evaluate the influence of Apolipoprotein E (APOE) gene polymorphism, a known modulator of lipid metabolism, on plasma lipid levels in patients with hepatosplenic schistosomiasis. Blood samples were used for APOE genotyping and to measure total cholesterol (TC), LDL-C, HDL-C and triglycerides. Schistosomiasis patients had reduced TC, LDL-C and triglycerides (25%, 38% and 32% lower, respectively; P<0.0001) compared to control individuals, whereas HDL-C was increased (10% higher; P = 0.0136). Frequency of the common alleles, ε2, ε3 and ε4, was similar (P = 0.3568) between controls (n = 108) and patients (n = 84), implying that APOE genotype did not affect susceptibility to the advanced stage of schistosomiasis. Nevertheless, while patient TC and LDL-C levels were significantly reduced for each allele (except TC in ε2 patients), changes in HDL-C and triglycerides were noted only for the less common ε2 and ε4 alleles. The most striking finding, however, was that accepted regulation of plasma lipid levels by APOE genotype was disrupted by schistosomiasis. Thus, while ε2 controls had higher TC and LDL-C than ε3 carriers, these parameters were lower in ε2 versus ε3 patients. Similarly, the inverse relationship of TG levels in controls (ε2>ε3>ε4) was absent in patients (ε2 or ε4>ε3), and the increase in HDL-C of ε2 or ε4 patients compared to ε3 patients was not seen in the control groups. We confirm that human schistosomiasis causes dyslipidemia and report for the first time that certain changes in plasma lipid and lipoprotein levels depend on APOE gene polymorphism. Importantly, we also concluded that S. mansoni disrupts the expected regulation of plasma lipids by the different ApoE isoforms. This finding suggests ways to identify new metabolic pathways affected by schistosomiasis and also potential molecular targets to treat associated morbidities.
Acioli, M D; de Carvalho, E F
1998-01-01
This study analyzes and compares several social participation concepts in health education processes to practical experiences with schistosomiasis prevention measures under the Northeast Endemic Disease Control Program (Brazilian Ministry of Health/World Bank, 1987). Using qualitative methods, institutional documents and discourses were interpreted (Sucam, FNS, and Ministry of Health). A field study was also performed (using interviews with community-based health agents and the general population) in the Zona da Mata region of Pernambuco (a historically endemic area for schistosomiasis), focused in the county of Amaraji. Comparing discourses and educational practices, we found factors that explain respective points of convergence and divergence, as well as elements linked to the social and historical process of the target population which systematically limit the efficacy of such educational measures.
Elimination of urogenital schistosomiasis in Iran: past history and the current situation.
Khademvatan, Shahram; Salmanzadeh, Shokrollah; Foroutan-Rad, Masoud; Ghomeshi, Mohammad
2016-09-01
In recent years, through a national programme for schistosomiasis control, this infection has been eliminated from Iran. The aim of this study was to report the process of significant decrease of urogenital schistosomiasis in southwestern Iran. During national programme surveillance for urogenital schistosomiasis control which was implemented by Centres for Disease Control and Prevention (CDC) of Khuzestan province from 1975 to 2013, more than 1·3 million urine samples were taken from inhabitants of high risk foci. All urine samples were gathered between 10:00 a.m and 02:00 p.m and, after centrifuging, specimens were tested under optical microscope in order to detect Schistosoma haematobium eggs. Data analysis was performed using SPSS 18 software. In this retrospective study significant reduction was seen in number of infections between 1975 and 2013. During the years 1975-1980, 1981-1990 and 1991-2000 there were 1582, 761 and 79 cases of S. haematobium, respectively. In 2001 only one case was reported from Ahvaz and indeed this was the last case of urogenital schistosomiasis in Khuzestan and of course, in Iran. Prevalence from 1·064% between 1975 and 1980 slumped to 0% in 2012-2013. During several projects for surveillance of urogenital schistosomiasis, selective population chemotherapy, snail control, population education, environmental improvement, etc were carried out throughout the surveillance period. According to elimination of S. haematobium in Khuzestan province, the only endemic region of Iran, control of disease, especially the campaign with intermediate host snails should be continued. Iran can be a successful model for countries suffering from this disease.
Schistosomiasis in the People's Republic of China: the Era of the Three Gorges Dam
McManus, Donald P.; Gray, Darren J.; Li, Yuesheng; Feng, Zheng; Williams, Gail M.; Stewart, Donald; Rey-Ladino, Jose; Ross, Allen G.
2010-01-01
Summary: The potential impact of the Three Gorges Dam (TGD) on schistosomiasis transmission in China has invoked considerable global concern. The TGD will result in changes in the water level and silt deposition downstream, favoring the reproduction of Oncomelania snails. Combined with blockages of the Yangtze River's tributaries, these changes will increase the schistosomiasis transmission season within the marshlands along the middle and lower reaches of the Yangtze River. The changing schistosome transmission dynamics necessitate a comprehensive strategy to control schistosomiasis. This review discusses aspects of the epidemiology and transmission of Schistosoma japonicum in China and considers the pathology, clinical outcomes, diagnosis, treatment, immunobiology, and genetics of schistosomiasis japonica together with an overview of current progress in vaccine development, all of which will have an impact on future control efforts. The use of synchronous praziquantel (PZQ) chemotherapy for humans and domestic animals is only temporarily effective, as schistosome reinfection occurs rapidly. Drug delivery requires a substantial infrastructure to regularly cover all parts of an area of endemicity. This makes chemotherapy expensive and, as compliance is often low, a less than satisfactory control option. There is increasing disquiet about the possibility that PZQ-resistant schistosomes will develop. Consequently, as mathematical modeling predicts, vaccine strategies represent an essential component in the future control of schistosomiasis in China. With the inclusion of focal mollusciciding, improvements in sanitation, and health education into the control scenario, China's target of reducing the level of schistosome infection to less than 1% by 2015 may be achievable. PMID:20375361
Zhou, Yi-Biao; Chen, Yue; Liang, Song; Song, Xiu-Xia; Chen, Geng-Xin; He, Zhong; Cai, Bin; Yihuo, Wu-Li; He, Zong-Gui; Jiang, Qing-Wu
2016-08-18
Schistosomiasis remains a serious public health issue in many tropical countries, with more than 700 million people at risk of infection. In China, a national integrated control strategy, aiming at blocking its transmission, has been carried out throughout endemic areas since 2005. A longitudinal study was conducted to determine the effects of different intervention measures on the transmission dynamics of S. japonicum in three study areas and the data were analyzed using a multi-host model. The multi-host model was also used to estimate the threshold of Oncomelania snail density for interrupting schistosomiasis transmission based on the longitudinal data as well as data from the national surveillance system for schistosomiasis. The data showed a continuous decline in the risk of human infection and the multi-host model fit the data well. The 25th, 50th and 75th percentiles, and the mean of estimated thresholds of Oncomelania snail density below which the schistosomiasis transmission cannot be sustained were 0.006, 0.009, 0.028 and 0.020 snails/0.11 m(2), respectively. The study results could help develop specific strategies of schistosomiasis control and elimination tailored to the local situation for each endemic area.
Nsowah-Nuamah, N N N; Aryeetey, M E; Jolayemi, E T; Wagatsuma, Y; Mensah, G; Dontwi, I K; Nkrumah, F K; Kojima, S
2004-05-01
Schistosoma haematobium infection could be associated with morbidity. Generally, the cost of schistosomiasis control is high and it becomes a burden for governments or non-governmental organisations to repeat control programs so as to reduce morbidity. There is therefore, the need to optimise the available meagre resources for its control. From 1993 to 1997 the Noguchi Memorial Institute for Medical Research of the University of Ghana carried out a schistosomiasis control program in southern Ghana. Using the generated data, an attempt is made to determine the timing of the second praziquantel treatment and the period needed after the second chemotherapy to have egg counts reduced to low levels in southern Ghana. It was revealed that the second praziquantel treatment in areas 1, 2, and 3 should be administered latest at 13.8, 11.8 and 13.2 months, respectively after the first one. Most importantly, it takes 24.4 months to bring egg counts to zero in area 3 while in area 1, it takes about 29 months after the second praziquantel treatment. Egg counts were not reduced to zero in area 2 after the second chemotherapy. At least passive health education and continuous safe water supply should support the chemotherapy in addition to weed removal at the water contact sites.
[Effect of comprehensive schistosomiasis control in Changzhou City from 2004 to 2014].
Ming-Zhen, He; Hong, Chen; Yi-Qing, Xie; Yong-Gen, Zou; Shi-Ying, Zhu
2015-12-14
To evaluate the effect of comprehensive schistosomiasis control in Changzhou City in recent 10 years, so as to provide the evidences for formulating the future prevention and control strategy. The work reports and the data of the schistosomiasis comprehensive control projects in Changzhou City from 2004 to 2014 were collected, the infection status of residents and livestock as well the Oncomelania hupensis snail situation were analyzed, and the implementation effect of the comprehensive control projects was evaluated. From 2004 to 2014, totally 215 368 person-times were examined, and the positive rate of the blood examinations of the population was 0.24% (478/198 356), and there were no positive cases detected out by using the miracidium hatching method. Totally 11 935 domestic animals were detected and no positives were found. From 2004 to 2014, the total area with snails was 92.27 hm 2 , and marshland, inland and mountain environments accounted for 34.75%, 34.82% and 30.43%, respectively. The newly discovered area with snails was 34.40 hm 2 , and marshland, inland and mountain environments accounted for 2.62%, 71.22% and 26.16%, respectively. Totally 8 511 snails were dissected and no schistosome infected snails were found. From 2004 to 2014, a total of 242 600 harmless toilets were built, 2 704 700 domestic animals were reared in pens, 5.82 km-long rivers were dredged, 2 250.11 hm 2 of protective forests were constructed, a total area of 625.79 hm 2 were controlled with molluscicides, and an area of 149.58 hm 2 were environmentally transformed. Totally 5.4 million people received health education. The awareness rate of knowledge on schistosomiasis control of residents was 96.00% in 2014. There exists the risks of snails import and diffusion and schistosomiasis resurrection in Changzhou City, but under the condition of continuous implementation of comprehensive control measures, the endemic situation of schistosomiasis is stable and the control achievement is consolidated in this city.
Getaneh, A; Tamrat, A; Tadesse, K
2015-07-01
Morbidity and mortality caused by schistosomiasis usually results from immunopathology. But the underlying mechanisms are not yet clearly understood. Th2-type immune response is thought to be dominant during chronic schistosomiasis, and upregulation of arginase-I is one component of this milieu. A cohort study was conducted to assess arginase activity in peripheral blood of humans with intestinal schistosomiasis in Wonji-Shoa Sugar Estate, Central Ethiopia. Laboratory-confirmed 30 Schistosoma mansoni-infected patients and 18 apparently healthy controls were recruited. Faecal egg count was carried out by Kato-Katz technique. Plasma and peripheral blood mononuclear cells (PBMCs) were isolated from whole blood. Activity of arginase in plasma and PBMC lysates was measured, and results were compared with that of controls. Twenty-one of 30 patients had light infection, whereas moderate and heavy intensity infections were observed in eight and only one patient(s), respectively. A significant increase in both PBMC (patients: 59.96 + 82.99, controls: 25.44 + 24.6 mU/mg protein, P < 0.0001) and plasma (patients: 1.61 + 2.19, controls: 0.31 + 0.73 mU/mL plasma, P < 0.0001) arginase activity was observed during human S. mansoni infection. Arginase activity increases in peripheral blood of patients with intestinal schistosomiasis. © 2015 John Wiley & Sons Ltd.
2014-01-01
Background Schistosomiasis japonica is still endemic in the People’s Republic of China (P.R. China) in five provinces of lake and marshland regions and in two provinces of mountainous regions. Studies elucidated that individual and community perception, attitudes towards schistosomiasis, and hygiene behaviors were crucial factors for preventing schistosomiasis. This study sought to assess the knowledge of, attitudes towards, and practices (KAP) relating to schistosomiasis in two subtypes of a mountainous region in Eryuan County, Yunnan Province, P.R. China. The study’s aim is to make suggestions for establishing more specific and effective control measures for disease transmission and interruption in two subtypes of a mountainous region with low-level infection rates. Methods A cross-sectional study of 3,000 inhabitants was carried out in the Yongle (plateau basin) and Xinzhuang (plateau canyon) communities of Eryuan County, Yunnan Province in November and December 2011. Stratified cluster random sampling was undertaken using a uniform set of quantitative questionnaires administered by trained assistants. This was further supported with qualitative data from in-depth interviews (IDIs) conducted with ten farmers and ten students. All participants were examined for schistosomiasis using both a serological test (indirect hemagglutination assay [IHA]) and a stool examination (Kato-Katz). Results The total schistosomiasis knowledge rate in Yongle (83.4%) was significantly lower than that in Xinzhuang (95.5%). In both communities, among the respondents aged 15 years or below, more than one third didn’t know the name, endemic areas, and animal reservoirs of schistosomiasis. The majority of respondents in Eryuan acquired their schistosomiasis knowledge from doctors, followed by handouts and hearing from others. The infection rate was once the highest in Yongle, but is now the highest in Xinzhuang, where there are more risk factors for schistosomiasis, such as frequently grazing cattle, digging vegetables or cutting grass in the field, as well as raising cattle by free grazing. Conclusion In short, Eryuan County’s overall knowledge rate of schistosomiasis was found to be high. Due to various dominating risk factors, different control strategies should be designed keeping in mind the two different subtypes of endemic areas for schistosomiasis in mountainous regions, namely plateau basins and plateau canyons. PMID:24955240
[Schistosomiasis in an ecotourism area in Minas Gerais State, Brazil].
Massara, Cristiano Lara; Amaral, Graciela Larissa; Caldeira, Roberta Lima; Drummond, Sandra Costa; Enk, Martin Johannes; Carvalho, Omar dos Santos
2008-07-01
This paper discusses schistosomiasis transmission in São José da Serra, a village with a population of 500 in the county of Jaboticatubas, Minas Gerais State, Brazil. The area receives thousands of visitors a year for ecotourism. The study was motivated by a case of acute schistosomiasis involving a couple that spent the 2007 Carnival (Mardi Gras) holiday in the area. Stool tests from 268 local residents (53.6% of the population) showed that 35 (13%) were positive for the infection. A comparison with a previous survey (2005) in the same location showed an increase in the schistosomiasis-positive rate from 9.6% to 12.5%, among the 56 individuals who participated in both surveys. A malacological survey of 65 Biomphalaria glabrata snails showed one specimen (1.5%) eliminating cercariae. In a similar survey in 2005, no positive snail specimens were found. The study indicates that active schistosomiasis transmission is occurring in the area, and that integrated educational programs are needed for both the local community and tourists.
Onile, Olugbenga Samson; Calder, Bridget; Soares, Nelson C; Anumudu, Chiaka I; Blackburn, Jonathan M
2017-11-01
Schistosomiasis is a chronic neglected tropical disease that is characterized by continued inflammatory challenges to the exposed population and it has been established as a possible risk factor in the aetiology of bladder cancer. Improved diagnosis of schistosomiasis and its associated pathology is possible through mass spectrometry to identify biomarkers among the infected population, which will influence early detection of the disease and its subtle morbidity. A high-throughput proteomic approach was used to analyse human urine samples for 49 volunteers from Eggua, a schistosomiasis endemic community in South-West, Nigeria. The individuals were previously screened for Schistosoma haematobium and structural bladder pathologies via microscopy and ultrasonography respectively. Samples were categorised into schistosomiasis, schistosomiasis with bladder pathology, bladder pathology, and a normal healthy control group. These samples were analysed to identify potential protein biomarkers. A total of 1306 proteins and 9701 unique peptides were observed in this study (FDR = 0.01). Fifty-four human proteins were found to be potential biomarkers for schistosomiasis and bladder pathologies due to schistosomiasis by label-free quantitative comparison between groups. Thirty-six (36) parasite-derived potential biomarkers were also identified, which include some existing putative schistosomiasis biomarkers that have been previously reported. Some of these proteins include Elongation factor 1 alpha, phosphopyruvate hydratase, histone H4 and heat shock proteins (HSP 60, HSP 70). These findings provide an in-depth analysis of potential schistosoma and human host protein biomarkers for diagnosis of chronic schistosomiasis caused by Schistosoma haematobium and its pathogenesis.
The control of helminths: nonreplicating infectious agents of man.
Warren, K S
1981-01-01
In the early part of the 20th century the basic strategy for the cost effective control of helminth diseases was established during a major global hookworm campaign. For schistosomiasis, the most important of present day helminth diseases, the methodology has had to be rediscovered slowly and laboriously. Presently, it is not in use in any large scale programs and is continually being criticized. What is particularly ironic is that this method of control is a logical approach given the unique biology of the helminth infections. The crux of the matter is that helminths are different from all other infectious agents including bacteria, viruses, fungi, and protozoa. Focus in this discussion of the control of helminths is on the following: major helminth infections; hookworm; schistosomiasis; and control of other major helminth infections. The 1st great attempt at control of a major helminth infection globally was initiated by the Rockefeller Foundation in 1913. Hookworm infection exists with the establishment of a single worm in the body, but hookworm disease occurs only when infection is heavy enough to result in clinical manifestations. The majority of people with hookworm have light infections without disease. Most of these facts were known early in the Rockefeller Foundation hookworm campaign and were used to develop an optimal, cost effective means of control. The targeting of treatment and use of single doses to markedly reduce the intensity of infection rather than multiple doses to achieve a cure is particularly poignant in that in 1925 the treatment of choice for hookworm was carbon tetrachloride. In the past decade a small number of workers have come to an understanding of the ecology of schistosomiasis and of cost effectiveness means for its control that are essentially identical to those reached by colleagues over 50 years ago. The concept of mass chemotherapy targeted toward that part of the population with the greatest prevalence and intensity of schistosomiasis, and that which was easiest to obtain, was developed. To render this approach highly cost effective, simple, inexpensive, and expeditious means of field diagnosis and treatment were created and tested in Kenya. These studies were performed without knowledge of similar findings in hookworm infections more than 50 years ago. The recommendations for Kenya are to use mass chemotherapy targeted to the infected 5-19 year old population. Treatment of this entire population twice over a 6-year span was estimated at a total cost of $9 million. This methodology of controlling disease rather than infection, which has been established for hookworm and suggested for schistosomiasis, seems to be the logical approach for controlling most of the other major helminth infections.
Schistosomiasis control through rural health units.
el Katsha, S; Watts, S
1995-01-01
In Egypt the main effort in the campaign against schistosomiasis involves providing free diagnosis and treatment through primary care facilities, especially rural health units. The prospects for improving these services are considered below.
Chen, Hai-ying; Hu, Guang-han; Song, Kuang-yu; Xiong, Zhi-wei; Wan, Bao-ping; Yang, Ping-yi; Hu, Jia; Peng, Guo-hua; Hu, Wei-Chen; Fu, Guo-Lan
2010-10-01
To study an intervention model of "schools without infected students with schistosoma japonica", to control and prevent students from schistosoma infection. Twelve primary schools of four heavy endemic counties (districts) with schistosomiasis in the Poyang Lake areas were selected as the study fields, of which, ten schools were the experimental groups, and the other two schools were the control groups by cluster random sampling. All enrolment students were the target population. The baseline survey was carried out in 2005, and an intervention model, "information dissemination + behavior participation + behavior encouragement", was applied in the experiment groups in 2006 - 2008, then the effect of intervention was assessed. Before intervention (2005), the anti-schistosomiasis knowledge awareness rate of experimental and control groups were 14.75% (324/2196) and 16.58% (91/549), and the different was not significant (χ(2) = 1.14, P > 0.05); the rate of accurate attitude of anti-schistosomiasis were 14.71% (323/2196) and 11.84% (65/549) in experimental and control groups, and the difference was not significant (χ(2) = 2.98, P > 0.05); the rate of contacting infected water were 15.44% (18 988/122 976) and 15.03% (4622/30 744) in experimental and control group and the difference was not significant (χ(2) = 3.13, P > 0.05); and the infection rate of schistosomiasis of experiment control groups were 9.65% (212/2196) and 10.56% (58/549), the difference was not significant (χ(2) = 0.41, P > 0.05). After one year intervention (2006), the anti-schistosomiasis knowledge awareness rate of experimental and control groups were 97.79% (2032/2078) and 18.11% (98/541), and the different was significant (χ(2) = 1794.31, P < 0.01); the rate of accurate attitude of anti-schistosomiasis were 99.09% (2059/2078) and 13.49% (73/541) in experimental and control group, and the difference was significant (χ(2) = 2077.45, P < 0.01). After 1 - 3 years intervention (2006 - 2008), there were no any contactors with infected water and infectors with schistosome in students of the experiment group in successive 3 years. While in the control group of the same period, the rate contacting infected water were 16.12% (4884/30 296), 11.11% (3079/27 720) and 12.25% (3451/28 168); the infection rate of schistosomiasis were 8.87% (48/541), 7.47% (37/495) and 7.95% (40/503), respectively. The intervention model of health promotion, "information dissemination + behavior participation + behavior encouragement", can effectively control and prevent students from infecting schistosoma japonica in heavy endemic areas with schistosomiasis.
Iida, F.; Iida, R.; Kamijo, H.; Takaso, K.; Miyazaki, Y.; Funabashi, W.; Tsuchiya, K.; Matsumoto, Y.
1999-01-01
In a preliminary study carried out in the study area we found that 19.1% (173/907) of patients with chronic liver disease and 51% (35/68) of hepatocellular carcinoma cases were infected with Japanese schistosomiasis. Analysis of data from 571 autopsies revealed a similarly high incidence of schistosomiasis among cases of hepatoma and other liver diseases. A prospective case-control study conducted over 10 years showed that hepatoma developed in 5.4% (26/484) of chronic schistosomiasis cases and in 7.5% (23/307) of patients with chronic liver disease (hepatitis, cirrhosis, etc). The difference was not statistically significant (P = 0.228). A high incidence of hepatitis C virus (HCV) antibody (HCVAb) was found in the schistosomiasis group (36.5%; 95% CI = 44.9-28.1%) and in the chronic liver disease group (56.0%), 39% of whom had chronic hepatitis (P = 0.028). Various factors that might have contributed to the development of hepatoma and schistosomiasis were investigated, but no evidence of a significant correlation between schistosomiasis and hepatoma was found. The high incidence of HCVAb was considered to have been responsible for the development of hepatocellular carcinoma in chronic schistosomiasis patients. The role of HBV infection in the development of hepatoma in schistosomiasis patients was not confirmed after an assay for HCVAb was included in the study. PMID:10444881
Meningher, Tal; Lerman, Galya; Regev-Rudzki, Neta; Gold, Daniel; Ben-Dov, Iddo Z; Sidi, Yechezkel; Avni, Dror; Schwartz, Eli
2017-02-01
Schistosomiasis traditionally has been diagnosed by detecting eggs in stool or urine. However, the sensitivity of these examinations is limited, especially in travelers with a low worm burden. Serologic tests have a greater sensitivity, but their results remain positive regardless of treatment and thus cannot be used for follow-up of patients. We hypothesized that detection of worm microRNAs (miRNAs) in serum can overcome the drawbacks of the existing diagnostic methods. Twenty-six returning travelers with schistosomiasis (based on positive results of serologic tests or detection of ova) and 17 healthy controls were included in the study. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) amplification of miRNA extracted directly from 500 µL of serum had limited sensitivity and specificity. However, qRT-PCR analysis of RNA extracted from 200 μL of serum extracellular vesicles detected 4 schistosomal miRNAs; the sensitivity and specificity of the 2 highest expressed miRNAs (bantam and miR-2c-3p) were 86% and 84%, respectively. In 7 patients with posttreatment serum available for analysis, we observed outcomes ranging from a reduction in the schistosomal miRNA level to full recovery from disease. qRT-PCR of pathogen miRNAs isolated from extracellular vesicles in sera from infected individuals may provide a new tool for diagnosing schistosomiasis in patients with a low parasite burden. This assay could also be used for evaluating the outcome of therapy, as well as disease-control programs. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.
Midzi, Nicholas; Mduluza, Takafira; Chimbari, Moses J; Tshuma, Clement; Charimari, Lincoln; Mhlanga, Gibson; Manangazira, Portia; Munyati, Shungu M; Phiri, Isaac; Mutambu, Susan L; Midzi, Stanley S; Ncube, Anastancia; Muranzi, Lawrence P; Rusakaniko, Simbarashe; Mutapi, Francisca
2014-08-01
Schistosomiasis and STH are among the list of neglected tropical diseases considered for control by the WHO. Although both diseases are endemic in Zimbabwe, no nationwide control interventions have been implemented. For this reason in 2009 the Zimbabwe Ministry of Health and Child Care included the two diseases in the 2009-2013 National Health Strategy highlighting the importance of understanding the distribution and burden of the diseases as a prerequisite for elimination interventions. It is against this background that a national survey was conducted. A countrywide cross-sectional survey was carried out in 280 primary schools in 68 districts between September 2010 and August 2011. Schistosoma haematobium was diagnosed using the urine filtration technique. Schistosoma mansoni and STH (hookworms, Trichuris trichiura, Ascaris lumbricoides) were diagnosed using both the Kato Katz and formol ether concentration techniques. Schistosomiasis was more prevalent country-wide (22.7%) than STH (5.5%). The prevalence of S. haematobium was 18.0% while that of S. mansoni was 7.2%. Hookworms were the most common STH with a prevalence of 3.2% followed by A. lumbricoides and T. trichiura with prevalence of 2.5% and 0.1%, respectively. The prevalence of heavy infection intensity as defined by WHO for any schistosome species was 5.8% (range 0%-18.3% in districts). Only light to moderate infection intensities were observed for STH species. The distribution of schistosomiasis and STH varied significantly between provinces, districts and schools (p<0.001). Overall, the prevalence of co-infection with schistosomiasis and STH was 1.5%. The actual co-endemicity of schistosomiasis and STH was observed in 43 (63.2%) of the 68 districts screened. This study provided comprehensive baseline data on the distribution of schistosomiasis and STH that formed the basis for initiating a national control and elimination programme for these two neglected tropical diseases in Zimbabwe.
Midzi, Nicholas; Mduluza, Takafira; Chimbari, Moses J.; Tshuma, Clement; Charimari, Lincoln; Mhlanga, Gibson; Manangazira, Portia; Munyati, Shungu M.; Phiri, Isaac; Mutambu, Susan L.; Midzi, Stanley S.; Ncube, Anastancia; Muranzi, Lawrence P.; Rusakaniko, Simbarashe; Mutapi, Francisca
2014-01-01
Background Schistosomiasis and STH are among the list of neglected tropical diseases considered for control by the WHO. Although both diseases are endemic in Zimbabwe, no nationwide control interventions have been implemented. For this reason in 2009 the Zimbabwe Ministry of Health and Child Care included the two diseases in the 2009–2013 National Health Strategy highlighting the importance of understanding the distribution and burden of the diseases as a prerequisite for elimination interventions. It is against this background that a national survey was conducted. Methodology A countrywide cross-sectional survey was carried out in 280 primary schools in 68 districts between September 2010 and August 2011. Schistosoma haematobium was diagnosed using the urine filtration technique. Schistosoma mansoni and STH (hookworms, Trichuris trichiura, Ascaris lumbricoides) were diagnosed using both the Kato Katz and formol ether concentration techniques. Main findings Schistosomiasis was more prevalent country-wide (22.7%) than STH (5.5%). The prevalence of S. haematobium was 18.0% while that of S. mansoni was 7.2%. Hookworms were the most common STH with a prevalence of 3.2% followed by A. lumbricoides and T. trichiura with prevalence of 2.5% and 0.1%, respectively. The prevalence of heavy infection intensity as defined by WHO for any schistosome species was 5.8% (range 0%–18.3% in districts). Only light to moderate infection intensities were observed for STH species. The distribution of schistosomiasis and STH varied significantly between provinces, districts and schools (p<0.001). Overall, the prevalence of co-infection with schistosomiasis and STH was 1.5%. The actual co-endemicity of schistosomiasis and STH was observed in 43 (63.2%) of the 68 districts screened. Conclusion and recommendations This study provided comprehensive baseline data on the distribution of schistosomiasis and STH that formed the basis for initiating a national control and elimination programme for these two neglected tropical diseases in Zimbabwe. PMID:25121489
Sleigh, A.; Jackson, S.; Li, X.; Huang, K.
1998-01-01
Reported are the results of a study of the political economy, management, and costs of the successful Guangxi schistosomiasis eradication programme, spanning 40 years from 1953 to 1992. For this purpose we analysed all government data and memoranda on the policy, management, technical support, finance, and the control strategy of the programme. We also interviewed many local staff involved in the programme over the 40-year period and obtained cost data from annual county-level records on seven major categories of variable costs. Schistosomiasis control in Guangxi began with one of the first examples of community participation and rapid assessment in public health history--the use of pre-franked envelopes to return disease questionnaires and suspect snails from rural areas. This approach quickly and accurately delineated the endemic area. This was Mao Zedong's "mass line", incorporating ideas and knowledge from peasants directly into services run for and by them, here the schistosomiasis control programme. Recognition by China's leaders that schistosomiasis was a great economic burden, steadfast prioritizing of the programme over 40 years, local innovative scientific study, agricultural and environmental focus on eradicating the snail hosts and boosting rural production, and mass community education and support were all key factors in the final success. Local leaders motivated programme staff and everyone involved knew the objectives. The programme was always multisectoral, with policy developed centrally, and strategy and collaboration encouraged and rewarded at the grass-roots. These features explain how a very poor autonomous region such as Guangxi finally eradicated schistosomiasis, spending less than US$ 0.50 per protected citizen per year; it is remarkable that the disease and snails were initially found across a large area of complex environments and modern drugs such as praziquantel were not available for most of the 40-year period. The lessons from Guangxi can be adapted elsewhere and should encourage other areas to control endemic schistosomiasis using methods devised to suit the local culture and geography. Images Fig. 2 PMID:9868841
Cao, Zhi-Guo; Li, Si; Zhao, Ya-E; Wang, Tian-Ping; Bergquist, Robert; Huang, Yin-Yin; Gao, Feng-Hua; Hu, Yi; Zhang, Zhi-Jie
2018-05-09
Anhui Province has been one of typical epidemic areas of schistosomiasis in East China as a wide range of large lake and marshland regions provide an ideal environment for growth and reproduction of the intermediate snail host. With the completion of the Yangtze River-Huaihe River Water Transfer Project (YHWTP), launched by the end of 2016, the epidemic areas are expected to expand and controlling schistosomiasis remains a challenge. Based on annual surveillance data at the county level in Anhui for the period 2006-2015, spatial and temporal cluster analyses were conducted to assess the pattern of risk through spatial (Local Moran's I and flexible scan statistic) and space-time scan statistic (Kulldorff). It was found that schistosomiasis sero-prevalence was dramatically reduced and maintained at a low level. Cluster results showed that spatial extent of schistosomiasis contracted, but snail distribution remained geographically stable across the study area. Clusters, both for schistosomiasis and snail presence, were common along the Yangtze River. Considering the effect of the ongoing YHWTP on the potential spread of schistosomiasis, Zongyang County and Anqing, which will be transected by the new water-transfer route, should be given a priority for strengthened surveillance and control. Attention should also be paid to Guichi since it is close to one of the planned inlets of the YHWTP. Copyright © 2018 Elsevier B.V. All rights reserved.
Requirements for sustainable schistosomiasis control.
Traoré, M
1996-01-01
In Mali the increased transmission of schistosomiasis following the construction of numerous reservoirs and irrigation schemes, together with experience gained in tackling the disease, have led to a major effort to train personnel in control methods, to achieve decentralized delivery and management, and to foster self-reliance in this field. The author outlines the essential components of a sound national control programme requiring long-term commitment.
Sady, Hany; Al-Mekhlafi, Hesham M.; Mahdy, Mohammed A. K.; Lim, Yvonne A. L.; Mahmud, Rohela; Surin, Johari
2013-01-01
Background Schistosomiasis, one of the most prevalent neglected tropical diseases, is a life-threatening public health problem in Yemen especially in rural communities. This cross-sectional study aims to determine the prevalence and associated risk factors of schistosomiasis among children in rural Yemen. Methods/Findings Urine and faecal samples were collected from 400 children. Urine samples were examined using filtration technique for the presence of Schistosoma haematobium eggs while faecal samples were examined using formalin-ether concentration and Kato Katz techniques for the presence of S. mansoni. Demographic, socioeconomic and environmental information were collected via a validated questionnaire. Overall, 31.8% of the participants were found to be positive for schistosomiasis; 23.8% were infected with S. haematobium and 9.3% were infected with S. mansoni. Moreover, 39.5% of the participants were anaemic whereas 9.5% had hepatosplenomegaly. The prevalence of schistosomiasis was significantly higher among children aged >10 years compared to those aged ≤10 years (P<0.05). Multivariate analysis confirmed that presence of other infected family member (P<0.001), low household monthly income (P = 0.003), using unsafe sources for drinking water (P = 0.003), living nearby stream/spring (P = 0.006) and living nearby pool/pond (P = 0.002) were the key factors significantly associated with schistosomiasis among these children. Conclusions/Significance This study reveals that schistosomiasis is still highly prevalent in Yemen. These findings support an urgent need to start an integrated, targeted and effective schistosomiasis control programme with a mission to move towards the elimination phase. Besides periodic drug distribution, health education and community mobilisation, provision of clean and safe drinking water, introduction of proper sanitation are imperative among these communities in order to curtail the transmission and morbidity caused by schistosomiasis. Screening and treating other infected family members should also be adopted by the public health authorities in combating this infection in these communities. PMID:23991235
Sady, Hany; Al-Mekhlafi, Hesham M; Mahdy, Mohammed A K; Lim, Yvonne A L; Mahmud, Rohela; Surin, Johari
2013-01-01
Schistosomiasis, one of the most prevalent neglected tropical diseases, is a life-threatening public health problem in Yemen especially in rural communities. This cross-sectional study aims to determine the prevalence and associated risk factors of schistosomiasis among children in rural Yemen. Urine and faecal samples were collected from 400 children. Urine samples were examined using filtration technique for the presence of Schistosoma haematobium eggs while faecal samples were examined using formalin-ether concentration and Kato Katz techniques for the presence of S. mansoni. Demographic, socioeconomic and environmental information were collected via a validated questionnaire. Overall, 31.8% of the participants were found to be positive for schistosomiasis; 23.8% were infected with S. haematobium and 9.3% were infected with S. mansoni. Moreover, 39.5% of the participants were anaemic whereas 9.5% had hepatosplenomegaly. The prevalence of schistosomiasis was significantly higher among children aged >10 years compared to those aged ≤ 10 years (P<0.05). Multivariate analysis confirmed that presence of other infected family member (P<0.001), low household monthly income (P = 0.003), using unsafe sources for drinking water (P = 0.003), living nearby stream/spring (P = 0.006) and living nearby pool/pond (P = 0.002) were the key factors significantly associated with schistosomiasis among these children. This study reveals that schistosomiasis is still highly prevalent in Yemen. These findings support an urgent need to start an integrated, targeted and effective schistosomiasis control programme with a mission to move towards the elimination phase. Besides periodic drug distribution, health education and community mobilisation, provision of clean and safe drinking water, introduction of proper sanitation are imperative among these communities in order to curtail the transmission and morbidity caused by schistosomiasis. Screening and treating other infected family members should also be adopted by the public health authorities in combating this infection in these communities.
Chen, L; Zhong, B; Xu, J; Li, R-Z; Cao, C-L
2016-01-01
Schistosomiasis control programme in The People's Republic of China had promoted the mass mobilization of health education in various forms, such as films, drama, traditional opera, poems, slogans, posters, exhibits. This paper is trying to review the impacts of those forms on different endemic settings and targeted populations. In the future, health education and health promotion will still be the effective strategy and one of the interventions in the national control programme for schistosomiasis and other infectious diseases, even in the pre- or posttransmission stages. With the social and economic development and improvement of people's living standard, it is necessary to establish a sustainable mechanism, in combination of health education with health guarantee of improving the quality of life, improving the production and living conditions, changing the unhealthy production methods and lifestyle of the residents in the endemic areas, in order to reach the goal of schistosomiasis elimination in The People's Republic of China. Copyright © 2016 Elsevier Ltd. All rights reserved.
Dembélé, Massitan; Bamani, Sanoussi; Dembélé, Robert; Traoré, Mamadou O.; Goita, Seydou; Traoré, Mamadou Namory; Sidibe, Abdoul Karim; Sam, Letitia; Tuinsma, Marjon; Toubali, Emily; MacArthur, Chad; Baker, Shawn K.; Zhang, Yaobi
2012-01-01
Background Mali is endemic for all five targeted major neglected tropical diseases (NTDs). As one of the five ‘fast-track’ countries supported with the United States Agency for International Development (USAID) funds, Mali started to integrate the activities of existing disease-specific national control programs on these diseases in 2007. The ultimate objectives are to eliminate lymphatic filariasis, onchocerciasis and trachoma as public health problems and to reduce morbidity caused by schistosomiasis and soil-transmitted helminthiasis through regular treatment to eligible populations, and the specific objectives were to achieve 80% program coverage and 100% geographical coverage yearly. The paper reports on the implementation of the integrated mass drug administration and the lessons learned. Methodology/Principal Findings The integrated control program was led by the Ministry of Health and coordinated by the national NTD Control Program. The drug packages were designed according to the disease endemicity in each district and delivered through various platforms to eligible populations involving the primary health care system. Treatment data were recorded and reported by the community drug distributors. After a pilot implementation of integrated drug delivery in three regions in 2007, the treatment for all five targeted NTDs was steadily scaled up to 100% geographical coverage by 2009, and program coverage has since been maintained at a high level: over 85% for lymphatic filariasis, over 90% for onchocerciasis and soil-transmitted helminthiasis, around 90% in school-age children for schistosomiasis, and 76–97% for trachoma. Around 10 million people have received one or more drug packages each year since 2009. No severe cases of adverse effects were reported. Conclusions/Significance Mali has scaled up the drug treatment to national coverage through integrated drug delivery involving the primary health care system. The successes and lessons learned in Mali can be valuable assets to other countries starting up their own integrated national NTD control programs. PMID:22448294
A Rapid Monitoring and Evaluation Method of Schistosomiasis Based on Spatial Information Technology.
Wang, Yong; Zhuang, Dafang
2015-12-12
Thanks to Spatial Information Technologies (SITs) such as Remote Sensing (RS) and Geographical Information System (GIS) that are being quickly developed and updated, SITs are being used more widely in the public health field. The use of SITs to study the characteristics of the temporal and spatial distribution of Schistosoma japonicum and to assess the risk of infection provides methods for the control and prevention of schistosomiasis japonica has gradually become a hot topic in the field. The purpose of the present paper was to use RS and GIS technology to develop an efficient method of prediction and assessment of the risk of schistosomiasis japonica. We choose the Yueyang region, close to the east DongTing Lake (Hunan Province, China), as the study area, where a recent serious outbreak of schistosomiasis japonica took place. We monitored and evaluated the transmission risk of schistosomiasis japonica in the region using SITs. Water distribution data were extracted from RS images. The ground temperature, ground humidity and vegetation index were calculated based on RS images. Additionally, the density of oncomelania snails, which are the Schistosoma japonicum intermediate host, was calculated on the base of RS data and field measurements. The spatial distribution of oncomelania snails was explored using SITs in order to estimate the area surrounding the residents with transmission risk of schistosomiasis japonica. Our research result demonstrated: (1) the risk factors for the transmission of schistosomiasis japonica were closely related to the living environment of oncomelania snails. Key factors such as water distribution, ground temperature, ground humidity and vegetation index can be quickly obtained and calculated from RS images; (2) using GIS technology and a RS deduction technique along with statistical regression models, the density distribution model of oncomelania snails could be quickly built; (3) using SITs and analysis with overlaying population distribution data, the range of transmission risk of schistosomiasis japonica of the study area can be quickly monitored and evaluated. This method will help support the decision making for the control and prevention of schistosomiasis and form a valuable application using SITs for the schistosomiasis research.
Li, Sheng-ming; Zhao, Zheng-yuan; Peng, Zai-zhi; Wang, Zhang-hua; Li, Yuan; Guo, Feng-ying; Ren, Guang-hui
2014-08-01
To comprehensively evaluate the effect of the program of treatment and assistance to advanced schistosomiasis patients in Hunan Province from 2004 to 2013. The fund investment of the program, the profits of hospitals and the improvement of the patients' health were investigated by data collection and questionnaire survey. The evaluation index system of treatment and assistance to advanced schistosomiasis in Hunan Province was constructed by the Delphi method and analytic hierarchy process, and the program was assessed comprehensively. The evaluation index system including 6 primary indices and 33 secondary indices was established. Among all the primary indices, the score of the treatment and assistance (22.25) was the highest, and that of the satisfaction assessment (8.15) was the lowest, and the score of the comprehensive assessment was 87.06. The average cure rate of the patients was 13.08% from 2004 to 2013. More than 60% of the patients' disease condition got better, and nearly 70% of the patients' psychological condition improved, and more than 70% of patients' self-help ability and social contact improved, as well as family happiness increased. In addition, the annual average cost for caretakers decreased by 2000 Yuan, and the profits of all the fixed-point hospitals for treatment and assistance increased. The effectiveness and efficiency of the treatment and assistance to advanced schistosomiasis patients in Hunan Province is obvious, and the government should continuously invest in the program.
Impact of the scale-up of piped water on urogenital schistosomiasis infection in rural South Africa
Azongo, Daniel K; Vandormael, Alain; Bärnighausen, Till; Appleton, Christopher
2018-01-01
Recent work has estimated that sub-Saharan Africa could lose US$3.5 billion of economic productivity every year as a result of schistosomiasis and soil-transmitted helminthiasis. One of the main interventions to control schistosomiasis is the provision of safe water to limit the contact with infected water bodies and break the cycle of transmission. To date, a rigorous quantification of the impact of safe water supplies on schistosomiasis is lacking. Using data from one of Africa’s largest population-based cohorts, we establish the impact of the scale-up of piped water in a typical rural South African population over a seven-year time horizon. High coverage of piped water in the community decreased a child’s risk of urogenital schistosomiasis infection eight-fold (adjusted odds ratio = 0.12, 95% CI 0.06–0.26, p<0.001). The provision of safe water could drive levels of urogenital schistosomiasis infection to low levels of endemicity in rural African settings. PMID:29460779
Zhang, Yumei; Jiang, Yanyan; Wang, Yanjuan; Liu, Hua; Shen, Yujuan; Yuan, Zhongying; Hu, Yuan; Xu, Yuxin; Cao, Jianping
2015-01-01
The current knowledge of immunological responses to schistosomiasis is insufficient for the development of vaccine and therapies. The role of T follicular helper (Tfh) cells in schistosome infections is not fully defined. The frequency of circulating Tfh cells and serum cytokine levels were analyzed in 11 patients with chronic schistosomiasis and 10 healthy controls (HC), who reside in an endemic area for Schistosomiasis japonicum. Significantly higher frequencies of circulating CXCR5+ CD4+ Tfh cells and higher expression levels of ICOS and PD-1 in CXCR5+ CD4+ Tfh cells were observed in patients with chronic schistosomiasis compared to HC. The levels of IL-21 in serum and the expression of IL-21 mRNA were higher in chronic schistosomiasis patients than in HC. Moreover, the frequency of circulating PD-1high CXCR5+ CD4+ Tfh cells positively correlated with the levels of IL-21 in serum from patients with chronic schistosomiasis. A positive correlation was also found between the frequency of PD-1high CXCR5+ CD4+ Tfh cells and the levels of soluble egg antigen (SEA)-specific antibodies in serum samples from the patient group. Our study is the first regarding Tfh cells in chronic human schistosomiasis and the finding indicate that PD-1high CXCR5+ CD4+Tfh cells might play an important role in the production of specific antibodies in schistosomiasis. This study contributes to the understanding of immune response to schistosomiasis and may provide helpful support in vaccine development. PMID:26221072
Zhang, Yumei; Jiang, Yanyan; Wang, Yanjuan; Liu, Hua; Shen, Yujuan; Yuan, Zhongying; Hu, Yuan; Xu, Yuxin; Cao, Jianping
2015-01-01
The current knowledge of immunological responses to schistosomiasis is insufficient for the development of vaccine and therapies. The role of T follicular helper (Tfh) cells in schistosome infections is not fully defined. The frequency of circulating Tfh cells and serum cytokine levels were analyzed in 11 patients with chronic schistosomiasis and 10 healthy controls (HC), who reside in an endemic area for Schistosomiasis japonicum. Significantly higher frequencies of circulating CXCR5(+) CD4(+) Tfh cells and higher expression levels of ICOS and PD-1 in CXCR5(+) CD4(+) Tfh cells were observed in patients with chronic schistosomiasis compared to HC. The levels of IL-21 in serum and the expression of IL-21 mRNA were higher in chronic schistosomiasis patients than in HC. Moreover, the frequency of circulating PD-1(high) CXCR5(+) CD4(+) Tfh cells positively correlated with the levels of IL-21 in serum from patients with chronic schistosomiasis. A positive correlation was also found between the frequency of PD-1(high) CXCR5(+) CD4(+) Tfh cells and the levels of soluble egg antigen (SEA)-specific antibodies in serum samples from the patient group. Our study is the first regarding Tfh cells in chronic human schistosomiasis and the finding indicate that PD-1(high) CXCR5(+) CD4(+)Tfh cells might play an important role in the production of specific antibodies in schistosomiasis. This study contributes to the understanding of immune response to schistosomiasis and may provide helpful support in vaccine development.
Schur, Nadine; Hürlimann, Eveline; Garba, Amadou; Traoré, Mamadou S.; Ndir, Omar; Ratard, Raoult C.; Tchuem Tchuenté, Louis-Albert; Kristensen, Thomas K.; Utzinger, Jürg; Vounatsou, Penelope
2011-01-01
Background Schistosomiasis is a water-based disease that is believed to affect over 200 million people with an estimated 97% of the infections concentrated in Africa. However, these statistics are largely based on population re-adjusted data originally published by Utroska and colleagues more than 20 years ago. Hence, these estimates are outdated due to large-scale preventive chemotherapy programs, improved sanitation, water resources development and management, among other reasons. For planning, coordination, and evaluation of control activities, it is essential to possess reliable schistosomiasis prevalence maps. Methodology We analyzed survey data compiled on a newly established open-access global neglected tropical diseases database (i) to create smooth empirical prevalence maps for Schistosoma mansoni and S. haematobium for individuals aged ≤20 years in West Africa, including Cameroon, and (ii) to derive country-specific prevalence estimates. We used Bayesian geostatistical models based on environmental predictors to take into account potential clustering due to common spatially structured exposures. Prediction at unobserved locations was facilitated by joint kriging. Principal Findings Our models revealed that 50.8 million individuals aged ≤20 years in West Africa are infected with either S. mansoni, or S. haematobium, or both species concurrently. The country prevalence estimates ranged between 0.5% (The Gambia) and 37.1% (Liberia) for S. mansoni, and between 17.6% (The Gambia) and 51.6% (Sierra Leone) for S. haematobium. We observed that the combined prevalence for both schistosome species is two-fold lower in Gambia than previously reported, while we found an almost two-fold higher estimate for Liberia (58.3%) than reported before (30.0%). Our predictions are likely to overestimate overall country prevalence, since modeling was based on children and adolescents up to the age of 20 years who are at highest risk of infection. Conclusion/Significance We present the first empirical estimates for S. mansoni and S. haematobium prevalence at high spatial resolution throughout West Africa. Our prediction maps allow prioritizing of interventions in a spatially explicit manner, and will be useful for monitoring and evaluation of schistosomiasis control programs. PMID:21695107
Ning-Bo, Huang; Peng, Huang; Zong-Ti, Shao; Xi-Guang, Feng; Yi, Dong; Guang-Huai, Yang; Jin-Song, Li; Yan-Hong, Zhang; Shao-Yun, Chen; Shou-Ju, Nie; Wen, Li
2016-03-11
To evaluate the effect of hydraulic schistosomiasis control project with ditches managed on Oncomelania hupensis snail control. From 2009 to 2011, the snail investigations and schistosomiasis surveillance were carried out in Dali City and Yongsheng County, two sites of national schistosomiasis surveillance. The history data of schistosomiasis control were collected and analyzed. At the harden sections of the water conservancy project with ditches managed in Shajing Village of Dali City, only one snail was found in 2010 with the density of living snails of 0.004 snails/0.1 m 2 , while the densities of living snails were respectively 0.080, 0.002 snails/0.1 m 2 and 0.007 snails/0.1 m2 in unhardened sections of the project from 2009 to 2011. No snails were found in the harden sections of the water conservancy project with ditches managed in Gaojiacun Village of Yongsheng County, while the densities of living snails were respectively 0.040, 0.030 snails/0.1 m2 and 0.040 snails/0.1 m2 in unhardened sections of the project from 2009 to 2011. After the ditches were hardened, no infected snails were found from 2009 to 2011, and the appearance rate of frames with snails and density of living snails were both decreased, while they were both higher in unhardened ditches. The hydraulic schistosomiasis control project has obvious effect on control snails, but the maintain work should be strengthened after the project is completed.
Graeden, Ellie; Kerr, Justin; Sorrell, Erin M.; Katz, Rebecca
2018-01-01
Managing infectious disease requires rapid and effective response to support decision making. The decisions are complex and require understanding of the diseases, disease intervention and control measures, and the disease-relevant characteristics of the local community. Though disease modeling frameworks have been developed to address these questions, the complexity of current models presents a significant barrier to community-level decision makers in using the outputs of the most scientifically robust methods to support pragmatic decisions about implementing a public health response effort, even for endemic diseases with which they are already familiar. Here, we describe the development of an application available on the internet, including from mobile devices, with a simple user interface, to support on-the-ground decision-making for integrating disease control programs, given local conditions and practical constraints. The model upon which the tool is built provides predictive analysis for the effectiveness of integration of schistosomiasis and malaria control, two diseases with extensive geographical and epidemiological overlap, and which result in significant morbidity and mortality in affected regions. Working with data from countries across sub-Saharan Africa and the Middle East, we present a proof-of-principle method and corresponding prototype tool to provide guidance on how to optimize integration of vertical disease control programs. This method and tool demonstrate significant progress in effectively translating the best available scientific models to support practical decision making on the ground with the potential to significantly increase the efficacy and cost-effectiveness of disease control. Author summary Designing and implementing effective programs for infectious disease control requires complex decision-making, informed by an understanding of the diseases, the types of disease interventions and control measures available, and the disease-relevant characteristics of the local community. Though disease modeling frameworks have been developed to address these questions and support decision-making, the complexity of current models presents a significant barrier to on-the-ground end users. The picture is further complicated when considering approaches for integration of different disease control programs, where co-infection dynamics, treatment interactions, and other variables must also be taken into account. Here, we describe the development of an application available on the internet with a simple user interface, to support on-the-ground decision-making for integrating disease control, given local conditions and practical constraints. The model upon which the tool is built provides predictive analysis for the effectiveness of integration of schistosomiasis and malaria control, two diseases with extensive geographical and epidemiological overlap. This proof-of-concept method and tool demonstrate significant progress in effectively translating the best available scientific models to support pragmatic decision-making on the ground, with the potential to significantly increase the impact and cost-effectiveness of disease control. PMID:29649260
[Prediction of schistosomiasis infection rates of population based on ARIMA-NARNN model].
Ke-Wei, Wang; Yu, Wu; Jin-Ping, Li; Yu-Yu, Jiang
2016-07-12
To explore the effect of the autoregressive integrated moving average model-nonlinear auto-regressive neural network (ARIMA-NARNN) model on predicting schistosomiasis infection rates of population. The ARIMA model, NARNN model and ARIMA-NARNN model were established based on monthly schistosomiasis infection rates from January 2005 to February 2015 in Jiangsu Province, China. The fitting and prediction performances of the three models were compared. Compared to the ARIMA model and NARNN model, the mean square error (MSE), mean absolute error (MAE) and mean absolute percentage error (MAPE) of the ARIMA-NARNN model were the least with the values of 0.011 1, 0.090 0 and 0.282 4, respectively. The ARIMA-NARNN model could effectively fit and predict schistosomiasis infection rates of population, which might have a great application value for the prevention and control of schistosomiasis.
Chadeka, Evans Asena; Nagi, Sachiyo; Sunahara, Toshihiko; Cheruiyot, Ngetich Benard; Bahati, Felix; Ozeki, Yuriko; Inoue, Manabu; Osada-Oka, Mayuko; Okabe, Mayuko; Hirayama, Yukio; Changoma, Mwatasa; Adachi, Keishi; Mwende, Faith; Kikuchi, Mihoko; Nakamura, Risa; Kalenda, Yombo Dan Justin; Kaneko, Satoshi; Hirayama, Kenji; Shimada, Masaaki; Ichinose, Yoshio; Njenga, Sammy M.; Matsumoto, Sohkichi
2017-01-01
Background Large-scale schistosomiasis control programs are implemented in regions with diverse social and economic environments. A key epidemiological feature of schistosomiasis is its small-scale heterogeneity. Locally profiling disease dynamics including risk factors associated with its transmission is essential for designing appropriate control programs. To determine spatial distribution of schistosomiasis and its drivers, we examined schoolchildren in Kwale, Kenya. Methodology/Principal findings We conducted a cross-sectional study of 368 schoolchildren from six primary schools. Soil-transmitted helminths and Schistosoma mansoni eggs in stool were evaluated by the Kato-Katz method. We measured the intensity of Schistosoma haematobium infection by urine filtration. The geometrical mean intensity of S. haematobium was 3.1 eggs/10 ml urine (school range, 1.4–9.2). The hookworm geometric mean intensity was 3.2 eggs/g feces (school range, 0–17.4). Heterogeneity in the intensity of S. haematobium and hookworm infections was evident in the study area. To identify factors associated with the intensity of helminth infections, we utilized negative binomial generalized linear mixed models. The intensity of S. haematobium infection was associated with religion and socioeconomic status (SES), while that of hookworm infection was related to SES, sex, distance to river and history of anthelmintic treatment. Conclusions/Significance Both S. haematobium and hookworm infections showed micro-geographical heterogeneities in this Kwale community. To confirm and explain our observation of high S. haematobium risk among Muslims, further extensive investigations are necessary. The observed small scale clustering of the S. haematobium and hookworm infections might imply less uniform strategies even at finer scale for efficient utilization of limited resources. PMID:28863133
UTZINGER, J.; RASO, G.; BROOKER, S.; DE SAVIGNY, D.; TANNER, M.; ØRNBJERG, N.; SINGER, B. H.; N’GORAN, E. K.
2009-01-01
SUMMARY In May 2001, the World Health Assembly (WHA) passed a resolution which urged member states to attain, by 2010, a minimum target of regularly administering anthelminthic drugs to at least 75% and up to 100% of all school-aged children at risk of morbidity. The refined global strategy for the prevention and control of schistosomiasis and soil-transmitted helminthiasis was issued in the following year and large-scale administration of anthelminthic drugs endorsed as the central feature. This strategy has subsequently been termed ‘preventive chemotherapy’. Clearly, the 2001 WHA resolution led the way for concurrently controlling multiple neglected tropical diseases. In this paper, we recall the schistosomiasis situation in Africa in mid-2003. Adhering to strategic guidelines issued by the World Health Organization, we estimate the projected annual treatment needs with praziquantel among the school-aged population and critically discuss these estimates. The important role of geospatial tools for disease risk mapping, surveillance and predictions for resource allocation is emphasised. We clarify that schistosomiasis is only one of many neglected tropical diseases and that considerable uncertainties remain regarding global burden estimates. We examine new control initiatives targeting schistosomiasis and other tropical diseases that are often neglected. The prospect and challenges of integrated control are discussed and the need for combining biomedical, educational and engineering strategies and geospatial tools for sustainable disease control are highlighted. We conclude that, for achieving integrated and sustainable control of neglected tropical diseases, a set of interventions must be tailored to a given endemic setting and fine-tuned over time in response to the changing nature and impact of control. Consequently, besides the environment, the prevailing demographic, health and social systems contexts need to be considered. PMID:19906318
[The Endemic Situation and Challenges of Major Parasitic Diseases in China].
Yan, Jun; Hu, Tao; Lei, Zheng-long
2015-12-01
During the twelfth "Five-year Plan" period, the Chinese government further strengthened the implementation of several medium and long-term plans on disease control, which resulted in the acceleration of the control of schistosomiasis, malaria and echinococcosis. To further elucidate the endemic status and control experience during the stage, this article described current situation on the major parasitic diseases and put forward the challenges and consequent countermeasures for planning the control programs in the next five years and laying a foundation for the next Five-year Planning.
Zhang, Gang-Gang; Zhao, An; Tang, Qi-Qiang; Zhu, Jing; Huang, Chao-Qing
2012-02-01
The questionnaire survey on knowledge, attitude and practice (KAP)of students left at home or not about schistosomiasis prevention and control showed that there were no statistically significant differences of the scores of KAP between the two groups of students (all P values were above 0.05).
CONTROL OF SCHISTOSOMIASIS IN THE GEZIRA IRRIGATION SCHEME, SUDAN.
Amin, Mutamad; Abubaker, Hwiada
2017-01-01
This paper analyses the changing patterns of infection with Schistosoma mansoni and S. haematobium in the Gezira Irrigation Scheme, Sudan. Taking a historical perspective, it shows the way in which factors such as ecology, biology, social and economic variables and politics have shaped patterns of infection, and how different kinds of strategies have been developed to control schistosomal infection over time. Wider political and economic issues at both national and international levels have shaped these strategies, influencing the prevalence and intensity of schistosomal infection at a local level. By highlighting the inter-play between the above-mentioned factors, the article reflects on the wisdom of prioritizing community-directed mass drug administration for the control of schistosomiasis in Gezira and elsewhere. The review demonstrates that not all efforts to control schistosomiasis are sustainable. A comprehensive control strategy involving political commitment, community participation and socioeconomic development is important for sustainable control of schistosomal infection.
The Global Epidemiological Situation of Schistosomiasis and New Approaches to Control and Research
Engels, D.; Chitsulo, L.; Montresor, A.; Savioli, L.
2017-01-01
While the distribution of schistosomiasis has changed over the last fifty years and there have been successful control programmes, the number of people estimated to be infected or at risk of infection has not been reduced. Today, 85% of the number of infected people are estimated to be on the African continent where few control efforts are made. In terms of disease burden, there is therefore a growing discrepancy between sub-Saharan Africa and the rest of the world. WHO has now developed a dual strategy for the control of schistosomiasis: a strategy for morbidity control adapted to the public health context in high burden areas, and a strategy to consolidate control in areas where a low endemic level has been reached and elimination may be feasible. Related to this new vision, some research needs are pointed out. PMID:12020886
Re-emerging schistosomiasis in hilly and mountainous areas of Sichuan, China.
Liang, Song; Yang, Changhong; Zhong, Bo; Qiu, Dongchuan
2006-01-01
Despite great strides in schistosomiasis control over the past several decades in Sichuan Province, China the disease has re-emerged in areas where it was previously controlled. We reviewed historical records and found that schistosomiasis had re-emerged in eight counties by the end of 2004 - seven of 21 counties with transmission control and one of 25 with transmission interruption as reported in 2001 were confirmed to have local disease transmission. The average "return time" (from control to re-emergence) was about eight years. The onset of re-emergence was commonly signalled by the occurrence of acute infections. Our survey results suggest that environmental and sociopolitical factors play an important role in re-emergence. The main challenge would be to consolidate and maintain effective control in the longer term until "real" eradication is achieved. This would be possible only by the formulation of a sustainable surveillance and control system. PMID:16501732
Xu, Jing; Zhu, Xing-Quan; Wang, Sheng-Yue; Xia, Chao-Ming
2012-01-01
Background Schistosomiasis japonica is a serious debilitating and sometimes fatal disease. Accurate diagnostic tests play a key role in patient management and control of the disease. However, currently available diagnostic methods are not ideal, and the detection of the parasite DNA in blood samples has turned out to be one of the most promising tools for the diagnosis of schistosomiasis. In our previous investigations, a 230-bp sequence from the highly repetitive retrotransposon SjR2 was identified and it showed high sensitivity and specificity for detecting Schistosoma japonicum DNA in the sera of rabbit model and patients. Recently, 29 retrotransposons were found in S. japonicum genome by our group. The present study highlighted the key factors for selecting a new perspective sensitive target DNA sequence for the diagnosis of schistosomiasis, which can serve as example for other parasitic pathogens. Methodology/Principal Findings In this study, we demonstrated that the key factors based on the bioinformatic analysis for selecting target sequence are the higher genome proportion, repetitive complete copies and partial copies, and active ESTs than the others in the chromosome genome. New primers based on 25 novel retrotransposons and SjR2 were designed and their sensitivity and specificity for detecting S. japonicum DNA were compared. The results showed that a new 303-bp sequence from non-long terminal repeat (LTR) retrotransposon (SjCHGCS19) had high sensitivity and specificity. The 303-bp target sequence was amplified from the sera of rabbit model at 3 d post-infection by nested-PCR and it became negative at 17 weeks post-treatment. Furthermore, the percentage sensitivity of the nested-PCR was 97.67% in 43 serum samples of S. japonicum-infected patients. Conclusions/Significance Our findings highlighted the key factors based on the bioinformatic analysis for selecting target sequence from S. japonicum genome, which provide basis for establishing powerful molecular diagnostic techniques that can be used for monitoring early infection and therapy efficacy to support schistosomiasis control programs. PMID:22479661
Liu, Yang; Zhong, Bo; Wu, Zi-Song; Liang, Song; Qiu, Dong-Chuan; Ma, Xiao
2017-04-07
Schistosomiasis remains a major public health concern in China. Since 2004, an integrated strategy was developed to control the transmission of Schistosoma japonicum in China. However, the long-term effectiveness of this integrated strategy for the interruption of schistosomiasis transmission remains unknown in the mountainous and hilly regions of China until now. This longitudinal study aims to evaluate the effectiveness of the integrated strategy on transmission interruption of schistosomiasis in Sichuan Province from 2005 through 2014. The data regarding replacement of bovines with machines, improved sanitation, access to clean water, construction of public toilets and household latrines, snail control, chemotherapy, and health education were captured from the annual report of the schistosomiasis control programmes in Sichuan Province from 2005 to 2014, and S. japonicum infection in humans, bovines and snails were estimated to evaluate the effectiveness of the integrated strategy. During the 10-year period from 2005 through 2014, a total of 536 568 machines were used to replace bovines, and 3 284 333 household lavatories and 15 523 public latrines were built. Tap water was supplied to 19 116 344 residents living in the endemic villages. A total of 230 098 hm 2 snail habitats were given molluscicide treatment, and 357 233 hm 2 snail habitats received environmental improvements. There were 7 268 138 humans and 840 845 bovines given praziquantel chemotherapy. During the 10-year study period, information, education and communication (IEC) materials were provided to village officers, teachers and schoolchildren. The 10-year implementation of the integrated strategy resulted in a great reduction in S. japonicum infection in humans, bovines and snails. Since 2007, no acute infection was detected, and no schistosomiasis cases or infected bovines were identified since 2012. In addition, the snail habitats reduced by 62.39% in 2014 as compared to that in 2005, and no S. japonicum infection was identified in snails since 2007. By 2014, 88.9% of the endemic counties achieved the transmission interruption of schistosomiasis and transmission control of schistosmiasis was achieved in the whole province in 2008. The government-directed and multi-department integrated strategy is effective for interrupting the transmission of schistosomiasis in the mountainous and hilly regions of China.
Kittur, Nupur; Binder, Sue; Campbell, Carl H; King, Charles H; Kinung'hi, Safari; Olsen, Annette; Magnussen, Pascal; Colley, Daniel G
2017-12-01
Preventive chemotherapy with praziquantel for schistosomiasis morbidity control is commonly done by mass drug administration (MDA). MDA regimen is usually based on prevalence in a given area, and effectiveness is evaluated by decreases in prevalence and/or intensity of infection after several years of implementation. Multiple studies and programs now find that even within well-implemented, multiyear, annual MDA programs there often remain locations that do not decline in prevalence and/or intensity to expected levels. We term such locations "persistent hotspots." To study and address persistent hotspots, investigators and neglected tropical disease (NTD) program managers need to define them based on changes in prevalence and/or intensity. But how should the data be analyzed to define a persistent hotspot? We have analyzed a dataset from an operational research study in western Tanzania after three annual MDAs using four different approaches to define persistent hotspots. The four approaches are 1) absolute percent change in prevalence; 2) percent change in prevalence; 3) change in World Health Organization guideline categories; 4) change (absolute or percent) in both prevalence and intensity. We compare and contrast the outcomes of these analyses. Our intent is to show how the same dataset yields different numbers of persistent hotspots depending on the approach used to define them. We suggest that investigators and NTD program managers use the approach most suited for their study or program, but whichever approach is used, it should be clearly stated so that comparisons can be made within and between studies and programs.
Kittur, Nupur; Binder, Sue; Campbell, Carl H.; King, Charles H.; Kinung’hi, Safari; Olsen, Annette; Magnussen, Pascal; Colley, Daniel G.
2017-01-01
Abstract. Preventive chemotherapy with praziquantel for schistosomiasis morbidity control is commonly done by mass drug administration (MDA). MDA regimen is usually based on prevalence in a given area, and effectiveness is evaluated by decreases in prevalence and/or intensity of infection after several years of implementation. Multiple studies and programs now find that even within well-implemented, multiyear, annual MDA programs there often remain locations that do not decline in prevalence and/or intensity to expected levels. We term such locations “persistent hotspots.” To study and address persistent hotspots, investigators and neglected tropical disease (NTD) program managers need to define them based on changes in prevalence and/or intensity. But how should the data be analyzed to define a persistent hotspot? We have analyzed a dataset from an operational research study in western Tanzania after three annual MDAs using four different approaches to define persistent hotspots. The four approaches are 1) absolute percent change in prevalence; 2) percent change in prevalence; 3) change in World Health Organization guideline categories; 4) change (absolute or percent) in both prevalence and intensity. We compare and contrast the outcomes of these analyses. Our intent is to show how the same dataset yields different numbers of persistent hotspots depending on the approach used to define them. We suggest that investigators and NTD program managers use the approach most suited for their study or program, but whichever approach is used, it should be clearly stated so that comparisons can be made within and between studies and programs. PMID:29016344
Shen, Li; Tao, Jian-xiu; Yu, Rui-fang; Shen, Guo-hong; Wu, Jun; Cai, Li; Cao, Chun-li; Xu, Jing; Li, Shi-zhu; Guo, Jia-gang
2014-06-01
To investigate the schistosomiasis japonica infection and preventive knowledge of immigration population in Jinshan District, Shanghai so as to provide the evidence for improving the control work. The immigration population from schistosomiasis endemic provinces and local people were screened by serum IHA screening for schistosome infection, and the positives were further examined by Kato-Katz technique and the miracidium hatching method. The schistosomiasis preventive knowledge and behaviors were investigated by questionnaires. A total of 579 were investigated with 348 immigration people and 231 local people, and among them, the male accounted for 72.0% and female accounted for 28.0%. In the immigration population, the main age group was 20-29 (56.0%), and 56.6% of the immigration had an education level at senior middle school or higher. The most proportion of immigration was from Anhui Province (36.2%). There were 4 IHA positive persons (1.15%) in the immigration, and 1 was positive in the stool test, and the schistosome infection rate was 0.29%. There were no positives in the local people. The schistosomiasis preventive knowledge of the immigration was generally poor, and some people' s behaviors of see doctor and medication were incorrect. There are schistosome infected persons among the immigration population from schistosomiasis endemic provinces, and their schistosomiasis prevention knowledge was poor, thus there is a schistosomiasis transmission risk.
Min-Jin, Peng; Han, Xiao; Jin, Shen; Meng-Ting, Gao; Shi-Yue, Li; Hong, Yan
2016-01-20
To explore the impact of self-efficacy on the behavior of contacting schistosome cercarial infested water among middle school students. In the transmission control area and endemic control area of the schistosomiasis endemic regions in Hubei Province, a total of 3 204 middle school students were selected through the stratified cluster random sampling method and investigated by questionnaires. The incidence rates of contacting infested water with Oncomelania hupensis snails during the past 3 and 12 months among the middle school students were 11.4% (364/3 204) and 14.8% (474/3 204) respectively, while those of contacting indefinite infested water during the past 3 and 12 months were 23.8% (762/3 204) and 28.0% (898/3 204) respectively. The awareness rate of schistosomiasis prevention and control knowledge was 82.1% (2 631/3 204). There were "knowledge-practice separation"in the prevention and control of schistosomiasis among the middle school students. The correlation analysis and Logistic regression analysis showed that the self-efficacy of schistosomiasis protective behavior of middle school students was a protective factor for contacting with infested water, with the adjusted odds ratio values of 0.882, 0.886, 0.914 and 0.927. Self-efficacy of schistosomiasis protective behavior is a protective factor for contacting with infested water among middle school students, and improving their self-efficacy may be an effective strategy to settle the problem of"knowledge-practice separation".
Li, Tao; Yang, Zhen; Cai, Hong-Jiao; Song, Li-Wei; Lu, Ke-Yu; Zhou, Zheng; Wu, Zai-De
2010-02-14
To explore the interventional effects and mechanism of in vitro cultivated Calculus Bovis compound preparation (ICCBco) on pulmonary lesions in portal hypertensive rabbits with schistosomiasis. The experimental group included 20 portal hypertensive rabbits with schistosomiasis treated by ICCBco. The control group included 20 portal hypertensive rabbits with schistosomiasis treated by praziquantel. The morphological changes of the pulmonary tissues were observed under light and electron microscopy. The expression of fibronectin (FN) and laminin (LN) in the lung tissues was analyzed by immunohistochemistry. Under light microscope, the alveolar exudation in the lung tissue was more frequently observed in the control group, while the alveolar space was fairly dry in the lung tissue of ICCBco group. Under electron microscope, more alveolar exudation in the lung tissue, and more macrophages, alveolar angiotelectasis and the blurred three-tier structure of alveolar-capillary barrier could be seen in the control group. In ICCBco group, fibers within the alveolar interspace slightly increased in some lung regions, and the structure of type I epithelium, basement membrane and endodermis was complete, and no obvious exudation from the alveolar space, and novascular congestion could be observed. There was a positive or strong positive expression of FN and LN in the lung tissue of the control group, while there was a negative or weak positive expression of FN and LN in ICCBco group. ICCBco can effectively prevent pulmonary complications in portal hypertensive rabbits with schistosomiasis by means of improving lung microcirculation and lowering the content of extracellular matrix.
Feng, Zong-liang; Xu, Cong-min; Yin, Hong-zhi; Hua, Jiao; Lai, Yu-hua; Zhao, Lin; Wu, Zhong-ping
2016-02-01
To understand the impact of Qionghai Lake wetland ecological protection construction on the prevalence of schistosomiasis, so as to provide the evidence for formulating the strategies for schistosomiasis control and prevention. A retrospective survey of the construction of Qionghai Lake wetland was performed, and eleven villages around the wetland were surveyed for schistosomiasis endemic situation. The influence of the wetland project on the schistosomiasis prevalence and Oncomelania hupensis snail status were investigated. Before the construction of Qionghai Lake wetland, the snail elimination and extended chemotherapy for residents was performed. After the project was finished, the roads and ditches were hardened. From 2009 to 2014, the schistosome infection rate of residents declined from 0.37% to 0. No schistosome infected snails were found and in recent 2 years, no snails were found. No mice were infected in the sentinel tests. The construction of Qionghai Lake wetland effectively eliminates snails, and interrupts the transmission of schistosomiasis. However, the environment of the wetland is more suitable for snail breeding, and therefore, the surveillance still should be strengthened.
[Surveillance of schistosomiasis in national surveillance sites of Zhenjiang City, 2005-2010].
Zhu, Xin-yun; Wu, Rong-feng; Shen, Xue-hui; Li, Ye-fang
2015-12-01
To master the changes of schistosomiasis epidemic situation in national surveillance sites of Zhenjiang City, Jiangsu Province. According to the scheme of the national schistosomiasis surveillance, the Shicheng Village of Yangzhong County and Sanzhou Village of Dantu District were selected as the national schistosomiasis surveillance sites, and from 2005 to 2010, the schistosomiasis morbidity and Oncomelania hupensis status were surveyed and the results were analyzed statistically. In 2010, in the Shicheng Village, the reduction rates of mean living snail density, infected snail density, area with infected snails, and positive blood tests in residents were 98.4%, 0, 0, 71.8% respectively, and in the Sanzhou Village, the reduction rates were 70.4%, 100%, 100% and 81.5%, respectively compared with those in 2005. No acute infections were found in the 2 villages during the period of 6 consecutive years. In the national surveillance sites of Zhenjiang City, the schistosomiasis morbidity has been effectively controlled. However, the areas with snails change little. Therefore, the comprehensive management of snail environment in the marshland should be strengthened in the future.
Sleigh, A.; Li, X.; Jackson, S.; Huang, K.
1998-01-01
Reported are the results of an analysis of a 40-year programme leading to eradication of schistosomiasis in Guangxi, China, a large, poor autonomous region of the country that had the heaviest global burden of the disease. We used historical county data and maps showing the initial distribution and density of Oncomelania snails and the initial prevalence of schistosomiasis to assess the correlation between snail occurrence and human infection. All annual county schistosomiasis reports were collected and analysed, including information on snail abundance and infection, human and animal infection control, stool examinations and patient treatments, clinical and serology examinations, skin test surveillance, patient follow-up, patient treatments, animal examinations, water supply and sanitation, and environmental modification. The findings bear witness to the laborious, systematic and scientific basis of the control programme and how it changed over the 40 years. Of note is the continual search for and treatment of cases, the killing of snails, and the permanent alteration of their habitats using mass community participation and methods adapted to local conditions. The programme has freed more than 10 million people from the risk of schistosomiasis and boosted rural economic development and health. The persistence, good record keeping, evolving and locally flexible strategies, and the clear focus of the control programme were crucial to its eventual success. PMID:9803587
Hodges, Mary H; Soares Magalhães, Ricardo J; Paye, Jusufu; Koroma, Joseph B; Sonnie, Mustapha; Clements, Archie; Zhang, Yaobi
2012-01-01
A national mapping of Schistosoma haematobium was conducted in Sierra Leone before the mass drug administration (MDA) with praziquantel. Together with the separate mapping of S. mansoni and soil-transmitted helminths, the national control programme was able to plan the MDA strategies according to the World Health Organization guidelines for preventive chemotherapy for these diseases. A total of 52 sites/schools were selected according to prior knowledge of S. haematobium endemicity taking into account a good spatial coverage within each district, and a total of 2293 children aged 9-14 years were examined. Spatial analysis showed that S. haematobium is heterogeneously distributed in the country with significant spatial clustering in the central and eastern regions of the country, most prevalent in Bo (24.6% and 8.79 eggs/10 ml), Koinadugu (20.4% and 3.53 eggs/10 ml) and Kono (25.3% and 7.91 eggs/10 ml) districts. By combining this map with the previously reported maps on intestinal schistosomiasis using a simple probabilistic model, the combined schistosomiasis prevalence map highlights the presence of high-risk communities in an extensive area in the northeastern half of the country. By further combining the hookworm prevalence map, the at-risk population of school-age children requiring integrated schistosomiasis/soil-transmitted helminth treatment regimens according to the coendemicity was estimated. The first comprehensive national mapping of urogenital schistosomiasis in Sierra Leone was conducted. Using a new method for calculating the combined prevalence of schistosomiasis using estimates from two separate surveys, we provided a robust coendemicity mapping for overall urogenital and intestinal schistosomiasis. We also produced a coendemicity map of schistosomiasis and hookworm. These coendemicity maps can be used to guide the decision making for MDA strategies in combination with the local knowledge and programme needs.
Gordon, Catherine A; Acosta, Luz P; Gobert, Geoffrey N; Olveda, Remigio M; Ross, Allen G; Williams, Gail M; Gray, Darren J; Harn, Donald; Li, Yuesheng; McManus, Donald P
2015-01-01
The Philippines has a population of approximately 103 million people, of which 6.7 million live in schistosomiasis-endemic areas with 1.8 million people being at risk of infection with Schistosoma japonicum. Although the country-wide prevalence of schistosomiasis japonica in the Philippines is relatively low, the prevalence of schistosomiasis can be high, approaching 65% in some endemic areas. Of the currently available microscopy-based diagnostic techniques for detecting schistosome infections in the Philippines and elsewhere, most exhibit varying diagnostic performances, with the Kato-Katz (KK) method having particularly poor sensitivity for detecting low intensity infections. This suggests that the actual prevalence of schistosomiasis japonica may be much higher than previous reports have indicated. Six barangay (villages) were selected to determine the prevalence of S. japonicum in humans in the municipality of Palapag, Northern Samar. Fecal samples were collected from 560 humans and examined by the KK method and a validated real-time PCR (qPCR) assay. A high S. japonicum prevalence (90.2%) was revealed using qPCR whereas the KK method indicated a lower prevalence (22.9%). The geometric mean eggs per gram (GMEPG) determined by the qPCR was 36.5 and 11.5 by the KK. These results, particularly those obtained by the qPCR, indicate that the prevalence of schistosomiasis in this region of the Philippines is much higher than historically reported. Despite being more expensive, qPCR can complement the KK procedure, particularly for surveillance and monitoring of areas where extensive schistosomiasis control has led to low prevalence and intensity infections and where schistosomiasis elimination is on the horizon, as for example in southern China.
Yajima, A.; Gabrielli, A. F.; Montresor, A.; Engels, D.
2017-01-01
The authors conducted a systematic literature review with the following aims: (i) to investigate how frequently soil-transmitted helminthiasis (STH) infections are endemic where schistosomiasis is present; and (ii) to assess the correlation between the risk level of schistosomiasis and that of STH. Among 155 sites on which data were collected and analyzed, schistosomiasis was present in 130 sites, all of which were also co-endemic for STH, whereas 25 sites were endemic only for STH. Out of 83 sites where at least one biannual round of preventive chemotherapy (PC) for schistosomiasis is recommended, 94% were also eligible for at least a yearly round of PC against STH. And among 21 sites where PC for schistosomiasis is recommended once a year, 81% were also eligible for at least a yearly round of PC for STH. This fact provides managers of control programmes with the operationally important indication that use of available information on endemicity of schistosomiasis is a valid tool to predict the presence of STH in the same geographical area as well as to estimate the need of PC for STH. The implementation of this tool is expected to save financial and human resources and help accelerate the scale-up of PC throughout the world. PMID:21215979
Zhao, Guang-Hui; Li, Juan; Blair, David; Li, Xiao-Yan; Elsheikha, Hany M; Lin, Rui-Qing; Zou, Feng-Cai; Zhu, Xing-Quan
2012-01-01
Schistosomiasis is a serious parasitic disease caused by blood-dwelling flukes of the genus Schistosoma. Throughout the world, schistosomiasis is associated with high rates of morbidity and mortality, with close to 800 million people at risk of infection. Precise methods for identification of Schistosoma species and diagnosis of schistosomiasis are crucial for an enhanced understanding of parasite epidemiology that informs effective antiparasitic treatment and preventive measures. Traditional approaches for the diagnosis of schistosomiasis include etiological, immunological and imaging techniques. Diagnosis of schistosomiasis has been revolutionized by the advent of new molecular technologies to amplify parasite nucleic acids. Among these, polymerase chain reaction-based methods have been useful in the analysis of genetic variation among Schistosoma spp. Mass spectrometry is now extending the range of biological molecules that can be detected. In this review, we summarize traditional, non-DNA-based diagnostic methods and then describe and discuss the current and developing molecular techniques for the diagnosis, species differentiation and phylogenetic analysis of Schistosoma spp. These exciting techniques provide foundations for further development of more effective and precise approaches to differentiate schistosomes and diagnose schistosomiasis in the clinic, and also have important implication for exploring novel measures to control schistosomiasis in the near future. Copyright © 2012 Elsevier Inc. All rights reserved.
Whole genome analysis of a schistosomiasis-transmitting freshwater snail
Adema, Coen M.; Hillier, LaDeana W.; Jones, Catherine S.; Loker, Eric S.; Knight, Matty; Minx, Patrick; Oliveira, Guilherme; Raghavan, Nithya; Shedlock, Andrew; do Amaral, Laurence Rodrigues; Arican-Goktas, Halime D.; Assis, Juliana G.; Baba, Elio Hideo; Baron, Olga L.; Bayne, Christopher J.; Bickham-Wright, Utibe; Biggar, Kyle K.; Blouin, Michael; Bonning, Bryony C.; Botka, Chris; Bridger, Joanna M.; Buckley, Katherine M.; Buddenborg, Sarah K.; Lima Caldeira, Roberta; Carleton, Julia; Carvalho, Omar S.; Castillo, Maria G.; Chalmers, Iain W.; Christensens, Mikkel; Clifton, Sandra; Cosseau, Celine; Coustau, Christine; Cripps, Richard M.; Cuesta-Astroz, Yesid; Cummins, Scott F.; di Stefano, Leon; Dinguirard, Nathalie; Duval, David; Emrich, Scott; Feschotte, Cédric; Feyereisen, Rene; FitzGerald, Peter; Fronick, Catrina; Fulton, Lucinda; Galinier, Richard; Gava, Sandra G.; Geusz, Michael; Geyer, Kathrin K.; Giraldo-Calderón, Gloria I.; de Souza Gomes, Matheus; Gordy, Michelle A.; Gourbal, Benjamin; Grunau, Christoph; Hanington, Patrick C.; Hoffmann, Karl F.; Hughes, Daniel; Humphries, Judith; Jackson, Daniel J.; Jannotti-Passos, Liana K.; de Jesus Jeremias, Wander; Jobling, Susan; Kamel, Bishoy; Kapusta, Aurélie; Kaur, Satwant; Koene, Joris M.; Kohn, Andrea B.; Lawson, Dan; Lawton, Scott P; Liang, Di; Limpanont, Yanin; Liu, Sijun; Lockyer, Anne E.; Lovato, TyAnna L.; Ludolf, Fernanda; Magrini, Vince; McManus, Donald P.; Medina, Monica; Misra, Milind; Mitta, Guillaume; Mkoji, Gerald M.; Montague, Michael J.; Montelongo, Cesar; Moroz, Leonid L.; Munoz-Torres, Monica C.; Niazi, Umar; Noble, Leslie R.; Oliveira, Francislon S.; Pais, Fabiano S.; Papenfuss, Anthony T.; Peace, Rob; Pena, Janeth J.; Pila, Emmanuel A.; Quelais, Titouan; Raney, Brian J.; Rast, Jonathan P.; Rollinson, David; Rosse, Izinara C.; Rotgans, Bronwyn; Routledge, Edwin J.; Ryan, Kathryn M.; Scholte, Larissa L. S.; Storey, Kenneth B.; Swain, Martin; Tennessen, Jacob A.; Tomlinson, Chad; Trujillo, Damian L.; Volpi, Emanuela V.; Walker, Anthony J.; Wang, Tianfang; Wannaporn, Ittiprasert; Warren, Wesley C.; Wu, Xiao-Jun; Yoshino, Timothy P.; Yusuf, Mohammed; Zhang, Si-Ming; Zhao, Min; Wilson, Richard K.
2017-01-01
Biomphalaria snails are instrumental in transmission of the human blood fluke Schistosoma mansoni. With the World Health Organization's goal to eliminate schistosomiasis as a global health problem by 2025, there is now renewed emphasis on snail control. Here, we characterize the genome of Biomphalaria glabrata, a lophotrochozoan protostome, and provide timely and important information on snail biology. We describe aspects of phero-perception, stress responses, immune function and regulation of gene expression that support the persistence of B. glabrata in the field and may define this species as a suitable snail host for S. mansoni. We identify several potential targets for developing novel control measures aimed at reducing snail-mediated transmission of schistosomiasis. PMID:28508897
Sun, Le-Ping; Tian, Zeng-Xi; Yang, Kun; Hong, Qing-Biao; Gao, Yang; Gao, Yuan; Zhang, Lian-Heng; Yang, Guo-Jing; Min, Jie; Ge, Jun; Wu, Hong-Hui; Huang, Yi-Xin; Liang, You-Sheng
2011-12-01
To evaluate the effect of comprehensive control for schistosomiasis in key areas of Jiangsu Province. The basic data and the data of implementation of comprehensive control measures were collected from the key areas of Jiangsu Province, including 30 townships, 87 marshlands and 78 anchor points. A field survey was carried out to investigate the Oncomelania snail status by using the systematic sampling method and schistosomiasis morbidity in humans and animals in the 12 key counties (districts). The changes of snail status and morbidity of humans and animals were statistically analyzed in key counties (districts) where comprehensive control measures was implemented, and the effects of schistosomiasis control before and after the implementation of the comprehensive control were compared. From 2008 to 2010, a total of 84 100 harmless latrines were constructed, 339 600 persons were examined, 2.6938 million people received health education, 112 000 protective creams and 798 000 publicity materials were allocated, 9 085 domestic animals were reared in pens, 11 800 domestic animals were examined, 130 high-risk cattle were eliminated in 30 key townships of 12 countries (districts), Jiangsu Province. A total of 19 640.78 hm2 were controlled with molluscicides, 798 warning tablets were placed, 116.07 hm2 of farmlands were ploughed up and planted, 306.80 hm2 were dug for fish culture, and 506.74 hm2 were planted with trees for snail control in 87 high-risk marshlands. A total of 118.83 million Yuan were invested into the water resources development projects, 39.82 km-long rivers were dredged, 70.04 km-long bank were concreted, 30 culvert gates were re-constructed, and 22 snail sedimentation tanks were built. In the 78 anchor points, 95 harmless public toilets were built, 3 192 stool container were allocated, 28 700 boatmen were examined, 71 600 protective creams and 53 200 publicity materials were allocated, and 46 600 persons received health education. Following the implementation of comprehensive control, the settings with infected snails, infected snail areas, infection rates of snails reduced from 75, 802.73 hm2 and 0.10% before the comprehensive control in 2007 to all 0 in 2010, with reduction rates of all 100%. The infection rates of schistosome in both humans and domestic animals appeared declining trends in 12 counties (districts) from 2005 to 2010, and the human infection rates were 0.16%, 0.04%, 0.02%, 0.02%, 0.01% and 0.01%, respectively, while being 0.11%, 0.05%, 0, 0, 0 and 0, respectively in domestic animals. During the period of comprehensive control, totally 45 transmission-controlled townships and 183 villages were newly added. In 2010, all of the 12 counties (districts) reached the criteria of schistosomiasis transmission control. The comprehensive control with emphasis on the key areas where infected snails are found, is an effective measure to further facilitate schistosomiasis control and rapidly control the transmission of schistosomiasis.
Schistosomiasis in Malawi: a systematic review.
Makaula, Peter; Sadalaki, John R; Muula, Adamson S; Kayuni, Sekeleghe; Jemu, Samuel; Bloch, Paul
2014-12-10
Schistosomiasis remains an important public health problem that undermines social and economic development in tropical regions of the world, mainly Sub-Saharan Africa. We are not aware of any systematic review of the literature of the epidemiology and transmission of schistosomiasis in Malawi since 1985. Therefore, we reviewed the current state of knowledge of schistosomiasis epidemiology and transmission in this country and identified knowledge gaps and relevant areas for future research and research governance. We conducted computer-aided literature searches of Medline, SCOPUS and Google Scholar using the keywords: "schistosomiasis", "Bilharzia", "Bulinus" and "Biomphalaria" in combination with "Malawi". These searches were supplemented by iterative reviews of reference lists for relevant publications in peer reviewed international scientific journals or other media. The recovered documents were reviewed for their year of publication, location of field or laboratory work, authorship characteristics, ethics review, funding sources as well as their findings regarding parasite and intermediate host species, environmental aspects, geographical distribution, seasonality of transmission, and infection prevalence and intensities. A total of 89 documents satisfied the inclusion criteria and were reviewed. Of these, 76 were published in international scientific journals, 68 were peer reviewed and 54 were original research studies. Most of the documents addressed urinary schistosomiasis and about two thirds of them dealt with the definitive host. Few documents addressed the parasites and the intermediate hosts. While urinary schistosomiasis occurs in most parts of Malawi, intestinal schistosomiasis mainly occurs in the central and southern highlands, Likoma Island and Lower Shire. Studies in selected communities estimated prevalence rates of up to 94.9% for Schistosoma haematobium and up to 67.0% for Schistosoma mansoni with considerable geographical variation. The main intermediate host species are Bulinus globosus and Bulinus nyassanus for urinary schistosomiasis and Biomphalaria pfeifferi for intestinal schistosomiasis. Seasonality of transmission tends to vary according to geographical, environmental, biological and behavioural factors. Transmission of schistosomiasis in Malawi appears to be highly focal, with considerable variation in space and time. Many locations have not been covered by epidemiological investigations and, thus, information on the transmission of schistosomiasis in Malawi remains fragmented. Functional infection risk assessment systems based on systematic investigations and surveillance are required for developing informed prevention and control strategies.
Gomes, Elainne Christine de Souza; Mesquita, Millena Carla da Silva; Rehn, Vitorina Nerivânia Covello; Nascimento, Wheverton Ricardo Correia do; Loyo, Rodrigo; Barbosa, Constança Simões
2016-01-01
Schistosomiasis is considered an endemic disease in Vitória de Santo Antão, Pernambuco, a district which has presented both high incidence and prevalence of it for decades. Poor environmental conditions lead to contamination of water sources in rural areas, which are used by the population during daily activities, resulting in typical transmission. Recently, there has been evidence of vector snails in urban areas, which could set a new model for schistosomiasis transmission in this district. To identify the new epidemiological situation for the urban transmission of schistosomiasis in Vitória de Santo Antão, Pernambuco. A malacological survey was conducted in all water sources in the city limits to investigate schistosomiasis vector snails (Biomphalaria spp.). The collected snails were examined for taxonomic identification and Schistosoma mansoni infection. All breeding sites were georeferenced to build risk maps through the TrackMaker PRO program and ArcGIS software. We identified 22 Biomphalaria straminea breeding sites and collected 1,704 snails. One of these breeding sites was identified as a source of transmission and seven as potential sources of transmission. The designed maps identified two risk areas of urban transmission of schistosomiasis and expansion areas for breeding sites, establishing an increased risk of transmission to the population. This study verified the existence of a new epidemiological situation in which the possibility of the urban transmission of the disease was confirmed.
Nono, Justin Komguep; Ndlovu, Hlumani; Aziz, Nada Abdel; Mpotje, Thabo; Hlaka, Lerato; Brombacher, Frank
2017-08-01
Interleukin-4 receptor (IL-4Rα) is critical for the initiation of type-2 immune responses and implicated in the pathogenesis of experimental schistosomiasis. IL-4Rα mediated type-2 responses are critical for the control of pathology during acute schistosomiasis. However, type-2 responses tightly associate with fibrogranulomatous inflammation that drives host pathology during chronic schistosomiasis. To address such controversy on the role of IL-4Rα, we generated a novel inducible IL-4Rα-deficient mouse model that allows for temporal knockdown of il-4rα gene after oral administration of Tamoxifen. Interrupting IL-4Rα mediated signaling during the acute phase impaired the development of protective type-2 immune responses, leading to rapid weight loss and premature death, confirming a protective role of IL-4Rα during acute schistosomiasis. Conversely, IL-4Rα removal at the chronic phase of schistosomiasis ameliorated the pathological fibro-granulomatous pathology and reversed liver scarification without affecting the host fitness. This amelioration of the morbidity was accompanied by a reduced Th2 response and increased frequencies of FoxP3+ Tregs and CD1dhiCD5+ Bregs. Collectively, these data demonstrate that IL-4Rα mediated signaling has two opposing functions during experimental schistosomiasis depending on the stage of advancement of the disease and indicate that interrupting IL-4Rα mediated signaling is a viable therapeutic strategy to ameliorate liver fibroproliferative pathology in diseases like chronic schistosomiasis.
Gazzinelli, Maria Flávia Carvalho; Kloos, Helmut; de Cássia Marques, Rita; dos Reis, Dener Carlos; Gazzinelli, Andrea
2009-01-01
This article examines changing common knowledge of elementary school children to scientific knowledge related to the relationship between water characteristics and the transmission of schistosomiasis through health education. A review of the literature and two case studies from rural elementary schools in Brazil show how the prevailing concept of dirty and polluted water, which has operated as an epistemological obstacle for acquiring scientific knowledge, may be related to symbolic thought and cultural parameters. Through an educational intervention not commonly applied to health programs involving elementary school students in two schistosomiasis-endemic rural communities in Brazil this paper describes the difficulties researchers encountered in changing the prevailing perception that very dirty and polluted water provides optimal conditions for schistosome transmission, to the scientifically accepted view that transmission occurs most often in visually clean, although fecally contaminated water. This conceptual difficulty may be largely explained in terms of the symbolism involved in clean and dirty water and the life-giving quality of water. Based on our results, we recommend that knowledge about water-related beliefs and concepts among school children should be considered in school-based health education programs in areas of endemic schistosomiasis and possibly other intestinal infections. PMID:18599008
Yang, Y; Zhou, Y-B; Song, X-X; Li, S-Z; Zhong, B; Wang, T-P; Bergquist, R; Zhou, X-N; Jiang, Q-W
2016-01-01
Among the three major schistosome species infecting human beings, Schistosoma japonicum is the only endemic species in The People's Republic of China. Schistosomiasis is endemic in 78 countries and regions and poses a severe threat to public health and socioeconomic development. Through more than 60years of hard work and endeavour, The People's Republic of China has made considerable achievements and reduced the morbidity and prevalence of this disease to the lowest level ever recorded, especially since the introduction of the new integrated control strategy in 2004. This review illustrates the strategies implemented by giving successful examples of schistosomiasis control from the different types of remaining endemic areas. The challenge to control or eliminate S. japonicum is analysed in order to provide useful information to policy makers and scientists. Copyright © 2016 Elsevier Ltd. All rights reserved.
Sanya, Richard E; Tumwesige, Edward; Elliott, Alison M; Seeley, Janet
2017-10-01
Praziquantel-based mass treatment is the main approach to controlling schistosomiasis mansoni in endemic areas. Interventions such as provision and use of safe water, minimising contact with infested water, disposal of stool in latrines and snail control provide key avenues to break the transmission cycle and can sustain the benefits of mass treatment in the long term. Efforts are also being made to develop a schistosomiasis vaccine which, if effective, might reduce the incidence of re-infection after treatment. However, any interventions deployed need to be acceptable to, and sustainable by, the target communities. In this qualitative study, we investigated the perceptions of six Lake Victoria island communities of Koome, Uganda, about interventions to control Schistosoma mansoni infection and their willingness to participate in Schistosoma vaccine trials. Thirty-two in-depth interviews, 12 key informant interviews and 10 focus group discussions were conducted. Data were analysed using a thematic content approach. Intestinal schistosomiasis was not regarded as a serious health problem because a mass treatment programme is in place. However, the communities lack safe water sources and latrines. Mass treatment with praziquantel, safe water supplies and use of toilets were deemed the most acceptable interventions by the participants. The communities are willing to participate in Schistosoma vaccine trials. Knowledge of a community's perception about interventions to control schistosomiasis can be valuable to policy makers and programme implementers intending to set up interventions co-managed by the community members. In this study, the views of the Lake Victoria island communities of Koome are presented. This study also provides data to guide further work on alternative interventions such as Schistosoma vaccine trials in these communities.
Tumwesige, Edward; Elliott, Alison M.; Seeley, Janet
2017-01-01
Background Praziquantel-based mass treatment is the main approach to controlling schistosomiasis mansoni in endemic areas. Interventions such as provision and use of safe water, minimising contact with infested water, disposal of stool in latrines and snail control provide key avenues to break the transmission cycle and can sustain the benefits of mass treatment in the long term. Efforts are also being made to develop a schistosomiasis vaccine which, if effective, might reduce the incidence of re-infection after treatment. However, any interventions deployed need to be acceptable to, and sustainable by, the target communities. Methods In this qualitative study, we investigated the perceptions of six Lake Victoria island communities of Koome, Uganda, about interventions to control Schistosoma mansoni infection and their willingness to participate in Schistosoma vaccine trials. Thirty-two in-depth interviews, 12 key informant interviews and 10 focus group discussions were conducted. Data were analysed using a thematic content approach. Findings Intestinal schistosomiasis was not regarded as a serious health problem because a mass treatment programme is in place. However, the communities lack safe water sources and latrines. Mass treatment with praziquantel, safe water supplies and use of toilets were deemed the most acceptable interventions by the participants. The communities are willing to participate in Schistosoma vaccine trials. Conclusion/Significance Knowledge of a community’s perception about interventions to control schistosomiasis can be valuable to policy makers and programme implementers intending to set up interventions co-managed by the community members. In this study, the views of the Lake Victoria island communities of Koome are presented. This study also provides data to guide further work on alternative interventions such as Schistosoma vaccine trials in these communities. PMID:28968470
Schistosomiasis: The World's Number One Health Problem
ERIC Educational Resources Information Center
Mallon, Elizabeth J.
1977-01-01
Provides an informative discussion of the disease called schistosomiasis. The discussion covers environmental factors contributing to the disease, its symptoms, the disease organism and its vectors, and treatment of the disease. The author points out the need for water and soil pollution control in disease prone areas. (MR)
2012-01-01
Background Schistosomiasis is a parasitic infection that continues to be a major public health problem in many developing countries being responsible for an estimated burden of at least 1.4 million disability-adjusted life years (DALYs) in Africa alone. Importantly, morbidity due to schistosomiasis has been greatly reduced in some parts of the world, including Zanzibar. The Zanzibar government is now committed to eliminate urogenital schistosomiasis. Over the next 3–5 years, the whole at-risk population will be administered praziquantel (40 mg/kg) biannually. Additionally, snail control and behaviour change interventions will be implemented in selected communities and the outcomes and impact measured in a randomized intervention trial. Methods/Design In this 5-year research study, on both Unguja and Pemba islands, urogenital schistosomiasis will be assessed in 45 communities with urine filtration and reagent strips in 4,500 schoolchildren aged 9–12 years annually, and in 4,500 first-year schoolchildren and 2,250 adults in years 1 and 5. Additionally, from first-year schoolchildren, a finger-prick blood sample will be collected and examined for Schistosoma haematobium infection biomarkers. Changes in prevalence and infection intensity will be assessed annually. Among the 45 communities, 15 were randomized for biannual snail control with niclosamide, in concordance with preventive chemotherapy campaigns. The reduction of Bulinus globosus snail populations and S. haematobium-infected snails will be investigated. In 15 other communities, interventions triggering behaviour change have been designed and will be implemented in collaboration with the community. A change in knowledge, attitudes and practices will be assessed annually through focus group discussions and in-depth interviews with schoolchildren, teachers, parents and community leaders. In all 45 communities, changes in the health system, water and sanitation infrastructure will be annually tracked by standardized questionnaire-interviews with community leaders. Additional issues potentially impacting on study outcomes and all incurring costs will be recordedand monitored longitudinally. Discussion Elimination of schistosomiasis has become a priority on the agenda of the Zanzibar government and the international community. Our study will contribute to identifying what, in addition to preventive chemotherapy, needs to be done to prevent, control, and ultimately eliminate schistosomiasis, and to draw lessons for current and future schistosomiasis elimination programmes in Africa and elsewhere. Trial registration ISRCTN48837681 PMID:23110494
Qian, Ying-Jun; Li, Shi-Zhu; Xu, Jun-Fang; Zhang, Li; Fu, Qing; Zhou, Xiao-Nong
2013-12-01
To set up a framework of indicators for schistosomiasis and malaria to guide the formulation and evaluation of vector-borne disease control policies focusing on adaptation to the negative impact of climate change. A 2-level indicator framework was set up on the basis of literature review, and Delphi method was applied to a total of 22 and 19 experts working on schistosomiasis and malaria, respectively. The result was analyzed to calculate the weight of various indicators. A total of 41 questionnaires was delivered, and 38 with valid response (92.7%). The system included 4 indicators at first level, i.e. surveillance, scientific research, disease control and intervention, and adaptation capacity building, with 25 indicators for schistosomiasis and 21 for malaria at the second level. Among indicators at the first level, disease surveillance ranked first with a weight of 0.32. Among the indicators at the second level, vector monitoring scored the highest in terms of both schistosomiasis and malaria. The indicators set up by Delphi method are practical,universal and effective ones using in the field, which is also useful to technically support the establishment of adaptation to climate change in the field of public health.
Favre, Tereza C.; Pereira, Ana P. B.; Galvão, Aline F.; Zani, Luciana C.; Barbosa, Constança S.; Pieri, Otávio S.
2009-01-01
Background Since its beginning in 1999, the Schistosomiasis Control Program within the Unified Health System (PCE-SUS) has registered a cumulative coverage of just 20% of the population from the Rainforest Zone of Pernambuco (ZMP), northeast Brazil. This jeopardizes the accomplishment of the minimum goal of the Fifty-Fourth World Health Assembly, resolution WHA54.19, of providing treatment for schistosomiasis and soil-transmitted helminthiases (STH) to 75% of school-aged children at risk, which requires attending at least 166,000 residents in the 7–14 age range by year 2010 in that important endemic area. In the present study, secondary demographic and parasitological data from a representative municipality of the ZMP are analyzed to provide evidence that the current, community-based approach to control schistosomiasis and STH is unlikely to attain the WHA-54.19 minimum goal and to suggest that school-based control actions are also needed. Methodology/Principal Findings Data available on the PCE-SUS activities related to diagnosis and treatment of the population from the study municipality were obtained from the State Secretary of Health of Pernambuco (SES/PE) for 2002–2006, complemented by the Municipal Secretary of Health (SMS) for 2003–2004. Data from a school-based stool survey carried out by the Schistosomiasis Reference Service of the Oswaldo Cruz Foundation (SRE/Fiocruz) in 2004 were used to provide information on infection status variation among school-aged children (7–14 years). According to the SES, from 2004 to 2006, only 2,977 (19.5%) of the estimated 15,288 residents of all ages were examined, of which 396 (13.3%) were positive for Schistosoma mansoni. Among these, only 180 (45.5%) were treated. According to the SMS, of the 1,766 examined in the 2003–2004 population stool survey 570 (32.3%) were children aged 7–14 years. One year later, the SRE/Fiocruz school survey revealed that the infection status among those children remained unchanged at 14%–15% prevalence. By 2006, the school-aged population was estimated at 2,981, of which 2,007 (67.3%) were enrolled as pupils. Conclusions It is suggested that in the most troubled municipalities individual diagnosis and treatment should be concentrated in school-aged children rather than the whole population. School-based actions involving teachers and children's families may help the health teams to scale up control actions in order to attain the WHA-54.19 minimum goal. This strategy should involve health and education organs and include both enrolled and non-enrolled children. PMID:19290040
Wang, Shuqi; Hu, Wei
2014-01-01
Schistosomiasis, caused by dioecious flatworms in the genus Schistosoma, is torturing people from many developing countries nowadays and frequently leads to severe morbidity and mortality of the patients. Praziquantel based chemotherapy and morbidity control for this disease adopted currently necessitate viable and efficient diagnostic technologies. Fortunately, those “-omics” researches, which rely on high-throughput experimental technologies to produce massive amounts of informative data, have substantially contributed to the exploitation and innovation of diagnostic tools of schistosomiasis. In its first section, this review provides a concise conclusion on the progresses pertaining to schistosomal “-omics” researches to date, followed by a comprehensive section on the diagnostic methods of schistosomiasis, especially those innovative ones based on the detection of antibodies, antigens, nucleic acids, and metabolites with a focus on those achievements inspired by “-omics” researches. Finally, suggestions about the design of future diagnostic tools of schistosomiasis are proposed, in order to better harness those data produced by “-omics” studies. PMID:25018752
[Research of prevalence of schistosomiasis in Hunan province, 1984-2015].
Li, F Y; Tan, H Z; Ren, G H; Jiang, Q; Wang, H L
2017-03-10
Objective: To analyze the prevalence of schistosomiasis in Hunan province, and provide scientific evidence for the control and elimination of schistosomiasis. Methods: The changes of infection rates of Schistosoma ( S .) japonicum among residents and cattle in Hunan from 1984 to 2015 were analyzed by using dynamic trend diagram; and the time regression model was used to fit the infection rates of S. japonicum , and predict the recent infection rate. Results: The overall infection rates of S. japonicum in Hunan from 1984 to 2015 showed downward trend (95.29% in residents and 95.16% in cattle). By using the linear regression model, the actual values of infection rates in residents and cattle were all in the 95% confidence intervals of the value predicted; and the prediction showed that the infection rates in the residents and cattle would continue to decrease from 2016 to 2020. Conclusion: The prevalence of schistosomiasis was in decline in Hunan. The regression model has a good effect in the short-term prediction of schistosomiasis prevalence.
Reduction of urogenital schistosomiasis with an integrated control project in Sudan.
Lee, Young-Ha; Jeong, Hoo Gn; Kong, Woo Hyun; Lee, Soon-Hyung; Cho, Han-Ik; Nam, Hae-Sung; Ismail, Hassan Ahmed Hassan Ahmed; Alla, Gibril Nouman Abd; Oh, Chung Hyeon; Hong, Sung-Tae
2015-01-01
Schistosomiasis remains a major public health concern in Sudan, particularly Schistosoma haematobium infection. This study presents the disease-reduction outcomes of an integrated control program for schistosomiasis in Al Jabalain locality of White Nile State, Sudan from 2009 through 2011. The total population of the project sites was 482,902, and the major target group for intervention among them was 78,615 primary school students. For the cross-sectional study of the prevalence, urine and stool specimens were examined using the urine sedimentation method and the Kato cellophane thick smear method, respectively. To assess the impacts of health education for students and a drinking water supply facility at Al Hidaib village, questionnaire survey was done. The overall prevalence for S. haematobium and S. mansoni at baseline was 28.5% and 0.4%, respectively. At follow-up survey after 6-9 months post-treatment, the prevalence of S. haematobium infection was reduced to 13.5% (95% CI = 0.331-0.462). A higher reduction in prevalence was observed among girls, those with moderately infected status (around 20%), and residents in rural areas, than among boys, those with high prevalence (>40%), and residents in urban areas. After health education, increased awareness about schistosomiasis was checked by questionnaire survey. Also, a drinking water facility was constructed at Al Hidaib village, where infection rate was reduced more compared to that in a neighboring village within the same unit. However, we found no significant change in the prevalence of S. mansoni infection between baseline and follow-up survey (95% CI = 0.933-6.891). At the end of the project, the prevalence of S. haematobium infection was reduced by more than 50% in comparison with the baseline rate. Approximately 200,000 subjects had received either praziquantel therapy, health education, or supply of clean water. To consolidate the achievements of this project, the integrated intervention should be adapted continuously.
Reduction of Urogenital Schistosomiasis with an Integrated Control Project in Sudan
Lee, Young-Ha; Jeong, Hoo Gn; Kong, Woo Hyun; Lee, Soon-Hyung; Cho, Han-Ik; Nam, Hae-Sung; Ismail, Hassan Ahmed Hassan Ahmed; Alla, Gibril Nouman Abd; Oh, Chung Hyeon; Hong, Sung-Tae
2015-01-01
Purpose Schistosomiasis remains a major public health concern in Sudan, particularly Schistosoma haematobium infection. This study presents the disease-reduction outcomes of an integrated control program for schistosomiasis in Al Jabalain locality of White Nile State, Sudan from 2009 through 2011. Methods The total population of the project sites was 482,902, and the major target group for intervention among them was 78,615 primary school students. For the cross-sectional study of the prevalence, urine and stool specimens were examined using the urine sedimentation method and the Kato cellophane thick smear method, respectively. To assess the impacts of health education for students and a drinking water supply facility at Al Hidaib village, questionnaire survey was done. Results The overall prevalence for S. haematobium and S. mansoni at baseline was 28.5% and 0.4%, respectively. At follow-up survey after 6–9 months post-treatment, the prevalence of S. haematobium infection was reduced to 13.5% (95% CI = 0.331–0.462). A higher reduction in prevalence was observed among girls, those with moderately infected status (around 20%), and residents in rural areas, than among boys, those with high prevalence (>40%), and residents in urban areas. After health education, increased awareness about schistosomiasis was checked by questionnaire survey. Also, a drinking water facility was constructed at Al Hidaib village, where infection rate was reduced more compared to that in a neighboring village within the same unit. However, we found no significant change in the prevalence of S. mansoni infection between baseline and follow-up survey (95% CI = 0.933–6.891). Conclusions At the end of the project, the prevalence of S. haematobium infection was reduced by more than 50% in comparison with the baseline rate. Approximately 200,000 subjects had received either praziquantel therapy, health education, or supply of clean water. To consolidate the achievements of this project, the integrated intervention should be adapted continuously. PMID:25569278
Yajima, A; Gabrielli, A F; Montresor, A; Engels, D
2011-02-01
The authors conducted a systematic literature review with the following aims: to investigate how frequently soil-transmitted helminthiasis (STH) infections are endemic where schistosomiasis is present; and to assess the correlation between the risk level of schistosomiasis and that of STH. Among 155 sites on which data were collected and analyzed, schistosomiasis was present in 130, all of which were also co-endemic for STH, whereas 25 sites were endemic only for STH. Ninety percent (117 out of 130) of the areas eligible for preventive chemotherapy (PC) against schistosomiasis are also eligible for PC against STH. This fact provides managers of control programmes with the operationally important indication that use of available information on endemicity of schistosomiasis is a valid tool to predict the presence of STH in the same geographical area and to estimate the need of PC for STH. The implementation of this tool is expected to save financial and human resources and help accelerate the scale-up of PC throughout the world. Copyright © 2010 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.
Olveda, Remigio M; Tallo, Veronica; Olveda, David U; Inobaya, Marianette T; Chau, Thao N; Ross, Allen G
2016-04-01
Zoonotic schistosomiasis has a long endemic history in the Philippines. Human mass drug administration has been the cornerstone of schistosomiasis control in the country for the past three decades. Recent publications utilizing retrospective national survey data have indicated that the national human prevalence of the disease is <1%, hence the disease is now close to elimination. However, the evidence for such a claim is weak, given that less than a third of the human population is currently being treated annually within endemic zones and only a third of those treated actually swallow the tablets. For those who consume the drug at the single oral dose of 40mg/kg, the estimated cure rate is 52% based on a recent meta-analysis. Thus, approximately 5% of the endemic human population is in reality receiving the appropriate treatment. To compound this public health problem, most of the bovines in the endemic communities are concurrently infected but are not treated under the current national control programme. Given this evidence, it is believed that the human prevalence of schistosomiasis within endemic regions has been grossly underestimated. Inherent flaws in the reporting of national schistosomiasis prevalence data are reported here, and the problems of utilizing national retrospective data in making geographic information system (GIS) risk maps and advising policy makers of the outcomes are highlighted. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
Bilharzia in the Philippines: past, present, and future.
Olveda, David U; Li, Yuesheng; Olveda, Remigio M; Lam, Alfred K; McManus, Donald P; Chau, Thao N P; Harn, Donald A; Williams, Gail M; Gray, Darren J; Ross, Allen G P
2014-01-01
Schistosomiasis japonica has a long history in the Philippines. In 1975, 24 endemic provinces were identified in the northern, central, and southern islands of the Philippines. More than five million people were at risk, with approximately one million infected. In 2003, new foci of infection were found in two provinces in the north and central areas. For the past 30 years, human mass drug administration (MDA), utilizing the drug praziquantel, has been the mainstay of control in the country. Recent studies have shown that the schistosomiasis prevalence ranges from 1% to 50% within different endemic zones. Severe end-organ morbidity is still present in many endemic areas, particularly in remote villages with poor treatment coverage. Moreover, subtle morbidities such as growth retardation, malnutrition, anemia, and poor cognitive function in infected children persist. There is now strong evidence that large mammals (e.g. water buffaloes, cattle) contribute significantly to disease transmission, complicating control efforts. Given the zoonotic nature of schistosomiasis in the Philippines, it is evident that the incidence, prevalence, and morbidity of the disease will not be controlled by MDA alone. There is a need for innovative cost-effective strategies to control schistosomiasis in the long term. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.
Controlling schistosomiasis with praziquantel: How much longer without a viable alternative?
Bergquist, Robert; Utzinger, Jürg; Keiser, Jennifer
2017-03-28
The current approach of morbidity control of schistosomiasis, a helminth disease of poverty with considerable public health and socioeconomic impact, is based on preventive chemotherapy with praziquantel. There is a pressing need for new drugs against this disease whose control entirely depends on this single drug that has been widely used over the past 40 years. We argue that a broader anthelminthic approach supplementing praziquantel with new antischistosomals targeting different parasite development stages would not only increase efficacy but also reduce the risk for drug resistance. Repositioning drugs already approved for other diseases provides a shortcut to clinical trials, as it is expected that such drugs rapidly pass the regulatory authorities. The antischistosomal properties of antimalarial drugs (e.g., semisynthetic artemisinins, synthetic trioxolanes, trioxaquines and mefloquine) and of drugs being developed or registered for other purposes (e.g., moxidectin and miltefosin), administered alone or in combination with praziquantel, have been tested in the laboratory and clinical trials. Another avenue to follow is the continued search for new antischistosomal properties in plants. Here, we summarise recent progress made in schistosomiasis chemotherapy, placing particular emphasis on repositioning of existing drugs against schistosomiasis.
Ajakaye, Oluwaremilekun G; Adedeji, Oluwatola I; Ajayi, Paul O
2017-07-01
Schistosomiasis is a parasitic disease and its distribution, in space and time, can be influenced by environmental factors such as rivers, elevation, slope, land surface temperature, land use/cover and rainfall. The aim of this study is to identify the areas with suitable conditions for schistosomiasis transmission on the basis of physical and environmental factors derived from satellite imagery and spatial analysis for Akure North Local Government Area (LGA) of Ondo State. Nigeria. This was done through methodology multicriteria evaluation (MCE) using Saaty's analytical hierarchy process (AHP). AHP is a multi-criteria decision method that uses hierarchical structures to represent a problem and makes decisions based on priority scales. In this research AHP was used to obtain the mapping weight or importance of each individual schistosomiasis risk factor. For the purpose of identifying areas of schistosomiasis risk, this study focused on temperature, drainage, elevation, rainfall, slope and land use/land cover as the factors controlling schistosomiasis incidence in the study area. It is by reclassifying and overlaying these factors that areas vulnerable to schistosomiasis were identified. The weighted overlay analysis was done after each factor was given the appropriate weight derived through the analytical hierarchical process. The prevalence of urinary schistosomiasis in the study area was also determined by parasitological analysis of urine samples collected through random sampling. The results showed varying risk of schistosomiasis with a larger portion of the area (82%) falling under the high and very high risk category. The study also showed that one community (Oba Ile) had the lowest risk of schistosomiasis while the risk increased in the four remaining communities (Iju, Igoba, Ita Ogbolu and Ogbese). The predictions made by the model correlated strongly with observations from field study. The high risk zones corresponded to known endemic communities. This study revealed that environmental factors can be used in identifying and predicting the transmission of schistosomiasis as well as effective monitoring of disease risk in newly established rural and agricultural communities.
Zheng, Weiwei; Yu, Huan; Wang, Xia; Qu, Weidong
2012-07-01
Pentachlorophenol (PCP) has been widely used for killing snails in areas of China where schistosomiasis is epidemic. With the re-emergence of schistosomiasis, the warranted production and consumption of PCP has inevitably resulted in persistent environmental contamination by it and its impurities, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). This study aimed to evaluate the contamination status and human burden of PCP and its impurities (PCDD/Fs) in China, considering the previous epidemic and re-emergence of schistosomiasis. We searched studies relevant to PCP occurrence in the environment and in humans in China. Data on snail elimination areas were included to estimate PCP consumption. Relevant publications were analyzed to distinguish PCDD/Fs contamination from PCP usage. PCP contamination was detected ubiquitously in various environmental media and in human samples; environmental levels were generally low, with the exception of some hot spots. In schistosomiasis-epidemic areas, there were significantly higher PCP levels in the environment and in humans than in control areas. Spatial disparities indicated the consistency between serious schistosomiasis epidemic areas and hot spots of PCP contamination. The data suggest an increased trend in PCP contamination of the environment. Specific PCDD/Fs contamination from PCP usage existed even at low environmental levels. The occurrence of PCP in the environment and in humans positively correlated with the epidemic of schistosomiasis. Thyroid-disrupting effects and cancer risk caused by PCP and PCDD/Fs even at low environmental levels in China's schistosomiasis-epidemic areas are of concern. Copyright © 2011 Elsevier Ltd. All rights reserved.
Changsong, Sun; Binggui, Yu; Hongyi, Liao; Yuhai, Dai; Xu, Xingjian; Huiguo, Zhu; Yong, Jiang
2002-05-01
Since the World Bank provided a loan for control of schistosomiasis in China, started from 1992, with the objective of a reduction of prevalence and intensity of the infection both in humans and animals by 40%, through mass chemotherapy in areas of high prevalence, and selective chemotherapy in areas with medium and low endemicity together with focal mollusciciding, the objective of morbidity control of the project has been reached in Hubei Province.
Ming-Zhen, He; Yi-Qing, Xie; Yan-Li, Guo; Hong, Chen; Yong-Gen, Zou; Shi-Ying, Zhu; You, Zhang
2016-12-21
To understand the status of knowledge, attitude, and practice of schistosomiasis prevention and control and infection status in Armed Police Forces stationed along the Yangtze River, so as to provide the reference for formulating the schistosomiasis prevention and control measures in Armed Police Forces. A questionnaire survey was conducted in the Armed Police Forces along the Yangtze River in Jiangsu Province, and the investigation content included social demographic data, schistosomiasis prevention knowledge, attitude and behavior. All the subjects were examined for Schistosoma japonicum infection. Totally 376 soldiers were investigated in 2 sites. The total passing rate of schistosomiasis knowledge was 72.87%. The passing rate among different age groups had no significant difference ( χ 2 =0.26, P > 0.05). The passing rate of soldiers from endemic areas was significantly higher than that of the soldiers from non-endemic areas ( χ 2 =4.71, P < 0.05). The passing rate of officers was significantly higher than that of the soldiers ( χ 2 = 4.21, P < 0.05). The passing rate of soldiers with the education levels of junior school, high school, college, undergraduate and above increased gradually, with a significant difference ( χ 2 =8.16, P < 0.05). The soldiers with positive attitude accounted for 93.88%. Among the water contact behaviors, training accounted for 17.55% and participating in the task (such as flood fighting and water work) accounted for 86.44%. When launching, the rate of taking protective measures was 52.93%. The rate of taking protective measures in the knowledge passing group was much higher than that in the knowledge failed group ( χ 2 =10.55, P < 0.05). The stool was harmlessly treated in the two camps. Among 376 soldiers, the positive rate of blood examinations was 0.53%, but the stool examinations were all negative. The overall level of knowledge and correct behavior of schistosomiasis prevention in the Armed Police Forces along the Yangtze River still should be improved. The better health education and behavior intervention are crucial to schistosomiasis prevention in the army.
1978-01-01
The article highlights specific aspects of the epidemiology of schistosomiasis where insufficient data are available on which to base appropriate control strategies. Emphasis is placed on the part that immunological techniques might play in improving the baseline epidemiological data. A study of acquired resistance to the disease is also important in relation to epidemiology and control. The clinical manifestations of the disease vary in different areas and further study of the relation between the clinical and pathological manifestations are therefore required. In relation to the intermediate host, the main priority for research concerns the definition of the location and time-patterns of transmission foci within any particular area: variations in transmission are of particular importance in relation to man-made water resources. Although chemotherapy will play an increasing role in control, its importance will depend on local conditions: coordinated and standardized trials are required of chemotherapeutic agents in different regions and in various defined groups of subjects. The effects of chemotherapy on immunity to reinfection and on immunopathology also require study. With all types of snail control-chemical, ecological, and biological-cost-effectiveness aspects are important. With chemicals, it is important to bear in mind other possible effects on the environment. In the field of water supplies and sanitation, several aspects are important in relation to schistosomiasis transmission and community involvement should be encouraged.
Le, Loc; Molehin, Adebayo J; Nash, Stewart; Sennoune, Souad R; Ahmad, Gul; Torben, Workineh; Zhang, Weidong; Siddiqui, Afzal A
2018-05-05
Schistosomiasis remains a serious chronic debilitating hepato-intestinal disease. Current control measures based on mass drug administration are inadequate due to sustained re-infection rates, low treatment coverage and emergence of drug resistance. Hence, there is an urgent need for a schistosomiasis vaccine for disease control. In this study, we assessed the anti-pathology efficacy of Schistosoma mansoni large subunit of calpain (Sm-p80)-based vaccine against schistosomiasis caused by infections with Schistosoma mansoni in baboons. We also evaluated the disease transmission-blocking potential of Sm-p80 vaccine. Immunisations with Sm-p80-based vaccine resulted in significant reduction of hepatic egg load in vaccinated baboons (67.7% reduction, p = 0.0032) when compared to the control animals, indicative of reduction in pathology. There was also a significant reduction in sizes of egg-induced granulomas in baboons immunised with Sm-p80 vaccine compared to their control counterparts. Egg hatching rate analysis revealed an overall 85.6% reduction (p = 0.0018) in vaccinated animals compared to the controls, highlighting the potential role of Sm-p80 vaccine in disease transmission. The findings on anti-pathology efficacy and transmission-blocking potential presented in this study have formed the basis for a large-scale double-blinded baboon experiment that is currently underway. Copyright © 2018 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.
Tian-Bi, Yves-Nathan T; Ouattara, Mamadou; Knopp, Stefanie; Coulibaly, Jean T; Hürlimann, Eveline; Webster, Bonnie; Allan, Fiona; Rollinson, David; Meïté, Aboulaye; Diakité, Nana R; Konan, Cyrille K; N'Goran, Eliézer K; Utzinger, Jürg
2018-01-29
To achieve a world free of schistosomiasis, the objective is to scale up control and elimination efforts in all endemic countries. Where interruption of transmission is considered feasible, countries are encouraged to implement a comprehensive intervention package, including preventive chemotherapy, information, education and communication (IEC), water, sanitation and hygiene (WASH), and snail control. In northern and central Côte d'Ivoire, transmission of Schistosoma haematobium is seasonal and elimination might be achieved. In a cluster-randomised trial, we will assess different treatment schemes to interrupt S. haematobium transmission and control soil-transmitted helminthiasis over a 3-year period. We will compare the impact of (i) arm A: annual mass drug administration (MDA) with praziquantel and albendazole before the peak schistosomiasis transmission season; (ii) arm B: annual MDA after the peak schistosomiasis transmission season; (iii) arm C: two yearly treatments before and after peak schistosomiasis transmission; and (iv) arm D: annual MDA before peak schistosomiasis transmission, coupled with chemical snail control using niclosamide. The prevalence and intensity of S. haematobium and soil-transmitted helminth infections will be assessed using urine filtration and Kato-Katz thick smears, respectively, in six administrative regions in northern and central parts of Côte d'Ivoire. Once a year, urine and stool samples will be collected and examined from 50 children aged 5-8 years, 100 children aged 9-12 years and 50 adults aged 20-55 years in each of 60 selected villages. Changes in S. haematobium and soil-transmitted helminth prevalence and intensity will be assessed between years and stratified by intervention arm. In the 15 villages randomly assigned to intervention arm D, intermediate host snails will be collected three times per year, before niclosamide is applied to the selected freshwater bodies. The snail abundance and infection rates over time will allow drawing inference on the force of transmission. This cluster-randomised intervention trial will elucidate whether in an area with seasonal transmission, the four different treatment schemes can interrupt S. haematobium transmission and control soil-transmitted helminthiasis. Lessons learned will help to guide schistosomiasis control and elimination programmes elsewhere in Africa. ISRCTN ISRCTN10926858 . Registered 21 December 2016. Retrospectively registered.
Liu, Y; Zhou, Y-B; Li, R-Z; Wan, J-J; Yang, Y; Qiu, D-C; Zhong, B
2016-01-01
Schistosomiasis is a parasitic disease that affects over 200million people worldwide in at least 76 countries, ranking second only after malaria in terms of its socio-economic and public health importance in tropical and subtropical areas of the world. Chinese surveillance data since the mid-1950s have shown that endemic areas are divided into three types based on geographical, ecological and epidemiological factors, such as marshland and lake region, plain region with waterway networks and hilly and mountainous region. As confirmed by numerous epidemiological investigations, schistosomiasis endemic areas of the mountainous type are distributed in 178 counties in 11 provinces of The People's Republic of China. Over the past several decades great success in transmission control has been achieved by implementation of control strategies that were suitable for the mountainous and hilly endemic region. Copyright © 2016 Elsevier Ltd. All rights reserved.
Transmission dynamics of schistosomiasis in Zimbabwe: A mathematical and GIS Approach
NASA Astrophysics Data System (ADS)
Ngarakana-Gwasira, E. T.; Bhunu, C. P.; Masocha, M.; Mashonjowa, E.
2016-06-01
Temperature and presence of water bodies are known to influence the transmission dynamics of schistosomiasis. In this work, effects of water bodies (taken in context of rainfall patterns) and temperature from 1950 to 2000 are considered in the model. With the aid of Geographic Information System (GIS), the reproduction number is mapped on the Zimbabwean country. Results of the mapping show high reproduction numbers along the Lowveld and the Zambezi valley catchment area. High reproduction numbers suggest high levels of schistosomiasis. This result suggests more control efforts should be targeted in these areas with high reproduction numbers.
Walz, Yvonne; Wegmann, Martin; Dech, Stefan; Vounatsou, Penelope; Poda, Jean-Noël; N'Goran, Eliézer K.; Utzinger, Jürg; Raso, Giovanna
2015-01-01
Background Schistosomiasis is the most widespread water-based disease in sub-Saharan Africa. Transmission is governed by the spatial distribution of specific freshwater snails that act as intermediate hosts and human water contact patterns. Remote sensing data have been utilized for spatially explicit risk profiling of schistosomiasis. We investigated the potential of remote sensing to characterize habitat conditions of parasite and intermediate host snails and discuss the relevance for public health. Methodology We employed high-resolution remote sensing data, environmental field measurements, and ecological data to model environmental suitability for schistosomiasis-related parasite and snail species. The model was developed for Burkina Faso using a habitat suitability index (HSI). The plausibility of remote sensing habitat variables was validated using field measurements. The established model was transferred to different ecological settings in Côte d’Ivoire and validated against readily available survey data from school-aged children. Principal Findings Environmental suitability for schistosomiasis transmission was spatially delineated and quantified by seven habitat variables derived from remote sensing data. The strengths and weaknesses highlighted by the plausibility analysis showed that temporal dynamic water and vegetation measures were particularly useful to model parasite and snail habitat suitability, whereas the measurement of water surface temperature and topographic variables did not perform appropriately. The transferability of the model showed significant relations between the HSI and infection prevalence in study sites of Côte d’Ivoire. Conclusions/Significance A predictive map of environmental suitability for schistosomiasis transmission can support measures to gain and sustain control. This is particularly relevant as emphasis is shifting from morbidity control to interrupting transmission. Further validation of our mechanistic model needs to be complemented by field data of parasite- and snail-related fitness. Our model provides a useful tool to monitor the development of new hotspots of potential schistosomiasis transmission based on regularly updated remote sensing data. PMID:26587839
Walz, Yvonne; Wegmann, Martin; Dech, Stefan; Vounatsou, Penelope; Poda, Jean-Noël; N'Goran, Eliézer K; Utzinger, Jürg; Raso, Giovanna
2015-11-01
Schistosomiasis is the most widespread water-based disease in sub-Saharan Africa. Transmission is governed by the spatial distribution of specific freshwater snails that act as intermediate hosts and human water contact patterns. Remote sensing data have been utilized for spatially explicit risk profiling of schistosomiasis. We investigated the potential of remote sensing to characterize habitat conditions of parasite and intermediate host snails and discuss the relevance for public health. We employed high-resolution remote sensing data, environmental field measurements, and ecological data to model environmental suitability for schistosomiasis-related parasite and snail species. The model was developed for Burkina Faso using a habitat suitability index (HSI). The plausibility of remote sensing habitat variables was validated using field measurements. The established model was transferred to different ecological settings in Côte d'Ivoire and validated against readily available survey data from school-aged children. Environmental suitability for schistosomiasis transmission was spatially delineated and quantified by seven habitat variables derived from remote sensing data. The strengths and weaknesses highlighted by the plausibility analysis showed that temporal dynamic water and vegetation measures were particularly useful to model parasite and snail habitat suitability, whereas the measurement of water surface temperature and topographic variables did not perform appropriately. The transferability of the model showed significant relations between the HSI and infection prevalence in study sites of Côte d'Ivoire. A predictive map of environmental suitability for schistosomiasis transmission can support measures to gain and sustain control. This is particularly relevant as emphasis is shifting from morbidity control to interrupting transmission. Further validation of our mechanistic model needs to be complemented by field data of parasite- and snail-related fitness. Our model provides a useful tool to monitor the development of new hotspots of potential schistosomiasis transmission based on regularly updated remote sensing data.
Yang, Liu; Liu, Juan-Juan
2013-04-01
To study the feasibility and effect of clinical nursing path in the standard management of advanced schistosomiasis patients with splenomegaly. A total of 64 advanced schistosomiasis patients with splenomegaly were randomly divided into a routine nursing group (control group) and a clinical nursing pathway group (CNP group), and the postoperative situation, average hospitalization days, cost of hospitalization and the satisfaction of the patients of the 2 groups were compared. The complications, average hospitalization days, costs of hospitalization in the CNP group were significantly decreased compared with those in the control group, and satisfaction rate of the patients in the CNP group increased from 81.25% to 100%. The implementation of CNP effectively reduces the length of hospitalization, costs and complications, and improves the satisfaction of the patients.
Mei-Zhi, Yuan; Jing-Ru, Sun; Tao, Chen; Xiao-Yu, Zhang; Liang-Cai, He; Jia-Song, Wang
2016-05-12
To evaluate the effect of the clinical nursing path integrated with the holistic nursing on advanced schistosomiasis patients with ascites. A total of 226 advanced schistosomiasis patients with ascites were randomly divided into a control group and an experimental group (113 cases each group). The subjects in the experimental group were nursed by the clinical nursing path integrated with the holistic nursing, while those in the control group were nursed only by the holistic nursing. Then the clinical relevant indexes of the two groups were observed, and the quality of life of the patients before and after hospital discharge was assessed. The improvement rate, satisfaction degree, and awareness rate of health knowledge of the patients in the experiment group were 93.8%, 100% and 97.4%, respectively, which were significantly higher than those of the control group (all P < 0.05). The mortality rate and the complication rate of the patients in the experimental group were 0 and 2.7%, respectively, which were significantly lower than those of the control group (both P < 0.05). In addition, the average hospitalization days and the hospitalization cost of the experiment group were (12.2 ± 0.7) d and (4 725.0 ± 310.1) Yuan respectively, which were less than those of the control group (both P < 0.01). When 6 months after the discharge from hospital, the quality of life of the patients in the experimental group in various fields was significantly better than that of the control group (all P < 0.05). The clinical nursing pathway integrated with holistic nursing can effectively improve the improvement rate and decrease the mortality of the advanced schistosomiasis patients with ascites; meanwhile, it can shorten the hospitalization time and save the hospitalization cost. Therefore, this nursing model is suitable for popularization and application in the treatment and nursing work of the advanced schistosomiasis assistance.
Swartz, Scott J; De Leo, Giulio A; Wood, Chelsea L; Sokolow, Susanne H
2015-12-01
Schistosomiasis - a parasitic disease that affects over 200 million people across the globe - is primarily transmitted between human definitive hosts and snail intermediate hosts. To reduce schistosomiasis transmission, some have advocated disrupting the schistosome life cycle through biological control of snails, achieved by boosting the abundance of snails' natural predators. But little is known about the effect of parasitic infection on predator-prey interactions, especially in the case of schistosomiasis. Here, we present the results of laboratory experiments performed on Bulinus truncatus and Biomphalaria glabrata snails to investigate: (i) rates of predation on schistosome-infected versus uninfected snails by a sympatric native river prawn, Macrobrachium vollenhovenii, and (ii) differences in snail behavior (including movement, refuge-seeking and anti-predator behavior) between infected and uninfected snails. In predation trials, prawns showed a preference for consuming snails infected with schistosome larvae. In behavioral trials, infected snails moved less quickly and less often than uninfected snails, and were less likely to avoid predation by exiting the water or hiding under substrate. Although the mechanism by which the parasite alters snail behavior remains unknown, these results provide insight into the effects of parasitic infection on predator-prey dynamics and suggest that boosting natural rates of predation on snails may be a useful strategy for reducing transmission in schistosomiasis hotspots. © 2015. Published by The Company of Biologists Ltd.
Chen, Xiaojun; Li, Wei; Zhang, Yang; Song, Xian; Xu, Lei; Xu, Zhipeng; Zhou, Sha; Zhu, Jifeng; Jin, Xin; Liu, Feng; Chen, Gengxin; Su, Chuan
2015-01-01
Background Schistosomiasis is a helminthic disease that affects more than 200 million people. An effective vaccine would be a major step towards eliminating the disease. Studies suggest that T follicular helper (Tfh) cells provide help to B cells to generate the long-term humoral immunity, which would be a crucial component of successful vaccines. Thus, understanding the biological characteristics of Tfh cells in patients with schistosomiasis, which has never been explored, is essential for vaccine design. Methodology/Principal Findings In this study, we investigated the biological characteristics of peripheral memory Tfh cells in schistosomiasis patients by flow cytometry. Our data showed that the frequencies of total and activated peripheral memory Tfh cells in patients were significantly increased during Schistosoma japonicum infection. Moreover, Tfh2 cells, which were reported to be a specific subpopulation to facilitate the generation of protective antibodies, were increased more greatly than other subpopulations of total peripheral memory Tfh cells in patients with schistosomiasis japonica. More importantly, our result showed significant correlations of the percentage of Tfh2 cells with both the frequency of plasma cells and the level of IgG antibody. In addition, our results showed that the percentage of T follicular regulatory (Tfr) cells was also increased in patients with schistosomiasis. Conclusions/Significance Our report is the first characterization of peripheral memory Tfh cells in schistosomasis patients, which not only provides potential targets to improve immune response to vaccination, but also is important for the development of vaccination strategies to control schistosomiasis. PMID:26284362
Savioli, Lorenzo; Albonico, Marco; Colley, Daniel G; Correa-Oliveira, Rodrigo; Fenwick, Alan; Green, Will; Kabatereine, Narcis; Kabore, Achille; Katz, Naftale; Klohe, Katharina; LoVerde, Philip T; Rollinson, David; Stothard, J Russell; Tchuem Tchuenté, Louis-Albert; Waltz, Johannes; Zhou, Xiao-Nong
2017-03-23
Schistosomiasis, one of the 17 neglected tropical diseases listed by the World Health Organization, presents a substantial public health and economic burden. Of the 261 million people requiring preventive chemotherapy for schistosomiasis in 2013, 92% of them lived in sub-Saharan Africa and only 12.7% received preventive chemotherapy. Moreover, in 2010, the WHO reported that schistosomiasis mortality could be as high as 280 000 per year in Africa alone.In May 2012 delegates to the sixty-fifth World Health Assembly adopted resolution WHA65.21 that called for the elimination of schistosomiasis, and foresees the regular treatment of at least 75% of school age children in at-risk areas. The resolution urged member states to intensify schistosomiasis control programmes and to initiate elimination campaigns where possible.Despite this, in June 2015, schistosomiasis was indicated to have the lowest level of preventive chemotherapy implementation in the spectrum of neglected tropical diseases. It was also highlighted as the disease most lacking in progress. This is perhaps unsurprising, given that it was also the only NTD with access to drug donations but without a coalition of stakeholders that collaborates to boost commitment and implementation.As a consequence, and to ensure that the WHO NTDs Roadmap Targets of 2012 and World Health Assembly Resolution WHA65.21 are met, the Global Schistosomiasis Alliance (GSA) has been set up. Diverse and representative, the GSA aims to be a partnership of endemic countries, academic and research institutions, international development agencies and foundations, international organizations, non-governmental development organizations, private sector companies and advocacy and resource mobilisation partners. Ultimately, the GSA calls for a partnership to work for the benefit of endemic countries by addressing health inequity and rural poverty.
Risk profiling of schistosomiasis using remote sensing: approaches, challenges and outlook.
Walz, Yvonne; Wegmann, Martin; Dech, Stefan; Raso, Giovanna; Utzinger, Jürg
2015-03-17
Schistosomiasis is a water-based disease that affects an estimated 250 million people, mainly in sub-Saharan Africa. The transmission of schistosomiasis is spatially and temporally restricted to freshwater bodies that contain schistosome cercariae released from specific snails that act as intermediate hosts. Our objective was to assess the contribution of remote sensing applications and to identify remaining challenges in its optimal application for schistosomiasis risk profiling in order to support public health authorities to better target control interventions. We reviewed the literature (i) to deepen our understanding of the ecology and the epidemiology of schistosomiasis, placing particular emphasis on remote sensing; and (ii) to fill an identified gap, namely interdisciplinary research that bridges different strands of scientific inquiry to enhance spatially explicit risk profiling. As a first step, we reviewed key factors that govern schistosomiasis risk. Secondly, we examined remote sensing data and variables that have been used for risk profiling of schistosomiasis. Thirdly, the linkage between the ecological consequence of environmental conditions and the respective measure of remote sensing data were synthesised. We found that the potential of remote sensing data for spatial risk profiling of schistosomiasis is - in principle - far greater than explored thus far. Importantly though, the application of remote sensing data requires a tailored approach that must be optimised by selecting specific remote sensing variables, considering the appropriate scale of observation and modelling within ecozones. Interestingly, prior studies that linked prevalence of Schistosoma infection to remotely sensed data did not reflect that there is a spatial gap between the parasite and intermediate host snail habitats where disease transmission occurs, and the location (community or school) where prevalence measures are usually derived from. Our findings imply that the potential of remote sensing data for risk profiling of schistosomiasis and other neglected tropical diseases has yet to be fully exploited.
[Effect of two-level community-based health education pattern on schistosomiasis control].
Xia, Zhang; He-Hua, Hu; Xiong, Liu; Hua-Ming, Zhang; Shi-Hao, He; Chuan-Yun, Xiao; Rong, Tian; Wei-Rong, Zhang; Cai-Xia, Cui; Xiao-Hong, Wen; Jun, Liu; Li-Ying, Yang; Mei, Chen; Chun-Li, Cao; Shi-Zhu, Li
2016-06-24
To implement a two-level community-based health education pattern of schistosomiasis in residents of endemic areas in marshland and lake regions, so as to explore the suitable pattern of health education under hypo-endemic situation. Two schistosomiasis endemic villages in Jiangling County, Hubei Province were collected as study areas, and among which, one village was treated as an intervention group, where the two-level community-based health education pattern as well as regular control measures was implemented; the other village was a control group, where only regular control measures were implemented. The awareness rates on schistosomiasis control, the rates of correct behavior and the compliance rates of examination, treatment and chemotherapy of the two groups before and after the intervention were compared. According to the results of the baseline survey in 2014, the awareness rates of schistosomiasis control of the intervention and control groups were 84.00% and 77.45%, respectively, the correct rates of behavior of the two groups were 72.00% and 63.73%, respectively, and the compliance rates of the treatment were 80.36% and 82.28%, respectively, there were no statistically significant differences between all the above rates of the two groups (all P > 0.05). After the intervention of the two-level community-based health education, the correct rates of behavior, and the compliance rates of examination and chemotherapy of the two groups were 92.31% and 80.37%, 95.11% and 82.55%, 84.13% and 63.64%, respectively, and the differences between all the rates above of the two groups were statistically significant (all P < 0.05). When compared to those before intervention, the growing rates of the compliance rates of examination, treatment and chemotherapy of the intervention group were 20.97%, 15.33% and 23.29%, respectively, while those of control group were 14.27%, 4.17%, -3.77%, respectively, the growing rates of the intervention groups were higher than those of the control groups. Through the two-level community-based pattern of health education, the compliance rates of examination and treatment of the residents have improved, and therefore, the pattern is suitable for popularization and application in marshland and lake regions.
Hu, Yi; Xiong, Chenglong; Zhang, Zhijie; Luo, Can; Ward, Michael; Gao, Jie; Zhang, Lijuan; Jiang, Qingwu
2014-06-01
The 10-year (1992-2001) World Bank Loan Project (WBLP) contributed greatly to schistosomiasis control in China. However, the re-emergence of schistosomiasis in recent years challenged the long-term progress of the WBLP strategy. In order to gain insight in the long-term progress of the WBLP, the spatial pattern of the epidemic was investigated in the Yangtze River Valley between 1999-2001 and 2007-2008. Two spatial cluster methods were jointly used to identify spatial clusters of cases. The magnitude and number of clusters varied during 1999-2001. It was found that prevalence of schistosomiasis had been greatly reduced and maintained at a low level during 2007-2008, with little change. Besides, spatial clusters most frequently occurred within 16 counties in the Dongting Lake region and within 5 counties in the Poyang Lake region. These findings precisely pointed out the prior places for future public health planning and resource allocation of schistosomiasis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
The basic reproductive ratio of Barbour's two-host schistosomiasis model with seasonal fluctuations.
Gao, Shu-Jing; Cao, Hua-Hua; He, Yu-Ying; Liu, Yu-Jiang; Zhang, Xiang-Yu; Yang, Guo-Jing; Zhou, Xiao-Nong
2017-01-25
Motivated by the first mathematical model for schistosomiasis proposed by Macdonald and Barbour's classical schistosomiasis model tracking the dynamics of infected human population and infected snail hosts in a community, in our previous study, we incorporated seasonal fluctuations into Barbour's model, but ignored the effect of bovine reservoir host in the transmission of schistosomiasis. Inspired by the findings from our previous work, the model was further improved by integrating two definitive hosts (human and bovine) and seasonal fluctuations, so as to understand the transmission dynamics of schistosomiasis japonica and evaluate the ongoing control measures in Liaonan village, Xingzi County, Jiangxi Province. The basic reproductive ratio R 0 and its computation formulae were derived by using the operator theory in functional analysis and the monodromy matrix theory. The mathematical methods for global dynamics of periodic systems were used in order to show that R 0 serves as a threshold value that determines whether there was disease outbreak or not. The parameter fitting and the ratio calculation were performed with surveillance data obtained from the village of Liaonan using numerical simulation. Sensitivity analysis was carried out in order to understand the impact of R 0 on seasonal fluctuations and snail host control. The modified basic reproductive ratios were compared with known results to illustrate the infection risk. The Barbour's two-host model with seasonal fluctuations was proposed. The implicit expression of R 0 for the model was given by the spectral radius of next infection operator. The R 0 s for the model ranged between 1.030 and 1.097 from 2003 to 2010 in the village of Liaonan, Xingzi County, China, with 1.097 recorded as the maximum value in 2005 but declined dramatically afterwards. In addition, we proved that the disease goes into extinction when R 0 is less than one and persists when R 0 is greater than one. Comparisons of the different improved models were also made. Based on the mechanism and characteristics of schistosomiasis transmission, Barbour's model was improved by considering seasonality. The implicit formula of R 0 for the model and its calculation were given. Theoretical results showed that R 0 gave a sharp threshold that determines whether the disease dies out or not. Simulations concluded that: (i) ignoring seasonality would overestimate the transmission risk of schistosomiasis, and (ii) mollusiciding is an effective control measure to curtail schistosomiasis transmission in Xingzi County when the removal rate of infected snails is small.
[Schistosomiasis: reproduction and expansion of the endemia to the state of Pernambuco in Brazil].
Barbosa, C S; da Silva, C B; Barbosa, F S
1996-12-01
Schistosomiasis mansoni can be considered an important public health problem in Northeastern Brazil, in spite of the reduction in the prevalence of the hepatosplenic clinical forms which have been attributed to the large scale use of chemotherapy in this country. However, the rise in the prevalence rates and the spread of this endemic disease to new areas show that schistosomiasis is assuming its must cruel expression: less lethal but more greatly incapacitating in terms of irreversible physical and moral damage to human beings. The state of Pernambuco presents growing rates for schistosomiasis infection in humans. The epidemiological profile of this disease displays high and consistent prevalence rates (up to 80%) in rural areas, and new cases of acute infection on the coast, where schistosomiasis has recently been introduced. The reproduction and expansion of this endemic disease can be better understood on the basic of a conception of structural and historical causation. The disease construction process should be reconstructed in the light of biological as well as the social, political and cultural factors which are jointly responsible for the present endemic situation. Within that frame work, the historical and socioeconomic features that interact with the parasite and give rise to the present proportions of the schistosomiasis epidemic in Pernambuco are discussed. The mode of occupation and use of the land, unemployment, under-nutrition, migration, etc., raise the question of the growing difficulties confronting the control of the disease, both in rural areas where populations are extremely mobile as well as in the poorly organized urban population. Epidemiological investigation is fulfilling its role in its attempts to understand the complex relationships of an intrinsecally social nature of the health/disease process between health problems and the quality of life for the purpose of producing consistent disease control models.
Schistosomiasis in Zambia: a systematic review of past and present experiences.
Kalinda, Chester; Chimbari, Moses J; Mukaratirwa, Samson
2018-04-30
The speedy rate of change in the environmental and socio-economics factors may increase the incidence, prevalence and risk of schistosomiasis infections in Zambia. However, available information does not provide a comprehensive understanding of the biogeography and distribution of the disease, ecology and population dynamics of intermediate host snails. The current study used an information-theoretical approach to understand the biogeography and prevalence schistosomiasis and identified knowledge gaps that would be useful to improve policy towards surveillance and eradication of intermediate hosts snails in Zambia. To summarise the existing knowledge and build on past and present experiences of schistosomiasis epidemiology for effective disease control in Zambia, a systematic search of literature for the period 2000-2017 was done on PubMed, Google Scholar and EBSCOhost. Using the key words: 'Schistosomiasis', 'Biomphalaria', 'Bulinus', 'Schistosoma mansoni', 'Schistosoma haematobium', and 'Zambia', in combination with Booleans terms 'AND' and 'OR', published reports/papers were obtained and reviewed independently for inclusion. Thirteen papers published in English that fulfilled the inclusion criteria were selected for the final review. The papers suggest that the risk of infection has increased over the years and this has been attributed to environmental, socio-economic and demographic factors. Furthermore, schistosomiasis is endemic in many parts of the country with infection due to Schistosoma haematobium being more prevalent than that due to S. mansoni. This review also found that S. haematobium was linked to genital lesions, thus increasing risks of contracting other diseases such as HIV and cervical cancer. For both S. haematobium and S. mansoni, environmental, socio-economic, and demographic factors were influential in the transmission and prevalence of the disease and highlight the need for detailed knowledge on ecological modelling and mapping the distribution of the disease and intermediate host snails for effective implementation of control strategies.
Clements, Archie C. A.; Deville, Marie-Alice; Ndayishimiye, Onésime; Brooker, Simon; Fenwick, Alan
2010-01-01
Summary OBJECTIVE To determine spatial patterns of co-endemicity of schistosomiasis mansoni and the soil-transmitted helminths (STHs) Ascaris lumbricoides, Trichuris trichiura and hookworm in the Great Lakes region of East Africa, to help plan integrated neglected tropical disease programmes in this region. METHOD Parasitological surveys were conducted in Uganda, Tanzania, Kenya and Burundi in 28 213 children in 404 schools. Bayesian geostatistical models were used to interpolate prevalence of these infections across the study area. Interpolated prevalence maps were overlaid to determine areas of co-endemicity. RESULTS In the Great Lakes region, prevalence was 18.1% for Schistosoma mansoni, 50.0% for hookworm, 6.8% for A. lumbricoides and 6.8% for T. trichiura. Hookworm infection was ubiquitous, whereas S. mansoni, A. lumbricoides and T. trichiura were highly focal. Most areas were endemic (prevalence ≥10%) or hyperendemic (prevalence ≥50%) for one or more STHs, whereas endemic areas for schistosomiasis mansoni were restricted to foci adjacent large perennial water bodies. CONCLUSION Because of the ubiquity of hookworm, treatment programmes are required for STH throughout the region but efficient schistosomiasis control should only be targeted at limited high-risk areas. Therefore, integration of schistosomiasis with STH control is only indicated in limited foci in East Africa. PMID:20409287
1980-10-01
Chemotherapeutic Studies on Schistosomiasis and Clinical, Epidemio- logical and Immunological Studies on Malaria in Amazonas ,- Brazil,.Along the Ituxi River...30 Sep 80. logical Studies on Malaria in Amazonas , Brazil, Along the Ituxi River. S. PERFORMING ORGANIZATION 14AME AND0 ADDRESS I0. PROGRAM ELEMENT...DDT-sprayed and unsprayed houses and analysis of the results relative to the incidence of malaria in the Amazonas study area.Efforts with the in vitro
Road to the elimination of schistosomiasis from Asia: the journey is far from over
Ross, Allen G.P.; Olveda, Remigio M.; Acosta, Luz; Harn, Donald A.; Chy, Delia; Li, Yuesheng; Gray, Darren J.; Gordon, Catherine A.; McManus, Donald P.; Williams, Gail M.
2015-01-01
Schistosomiasis is a neglected tropical disease with a very long endemic history in Asia. Great strides have been made to control the disease in China and the Philippines but the road to elimination is far from over, given the zoonotic nature of the schistosome parasites in both countries. PMID:23973709
Massa, K; Olsen, A; Sheshe, A; Ntakamulenga, R; Ndawi, B; Magnussen, P
2009-11-01
Control programmes generally use a school-based strategy of mass drug administration to reduce morbidity of schistosomiasis and soil-transmitted helminthiasis (STH) in school-aged populations. The success of school-based programmes depends on treatment coverage. The community-directed treatment (ComDT) approach has been implemented in the control of onchocerciasis and lymphatic filariasis in Africa and improves treatment coverage. This study compared the treatment coverage between the ComDT approach and the school-based treatment approach, where non-enrolled school-aged children were invited for treatment, in the control of schistosomiasis and STH among enrolled and non-enrolled school-aged children. Coverage during the first treatment round among enrolled children was similar for the two approaches (ComDT: 80.3% versus school: 82.1%, P=0.072). However, for the non-enrolled children the ComDT approach achieved a significantly higher coverage than the school-based approach (80.0 versus 59.2%, P<0.001). Similar treatment coverage levels were attained at the second treatment round. Again, equal levels of treatment coverage were found between the two approaches for the enrolled school-aged children, while the ComDT approach achieved a significantly higher coverage in the non-enrolled children. The results of this study showed that the ComDT approach can obtain significantly higher treatment coverage among the non-enrolled school-aged children compared to the school-based treatment approach for the control of schistosomiasis and STH.
Tchuenté, L A Tchuem; N'goran, E K
2009-11-01
Schistosomiasis and soil-transmitted helminthiasis occur throughout the developing world and remain a major public health problem in the poorest communities with enormous consequences for development. The extent of the problem has long been neglected because these diseases rarely kill at a young age and also because of their insidious nature. Today there exists a momentum and an unprecedented opportunity for a cost-effective control of these neglected tropical diseases. The control of these diseases has become a priority on the agenda of many governments, donors and international agencies. This paper highlights the progress made and future control activities in Cameroon and Côte d'Ivoire, where schistosomiasis and soil-transmitted helminthiasis control measures have been implemented over the past decade with limited budgets. In Cameroon, deworming activities were increased to encompass all ten regions in 2007 as a result of a co-ordinated effort of the Ministry of Health and the Ministry of Education with national and international partners. In Côte d'Ivoire, focal control activities were achieved with support from various partners. Prospects, opportunities and challenges for the control of neglected tropical diseases in these two countries are discussed.
Liu, Rong; Dong, Hui-Fen; Jiang, Ming-Sen
2012-05-01
In 2009, Wang et al.'s field trial published in the New England Journal of Medicine, reported that a comprehensive strategy aiming to reduce the roles of humans and cattle as sources of Schistosoma japonicum infection in snails was implemented and proved effective and promising in dramatically reducing the percentage of infected humans and snails, which had been extended to other endemic provinces in China afterwards. This implies that the integrated schistosomiasis-control strategies of interventions including political will, financial support and residents' participation to control human and bovine sources of S. japonicum infection in snails may direct to successfully interrupt the parasitic transmission and to ultimately eliminate schistosomiasis. Confusingly, however, the role of health education, which is a critical part of the integrated strategy and should play an active role in schistosomiasis control, was not reflected. We wish the authors to provide the readers a better and clearer statement of the role of health education as part of the integrated control strategy and so we write this comment.
Gordon, Catherine A; Acosta, Luz P; Gobert, Geoffrey N; Jiz, Mario; Olveda, Remigio M; Ross, Allen G; Gray, Darren J; Williams, Gail M; Harn, Donald; Li, Yuesheng; McManus, Donald P
2015-02-01
The cause of zoonotic schistosomiasis in the Philippines is Schistosoma japonicum, which infects up to 46 mammalian hosts, including humans and bovines. In China, water buffaloes have been identified as major reservoir hosts for schistosomiasis japonica, contributing up to 75% of human transmission. In the Philippines, water buffaloes (carabao; Bubalus bubalis carabanesis) have, historically, been considered unimportant reservoirs. We therefore revisited the possible role of bovines in schistosome transmission in the Philippines, using the recently described formalin-ethyl acetate sedimentation (FEA-SD) technique and a qPCR assay to examine fecal samples from 153 bovines (both carabao and cattle) from six barangays in Northern Samar. A high prevalence of S. japonicum was found using qPCR and FEA-SD in both cattle (87.50% and 77.08%, respectively) and carabao (80.00% and 55.24%, respectively). The average daily egg output for each bovine was calculated at 195,000. High prevalence and infection intensity of F. gigantica was also found in the bovines by qPCR and FEA-SD (95.33% and 96.00%, respectively). The identification of bovines as major reservoir hosts for S. japonicum transmission suggests that bovine treatment and/or vaccination, as one becomes available, should be included in any future control program that aims to reduce the disease burden due to schistosomiasis in the Philippines.
Gordon, Catherine A.; Acosta, Luz P.; Gobert, Geoffrey N.; Jiz, Mario; Olveda, Remigio M.; Ross, Allen G.; Gray, Darren J.; Williams, Gail M.; Harn, Donald; Li, Yuesheng; McManus, Donald P.
2015-01-01
The cause of zoonotic schistosomiasis in the Philippines is Schistosoma japonicum, which infects up to 46 mammalian hosts, including humans and bovines. In China, water buffaloes have been identified as major reservoir hosts for schistosomiasis japonica, contributing up to 75% of human transmission. In the Philippines, water buffaloes (carabao; Bubalus bubalis carabanesis) have, historically, been considered unimportant reservoirs. We therefore revisited the possible role of bovines in schistosome transmission in the Philippines, using the recently described formalin-ethyl acetate sedimentation (FEA-SD) technique and a qPCR assay to examine fecal samples from 153 bovines (both carabao and cattle) from six barangays in Northern Samar. A high prevalence of S. japonicum was found using qPCR and FEA-SD in both cattle (87.50% and 77.08%, respectively) and carabao (80.00% and 55.24%, respectively). The average daily egg output for each bovine was calculated at 195,000. High prevalence and infection intensity of F. gigantica was also found in the bovines by qPCR and FEA-SD (95.33% and 96.00%, respectively). The identification of bovines as major reservoir hosts for S. japonicum transmission suggests that bovine treatment and/or vaccination, as one becomes available, should be included in any future control program that aims to reduce the disease burden due to schistosomiasis in the Philippines. PMID:25643317
Administration of praziquantel to pregnant and lactating women.
Olds, G Richard
2003-05-01
Praziquantel (PZQ) is the safest of all anti-helminthics and now forms the backbone for all national control programs against schistosomiasis (Med. Res. Rev. 3 (1983) 147-200; Bull. WHO 57 (1979) 767-771; Wegner, D.H.G, Therapeutic Drugs (1991), Churchill Livingstone; Adv. Intern. Med. 32 (1987) 193-206; Drugs 42 (1991) 379-405; Pharmac. Ther. 68 (1995) 35-85; Ann. Intern. Med. 110 (1989) 290-296). Despite its lack of known toxicity, the drug was not tested on pregnant or lactating women prior to release. It is currently listed as Pregnancy Category B by the US FDA, which is a drug presumed safe based in animal studies. Unfortunately, this has been interpreted by most national control programs and WHO (1998) to exclude lactating and pregnant women from treatment. In fact, some experts advocate excluding adolescent girls from mass treatment campaigns over this issue. As a result, a large number of women living in endemic countries are currently left untreated or have treatment significantly delayed. A review of the current known toxicology of PZQ, combined with over two decades of clinical experience with this drug, suggest very low potential for adverse effects on either the mother or her unborn child. In contrast, significant animal and human data are presented in this review that suggest both the pregnant woman and her unborn fetus suffer morbid sequella from schistosomiasis. A double-blind placebo-controlled trial that could resolve this issue would require a very large and expensive study and in light of the above facts might not now be ethically appropriate. The author concludes that pregnant women should be treated with PZQ, that women of childbearing age should be included in all mass treatment programs and that lactating women are not systematically excluded from treatment.
Rujeni, Nadine; Morona, Domenica; Ruberanziza, Eugene; Mazigo, Humphrey D
2017-03-01
Even though Rwanda lies within a region that has a high prevalence of schistosomiasis and soil-transmitted helminth (STH) infections, epidemiological information regarding these infections in the country remains scarce. The present review attempts to compile the available data on schistosomiasis and STHs, from 1940 to 2014, to provide an insight on the epidemiological profile of these infections. This information will, in turn, support the design and implementation of sustainable control measures. The available records indicate that only Schistosoma mansoni and all the major species of STHs are endemic in Rwanda. In 2008, the national prevalence of S. mansoni was reported to be 2.7%, ranging from 0 to 69.5%, and that of STH infections was 65.8% (diagnosed using the Kato-Katz technique). The prevalence of these infections varies from one district to another, with schoolchildren remaining a highly affected group. The main control approach is mass drug administration using albendazole and praziquantel, mostly targeting school-aged children in school environments. In 2008, adult individuals living in areas with a prevalence of S. mansoni ≥30% were also included in the mass drug administration programme. However, despite Rwanda achieving an almost 100% coverage of this programme in 2008-2010, the transmission of S. mansoni and STHs continues to take place, as illustrated by the most recent surveys. If Rwanda is to achieve sustainable control and elimination of schistosomiasis and STHs, there is a need to revise the country's control strategy and adopt an integrated control approach that involves a combination of measures.
Optimising cluster survey design for planning schistosomiasis preventive chemotherapy.
Knowles, Sarah C L; Sturrock, Hugh J W; Turner, Hugo; Whitton, Jane M; Gower, Charlotte M; Jemu, Samuel; Phillips, Anna E; Meite, Aboulaye; Thomas, Brent; Kollie, Karsor; Thomas, Catherine; Rebollo, Maria P; Styles, Ben; Clements, Michelle; Fenwick, Alan; Harrison, Wendy E; Fleming, Fiona M
2017-05-01
The cornerstone of current schistosomiasis control programmes is delivery of praziquantel to at-risk populations. Such preventive chemotherapy requires accurate information on the geographic distribution of infection, yet the performance of alternative survey designs for estimating prevalence and converting this into treatment decisions has not been thoroughly evaluated. We used baseline schistosomiasis mapping surveys from three countries (Malawi, Côte d'Ivoire and Liberia) to generate spatially realistic gold standard datasets, against which we tested alternative two-stage cluster survey designs. We assessed how sampling different numbers of schools per district (2-20) and children per school (10-50) influences the accuracy of prevalence estimates and treatment class assignment, and we compared survey cost-efficiency using data from Malawi. Due to the focal nature of schistosomiasis, up to 53% simulated surveys involving 2-5 schools per district failed to detect schistosomiasis in low endemicity areas (1-10% prevalence). Increasing the number of schools surveyed per district improved treatment class assignment far more than increasing the number of children sampled per school. For Malawi, surveys of 15 schools per district and 20-30 children per school reliably detected endemic schistosomiasis and maximised cost-efficiency. In sensitivity analyses where treatment costs and the country considered were varied, optimal survey size was remarkably consistent, with cost-efficiency maximised at 15-20 schools per district. Among two-stage cluster surveys for schistosomiasis, our simulations indicated that surveying 15-20 schools per district and 20-30 children per school optimised cost-efficiency and minimised the risk of under-treatment, with surveys involving more schools of greater cost-efficiency as treatment costs rose.
Zhu, Jing; Zhao, An; Wang, Li-Wei; Zhang, Wen-Xin; Huang, Chao-Qing; Tang, Qi-Qiang
2013-10-01
To quantitatively evaluate the intervention effect of schistosomiasis health education on the knowledge, attitude and behavior (KAP) among the primary school students. A questionnaire was designed to collect baseline data. Questionnairing was conducted among students of grades 3 and 4 from the Central Primary School, Liyuzhou Primary School, and Meichi Primary School in Wuxing Farm of Nanchang City in June 2010. Eighty-four students from Central Primary School were selected as experiment group, and 62 students in the other two schools served as control group. Health education intervention (knowledge lectures, information dissemination, intensive education and so on) was conducted for the students in experiment group from September 2010 to October 2011. Final KAP questionnaire survey was carried out after intervention. A KAP hierarchical evaluation method was used to calculate the KAP scores in the two groups before and after intervention. After health education, the total KAP score in experiment group increased from 8.40 before education to 9.36 (t = 2.994 4, P < 0.01), higher than that of the control (8.53, t = 5.335 5, P < 0.01). The scores of knowledge, attitude and behavior of schistosomiasis control increased from 6.16, 9.10, and 8.67 before education to 8.12, 9.86, and 9.45 after education in experiment group (t = 5.716 8, P < 0.01; t = 3.2764, P < 0.01; t = 3.276 4, P < 0.01), respectively. Compared to the experiment group, after health education the scores of knowledge (6.34, t = 3.517 5, P < 0.01) and attitude of schistosomiasis control (9.43, t = 2.311 9, P < 0.05) were lower in control group; but no significant difference was found on the score of behavior between the two groups. After health education, the scores of 26 indices in experiment group were higher than that of the control and before education. The health education intervention is effective for schistosomiasis control in the experiment school.
Ecotourism as a source of infection with Schistosoma mansoni in Minas Gerais, Brazil.
Murta, Felipe Leão Gomes; Massara, Cristiano Lara; Nogueira, Joyce Favacho Cardoso; Dos Santos Carvalho, Omar; de Mendonça, Cristiane Lafetá Furtado; Pinheiro, Viviane Aparecida Oliveira; Enk, Martin Johannes
2016-01-01
In recent years, a new pattern of schistosomiasis transmission has been described which is related to recreational activities associated with rural or ecological tourism and migratory flows and accompanying changes in social dynamics in Brazil. The objective of this report is to describe two schistosomiasis outbreaks that occurred during the practice of rural tourism in Minas Gerais, Brazil, and review this pattern of transmission within the wider context of schistosomiasis control. The first outbreak was characterized by its high infection rate, showing that 59 % of the exposed eco-tourists became positive for infection with Schistosoma mansoni . In addition, all three disease transmitting species of intermediate host snails were found in the area. In the second outbreak, all members of one tourist family were infected and reported contact with water in a well-known tourist area. The malacological survey in the region revealed an infection rate with S. mansoni of 8.3 % among the collected snails. Infection of urban dwellers that report contact with contaminated water associated with ecotourism represents a new pattern of disease transmission and dissemination. The infection with the disease at these occasions finds its expression in outbreaks of acute schistosomiasis among internal tourists to rural areas. Therefore, epidemiological surveillance in endemic areas should be aware of this schistosomiasis transmission pattern, and a multidisciplinary approach, most of all sanitation and health education measures, is required in order increase the efficiency of control strategies.
Exploring molecular variation in Schistosoma japonicum in China.
Young, Neil D; Chan, Kok-Gan; Korhonen, Pasi K; Min Chong, Teik; Ee, Robson; Mohandas, Namitha; Koehler, Anson V; Lim, Yan-Lue; Hofmann, Andreas; Jex, Aaron R; Qian, Baozhen; Chilton, Neil B; Gobert, Geoffrey N; McManus, Donald P; Tan, Patrick; Webster, Bonnie L; Rollinson, David; Gasser, Robin B
2015-12-01
Schistosomiasis is a neglected tropical disease that affects more than 200 million people worldwide. The main disease-causing agents, Schistosoma japonicum, S. mansoni and S. haematobium, are blood flukes that have complex life cycles involving a snail intermediate host. In Asia, S. japonicum causes hepatointestinal disease (schistosomiasis japonica) and is challenging to control due to a broad distribution of its snail hosts and range of animal reservoir hosts. In China, extensive efforts have been underway to control this parasite, but genetic variability in S. japonicum populations could represent an obstacle to eliminating schistosomiasis japonica. Although a draft genome sequence is available for S. japonicum, there has been no previous study of molecular variation in this parasite on a genome-wide scale. In this study, we conducted the first deep genomic exploration of seven S. japonicum populations from mainland China, constructed phylogenies using mitochondrial and nuclear genomic data sets, and established considerable variation between some of the populations in genes inferred to be linked to key cellular processes and/or pathogen-host interactions. Based on the findings from this study, we propose that verifying intraspecific conservation in vaccine or drug target candidates is an important first step toward developing effective vaccines and chemotherapies against schistosomiasis.
El-Adawy, Hosny; Abdelwhab, Elsayed M.
2017-01-01
Egypt has a unique geographical location connecting the three old-world continents Africa, Asia and Europe. It is the country with the highest population density in the Middle East, Northern Africa and the Mediterranean basin. This review summarizes the prevalence, reservoirs, sources of human infection and control regimes of common bacterial, parasitic and viral zoonoses in animals and humans in Egypt. There is a gap of knowledge conerning the epidemiology of zoonotic diseases at the human-animal interface in different localities in Egypt. Some zoonotic agents are “exotic” for Egypt (e.g., MERS-CoV and Crimean-Congo hemorrhagic fever virus), others are endemic (e.g., Brucellosis, Schistosomiasis and Avian influenza). Transboundary transmission of emerging pathogens from and to Egypt occurred via different routes, mainly importation/exportation of apparently healthy animals or migratory birds. Control of the infectious agents and multidrug resistant bacteria in the veterinary sector is on the frontline for infection control in humans. The implementation of control programs significantly decreased the prevalence of some zoonoses, such as schistosomiasis and fascioliasis, in some localities within the country. Sustainable awareness, education and training targeting groups at high risk (veterinarians, farmers, abattoir workers, nurses, etc.) are important to lessen the burden of zoonotic diseases among Egyptians. There is an urgent need for collaborative surveillance and intervention plans for the control of these diseases in Egypt. PMID:28754024
Helmy, Yosra A; El-Adawy, Hosny; Abdelwhab, Elsayed M
2017-07-21
Egypt has a unique geographical location connecting the three old-world continents Africa, Asia and Europe. It is the country with the highest population density in the Middle East, Northern Africa and the Mediterranean basin. This review summarizes the prevalence, reservoirs, sources of human infection and control regimes of common bacterial, parasitic and viral zoonoses in animals and humans in Egypt. There is a gap of knowledge conerning the epidemiology of zoonotic diseases at the human-animal interface in different localities in Egypt. Some zoonotic agents are "exotic" for Egypt (e.g., MERS-CoV and Crimean-Congo hemorrhagic fever virus), others are endemic (e.g., Brucellosis, Schistosomiasis and Avian influenza). Transboundary transmission of emerging pathogens from and to Egypt occurred via different routes, mainly importation/exportation of apparently healthy animals or migratory birds. Control of the infectious agents and multidrug resistant bacteria in the veterinary sector is on the frontline for infection control in humans. The implementation of control programs significantly decreased the prevalence of some zoonoses, such as schistosomiasis and fascioliasis, in some localities within the country. Sustainable awareness, education and training targeting groups at high risk (veterinarians, farmers, abattoir workers, nurses, etc.) are important to lessen the burden of zoonotic diseases among Egyptians. There is an urgent need for collaborative surveillance and intervention plans for the control of these diseases in Egypt.
Malone, J B; Bergquist, N R; Huh, O K; Bavia, M E; Bernardi, M; El Bahy, M M; Fuentes, M V; Kristensen, T K; McCarroll, J C; Yilma, J M; Zhou, X N
2001-04-27
At a team residency sponsored by the Rockefeller Foundation in Bellagio, Italy, 10-14 April 2000 an organizational plan was conceived to create a global network of collaborating health workers and earth scientists dedicated to the development of computer-based models that can be used for improved control programs for schistosomiasis and other snail-borne diseases of medical and veterinary importance. The models will be assembled using GIS methods, global climate model data, sensor data from earth observing satellites, disease prevalence data, the distribution and abundance of snail hosts, and digital maps of key environmental factors that affect development and propagation of snail-borne disease agents. A work plan was developed for research collaboration and data sharing, recruitment of new contributing researchers, and means of access of other medical scientists and national control program managers to GIS models that may be used for more effective control of snail-borne disease. Agreement was reached on the use of compatible GIS formats, software, methods and data resources, including the definition of a 'minimum medical database' to enable seamless incorporation of results from each regional GIS project into a global model. The collaboration plan calls for linking a 'central resource group' at the World Health Organization, the Food and Agriculture Organization, Louisiana State University and the Danish Bilharziasis Laboratory with regional GIS networks to be initiated in Eastern Africa, Southern Africa, West Africa, Latin America and Southern Asia. An Internet site, www.gnosisGIS.org, (GIS Network On Snail-borne Infections with special reference to Schistosomiasis), has been initiated to allow interaction of team members as a 'virtual research group'. When completed, the site will point users to a toolbox of common resources resident on computers at member organizations, provide assistance on routine use of GIS health maps in selected national disease control programs and provide a forum for development of GIS models to predict the health impacts of water development projects and climate variation.
Using a Hybrid Model to Forecast the Prevalence of Schistosomiasis in Humans.
Zhou, Lingling; Xia, Jing; Yu, Lijing; Wang, Ying; Shi, Yun; Cai, Shunxiang; Nie, Shaofa
2016-03-23
We previously proposed a hybrid model combining both the autoregressive integrated moving average (ARIMA) and the nonlinear autoregressive neural network (NARNN) models in forecasting schistosomiasis. Our purpose in the current study was to forecast the annual prevalence of human schistosomiasis in Yangxin County, using our ARIMA-NARNN model, thereby further certifying the reliability of our hybrid model. We used the ARIMA, NARNN and ARIMA-NARNN models to fit and forecast the annual prevalence of schistosomiasis. The modeling time range included was the annual prevalence from 1956 to 2008 while the testing time range included was from 2009 to 2012. The mean square error (MSE), mean absolute error (MAE) and mean absolute percentage error (MAPE) were used to measure the model performance. We reconstructed the hybrid model to forecast the annual prevalence from 2013 to 2016. The modeling and testing errors generated by the ARIMA-NARNN model were lower than those obtained from either the single ARIMA or NARNN models. The predicted annual prevalence from 2013 to 2016 demonstrated an initial decreasing trend, followed by an increase. The ARIMA-NARNN model can be well applied to analyze surveillance data for early warning systems for the control and elimination of schistosomiasis.
Reinhard-Rupp, Jutta; Klohe, Katharina
2017-08-03
Schistosomiasis is a parasitic disease caused by blood flukes. The disease is caused by an inflammatory reaction to parasite eggs retained in the liver, bladder and reproductive organs. According to 2017 World Health Organization (WHO) estimates 220 million people are potentially infected, from which probably 10% are children under 6 years of age. The regular treatment approach of a single, oral dose of 40 mg/kg body weight with praziquantel however, is difficult for children under the age of 6, leaving them without a treatment option. In order to address this important gap in treatment target populations, an international public-private partnership that works on a not-for-profit basis in the field of drug research and development for schistosomiasis was established in 2012. This is called the Pediatric Praziquantel Consortium. Its mission was and continues to be to develop, register and provide access to a suitable pediatric praziquantel formulation for treating schistosomiasis in preschool-age children (3-6 months up to 6 years). The Target Product Profile for the pediatric formulation of praziquantel that would be suitable to treat children as young as 3-6 months was then defined by a group of experts, including members from the Pediatric Praziquantel Consortium partner organizations as well as experts from WHO (as observer) and schistosomiasis endemic countries. The development of the drug is ongoing and the Pediatric Praziquantel Consortium aims to submit the regulatory dossier for marketing approval in endemic countries and WHO prequalification in 2018/19 with approval and product launch for schistosomiasis pediatric case management in key endemic countries in 2019. Ultimately, the goal is for the product to be considered for a large-scale mass distribution program by 2022.
Why reinvent the wheel? Lessons in schistosomiasis control from the past.
Shiff, Clive
2017-10-01
Schistosomiasis has been of concern to local health authorities for most of the last century, and in spite of a lack of effective chemotherapy, the disease was dealt with quite effectively in many endemic countries by snail control and environmental management [1]. Much of this work was reported in journals prior to the electronic era but, sadly, seems to have been subsequently ignored. For many years, there followed a global hiatus on schistosomiasis control, and much of the local expertise was lost, but many things have changed more recently, mainly with the advent of generic and affordable praziquantel. With the increased availability of this drug, there has been an increasing interest in readdressing schistosomes as well as other neglected tropical diseases (NTDs). The strategic approach for this had been based almost exclusively on chemotherapy. Recently, however, questions arose about this strategy with evidence that chemotherapy alone was not succeeding [2]. Additional strategies were needed, and the "Towards Elimination of Schistosomiasis" (TES) 2017 Conference in Cameroon stressed an integrated PHASE strategy. This was in line with the WHO-NTD and WHO-AFRO 2014-2020 Regional Strategy on NTDs and directed emphasis on transmission control. Subsequently, this emphasis was discussed in a comprehensive review [3] that stressed the importance of such additions to any elimination programme. In reality, this means focusing on the aquatic snail hosts where and when transmission occurs, defining other risk factors such as water contact and latrine design and identifying improved sanitation and health education as essential components for elimination. For schistosomiasis reduction during the mid-20th century, transmission control was used extensively, but these facts are not well reported. Recent reviews have attempted to cover previous research [4,5], but sadly, they have left major knowledge gaps, particularly from Africa. These omissions also occurred in a recent WHO pamphlet on molluscicides [6]. Sadly, search engines used to retrieve information appear to miss much done by 5 African research institutes active from 1950 to 1990. It seems appropriate to take a look back to a time when fieldwork was a focus of research and transmission control was emphasised.
Shen, Ye; King, Charles H; Binder, Sue; Zhang, Feng; Whalen, Christopher C; Evan Secor, W; Montgomery, Susan P; Mwinzi, Pauline N M; Olsen, Annette; Magnussen, Pascal; Kinung'hi, Safari; Phillips, Anna E; Nalá, Rassul; Ferro, Josefo; Aurelio, H Osvaldo; Fleming, Fiona; Garba, Amadou; Hamidou, Amina; Fenwick, Alan; Campbell, Carl H; Colley, Daniel G
2017-09-29
The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) focus is on randomized trials of different approaches to mass drug administration (MDA) in endemic countries in Africa. Because their studies provided an opportunity to evaluate the effects of mass treatment on Schistosoma-associated morbidity, nested cohort studies were developed within SCORE's intervention trials to monitor changes in a suite of schistosomiasis disease outcomes. This paper describes the process SCORE used to select markers for prospective monitoring and the baseline prevalence of these morbidities in four parallel cohort studies. In July 2009, SCORE hosted a discussion of the potential impact of MDA on morbidities due to Schistosoma infection that might be measured in the context of multi-year control. Candidate markers were reviewed and selected for study implementation. Baseline data were then collected from cohorts of children in four country studies: two in high endemic S. mansoni sites (Kenya and Tanzania), and two in high endemic S. haematobium sites (Niger and Mozambique), these cohorts to be followed prospectively over 5 years. At baseline, 62% of children in the S. mansoni sites had detectable eggs in their stool, and 10% had heavy infections (≥ 400 eggs/g feces). Heavy S. mansoni infections were found to be associated with increased baseline risk of anemia, although children with moderate or heavy intensity infections had lower risk of physical wasting. Prevalence of egg-positive infection in the combined S. haematobium cohorts was 27%, with 5% of individuals having heavy infection (≥50 eggs/10 mL urine). At baseline, light intensity S. haematobium infection was associated with anemia and with lower scores in the social domain of health-related quality-of-life (HRQoL) assessed by Pediatric Quality of Life Inventory. Our consensus on practical markers of Schistosoma-associated morbidity indicated that height, weight, hemoglobin, exercise tolerance, HRQoL, and ultrasound abnormalities could be used as reference points for gauging treatment impact. Data collected over five years of program implementation will provide guidance for future evaluation of morbidity control in areas endemic for schistosomiasis. These cohort studies are registered and performed in conjunction with the International Standard Randomised Controlled Trial Registry trials ISRCTN16755535 , ISRCTN14117624 , ISRCTN95819193 , and ISRCTN32045736 .
Immunization of Baboons with Schistosoma mansoni Cercariae attenuated by gamma irradiation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stek, M.; Minard, P.; Dean, D.A.
1981-06-01
Studies on the efficacy of a vaccine against schistosomiasis in young baboons (Papio anubis) disclosed that immunization with Schistosoma mansoni cercariae attenuated by gamma irradiation induced significant protection against subsequent infection with normal, viable S. mansoni cercariae. Such immunization resulted in reduced worm burdens (70 percent) and egg excretion rates (82 percent). These results support immunization as a potential method for schistosomiasis control.
Immunization of baboons with Schistosoma mansoni cercariae attenuated by gamma irradiation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stek, M. Jr.; Minard, P.; Dean, D.A.
1981-06-26
Studies on the efficacy of a vaccine against schistosomiasis in young baboons (Papio anubis) disclosed that immunization with Schistosoma mansoni cercariae attenuated by gamma irradiation induced significant protection against subsequent infection with normal, viable S. mansoni cercariae. Such immunization resulted in reduced worm burdens (70%) and egg excretion rates (82%). These results support immunization as a potential method for schistosomiasis control.
Knopp, Stefanie; Person, Bobbie; Ame, Shaali M.; Mohammed, Khalfan A.; Ali, Said M.; Khamis, I. Simba; Rabone, Muriel; Allan, Fiona; Gouvras, Anouk; Blair, Lynsey; Fenwick, Alan; Utzinger, Jürg; Rollinson, David
2013-01-01
Background Gaining and sustaining control of schistosomiasis and, whenever feasible, achieving local elimination are the year 2020 targets set by the World Health Organization. In Zanzibar, various institutions and stakeholders have joined forces to eliminate urogenital schistosomiasis within 5 years. We report baseline findings before the onset of a randomized intervention trial designed to assess the differential impact of community-based praziquantel administration, snail control, and behavior change interventions. Methodology In early 2012, a baseline parasitological survey was conducted in ∼20,000 people from 90 communities in Unguja and Pemba. Risk factors for schistosomiasis were assessed by administering a questionnaire to adults. In selected communities, local knowledge about schistosomiasis transmission and prevention was determined in focus group discussions and in-depths interviews. Intermediate host snails were collected and examined for shedding of cercariae. Principal Findings The baseline Schistosoma haematobium prevalence in school children and adults was 4.3% (range: 0–19.7%) and 2.7% (range: 0–26.5%) in Unguja, and 8.9% (range: 0–31.8%) and 5.5% (range: 0–23.4%) in Pemba, respectively. Heavy infections were detected in 15.1% and 35.6% of the positive school children in Unguja and Pemba, respectively. Males were at higher risk than females (odds ratio (OR): 1.45; 95% confidence interval (CI): 1.03–2.03). Decreasing adult age (OR: 1.04; CI: 1.02–1.06), being born in Pemba (OR: 1.48; CI: 1.02–2.13) or Tanzania (OR: 2.36; CI: 1.16–4.78), and use of freshwater (OR: 2.15; CI: 1.53–3.03) showed higher odds of infection. Community knowledge about schistosomiasis was low. Only few infected Bulinus snails were found. Conclusions/Significance The relatively low S. haematobium prevalence in Zanzibar is a promising starting point for elimination. However, there is a need to improve community knowledge about disease transmission and prevention. Control measures tailored to the local context, placing particular attention to hot-spot areas, high-risk groups, and individuals, will be necessary if elimination is to be achieved. PMID:24147165
Optimising cluster survey design for planning schistosomiasis preventive chemotherapy
Sturrock, Hugh J. W.; Turner, Hugo; Whitton, Jane M.; Gower, Charlotte M.; Jemu, Samuel; Phillips, Anna E.; Meite, Aboulaye; Thomas, Brent; Kollie, Karsor; Thomas, Catherine; Rebollo, Maria P.; Styles, Ben; Clements, Michelle; Fenwick, Alan; Harrison, Wendy E.; Fleming, Fiona M.
2017-01-01
Background The cornerstone of current schistosomiasis control programmes is delivery of praziquantel to at-risk populations. Such preventive chemotherapy requires accurate information on the geographic distribution of infection, yet the performance of alternative survey designs for estimating prevalence and converting this into treatment decisions has not been thoroughly evaluated. Methodology/Principal findings We used baseline schistosomiasis mapping surveys from three countries (Malawi, Côte d’Ivoire and Liberia) to generate spatially realistic gold standard datasets, against which we tested alternative two-stage cluster survey designs. We assessed how sampling different numbers of schools per district (2–20) and children per school (10–50) influences the accuracy of prevalence estimates and treatment class assignment, and we compared survey cost-efficiency using data from Malawi. Due to the focal nature of schistosomiasis, up to 53% simulated surveys involving 2–5 schools per district failed to detect schistosomiasis in low endemicity areas (1–10% prevalence). Increasing the number of schools surveyed per district improved treatment class assignment far more than increasing the number of children sampled per school. For Malawi, surveys of 15 schools per district and 20–30 children per school reliably detected endemic schistosomiasis and maximised cost-efficiency. In sensitivity analyses where treatment costs and the country considered were varied, optimal survey size was remarkably consistent, with cost-efficiency maximised at 15–20 schools per district. Conclusions/Significance Among two-stage cluster surveys for schistosomiasis, our simulations indicated that surveying 15–20 schools per district and 20–30 children per school optimised cost-efficiency and minimised the risk of under-treatment, with surveys involving more schools of greater cost-efficiency as treatment costs rose. PMID:28552961
Finkelstein, Julia L; Schleinitz, Mark D; Carabin, Hélène; McGarvey, Stephen T
2008-03-05
Schistosomiasis is among the most prevalent parasitic infections worldwide. However, current Global Burden of Disease (GBD) disability-adjusted life year estimates indicate that its population-level impact is negligible. Recent studies suggest that GBD methodologies may significantly underestimate the burden of parasitic diseases, including schistosomiasis. Furthermore, strain-specific disability weights have not been established for schistosomiasis, and the magnitude of human disease burden due to Schistosoma japonicum remains controversial. We used a decision model to quantify an alternative disability weight estimate of the burden of human disease due to S. japonicum. We reviewed S. japonicum morbidity data, and constructed decision trees for all infected persons and two age-specific strata, <15 years (y) and > or =15 y. We conducted stochastic and probabilistic sensitivity analyses for each model. Infection with S. japonicum was associated with an average disability weight of 0.132, with age-specific disability weights of 0.098 (<15 y) and 0.186 (> or =15 y). Re-estimated disability weights were seven to 46 times greater than current GBD measures; no simulations produced disability weight estimates lower than 0.009. Nutritional morbidities had the greatest contribution to the S. japonicum disability weight in the <15 y model, whereas major organ pathologies were the most critical variables in the older age group. GBD disability weights for schistosomiasis urgently need to be revised, and species-specific disability weights should be established. Even a marginal increase in current estimates would result in a substantial rise in the estimated global burden of schistosomiasis, and have considerable implications for public health prioritization and resource allocation for schistosomiasis research, monitoring, and control.
Finkelstein, Julia L.; Schleinitz, Mark D.; Carabin, Hélène; McGarvey, Stephen T.
2008-01-01
Schistosomiasis is among the most prevalent parasitic infections worldwide. However, current Global Burden of Disease (GBD) disability-adjusted life year estimates indicate that its population-level impact is negligible. Recent studies suggest that GBD methodologies may significantly underestimate the burden of parasitic diseases, including schistosomiasis. Furthermore, strain-specific disability weights have not been established for schistosomiasis, and the magnitude of human disease burden due to Schistosoma japonicum remains controversial. We used a decision model to quantify an alternative disability weight estimate of the burden of human disease due to S. japonicum. We reviewed S. japonicum morbidity data, and constructed decision trees for all infected persons and two age-specific strata, <15 years (y) and ≥15 y. We conducted stochastic and probabilistic sensitivity analyses for each model. Infection with S. japonicum was associated with an average disability weight of 0.132, with age-specific disability weights of 0.098 (<15 y) and 0.186 (≥15 y). Re-estimated disability weights were seven to 46 times greater than current GBD measures; no simulations produced disability weight estimates lower than 0.009. Nutritional morbidities had the greatest contribution to the S. japonicum disability weight in the <15 y model, whereas major organ pathologies were the most critical variables in the older age group. GBD disability weights for schistosomiasis urgently need to be revised, and species-specific disability weights should be established. Even a marginal increase in current estimates would result in a substantial rise in the estimated global burden of schistosomiasis, and have considerable implications for public health prioritization and resource allocation for schistosomiasis research, monitoring, and control. PMID:18320018
Pedersen, Ulrik B; Karagiannis-Voules, Dimitrios-Alexios; Midzi, Nicholas; Mduluza, Tkafira; Mukaratirwa, Samson; Fensholt, Rasmus; Vennervald, Birgitte J; Kristensen, Thomas K; Vounatsou, Penelope; Stensgaard, Anna-Sofie
2017-05-08
Temperature, precipitation and humidity are known to be important factors for the development of schistosome parasites as well as their intermediate snail hosts. Climate therefore plays an important role in determining the geographical distribution of schistosomiasis and it is expected that climate change will alter distribution and transmission patterns. Reliable predictions of distribution changes and likely transmission scenarios are key to efficient schistosomiasis intervention-planning. However, it is often difficult to assess the direction and magnitude of the impact on schistosomiasis induced by climate change, as well as the temporal transferability and predictive accuracy of the models, as prevalence data is often only available from one point in time. We evaluated potential climate-induced changes on the geographical distribution of schistosomiasis in Zimbabwe using prevalence data from two points in time, 29 years apart; to our knowledge, this is the first study investigating this over such a long time period. We applied historical weather data and matched prevalence data of two schistosome species (Schistosoma haematobium and S. mansoni). For each time period studied, a Bayesian geostatistical model was fitted to a range of climatic, environmental and other potential risk factors to identify significant predictors that could help us to obtain spatially explicit schistosomiasis risk estimates for Zimbabwe. The observed general downward trend in schistosomiasis prevalence for Zimbabwe from 1981 and the period preceding a survey and control campaign in 2010 parallels a shift towards a drier and warmer climate. However, a statistically significant relationship between climate change and the change in prevalence could not be established.
Downs, Jennifer A; Dupnik, Kathryn M; van Dam, Govert J; Urassa, Mark; Lutonja, Peter; Kornelis, Dieuwke; de Dood, Claudia J; Hoekstra, Pytsje; Kanjala, Chifundo; Isingo, Raphael; Peck, Robert N; Lee, Myung Hee; Corstjens, Paul L A M; Todd, Jim; Changalucha, John M; Johnson, Warren D; Fitzgerald, Daniel W
2017-09-01
Schistosomiasis affects 218 million people worldwide, with most infections in Africa. Prevalence studies suggest that people with chronic schistosomiasis may have higher risk of HIV-1 acquisition and impaired ability to control HIV-1 replication once infected. We hypothesized that: (1) pre-existing schistosome infection may increase the odds of HIV-1 acquisition and that the effects may differ between men and women, and (2) individuals with active schistosome infection at the time of HIV-1 acquisition may have impaired immune control of HIV-1, resulting in higher HIV-1 viral loads at HIV-1 seroconversion. We conducted a nested case-control study within a large population-based survey of HIV-1 transmission in Tanzania. A population of adults from seven villages was tested for HIV in 2007, 2010, and 2013 and dried blood spots were archived for future studies with participants' consent. Approximately 40% of this population has Schistosoma mansoni infection, and 2% has S. haematobium. We tested for schistosome antigens in the pre- and post-HIV-1-seroconversion blood spots of people who acquired HIV-1. We also tested blood spots of matched controls who did not acquire HIV-1 and calculated the odds that a person with schistosomiasis would become HIV-1-infected compared to these matched controls. Analysis was stratified by gender. We compared 73 HIV-1 seroconverters with 265 controls. Women with schistosome infections had a higher odds of HIV-1 acquisition than those without (adjusted OR = 2.8 [1.2-6.6], p = 0.019). Schistosome-infected men did not have an increased odds of HIV-1 acquisition (adjusted OR = 0.7 [0.3-1.8], p = 0.42). We additionally compared HIV-1 RNA levels in the post-seroconversion blood spots in HIV-1 seroconverters with schistosomiasis versus those without who became HIV-infected in 2010, before antiretroviral therapy was widely available in the region. The median whole blood HIV-1 RNA level in the 15 HIV-1 seroconverters with schistosome infection was significantly higher than in the 22 without schistosomiasis: 4.4 [3.9-4.6] log10 copies/mL versus 3.7 [3.2-4.3], p = 0.017. We confirm, in an area with endemic S. mansoni, that pre-existing schistosome infection increases odds of HIV-1 acquisition in women and raises HIV-1 viral load at the time of HIV-1 seroconversion. This is the first study to demonstrate the effect of schistosome infection on HIV-1 susceptibility and viral control, and to differentiate effects by gender. Validation studies will be needed at additional sites.
Hürlimann, Eveline; Schur, Nadine; Boutsika, Konstantina; Stensgaard, Anna-Sofie; Laserna de Himpsl, Maiti; Ziegelbauer, Kathrin; Laizer, Nassor; Camenzind, Lukas; Di Pasquale, Aurelio; Ekpo, Uwem F; Simoonga, Christopher; Mushinge, Gabriel; Saarnak, Christopher F L; Utzinger, Jürg; Kristensen, Thomas K; Vounatsou, Penelope
2011-12-01
After many years of general neglect, interest has grown and efforts came under way for the mapping, control, surveillance, and eventual elimination of neglected tropical diseases (NTDs). Disease risk estimates are a key feature to target control interventions, and serve as a benchmark for monitoring and evaluation. What is currently missing is a georeferenced global database for NTDs providing open-access to the available survey data that is constantly updated and can be utilized by researchers and disease control managers to support other relevant stakeholders. We describe the steps taken toward the development of such a database that can be employed for spatial disease risk modeling and control of NTDs. With an emphasis on schistosomiasis in Africa, we systematically searched the literature (peer-reviewed journals and 'grey literature'), contacted Ministries of Health and research institutions in schistosomiasis-endemic countries for location-specific prevalence data and survey details (e.g., study population, year of survey and diagnostic techniques). The data were extracted, georeferenced, and stored in a MySQL database with a web interface allowing free database access and data management. At the beginning of 2011, our database contained more than 12,000 georeferenced schistosomiasis survey locations from 35 African countries available under http://www.gntd.org. Currently, the database is expanded to a global repository, including a host of other NTDs, e.g. soil-transmitted helminthiasis and leishmaniasis. An open-access, spatially explicit NTD database offers unique opportunities for disease risk modeling, targeting control interventions, disease monitoring, and surveillance. Moreover, it allows for detailed geostatistical analyses of disease distribution in space and time. With an initial focus on schistosomiasis in Africa, we demonstrate the proof-of-concept that the establishment and running of a global NTD database is feasible and should be expanded without delay.
Andrade de Araújo, Hallysson Douglas; Dos Santos Silva, Luanna Ribeiro; de Siqueira, Williams Nascimento; Martins da Fonseca, Caíque Silveira; da Silva, Nicácio Henrique; de Albuquerque Melo, Ana Maria Mendonça; Barroso Martins, Mônica Cristina; de Menezes Lima, Vera Lúcia
2018-04-01
This text presents complementary data corresponding to schistosomiasis mansoni's vector control and enviromental toxicity using usnic acid. These informations support our research article "Toxicity of Usnic Acid from Cladonia substellata (Lichen) to embryos and adults of Biomphalaria glabrata " by Araújo et al. [1], and focuses on the analysis of the detailed data regarding the different concentrations of Usnic Acid and their efficiency to B. glabrata mortality and non-viability, as also to environmental toxicity, evaluated by A. salina mortality.
Hodges, Mary; Koroma, Manso M; Baldé, Mamadou S; Turay, Hamid; Fofanah, Ibrahim; Divall, Mark J; Winkler, Mirko S; Zhang, Yaobi
2011-11-01
A cross-sectional survey was undertaken in children aged 9-14 years in Beyla and Macenta Prefectures, Forest Guinea. Stool samples were examined by Kato-Katz and urine samples were examined by the centrifugation method. The overall prevalence and intensity of infection was 66.2% and 462.4 eggs per gram of faeces (epg) for Schistosoma mansoni, 21.0% and 17.8 eggs per 10ml of urine for S. haematobium, 51.2% and 507.5 epg for hookworm, 8.1% and 89.1 epg for Ascaris lumbricoides and 2.4% and 16.7 epg for Trichuris trichiura. The overall prevalence of schistosomiasis (S. mansoni and/or S. haematobium) was 70.7%. The prevalence of schistosomiasis was similar to those reported in the 1990s in the region; however, the prevalence of soil-transmitted helminths has since fallen. These findings illustrate the need for schistosomiasis control in Guinea. Copyright © 2011 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.
Cronin, Thomas; Sheppard, James; de Wildt, Gilles
2013-01-01
Schistosomiasis is a chronic and debilitating parasitic disease acquired through contact with infested freshwater. An essential component of its control is passive case finding, which, in order to be effective, requires a detailed understanding of health-seeking behaviour. This study aimed to systematically review evidence on health-seeking behaviour for schistosomiasis, in order to determine factors influencing use or non-use of modern health services for the infection. Quantitative, qualitative and mixed method studies reporting on factors related to seeking treatment from modern health services for schistosomiasis were obtained, combining electronic and hand searching. Data extraction and quality assessment of the included articles were performed, with all studies qualitatively analysed using thematic synthesis. A total of 19 studies were included in the review. Six themes were identified from the analysis: biomedical knowledge on schistosomiasis, perceptions of modern treatment and health services, financial considerations of treatment, perceptions on the symptoms, stigma of the infection, and physical location and community. These findings were consistent across studies of different design, setting and quality. Many of the themes identified echo existing literature on health-seeking behaviour. The synthesis also highlighted the role of stigma, and aspects of the physical location and community that may affect treatment-seeking for schistosomiasis. Health education programmes that intend to improve the utilisation of modern health services for the infection need to acknowledge the multiple determinants influencing their use. Future research should move beyond describing health-seeking behaviour to identifying the factors that underlay such behaviour.
Siza, Julius E.; Kaatano, Godfrey M.; Chai, Jong-Yil; Eom, Keeseon S.; Rim, Han-Jong; Yong, Tai-Soon; Min, Duk-Young; Chang, Su Young; Ko, Yunsuk; Changalucha, John M.
2015-01-01
The objectives of this study was to conduct a survey on schistosomiasis and soil-transmitted helminth (STH) infections in order to come up with feasible control strategies in Lake Victoria basin, Tanzania. Depending on the size of the school, 150-200 schoolchildren were recruited for the study. Duplicate Kato-Katz stool smears were prepared from each child and microscopically examined for Schistosoma mansoni and STHs. Urine specimens were examined for Schistosoma haematobium eggs using the filtration technique. After the survey, mass drug administration was done using praziquantel and albendazole for schistosomiasis and STHs infections, respectively. A total of 5,952 schoolchildren from 36 schools were recruited for the study and had their stool and urine specimens examined. Out of 5,952 schoolchildren, 898 (15.1%) were positive for S. mansoni, 754 (12.6%) for hookworms, 188 (3.2%) for Ascaris lumblicoides, and 5 (0.008%) for Trichuris trichiura. Out of 5,826 schoolchildren who provided urine samples, 519 (8.9%) were positive for S. haematobium eggs. The results revealed that intestinal schistosomiasis, urogenital schistosomiasis, and STH infections are highly prevalent throughought the lake basin. The high prevalence of intestinal and urogenital schistosomisiasis in the study area was a function of the distance from Lake Victoria, the former being more prevalent at localities close to the lake, whilst the latter is more so away from it. Control of schistosomiasis and STHs in the study area requires an integrated strategy that involves provision of health education to communities, regular treatments, and provision of adequate safe water supply and sanitation facilities. PMID:26537030
Siza, Julius E; Kaatano, Godfrey M; Chai, Jong-Yil; Eom, Keeseon S; Rim, Han-Jong; Yong, Tai-Soon; Min, Duk-Young; Chang, Su Young; Ko, Yunsuk; Changalucha, John M
2015-10-01
The objectives of this study was to conduct a survey on schistosomiasis and soil-transmitted helminth (STH) infections in order to come up with feasible control strategies in Lake Victoria basin, Tanzania. Depending on the size of the school, 150-200 schoolchildren were recruited for the study. Duplicate Kato-Katz stool smears were prepared from each child and microscopically examined for Schistosoma mansoni and STHs. Urine specimens were examined for Schistosoma haematobium eggs using the filtration technique. After the survey, mass drug administration was done using praziquantel and albendazole for schistosomiasis and STHs infections, respectively. A total of 5,952 schoolchildren from 36 schools were recruited for the study and had their stool and urine specimens examined. Out of 5,952 schoolchildren, 898 (15.1%) were positive for S. mansoni, 754 (12.6%) for hookworms, 188 (3.2%) for Ascaris lumblicoides, and 5 (0.008%) for Trichuris trichiura. Out of 5,826 schoolchildren who provided urine samples, 519 (8.9%) were positive for S. haematobium eggs. The results revealed that intestinal schistosomiasis, urogenital schistosomiasis, and STH infections are highly prevalent throughought the lake basin. The high prevalence of intestinal and urogenital schistosomisiasis in the study area was a function of the distance from Lake Victoria, the former being more prevalent at localities close to the lake, whilst the latter is more so away from it. Control of schistosomiasis and STHs in the study area requires an integrated strategy that involves provision of health education to communities, regular treatments, and provision of adequate safe water supply and sanitation facilities.
The role of ST2 and ST2 genetic variants in schistosomiasis.
Long, Xin; Daya, Michelle; Zhao, Jianping; Rafaels, Nicholas; Liang, Huifang; Potee, Joseph; Campbell, Monica; Zhang, Bixiang; Araujo, Maria Ilma; Oliveira, Ricardo R; Mathias, Rasika A; Gao, Li; Ruczinski, Ingo; Georas, Steve N; Vercelli, Donata; Beaty, Terri H; Barnes, Kathleen C; Chen, Xiaoping; Chen, Qian
2017-11-01
Chronic schistosomiasis and its severe complication, periportal fibrosis, are characterized by a predominant T h 2 response. To date, specific single nucleotide polymorphisms in ST2 have been some of the most consistently associated genetic variants for asthma. We investigated the role of ST2 (a receptor for the T h 2 cytokine IL-33) in chronic and late-stage schistosomiasis caused by Schistosoma japonicum and the potential effect of ST2 genetic variants on stage of disease and ST2 expression. We recruited 947 adult participants (339 with end-stage schistosomiasis and liver cirrhosis, 307 with chronic infections without liver fibrosis, and 301 health controls) from a S japonicum-endemic area (Hubei, China). Six ST2 single nucleotide polymorphisms were genotyped. Serum soluble ST2 (sST2) was measured by ELISA, and ST2 expression in normal liver tissues, Hepatitis B virus-induced fibrotic liver tissues, and S japonicum-induced fibrotic liver tissues was measured by immunohistochemistry. We found sST2 levels were significantly higher in the end-stage group (36.04 [95% CI, 33.85-38.37]) compared with chronic cases and controls (22.7 [95% CI, 22.0-23.4], P < 1E-10). In addition, S japonicum-induced fibrotic liver tissues showed increased ST2 staining compared with normal liver tissues (P = .0001). Markers rs12712135, rs1420101, and rs6543119 were strongly associated with sST2 levels (P = 2E-10, 5E-05, and 6E-05, respectively), and these results were replicated in an independent cohort from Brazil living in a S mansoni endemic region. We demonstrate for the first time that end-stage schistosomiasis is associated with elevated sST2 levels and show that ST2 genetic variants are associated with sST2 levels in patients with schistosomiasis. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
Kabore, Achille; Ibikounle, Moudachirou; Tougoue, Jean Jacques; Mupoyi, Sylvain; Ndombe, Martin; Shannon, Scott; Ottesen, Eric A; Mukunda, Faustin; Awaca, Naomi
2017-02-01
Schistosomiasis (SCH) and soil-transmitted helminthiasis (STH) are widely distributed in the Democratic Republic of the Congo (DRC) and constitute a serious public health problem. As recommended by the World Health Organization (WHO), before launching mass chemotherapy to control these diseases, parasitological surveys were conducted in sentinel sites in six health zones (HZs) in Bandundu and Maniema provinces. Baseline prevalence and intensity of infection for SCH and STH were determined to establish the appropriate treatment plan using Praziquantel (PZQ) and Albendazole (ALB). Parasitological surveys were conducted from April to May 2015 in twenty-six selected sampling units (schools) for baseline mapping in six HZs: Fifty school children (25 females and 25 males) aged 9-15 years were randomly selected per sampling unit. A total of 1300 samples (urine and stool) were examined using haematuria dipsticks, parasite-egg filtration and the point-of-care Circulating Cathodic Antigen (POC-CCA) assay for urine samples and the Kato-Katz technique for stool specimens. Three species of schistosomes (S. mansoni, S. haematobium and S. intercalatum) and three groups of STH (hookworm, Ascaris and Trichuris) were detected at variable prevalence and intensity among the schools, the HZs and the provinces. In Bandundu, no SCH was detected by either Kato-Katz or the POC-CCA technique, despite a high prevalence of STH with 68% and 80% at Kiri and Pendjua HZs, respectively. In Maniema, intestinal schistosomiasis was detected by both Kato-Katz and POC-CCA with an average prevalence by Kato-Katz of 32.8% and by POC-CCA of 42.1%. Comparative studies confirmed the greater sensitivity (and operational feasibility) of the POC-CCA test on urine compared to Kato-Katz examination of stool for diagnosing intestinal schistosomiasis even in areas of comparatively light infections. STH was widely distributed and present in all HZs with a mean prevalence (95% CI) of 59.62% (46.00-65.00%). The prevalence of hookworm, roundworm and whipworm were 51.62% (32.40%-71.50%), 15.77% (0.50%-39.60%) and 13.46 (0.50%-33.20%), respectively. This study provided the evidence base for implementing programs targeting SCH and STH in these Health Zones. Observations also reinforce the operational value and feasibility of the POC-CCA test to detect S. mansoni and, for the first time, S. intercalatum infections in a routine NTD program setting. Copyright © 2016 Elsevier B.V. All rights reserved.
Hu, Yi; Xia, Congcong; Li, Shizhu; Ward, Michael P; Luo, Can; Gao, Fenghua; Wang, Qizhi; Zhang, Shiqing; Zhang, Zhijie
2017-04-17
Schistosomiasis is a water-borne disease caused by trematode worms belonging to genus Schistosoma, which is prevalent most of the developing world. Transmission of the disease is usually associated with multiple biological characteristics and social factors but also factors can play a role. Few studies have assessed the exact and interactive influence of each factor promoting schistosomiasis transmission. We used a series of different detectors (i.e., specific detector, risk detector, ecological detector and interaction detector) to evaluate separate and interactive effects of the environmental factors on schistosomiasis prevalence. Specifically, (i) specific detector quantifies the impact of a risk factor on an observed spatial disease pattern, which were ranked statistically by a value of Power of Determinate (PD) calculation; (ii) risk detector detects high risk areas of a disease on the condition that the study area is stratified by a potential risk factor; (iii) ecological detector explores whether a risk factor is more significant than another in controlling the spatial pattern of a disease; (iv) interaction detector probes whether two risk factors when taken together weaken or enhance one another, or whether they are independent in developing a disease. Infection data of schistosomiasis based on conventional surveys were obtained at the county level from the health authorities in Anhui Province, China and used in combination with information from Chinese weather stations and internationally available environmental data. The specific detector identified various factors of potential importance as follows: Proximity to Yangtze River (0.322) > Land cover (0.285) > sunshine hours (0.256) > population density (0.109) > altitude (0.090) > the normalized different vegetation index (NDVI) (0.077) > land surface temperature at daytime (LST day ) (0.007). The risk detector indicated that areas of schistosomiasis high risk were located within a buffer distance of 50 km from Yangtze River. The ecological detector disclosed that the factors investigated have significantly different effects. The interaction detector revealed that interaction between the factors enhanced their main effects in most cases. Proximity to Yangtze River had the strongest effect on schistosomiasis prevalence followed by land cover and sunshine hours, while the remaining factors had only weak influence. Interaction between factors played an even more important role in influencing schistosomiasis prevalence than each factor on its own. High risk regions influenced by strong interactions need to be targeted for disease control intervention.
Using a Hybrid Model to Forecast the Prevalence of Schistosomiasis in Humans
Zhou, Lingling; Xia, Jing; Yu, Lijing; Wang, Ying; Shi, Yun; Cai, Shunxiang; Nie, Shaofa
2016-01-01
Background: We previously proposed a hybrid model combining both the autoregressive integrated moving average (ARIMA) and the nonlinear autoregressive neural network (NARNN) models in forecasting schistosomiasis. Our purpose in the current study was to forecast the annual prevalence of human schistosomiasis in Yangxin County, using our ARIMA-NARNN model, thereby further certifying the reliability of our hybrid model. Methods: We used the ARIMA, NARNN and ARIMA-NARNN models to fit and forecast the annual prevalence of schistosomiasis. The modeling time range included was the annual prevalence from 1956 to 2008 while the testing time range included was from 2009 to 2012. The mean square error (MSE), mean absolute error (MAE) and mean absolute percentage error (MAPE) were used to measure the model performance. We reconstructed the hybrid model to forecast the annual prevalence from 2013 to 2016. Results: The modeling and testing errors generated by the ARIMA-NARNN model were lower than those obtained from either the single ARIMA or NARNN models. The predicted annual prevalence from 2013 to 2016 demonstrated an initial decreasing trend, followed by an increase. Conclusions: The ARIMA-NARNN model can be well applied to analyze surveillance data for early warning systems for the control and elimination of schistosomiasis. PMID:27023573
Xiao-Jun, Meng; Sheng-Hua, Zong; Xuan, Zhang; Dong-Lin, Gao; Yan-Hua, Qian; Bing, Lu
2017-07-27
To establish a risk assessing indicator system after the transmission interruption of schistosomiasis in Wuxi City, so as to provide evidences for formulating strategies on schistosomiasis control and prevention. A primary risk assessing indicator system was established based on the literature review. Alternative indicators were scored and screened to establish a final indicator system through two rounds of Delphy method and the related normalized weights and combined weights were also calculated. The risk assessing indicator system was established through two rounds of expert consultation including 3 first grade indicators and 15 second grade indicators. Among the first grade indicators, the normalized weights of natural environment, key populations and social environment were 0.370 6, 0.292 9 and 0.336 5, respectively. Among the second grade indicators, the migrant population accounted for the highest combined weight of 0.125 2 compared to domestic animal of 0.037 1. The authority degree among the first grade indicators was between 0.91 and 0.93, while the authority degree among the second grade indicators was between 0.79 and 0.92. The scientific and authoritative risk assessing indicator system after the transmission interruption of schistosomiasis is established, which provides the evidences for risk assessment on schistosomiasis transmission in Wuxi City.
Adriko, M; Tinkitina, B; Tukahebw, E M; Standley, C J; Stothard, J R; Kabatereine, N B
2018-06-20
Lango region is the only known endemic region for urinary and intestinal schistosomiasis in Uganda. Although there has been no significant improvement in sanitation and safe water supply in the region over years, the endemicity and prevalence of Schistosoma haematobium, in particular, have declined, perhaps due to yearly mass treatment campaigns implemented since 2003. We report the epidemiology of Urinary and Intestinal schistosomiasis in Lango since 1951-2011 determined through Microscopic examinations for S.mansoni and S.haematobium respectively. A retrospective data review from 195-2011 was done to establish the prevalence over the years in the region. We performed Poisson regression analysis to observe trends in epidemiology before and after control was initiated in 2002. In addition, malacological surveys were undertaken in 2007 to assess local transmission potential. Contrary to earlier records, S. haematobium was low and confined to a few putative foci, with declined in infections from 28.2% in 1951 to 2.48% by 2011. Although this decline can be attributed to control, this was already much lower in 1967 than 1951, long before control interventions began suggesting that environmental changes may have made the habitat less suitable for the transmission of S.haematobium. Compared to the historical records S.mansoni prevalence first increased up immediately before control interventions in 2003, significantly declined (p=<0.001) until 2007. However, in 2007 and 2011 declined insignificant, (p = 0.656). No snail has ever been isolated shedding S.haematobium cercariae but many Bulinus snail spp were found shedding S.bovis cercariae. This suggests that a combination of environmental and mass treatment has had a significant impact on transmission in Lango region. Copyright © 2018. Published by Elsevier B.V.
Perez-Saez, Javier; Mande, Theophile; Ceperley, Natalie; Bertuzzo, Enrico; Mari, Lorenzo; Rinaldo, Andrea
2016-01-01
We report about field and theoretical studies on the ecology of the aquatic snails (Bulinus spp. and Biomphalaria pfeifferi) that serve as obligate intermediate hosts in the complex life cycle of the parasites causing human schistosomiasis. Snail abundance fosters disease transmission, and thus the dynamics of snail populations are critically important for schistosomiasis modeling and control. Here, we single out hydrological drivers and density dependence (or lack of it) of ecological growth rates of local snail populations by contrasting novel ecological and environmental data with various models of host demography. Specifically, we study various natural and man-made habitats across Burkina Faso’s highly seasonal climatic zones. Demographic models are ranked through formal model comparison and structural risk minimization. The latter allows us to evaluate the suitability of population models while clarifying the relevant covariates that explain empirical observations of snail abundance under the actual climatic forcings experienced by the various field sites. Our results link quantitatively hydrological drivers to distinct population dynamics through specific density feedbacks, and show that statistical methods based on model averaging provide reliable snail abundance projections. The consistency of our ranking results suggests the use of ad hoc models of snail demography depending on habitat type (e.g., natural vs. man-made) and hydrological characteristics (e.g., ephemeral vs. permanent). Implications for risk mapping and space-time allocation of control measures in schistosomiasis-endemic contexts are discussed. PMID:27162339
Perez-Saez, Javier; Mande, Theophile; Ceperley, Natalie; Bertuzzo, Enrico; Mari, Lorenzo; Gatto, Marino; Rinaldo, Andrea
2016-06-07
We report about field and theoretical studies on the ecology of the aquatic snails (Bulinus spp. and Biomphalaria pfeifferi) that serve as obligate intermediate hosts in the complex life cycle of the parasites causing human schistosomiasis. Snail abundance fosters disease transmission, and thus the dynamics of snail populations are critically important for schistosomiasis modeling and control. Here, we single out hydrological drivers and density dependence (or lack of it) of ecological growth rates of local snail populations by contrasting novel ecological and environmental data with various models of host demography. Specifically, we study various natural and man-made habitats across Burkina Faso's highly seasonal climatic zones. Demographic models are ranked through formal model comparison and structural risk minimization. The latter allows us to evaluate the suitability of population models while clarifying the relevant covariates that explain empirical observations of snail abundance under the actual climatic forcings experienced by the various field sites. Our results link quantitatively hydrological drivers to distinct population dynamics through specific density feedbacks, and show that statistical methods based on model averaging provide reliable snail abundance projections. The consistency of our ranking results suggests the use of ad hoc models of snail demography depending on habitat type (e.g., natural vs. man-made) and hydrological characteristics (e.g., ephemeral vs. permanent). Implications for risk mapping and space-time allocation of control measures in schistosomiasis-endemic contexts are discussed.
Lo, Nathan C; Addiss, David G; Hotez, Peter J; King, Charles H; Stothard, J Russell; Evans, Darin S; Colley, Daniel G; Lin, William; Coulibaly, Jean T; Bustinduy, Amaya L; Raso, Giovanna; Bendavid, Eran; Bogoch, Isaac I; Fenwick, Alan; Savioli, Lorenzo; Molyneux, David; Utzinger, Jürg; Andrews, Jason R
2017-02-01
In 2001, the World Health Assembly (WHA) passed the landmark WHA 54.19 resolution for global scale-up of mass administration of anthelmintic drugs for morbidity control of schistosomiasis and soil-transmitted helminthiasis, which affect more than 1·5 billion of the world's poorest people. Since then, more than a decade of research and experience has yielded crucial knowledge on the control and elimination of these helminthiases. However, the global strategy has remained largely unchanged since the original 2001 WHA resolution and associated WHO guidelines on preventive chemotherapy. In this Personal View, we highlight recent advances that, taken together, support a call to revise the global strategy and guidelines for preventive chemotherapy and complementary interventions against schistosomiasis and soil-transmitted helminthiasis. These advances include the development of guidance that is specific to goals of morbidity control and elimination of transmission. We quantify the result of forgoing this opportunity by computing the yearly disease burden, mortality, and lost economic productivity associated with maintaining the status quo. Without change, we estimate that the population of sub-Saharan Africa will probably lose 2·3 million disability-adjusted life-years and US$3·5 billion of economic productivity every year, which is comparable to recent acute epidemics, including the 2014 Ebola and 2015 Zika epidemics. We propose that the time is now to strengthen the global strategy to address the substantial disease burden of schistosomiasis and soil-transmitted helminthiasis. Copyright © 2017 Elsevier Ltd. All rights reserved.
Zhang, J-F; Xu, J; Bergquist, R; Yu, L-L; Yan, X-L; Zhu, H-Q; Wen, L-Y
2016-01-01
Schistosomiasis, caused by Schistosoma japonicum infection to human, has a documented history of more than 2100years in The People's Republic of China. In spite of great progress in controlling the disease, it is still one of the most serious parasitic diseases in the country. The study and use of diagnostic techniques play an important role in the targeting of chemotherapy that has been continuously applied in the national schistosomiasis control programme for several decades. This paper reviews the development and application of parasitological, immunodiagnostic and molecular diagnostic technology for S. japonicum in The People's Republic of China with a brief mention of diagnostic imagery, such as ultrasound and radiology. When analysing the efficacy and performance characteristics of the main diagnostic techniques in current use, it becomes apparent that approaches that worked well in the past are less suitable now as successful control has shifted the endemic situation towards control and interruption of transmission. The conclusion is that a mutable approach must be adopted choosing the most appropriate diagnostic technique for each control stage (and area), thus modifying the methodology according to the prevailing diagnostic needs in terms of sensitivity and specificity. Copyright © 2016 Elsevier Ltd. All rights reserved.
Toledo, Chelsea E; Jacobson, Julie; Wainwright, Emily C; Ottesen, Eric A; Lammie, Patrick J
2016-03-01
While global programs targeting the control or elimination of five of the neglected tropical diseases (NTDs)-lymphatic filariasis, onchocerciasis, soil-transmitted helminthiasis, schistosomiasis and trachoma-are well underway, they still face many operational challenges. Because of the urgency of 2020 program targets, the Bill & Melinda Gates Foundation and the U.S. Agency for International Development devised a novel rapid research response (RRR) framework to engage national programs, researchers, implementers and WHO in a Coalition for Operational Research on NTDs. After 2 years, this effort has succeeded as an important basis for the research response to programmatic challenges facing NTD programs. © The Author 2016. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.
A new global strategy for the elimination of schistosomiasis.
Ross, Allen G P; Chau, Thao N; Inobaya, Marianette T; Olveda, Remigio M; Li, Yuesheng; Harn, Donald A
2017-01-01
Mass drug administration utilising a single oral dose of 40mg/kg of praziquantel (PZQ) has been endorsed and advocated by the World Health Organisation (WHO) for the global control and elimination of schistosomiasis. However, this strategy is failing primarily because the drugs are not getting to the people who need them the most. The current global coverage is 20%, the drug compliance rate is less than 50%, and the drug efficacy is approximately 50%. Thus in reality, only about 5% of the reservoir human population is actually receiving intermittent chemotherapy. Despite claims that more of the drug will soon be made available the current strategy is inherently flawed and will not lead to disease elimination. We discuss the many practical issues related to this global strategy, and advocate for an integrated control strategy targeting the life cycle and the most at-risk. Moreover, we discuss how an integrated control package for schistosomiasis should fit within a larger integrated health package for rural and remote villages in the developing world. A holistic health system approach is required to achieve sustainable control and ultimately disease elimination. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.
Colley, Daniel G; Andros, Tamara S; Campbell, Carl H
2017-03-22
Mapping and diagnosis of infections by the three major schistosome species (Schistosoma haematobium, S. mansoni and S. japonicum) has been done with assays that are known to be specific but increasingly insensitive as prevalence declines or in areas with already low prevalence of infection. This becomes a true challenge to achieving the goal of elimination of schistosomiasis because the multiplicative portion of the life-cycle of schistosomes, in the snail vector, favors continued transmission as long as even a few people maintain low numbers of worms that pass eggs in their excreta. New mapping tools based on detection of worm antigens (circulating cathodic antigen - CCA; circulating anodic antigen - CAA) in urine of those infected are highly sensitive and the CAA assay is reported to be highly specific. Using these tools in areas of low prevalence of all three of these species of schistosomes has demonstrated that more people harbor adult worms than are regularly excreting eggs at a level detectable by the usual stool assay (Kato-Katz) or by urine filtration. In very low prevalence areas this is sometimes 6- to10-fold more. Faced with what appears to be a sizable population of "egg-negative/worm-positive schistosomiasis" especially in areas of very low prevalence, national NTD programs are confounded about what guidelines and strategies they should enact if they are to proceed toward a goal of elimination. There is a critical need for continued evaluation of the assays involved and to understand the contribution of this "egg-negative/worm-positive schistosomiasis" condition to both individual morbidity and community transmission. There is also a critical need for new guidelines based on the use of these more sensitive assays for those national NTD programs that wish to move forward to strategies designed for elimination.
Schistosomes, snails and satellites.
Brooker, S
2002-05-01
This paper gives an overview of the recent progress made in the use and application of geographical information systems (GIS) and remotely sensed (RS) satellite sensor data for the epidemiology and control of schistosomiasis in sub-Saharan Africa. Details are given of the use of GIS to collate, map and analyse available parasitological data. The use of RS data to understand better the broad scale environmental factors influencing schistosome distribution is defined and examples detailed for the prediction of schistosomiasis in unsampled areas. Finally, the current practical application of GIS and remote sensing are reviewed in the context of national control programmes.
Inobaya, Marianette T; Chau, Thao N; Ng, Shu-Kay; MacDougall, Colin; Olveda, Remigio M; Tallo, Veronica L; Landicho, Jhoys M; Malacad, Carol M; Aligato, Mila F; Guevarra, Jerric R; Ross, Allen G
2018-01-01
Schistosomiasis control is centred on preventive chemotherapy through mass drug administration (MDA). However, endemic countries continue to struggle to attain target coverage rates and patient compliance. In the Philippines, barangay health workers (BHWs) play a vital role in the coordination of MDA, acting as advocates, implementers, and educators. The aim of this study was to determine whether BHW knowledge and attitudes towards schistosomiasis and MDA is sufficient and correlated with resident knowledge and drug compliance. A cross-sectional survey was conducted in 2015 among 2186 residents and 224 BHWs in the province of Northern Samar, the Philippines using a structured survey questionnaire. BHWs showed good familiarity on how schistosomiasis is acquired and diagnosed. Nevertheless, both BHWs and residents had poor awareness of the signs and symptoms of schistosomiasis, disease prevention, and treatment options. There was no correlation between the knowledge scores of the BHWs and the residents (r=0.080, p=0.722). Kruskal-Wallis analysis revealed significant differences in BHW knowledge scores between the low (3.29, 95% confidence interval 3.16-3.36), moderate (3.61, 95% confidence interval 3.49-3.69), and high (4.05, 95% confidence interval 3.77-4.13) compliance village groups (p=0.002), with the high compliance areas having the highest mean knowledge scores. This study highlights the importance of community health workers in obtaining the World Health Organization drug coverage rate of 75% and improving compliance with MDA in the community. Investing in the education of community health workers with appropriate disease-specific training is crucial if disease elimination is ultimately to be achieved. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.
Yang, Guo-Jing; Sun, Le-Ping; Hong, Qing-Biao; Zhu, Hong-Ru; Yang, Kun; Gao, Qi; Zhou, Xiao-Nong
2012-11-14
The application of chemical molluscicides is still one of the most effective measures for schistosomiasis control in P. R. China. By applying diverse molluscicide treatment scenarios on different snail densities in the field, we attempted to understand the cost-effectiveness of molluscicide application so as to prescribe an optimal management approach to control intermediate host snail Oncomelania hupensis under acceptable thresholds based on the goal of the National Schistosomiasis Control Programme. The molluscicidal field trial was carried out in the marshland of an island along the Yangtze River, Jiangsu province, P.R. China in October 2010. Three plots in the island representing low-density, medium-density and high-density groups were identified after the baseline survey on snail density. Each snail density plot was divided into four experimental units in which molluscicide (50% niclosamide ethanolamine salt wettable powder) was applied once, twice, trice and four times, respectively. The logistic regression model to correlate snail mortality rate with the covariates of number of molluscicidal treatment and snail density, and a linear regression model to investigate the relationship between cost-effectiveness and number of molluscicidal treatment as well as snail density were established. The study revealed that increase in the number of molluscicide treatments led to increased snail mortality across all three population density groups. The most cost-effective regimen was seen in the high snail density group with a single molluscicide treatment. For both high and low density groups, the more times molluscicide were applied, the less cost-effectiveness was. However, for the median density group, the level of cost-effectiveness for two applications was slightly higher than that in one time. We concluded that different stages of the national schistosomiasis control/elimination programme, namely morbidity control, transmission control and transmission interruption, should utilize different molluscicide treatment strategies to maximize cost-effectiveness.
[Effect of jian-gan-le on advanced schistosomiasis].
He, Zheng-Wen; Wang, You-Bin; Huang, Wen-Jun
2011-06-01
A total of 80 cases of advanced schistosomiasis were selected and divided into an experiment group and a control group, 40 cases each group, by the random sampling method. The patients in the experiment group were administered with Jian-gan-le, and the patients in the control group received compound purple granules. In the experiment group, the curative rate was 25.0%, the improving rate was 70.0%, the inefficacy rate was 5%, and the efficiency rate was 95.0%. In the control group, the curative rate was 12.5%, the improving rate was 75%, the inefficacy rate was 12.5%. There was no statistic difference between the 2 groups (P all > 0.05). The expense was cheaper in the experiment group than in the control group.
Schistosomiasis: eradication or control
DOE Office of Scientific and Technical Information (OSTI.GOV)
Strickland, G.T.
Schistosomiasis cannot be eradicated from the world at this time. However, it can be eradicated from focal areas where major improvements in the standard of living have occurred. In most areas control of biological transmission can be obtained by a systematic use of chemotherapy along with other methods including control of snails and reduction in both water contamination and contact. In some areas, where the prevalence and intensity of infection are very high, the only reasonable objective is control of the disease. Disease morbidity correlates with intensity of infection and can probably be reduced with repeated courses of chemotherapy. Themore » appropriate application of a schistosomal vaccine, when it becomes available, will expedite the eradication of this parasite, which infects greater than 200 million people.« less
Rasoamanamihaja, Clara Fabienne; Rahetilahy, Alain Marcel; Ranjatoarivony, Bruno; Dhanani, Neerav; Andriamaro, Luciano; Andrianarisoa, Samuel Hermas; Jourdan, Peter Mark
2016-01-27
Schistosomiasis affects more than 800 million people, mostly in sub-Saharan Africa. A baseline sentinel site study was conducted in the Western half of Madagascar to determine the prevalence and intensity of schistosomiasis and soil-transmitted helminth (STH) infections prior to mass drug administration, and to explore the associations between infection and school attendance, and access to water, sanitation and hygiene (WASH) facilities. A three-stage, cluster-randomised cross-sectional study was conducted in 29 sentinel sites in October 2015. Twenty school attending and 4 non-attending children in each of the age groups from 7 to 10 years old were randomly selected at each site for detection of Schistosoma haematobium eggs in a single urine slide by filtration, and of S. mansoni, Ascaris lumbricoides, Trichuris trichiura and hookworm eggs in duplicate Kato-Katz slides from a single stool sample. School attendance was registered individually, and school-level access to WASH facilities was scored through pre-defined observed and reported factors. Logistic regression analysis was performed, adjusting for gender, age and study site. School-level WASH status was analysed using Spearman's rank correlation coefficient. A total of 1,958 children were included. The prevalence of S. haematobium infection and heavy-intensity infection was 30.5% and 15.1%, respectively. The prevalence of S. mansoni infection and heavy-intensity infection was 5.0% and 0.9%, respectively. The prevalence of any STH infection was 4.7%. There was no significant difference in prevalence of infection or heavy-intensity infection of either schistosome species between attending and non-attending children, apart from heavy-intensity S. mansoni infection that was significantly more common in children who did not attend school regularly (aOR = 7.5 (95% CI = 1.1-49.5); p = 0.037). Only a minority of schools had adequate access to WASH facilities, and in this study, we found no significant association between school-level WASH status and schistosomiasis. This study found an alarmingly high prevalence and intensity of schistosomiasis, and the results warrant urgent scale-up of the national NTD control programme that will need to include both non-attending and attending school-age children in order to reach WHO roadmap targets for the control of schistosomiasis by 2020.
Knowledge, attitude, and practices towards schistosomiasis among rural population in Yemen.
Sady, Hany; Al-Mekhlafi, Hesham M; Atroosh, Wahib M; Al-Delaimy, Ahmed K; Nasr, Nabil A; Dawaki, Salwa; Al-Areeqi, Mona A; Ithoi, Init; Abdulsalam, Awatif M; Chua, Kek Heng; Surin, Johari
2015-08-25
Schistosomiasis is highly prevalent in Yemen, with an estimated 3 million cases, particularly among rural communities. This community-based study aims to evaluate the knowledge, attitude and practices (KAP) on schistosomiasis among rural communities in Yemen. A cross-sectional study was carried out among 250 households from ten rural districts in Yemen. Overall, 400 children were screened for urogenital and intestinal schistosomiasis. Moreover, parents were interviewed using a pre-tested questionnaire to collect information about the demographic and socioeconomic information and their KAP concerning schistosomiasis. A total of 127 (31.8%) children were found to be excreting schistosome eggs in either their urine or faeces (22.5% S. haematobium and 8.0% S. mansoni). Although 92.4% of the respondents had heard about schistosomiasis, 49.8%, 68.0% and 47.2% had knowledge concerning the transmission, signs and symptoms, and prevention, respectively. In addition, 77.1% considered schistosomiasis as harmful while 48.5% believed that schistosomiasis could be prevented, albeit their practices to prevent infections were still inadequate. Significant associations between the KAP and age, education, employment status and household monthly income were reported (P < 0.05). Moreover, a significantly higher level of knowledge was reported among the respondents who had infected children compared to those with no infected family members (P < 0.05). Multiple logistic regression analysis revealed that the level of education and the history of schistosomiasis were the most important factors associated with the KAP concerning schistosomiasis among this population. This study reveals that knowledge about the cause, transmission, symptoms and prevention of schistosomiasis among the rural population in Yemen was inadequate, and that this could be a challenging obstacle to the elimination of schistosomiasis in these communities. Besides the current mass drug administration, school and community-based health education regarding schistosomiasis is imperative among these communities to significantly reduce the transmission and morbidity of schistosomiasis.
Miller-Fellows, Sarah C.; Howard, Laura; Kramer, Rebekah; Hildebrand, Vanessa; Furin, Jennifer; Mutuku, Francis M.; Mukoko, Dunstan; Ivy, Julianne A.
2017-01-01
Background Previous research has documented an increased risk of subfertility in areas of sub-Saharan Africa, as well as an ecological association between urogenital schistosomiasis prevalence and decreased fertility. This pilot project examined reproductive patterns and the potential effects of childhood urogenital Schistosoma haematobium infection and individual treatment experience on adult subfertility among women who were long-term residents in an S. haematobium-endemic region of coastal Kenya. Methodology/Principal findings We analyzed findings from 162 in-depth interviews with women of childbearing age in a rural, coastal community, linking them, if possible, to their individual treatment records from previous multi-year longitudinal studies of parasitic infections. Reproductive histories indicated a much local higher local rate of subfertility (44%) than worldwide averages (8–12%). Although, due to the very high regional prevalence of schistosomiasis, a clear relationship could not be demonstrated between a history of S. haematobium infection and adult subfertility, among a convenience sub-sample of 61 women who had received documented treatment during previous interventional trials, a significant association was found between age at first anti-schistosomal treatment and later fertility in adulthood, with those women treated before age 21 significantly less likely to have subfertility (P = 0.001). Conclusions/Significance The high subfertility rate documented in this pilot study suggests the importance of programs to prevent and treat pelvic infections in their early stages to preclude reproductive tract damage. The available documented treatment data also suggest that early anti-schistosomal treatment may prevent the fertility-damaging effects of urogenital schistosomiasis, and lend support for programs that provide universal treatment of children in S. haematobium-endemic regions. PMID:29176778
Miller-Fellows, Sarah C; Howard, Laura; Kramer, Rebekah; Hildebrand, Vanessa; Furin, Jennifer; Mutuku, Francis M; Mukoko, Dunstan; Ivy, Julianne A; King, Charles H
2017-11-01
Previous research has documented an increased risk of subfertility in areas of sub-Saharan Africa, as well as an ecological association between urogenital schistosomiasis prevalence and decreased fertility. This pilot project examined reproductive patterns and the potential effects of childhood urogenital Schistosoma haematobium infection and individual treatment experience on adult subfertility among women who were long-term residents in an S. haematobium-endemic region of coastal Kenya. We analyzed findings from 162 in-depth interviews with women of childbearing age in a rural, coastal community, linking them, if possible, to their individual treatment records from previous multi-year longitudinal studies of parasitic infections. Reproductive histories indicated a much local higher local rate of subfertility (44%) than worldwide averages (8-12%). Although, due to the very high regional prevalence of schistosomiasis, a clear relationship could not be demonstrated between a history of S. haematobium infection and adult subfertility, among a convenience sub-sample of 61 women who had received documented treatment during previous interventional trials, a significant association was found between age at first anti-schistosomal treatment and later fertility in adulthood, with those women treated before age 21 significantly less likely to have subfertility (P = 0.001). The high subfertility rate documented in this pilot study suggests the importance of programs to prevent and treat pelvic infections in their early stages to preclude reproductive tract damage. The available documented treatment data also suggest that early anti-schistosomal treatment may prevent the fertility-damaging effects of urogenital schistosomiasis, and lend support for programs that provide universal treatment of children in S. haematobium-endemic regions.
A new approach to modelling schistosomiasis transmission based on stratified worm burden.
Gurarie, D; King, C H; Wang, X
2010-11-01
Multiple factors affect schistosomiasis transmission in distributed meta-population systems including age, behaviour, and environment. The traditional approach to modelling macroparasite transmission often exploits the 'mean worm burden' (MWB) formulation for human hosts. However, typical worm distribution in humans is overdispersed, and classic models either ignore this characteristic or make ad hoc assumptions about its pattern (e.g., by assuming a negative binomial distribution). Such oversimplifications can give wrong predictions for the impact of control interventions. We propose a new modelling approach to macro-parasite transmission by stratifying human populations according to worm burden, and replacing MWB dynamics with that of 'population strata'. We developed proper calibration procedures for such multi-component systems, based on typical epidemiological and demographic field data, and implemented them using Wolfram Mathematica. Model programming and calibration proved to be straightforward. Our calibrated system provided good agreement with the individual level field data from the Msambweni region of eastern Kenya. The Stratified Worm Burden (SWB) approach offers many advantages, in that it accounts naturally for overdispersion and accommodates other important factors and measures of human infection and demographics. Future work will apply this model and methodology to evaluate innovative control intervention strategies, including expanded drug treatment programmes proposed by the World Health Organization and its partners.
Yin-Ping, Zuo; Dao-Jian, Zhu; Guang-Lin, Du; Kai, Tang; Yu-Cai, Ma; Zheng-Qiu, Zhang; Shao-Zhou, Chen; Fubiao, Wang; Hong-Ping, Tang; Jin, Zhang; Le-Ping, Sun
2016-08-02
To evaluate the potential risk of schistosomiasis transmission in the area along the Yangtze River in Yangzhou City, so as to provide evidences for establishing a post-transmission surveillance system for schistosomiasis in marshland regions. The water infectivity, floating boatmen and fishermen infection, reservoir host infection and wild feces contamination were investigated in five districts/counties along the Yangtze River in Yangzhou City, including Guangling, Hanjiang, Jiangdu, Yizheng and Development Zone, and the transmission factors and risky characteristics were assessed after interruption of schistosomiasis transmission in marshland regions. A total of 15 key water regions were identified in the area along the Yangtze River in Yangzhou City in 2015. A total of 1 500 sentinel mice were placed, after breeding, their overall survival rate was 99.33%; 1 490 were dissected, with no schistosome infection. Of the 5 576 floating boatmen and fishermen examined, no schistosome infection was observed, and among the 3 566 domestic animals (including 171 cattle, 1 895 sheep and 1 500 pigs), no infections were detected. During the period between January and March, 2016, there were 3 200 mouse traps placed on 8 marshlands, and 62 wild mice were captured from 6 marshlands, with a capture rate of 1.94%, and no schistosomeinfected wild mice were seen. In addition, there were 35 pieces of fresh wild feces captured from 7 marshlands, including 11 pieces of bovine feces (31.43%), 17 pieces of sheep feces (48.57%), 2 pieces of dog feces (5.71%) and 5 pieces of other feces (14.29%), and no infections were detected. There is a low risk of schistosomiasis transmission in the area along the Yangtze River in Yangzhou City. However, the contamination of feces from bovine and sheep that are freely pastured on marshlands is a big threat to schistosomiasis control.
Are Ca2+ channels targets of praziquantel action?
Greenberg, Robert M
2005-01-01
Praziquantel is the current drug of choice for the control of schistosomiasis. It is highly effective against all species of schistosomes and shows minimal adverse effects. Though introduced for the treatment of schistosomiasis more than 20 years ago, the mode of action of praziquantel remains to be elucidated. This review will focus on advances in defining the molecular target of praziquantel action, with particular emphasis on recent work indicating an important role for voltage-gated calcium channels.
Liu, Qin; Tian, Li-Guang; Xiao, Shu-Hua; Qi, Zhen; Steinmann, Peter; Mak, Tippi K; Utzinger, Jürg; Zhou, Xiao-Nong
2008-01-01
The economy of China continues to boom and so have its biomedical research and related publishing activities. Several so-called neglected tropical diseases that are most common in the developing world are still rampant or even emerging in some parts of China. The purpose of this article is to document the significant research potential from the Chinese biomedical bibliographic databases. The research contributions from China in the epidemiology and control of schistosomiasis provide an excellent illustration. We searched two widely used databases, namely China National Knowledge Infrastructure (CNKI) and VIP Information (VIP). Employing the keyword "Schistosoma" () and covering the period 1990–2006, we obtained 10,244 hits in the CNKI database and 5,975 in VIP. We examined 10 Chinese biomedical journals that published the highest number of original research articles on schistosomiasis for issues including languages and open access. Although most of the journals are published in Chinese, English abstracts are usually available. Open access to full articles was available in China Tropical Medicine in 2005/2006 and is granted by the Chinese Journal of Parasitology and Parasitic Diseases since 2003; none of the other journals examined offered open access. We reviewed (i) the discovery and development of antischistosomal drugs, (ii) the progress made with molluscicides and (iii) environmental management for schistosomiasis control in China over the past 20 years. In conclusion, significant research is published in the Chinese literature, which is relevant for local control measures and global scientific knowledge. Open access should be encouraged and language barriers removed so the wealth of Chinese research can be more fully appreciated by the scientific community. PMID:18826598
The socio-economic effects of tropical diseases in Nigeria.
Umeh, J C; Amali, O; Umeh, E U
2004-06-01
Urinary schistosomiasis is the most prevalent of the endemic tropical diseases: 48% of the population is afflicted in the study area. The socio-economic, environmental and health-seeking behavioural characteristics of the population are conducive to the spread of urinary schistosomiasis. The attitudes considered include knowledge of what causes the disease and how to control it, attitude toward the disease, care of oneself, hygiene and sanitation. The effect of such social variables as stigmatisation, and environmental variables such as water source is also considered. We find that a unit increase in the hygiene/sanitation index for adult males and adult females lead to a reduction of about 7.3 and 4.0 eggs S. haematobium in 10 ml urine sample, respectively. Thus, simple hygienic activities such as keeping the immediate environment of the household free from human wastes contribute substantially to disease control. Furthermore, prevalence of the disease is higher among males. Losses from work attributed to urinary schistosomiasis are high. Average values of key socio-economic variables-labour flow for land clearing, farm size and cash income-computed for farm families with high urinary schistosomiasis intensity in the sample are 1085 h, 1.4 ha and N 1,432 (US dollars 65) respectively. The corresponding figures for farm families free from the disease are significantly higher: 1325 h, 1.9 ha and N 3,759 (US dollars 171), respectively.
Esrey, S. A.; Potash, J. B.; Roberts, L.; Shiff, C.
1991-01-01
A total of 144 studies were analysed to examine the impact of improved water supply and sanitation facilities on ascariasis, diarrhoea, dracunculiasis, hookworm infection, schistosomiasis, and trachoma. These diseases were selected because they are widespread and illustrate the variety of mechanisms through which improved water and sanitation can protect people. Disease-specific median reduction levels were calculated for all studies, and separately for the more methodologically rigorous ones. For the latter studies, the median reduction in morbidity for diarrhoea, trachoma, and ascariasis induced by water supplies and/or sanitation was 26%, 27%, and 29%, respectively; the median reduction for schistosomiasis and dracunculiasis was higher, at 77% and 78%, respectively. All studies of hookworm infection were flawed apart from one, which reported a 4% reduction in incidence. For hookworm infection, ascariasis, and schistosomiasis, the reduction in disease severity, as measured in egg counts, was greater than that in incidence or prevalence. Child mortality fell by 55%, which suggests that water and sanitation have a substantial impact on child survival. Water for personal and domestic hygiene was important in reducing the rates of ascariasis, diarrhoea, schistosomiasis, and trachoma. Sanitation facilities decreased diarrhoea morbidity and mortality and the severity of hookworm infection. Better water quality reduced the incidence of dracunculiasis, but its role in diarrhoeal disease control was less important than that of sanitation and hygiene. PMID:1835675
Effect of School Based Treatment on the Prevalence of Schistosomiasis in Endemic Area in Yemen
Abdulrab, A; Salem, A; Algobati, F; Saleh, S; Shibani, K; Albuthigi, R
2013-01-01
Background Schistosomiasis and soil transmitted infection is a major health problem of children from rural areas of developing countries including Yemen. In an attempt to reduce this burden, the Ministry of Public Health and Population in Yemen established in 2002 a programme for Schistosomal, soil transmitted infection control that aimed to reduce morbidity and prevalence rates of Schistosomiasis, and Soil transmitted helminthes to less than 5% by 2015. The study was conducted to assess the current prevalence and intensity of schistosomal infection among schoolchildren in rural areas of the Taiz governorate after 6 years of running National Control Programme. Methods Grade 3 schoolchildren from Shara'b Al-Raona district of Taiz Governorate were examined for infections with Schistosoma mansoni using Modified Kato–Katz method and S. haematobium applying filtration method in 1998/1999, comparing the prevalence and intensity of infection with base line study, which was done 6 years ago. Results The S. mansoni prevalence in the study population was 31%, while the prevalence of S. haematobium was 18.6%. This result considerably is similar to the prevalence of base line study. The intensity of mild, moderate and severe infection for S. mansoni reached to 15.9%, 60.6% & 23.5% respectively. The severity of S. haematobium infection was 68.4%. It was exceptionally found that the prevalence of S. haematobium is increased. Conclusion The high prevalence of schistosomiasis and low effectiveness of control programme against schistosomal infection in the study area demands consideration of alternative treatment approaches. PMID:23914234
Spatio-temporal modeling with GIS and remote sensing for schistosomiasis control in Sichuan, China
NASA Astrophysics Data System (ADS)
Xu, Bing
Schistosomiasis is a water-borne parasitic disease endemic in tropical and subtropical areas. Its transmission requires certain kind of snail as the intermediate host. Some efforts have been made to mapping snail habitats with remote sensing and schistosomiasis transmission modeling. However, the modeling is limited to isolated residential groups and does not include spatial interaction among those groups. Remotely sensed data are only used in snail habitat classification, not in estimation of snail abundance that is an important parameter in schistosomiasis transmission modeling. This research overcomes the above two problems using innovative geographic information system (GIS) and remote sensing technology. A mountainous environment near Xichang, China, is chosen as the test site. Environmental and epidemiological data are stored in a GIS to support modeling. Snail abundance is estimated from land-cover and land-use fractions derived from high spatial resolution IKONOS satellite data. Spatial interaction is determined in consideration of neighborhoods, group areas, relative slopes among groups, and natural barriers. Land-cover and land-use information extracted from 4 m high resolution IKONOS data is used as reference in scaling up to the regional level. The scale-up is done with coarser resolution satellite data including Landsat Thematic Mapper (TM), EO-1 Advanced Land Imager (ALI) and Hyperion data all at 30 m resolution. Snail abundance is estimated by regressing snail survey data with land-cover and land-use fractions. An R2 of 0.87 is obtained between the average snail density predicted and that surveyed at the group level. With such a model, a snail density map is generated for all residential groups in the study area. A spatio-temporal model of schistosomiasis transmission is finally built to incorporate the spatial interaction caused by miracidia and cercaria migration. Comparing the model results with and without spatial interaction has revealed a number of advantages of the spatio-temporal model. Particularly, with the inclusion of spatial interaction, more effective control of schistosomiasis transmission over the whole study area can be achieved.
Hürlimann, Eveline; Schur, Nadine; Boutsika, Konstantina; Stensgaard, Anna-Sofie; Laserna de Himpsl, Maiti; Ziegelbauer, Kathrin; Laizer, Nassor; Camenzind, Lukas; Di Pasquale, Aurelio; Ekpo, Uwem F.; Simoonga, Christopher; Mushinge, Gabriel; Saarnak, Christopher F. L.; Utzinger, Jürg; Kristensen, Thomas K.; Vounatsou, Penelope
2011-01-01
Background After many years of general neglect, interest has grown and efforts came under way for the mapping, control, surveillance, and eventual elimination of neglected tropical diseases (NTDs). Disease risk estimates are a key feature to target control interventions, and serve as a benchmark for monitoring and evaluation. What is currently missing is a georeferenced global database for NTDs providing open-access to the available survey data that is constantly updated and can be utilized by researchers and disease control managers to support other relevant stakeholders. We describe the steps taken toward the development of such a database that can be employed for spatial disease risk modeling and control of NTDs. Methodology With an emphasis on schistosomiasis in Africa, we systematically searched the literature (peer-reviewed journals and ‘grey literature’), contacted Ministries of Health and research institutions in schistosomiasis-endemic countries for location-specific prevalence data and survey details (e.g., study population, year of survey and diagnostic techniques). The data were extracted, georeferenced, and stored in a MySQL database with a web interface allowing free database access and data management. Principal Findings At the beginning of 2011, our database contained more than 12,000 georeferenced schistosomiasis survey locations from 35 African countries available under http://www.gntd.org. Currently, the database is expanded to a global repository, including a host of other NTDs, e.g. soil-transmitted helminthiasis and leishmaniasis. Conclusions An open-access, spatially explicit NTD database offers unique opportunities for disease risk modeling, targeting control interventions, disease monitoring, and surveillance. Moreover, it allows for detailed geostatistical analyses of disease distribution in space and time. With an initial focus on schistosomiasis in Africa, we demonstrate the proof-of-concept that the establishment and running of a global NTD database is feasible and should be expanded without delay. PMID:22180793
Integrated control programmes for schistosomiasis and other helminth infections in P.R. China.
Xu, Jing; Xu, Jun-Fang; Li, Shi-Zhu; Zhang, Li-Juan; Wang, Qiang; Zhu, Hui-Hui; Zhou, Xiao-Nong
2015-01-01
The prevalence of human schistosomiasis and soil-transmitted helminthiasis (STH) has decreased significantly in the People's Republic of China (P.R. China), particularly after 2005 when the national control programmes were reinforced by forming of integrated control strategies. Furthermore, social-economic development also contributed to the decrease of schistosome and soil-transmitted helminth infections. The prevalence of the zoonotic helminthiasis, including clonorchiasis and echinococcosis, on the other hand, is either underestimated or has in fact increased due to changes in social and environmental factors. In comparison with the control strategies in force and their effects on those four kinds of helminthiasis, the challenges and control priorities for the potential transfer from control to elimination of each disease is reviewed, to provide evidence for policy-makers to act upon. Copyright © 2013 Elsevier B.V. All rights reserved.
Epidemiology and Control of Malaria, Leishmaniasis and Schistosomiasis
1985-11-01
We have permanent laboratory and living quarters in Caatinga do Moura, Bahia, an area of high endemicity for SchistoQoaQ mansoni. Malaria is a major...permitting instantaneous analysis of data and immediate feed-back of data analysis to the Brazil lab. In the schistosomiasis field study area at Caatinga ...from 67% (30/45) for the wild guinea pig (Cavia perjea) to 11% (3/27) for the field mouse (Akodon sp.). In two sites near Caatinga do Moura, a highly
Meurs, Lynn; Brienen, Eric; Mbow, Moustapha; Ochola, Elizabeth A; Mboup, Souleymane; Karanja, Diana M S; Secor, W Evan; Polman, Katja; van Lieshout, Lisette
2015-01-01
The current reference test for the detection of S. mansoni in endemic areas is stool microscopy based on one or more Kato-Katz stool smears. However, stool microscopy has several shortcomings that greatly affect the efficacy of current schistosomiasis control programs. A highly specific multiplex real-time polymerase chain reaction (PCR) targeting the Schistosoma internal transcriber-spacer-2 sequence (ITS2) was developed by our group a few years ago, but so far this PCR has been applied mostly on urine samples. Here, we performed more in-depth evaluation of the ITS2 PCR as an alternative method to standard microscopy for the detection and quantification of Schistosoma spp. in stool samples. Microscopy and PCR were performed in a Senegalese community (n = 197) in an area with high S. mansoni transmission and co-occurrence of S. haematobium, and in Kenyan schoolchildren (n = 760) from an area with comparatively low S. mansoni transmission. Despite the differences in Schistosoma endemicity the PCR performed very similarly in both areas; 13-15% more infections were detected by PCR when comparing to microscopy of a single stool sample. Even when 2-3 stool samples were used for microscopy, PCR on one stool sample detected more infections, especially in people with light-intensity infections and in children from low-risk schools. The low prevalence of soil-transmitted helminthiasis in both populations was confirmed by an additional multiplex PCR. The ITS2-based PCR was more sensitive than standard microscopy in detecting Schistosoma spp. This would be particularly useful for S. mansoni detection in low transmission areas, and post-control settings, and as such improve schistosomiasis control programs, epidemiological research, and quality control of microscopy. Moreover, it can be complemented with other (multiplex real-time) PCRs to detect a wider range of helminths and thus enhance effectiveness of current integrated control and elimination strategies for neglected tropical diseases.
Clinicopathological patterns and distribution of Schistosomiasis in Asir Region.
Morad, N A; Khan, A R
2001-06-01
The objective of this study is to report, for the first time, the histopathologic pattern of Schistosomiasis from the Asir Region and to compare it to patterns reported from other regions of the Kingdom of Saudi Arabia. Several studies have reported the patterns of Schistosomiasis in other regions of the Kingdom of Saudi Arabia and other countries where Schistosomiasis is endemic. Schistosomiasis is endemic in certain areas of Asir region, however no data is available concerning the clinicopathological pattern of Schistosomiasis in the Asir Region. This is a retrospective analysis of 217 cases of Schistosomiasis from surgical and biopsy files of Asir Central Hospital during a period from January 1990 to October 1999. Our study revealed that Schistosomiasis was more common among the expatriate population of Asir Region than Saudi nationals residing in this area. The urinary tract was most commonly involved, and then in descending frequency came the vermiform appendix, liver and large bowel. These findings are somewhat different from those observed in the Riyadh Region where the vermiform appendix was the most commonly affected organ. Based on the histopathologic pattern, our study describes the pattern of Schistosomiasis in the Asir Region and may serve as a base-line for future research work.
Potential of Sentinel Satellites for Schistosomiasis Monitoring
NASA Astrophysics Data System (ADS)
Li, C.-R.; Tang, L.-L.; Niu, H.-B.; Zhou, X.-N.; Liu, Z.-Y.; Ma, L.-L.; Zhou, Y.-S.
2012-04-01
Schistosomiasis is a parasitic disease that menaces human health. In terms of impact this disease is second only to malaria as the most devastating parasitic disease. Oncomelania hupensis is the unique intermediate host of Schistosoma, and hence monitoring and controlling of the number of oncomelania is key to reduce the risk of schistosomiasis transmission. Remote sensing technology can real-timely access the large-scale environmental factors related to oncomelania breeding and reproduction, such as temperature, moisture, vegetation, soil, and rainfall, and can also provide the efficient information to determine the location, area, and spread tendency of oncomelania. Many studies show that the correlation coefficient between oncomelania densities and remote sensing environmental factors depends largely on suitable and high quality remote sensing data used in retrieve environmental factors. Research achievements on retrieving environmental factors (which are related to the living, multiplying and transmission of oncomelania) by multi-source remote data are shown firstly, including: (a) Vegetation information (e.g., Modified Soil-Adjusted Vegetation Index, Normalized Difference Moisture Index, Fractional Vegetation Cover) extracted from optical remote sensing data, such as Landsat TM, HJ-1A/HSI image; (b) Surface temperature retrieval from Thermal Infrared (TIR) and passive-microwave remote sensing data; (c) Water region, soil moisture, forest height retrieval from synthetic aperture radar data, such as Envisat SAR, DLR's ESAR image. Base on which, the requirements of environmental factor accuracy for schistosomiasis monitoring will be analyzed and summarized. Our work on applying remote sensing technique to schistosomiasis monitoring is then presented. The fuzzy information theory is employed to analyze the sensitivity and feasibility relation between oncomelania densities and environmental factors. Then a mechanism model of predicting oncomelania distribution and densities is developed. The new model is validated with field data of Dongting Lake and the dynamic monitoring of schistosomiasis breeding in Dongting Lake region is presented. Finally, emphasis are placed on analyzing the potential of Sentinel satellites for schistosomiasis monitoring. The requirements of optical high resolution data on spectral resolution, spatial resolution, radiometric resolution/accuracy, as well as the requirements of synthetic aperture radar data on operation frequency, spatial resolution, polarization, radiometric accuracy, repeat cycle are presented and then compared with the parameters of Sentinel satellites. The parameters of Sentinel satellites are also compared with those of available remote satellites, such as Envisat, Landsat, whose data are being used for schistosomiasis monitoring. The application potential of Sentinel satellites for the schistosomiasis monitoring will be concluded in the end, which will benefit for the mission operation, model development, etc.
Kinung'hi, Safari M; Mazigo, Humphrey D; Dunne, David W; Kepha, Stella; Kaatano, Godfrey; Kishamawe, Coleman; Ndokeji, Samuel; Angelo, Teckla; Nuwaha, Fred
2017-11-09
Schistosomiasis represents a major public health problem in Tanzania despite ongoing national control efforts. This study examined whether intestinal schistosomiasis is associated with malaria and assessed the contribution of intestinal schistosomiasis and malaria on anaemia and undernutrition in school children in Mara region, North-western Tanzania. Stool samples were collected from each of 928 school children randomly selected from 5 schools and examined for intestinal schistosomiasis using the Kato Katz method. Finger prick blood samples were collected and examined for malaria parasites and haemoglobin concentrations using the Giemsa stain and Haemocue methods, respectively. Nutritional status was assessed by taking anthropometric measurements. The overall prevalence and infection intensity of S. mansoni was 85.6% (794/928) and 192 (100-278), respectively. The prevalence of malaria was 27.4% (254/928) with significant differences among villages (χ 2 = 96.11, p < 0.001). The prevalence of anaemia was 42.3% (392/928) with significant differences among villages (χ 2 = 39.61, p < 0.001). The prevalence of stunting, thinness and underweight was 21, 6.8 and 1.3%, respectively. Stunting varied significantly by sex (χ 2 = 267.8, p < 0.001), age group (χ 2 = 96.4, p < 0.001) and by village (χ 2 = 20.5, p < 0.001). Out of the 825 infected children, 217 (26.4%) had multiple parasite infections (two to three parasites). The prevalence of co-infections occurred more frequently in boys than in girls (χ 2 = 21.65, p = 0.010). Mean haemoglobin concentrations for co-infected children was significantly lower than that of children not co-infected (115.2 vs 119.6; t = 0.01, p = 0.002). Co-infected children were more likely to be stunted than children who were not co-infected (χ 2 = 11.6, p = 0.003). On multivariate analysis, age group, village of residence and severe anaemia were significant predictors of stunting after adjusting for sex and infection status. Intestinal schistosomiasis and malaria are prevalent in Mara region. Coinfections of these parasites as well as chronic undernutrition were also common. We recommend Mara region to be included in national schistosomiasis control programmes.
[Strategic thinking of the construction of national schistosomiasis laboratory network in China].
Qin, Zhi-Qiang; Xu, Jing; Feng, Ting; Zhu, Hong-Qing; Li, Shi-Zhu; Xiao, Ning; Zhou, Xiao-Nong
2013-08-01
A schistosomiasis laboratory network and its quality assurance system have been built and will be more and more perfect in China. This paper introduces the present situation of schistosomiasis diagnosis in China and expounds the basic ideas and the progress in the construction of schistosomiasis network platform. Furthermore, the face of schistosomiasis diagnosis network platform construction and operation of the challenge and the future work will be put forward in the latter part of this paper.
Savaya Alkalay, Amit; Rosen, Ohad; Sokolow, Susanne H; Faye, Yacinthe P W; Faye, Djibril S; Aflalo, Eliahu D; Jouanard, Nicolas; Zilberg, Dina; Huttinger, Elizabeth; Sagi, Amir
2014-08-01
Early malacological literature suggests that the outbreak of schistosomiasis, a parasitic disease transmitted by aquatic snails, in the Senegal River basin occurred due to ecological changes resulting from the construction of the Diama dam. The common treatment, the drug praziquantel, does not protect from the high risk of re-infection due to human contact with infested water on a daily basis. The construction of the dam interfered with the life cycle of the prawn Macrobrachium vollenhovenii by blocking its access to breeding grounds in the estuary. These prawns were demonstrated to be potential biological control agents, being effective predators of Schistosoma-susceptible snails. Here, we propose a responsible restocking strategy using all-male prawn populations which could provide sustainable disease control. Male prawns reach a larger size and have a lower tendency to migrate than females. We, therefore, expect that periodic restocking of all-male juveniles will decrease the prevalence of schistosomiasis and increase villagers' welfare. In this interdisciplinary study, we examined current prawn abundance along the river basin, complemented with a retrospective questionnaire completed by local fishermen. We revealed the current absence of prawns upriver and thus demonstrated the need for restocking. Since male prawns are suggested to be preferable for bio-control, we laid the molecular foundation for production of all-male M. vollenhovenii through a complete sequencing of the insulin-like androgenic gland-encoding gene (IAG), which is responsible for sexual differentiation in crustaceans. We also conducted bioinformatics and immunohistochemistry analyses to demonstrate the similarity of this sequence to the IAG of another Macrobrachium species in which neo-females are produced and their progeny are 100% males. At least 100 million people at risk of schistosomiasis are residents of areas that experienced water management manipulations. Our suggested non-breeding sustainable model of control-if proven successful-could prevent re-infections and thus prove useful throughout the world.
Lo, Nathan C.; Addiss, David G.; Hotez, Peter J.; King, Charles H.; Stothard, J. Russell; Evans, Darin S.; Colley, Daniel G.; Lin, William; Coulibaly, Jean T.; Bustinduy, Amaya L.; Raso, Giovanna; Bendavid, Eran; Bogoch, Isaac I.; Fenwick, Alan; Savioli, Lorenzo; Molyneux, David; Utzinger, Jürg; Andrews, Jason R.
2016-01-01
Summary In 2001, the World Health Assembly (WHA) passed the landmark WHA 54.19 resolution for global scale up of mass administration of anthelminthic drugs for morbidity control of schistosomiasis and soil-transmitted helminthiasis (STH), which affect over 1.5 billion of the world's poorest people. Since then, over a decade of research and experience has yielded critical new knowledge on the control and elimination of these helminthiases. However, the global strategy has remained largely unchanged since the original 2001 WHA resolution and associated World Health Organization (WHO) guidelines on preventive chemotherapy. Here, we highlight recent advances that, taken together, support a call to revise the global strategy and guidelines for preventive chemotherapy and complementary interventions against schistosomiasis and STH. This includes the development of guidance that is specific to goals of “morbidity control” and “elimination of transmission.” We quantify the result of forgoing this opportunity by computing the yearly disease burden, mortality, and lost economic productivity associated with maintaining status quo. Without change, we estimate that the population of sub-Saharan Africa will likely lose 2.3 million disability-adjusted life years and US$3.5 billion of economic productivity every year, which is comparable to recent acute epidemics, including the 2014 Ebola and 2015 Zika epidemics. We propose that the time is now to strengthen the global strategy to address the substantial disease burden of schistosomiasis and STH. PMID:27914852
Interventions for treating schistosomiasis mansoni.
Saconato, H; Atallah, A
2000-01-01
Schistosomiasis is a parasite that is carried by freshwater snails. The intestinal form infects the intestine, liver and spleen and can be fatal. The objective of this review was to assess the effects of oxamniquine or praziquantel for treating Schistosomiasis mansoni We searched the Cochrane Infectious Diseases Group trials register, the Cochrane Controlled Trials Register, Medline, Lilacs and reference lists of articles. The Revista da Sociedade Brasileira de Medicina Tropical and Brazilian Tropical Medicine Congress abstracts were handsearched Randomised and quasi-randomised trials comparing oxamniquine and/or praziquantel to placebo for the treatment of Schistosomiasis mansoni. Two reviewers independently assessed trial quality and extracted data. Thirteen trials met the inclusion criteria. Praziquantel and oxamniquine were effective in curing Schistosoma mansoni infection when compared to placebo. In Africa, praziquantel 40 mg/Kg is more effective than oxamniquine 15 mg/Kg in individuals older than 14 years (OR 3.54, 95%CI 1.70, 7.38), but no difference was found when compared with oxamniquine 30 mg/Kg (OR 0.29, 95%CI 0.08, 1.01). In Brazil, praziquantel was equally effective when compared with oxamniquine in individuals older than 14 years (OR 1.70, 95%CI 0.83, 3.49). Both drugs appear safe. There was no difference in reinfection rate between zinc supplementation and placebo (OR 0.82, 95%CI 0.47, 1.41). IPraziquantel and oxamniquine both appear to be effective for the treatment of Schistosomiasis mansoni, although lower doses of oxamniquine (less than 30 milligrams per kilogram) may not be as effective.
NASA Astrophysics Data System (ADS)
Tay, S. K.; Amekudzi, L. K.; Tagoe, G.
2012-04-01
A study has been conducted to determine the impact of climate variability on Schistosoma haematobium infection among patients and school children in Sunyani between 2006 and 2009. Urine samples from the subjects were collected and examined in the laboratory using the filtration technique for the detection and quantification of Schistosomiasis haematobium eggs. The prevalence rate of urinary schistosomiasis at the Sunyani Regional Hospital for 2006, 2007, 2008 and 2009 were found to be 0.24%, 0.55%, 0.55% and 0.75% respectively while that for Methodist Junior High School in 2008 and 2009 were 60.1% and 60.3% respectively. A decrease in the relative humidity and average annual rainfall were identified as factors contributory to the increase in urinary Schistosomiasis prevalence rate. The temperature values obtained throughout the study period did not have any significant effect on the prevalence rate. The temperature values, however, were those that enhanced cercarial incubation (15-35˚C) with a resultant increase in shedding of cercariae leading to more infections among water contacts. The infection rate due to stream Amama was 20.1%, while that due to river Tano was 36.6%. The highest risk group was children aged 15-19 years. Praziquantel was administered to treat the infection, producing a cure rate of 93%. Recognition of urinary Schistosomiasis as a public health problem in Ghana is the main challenge to prevention and control of the disease.
Brendel, Benjamin
2017-09-01
This article analyzes the modernization campaigns in Egypt in the 1960s and early 1970s. The regulation of the Nile by the Aswan High Dam and the resulting irrigation projects caused the rate of schistosomiasis infestation in the population to rise. The result was a discourse between experts from the global north and Egyptian elites about modernization, development aid, dam building and health care. The fight against schistosomiasis was like a cipher, which combined different power-laden concepts and arguments. This article will decode the cipher and allow a deeper look into the contemporary dimensions of power bound to this subject. The text is conceived around three thematic axes. The first deals with the discursive interplay of modernization, health and development aid in and for Egypt. The second focuses on far-reaching and long-standing arguments within an international expert discourse about these concepts. Finally, the third presents an exemplary case study of West German health and development aid for fighting schistosomiasis in the Egyptian Fayoum oasis.
Schistosomiasis in Belgian military personnel returning from the Democratic Republic of Congo.
Aerssens, Cptannelies; De Vos, Daniel; Pirnay, Jean-Paul; Yansouni, Cedric; Clerinx, Joannes; Van Gompel, Alfons; Soentjens, Patrick
2011-11-01
The detection of schistosomiasis cases among Belgian military personnel returning from a mission in the Democratic Republic of Congo (DRC) prompted a nested case-control study of all military personnel deployed in the DRC between 2005 and 2008 to identify all infections and to start appropriate treatment. Of 197 patients exposed at Lake Tanganyika in the Kalemie area of DRC, 49 (24.9%) were diagnosed with schistosomiasis. Swimming was significantly more frequent than wading in the seropositive group than in the seronegative group (88.9% vs. 73.6%; odds ratio [OR], 2.86; 95% confidence interval [CI], 0.97-9.01). Thirty-one of 49 patients (63.3%) were symptomatic; including skin problems in 34.7%, respiratory symptoms in 12.2%, fever in 14.3%, and 51.0% with gastrointestinal problems. Median eosinophil counts were significantly higher in seropositive patients (375 vs. 138 per tL; Wilcoxon rank sum test [Ws] = 10,559.00; p < 0.01; r = -0.49). In total, 20 (40.8%) of the 49 patients were treated for symptomatic infections and the remainder for asymptomatic schistosomiasis. Our study emphasizes the need for active systematic post-tropical screening in military personnel after deployment to Schistosoma-endemic regions of the world.
Sokolow, Susanne H.; Jones, Isabel J.; Jocque, Merlijn M. T.; La, Diana; Cords, Olivia; Knight, Anika; Lund, Andrea; Wood, Chelsea L.; Lafferty, Kevin D.; Hoover, Christopher M.; Collender, Phillip A.; Remais, Justin V.; Lopez-Carr, David; Fisk, Jonathan; Kuris, Armand M.; De Leo, Giulio A.
2017-01-01
Dams have long been associated with elevated burdens of human schistosomiasis, but how dams increase disease is not always clear, in part because dams have many ecological and socio-economic effects. A recent hypothesis argues that dams block reproduction of the migratory river prawns that eat the snail hosts of schistosomiasis. In the Senegal River Basin, there is evidence that prawn populations declined and schistosomiasis increased after completion of the Diama Dam. Restoring prawns to a water-access site upstream of the dam reduced snail density and reinfection rates in people. However, whether a similar cascade of effects (from dams to prawns to snails to human schistosomiasis) occurs elsewhere is unknown. Here, we examine large dams worldwide and identify where their catchments intersect with endemic schistosomiasis and the historical habitat ranges of large, migratory Macrobrachium spp. prawns. River prawn habitats are widespread, and we estimate that 277–385 million people live within schistosomiasis-endemic regions where river prawns are or were present (out of the 800 million people who are at risk of schistosomiasis). Using a published repository of schistosomiasis studies in sub-Saharan Africa, we compared infection before and after the construction of 14 large dams for people living in: (i) upstream catchments within historical habitats of native prawns, (ii) comparable undammed watersheds, and (iii) dammed catchments beyond the historical reach of migratory prawns. Damming was followed by greater increases in schistosomiasis within prawn habitats than outside prawn habitats. We estimate that one third to one half of the global population-at-risk of schistosomiasis could benefit from restoration of native prawns. Because dams block prawn migrations, our results suggest that prawn extirpation contributes to the sharp increase of schistosomiasis after damming, and points to prawn restoration as an ecological solution for reducing human disease.
NASA Astrophysics Data System (ADS)
Sokolow, S. H.; Jones, I. J.; La, D.; Cords, O.; Knight, A.; Lund, A.; Wood, C. L.; Lafferty, K. D.; Kuris, A. M.; Hoover, C.; Collender, P. A.; Remais, J.; Lopez-Carr, D.; De Leo, G.
2016-12-01
Dams have long been associated with elevated burdens of human schistosomiasis, but how dams increase disease is not always clear, in part because dams have many ecological and socioeconomic effects. A recent hypothesis argues that dams block reproduction of the migratory river prawns that eat the snail hosts of schistosomiasis. In the Senegal River Basin, there is evidence that prawn populations declined and schistosomiasis increased after completion of the Diama Dam. Restoring prawns to a water-access site upstream of the dam reduced snail density and reinfection rates in people. However, whether a similar cascade of effects (from dams to prawns to snails to human schistosomiasis) occurs elsewhere is unknown. Here, we examine large dams worldwide and identify where their catchments intersect with endemic schistosomiasis and the historical habitat ranges of large, migratory Macrobrachium spp. prawns. River prawn habitats are widespread, and we estimate that 277 to 385 million people live within schistosomiasis-endemic regions where river prawns are or were present (out of the 800 million people who are at risk of schistosomiasis). Using a published repository of schistosomiasis studies in sub-Saharan Africa, we compared infection before and after the construction of 14 large dams for people living in: (1) upstream catchments within historical habitats of native prawns, (2) comparable undammed watersheds, and (3) dammed catchments beyond the historical reach of migratory prawns. Damming was followed by greater increases in schistosomiasis within prawn habitats than outside prawn habitats. We estimate that one third to one half of the global population-at-risk of schistosomiasis could benefit from restoring native prawns. Because dams block prawn migrations, our results suggest that prawn extirpation contributes to the sharp increase of schistosomiasis after damming, and points to prawn restoration as an ecological solution for reducing human disease.
Sokolow, Susanne H; Jones, Isabel J; Jocque, Merlijn; La, Diana; Cords, Olivia; Knight, Anika; Lund, Andrea; Wood, Chelsea L; Lafferty, Kevin D; Hoover, Christopher M; Collender, Phillip A; Remais, Justin V; Lopez-Carr, David; Fisk, Jonathan; Kuris, Armand M; De Leo, Giulio A
2017-06-05
Dams have long been associated with elevated burdens of human schistosomiasis, but how dams increase disease is not always clear, in part because dams have many ecological and socio-economic effects. A recent hypothesis argues that dams block reproduction of the migratory river prawns that eat the snail hosts of schistosomiasis. In the Senegal River Basin, there is evidence that prawn populations declined and schistosomiasis increased after completion of the Diama Dam. Restoring prawns to a water-access site upstream of the dam reduced snail density and reinfection rates in people. However, whether a similar cascade of effects (from dams to prawns to snails to human schistosomiasis) occurs elsewhere is unknown. Here, we examine large dams worldwide and identify where their catchments intersect with endemic schistosomiasis and the historical habitat ranges of large, migratory Macrobrachium spp. prawns. River prawn habitats are widespread, and we estimate that 277-385 million people live within schistosomiasis-endemic regions where river prawns are or were present (out of the 800 million people who are at risk of schistosomiasis). Using a published repository of schistosomiasis studies in sub-Saharan Africa, we compared infection before and after the construction of 14 large dams for people living in: (i) upstream catchments within historical habitats of native prawns, (ii) comparable undammed watersheds, and (iii) dammed catchments beyond the historical reach of migratory prawns. Damming was followed by greater increases in schistosomiasis within prawn habitats than outside prawn habitats. We estimate that one third to one half of the global population-at-risk of schistosomiasis could benefit from restoration of native prawns. Because dams block prawn migrations, our results suggest that prawn extirpation contributes to the sharp increase of schistosomiasis after damming, and points to prawn restoration as an ecological solution for reducing human disease.This article is part of the themed issue 'Conservation, biodiversity and infectious disease: scientific evidence and policy implications'. © 2017 The Authors.
Jones, Isabel J.; Jocque, Merlijn; La, Diana; Cords, Olivia; Knight, Anika; Lund, Andrea; Lafferty, Kevin D.; Hoover, Christopher M.; Collender, Phillip A.; Remais, Justin V.; Lopez-Carr, David; Kuris, Armand M.; De Leo, Giulio A.
2017-01-01
Dams have long been associated with elevated burdens of human schistosomiasis, but how dams increase disease is not always clear, in part because dams have many ecological and socio-economic effects. A recent hypothesis argues that dams block reproduction of the migratory river prawns that eat the snail hosts of schistosomiasis. In the Senegal River Basin, there is evidence that prawn populations declined and schistosomiasis increased after completion of the Diama Dam. Restoring prawns to a water-access site upstream of the dam reduced snail density and reinfection rates in people. However, whether a similar cascade of effects (from dams to prawns to snails to human schistosomiasis) occurs elsewhere is unknown. Here, we examine large dams worldwide and identify where their catchments intersect with endemic schistosomiasis and the historical habitat ranges of large, migratory Macrobrachium spp. prawns. River prawn habitats are widespread, and we estimate that 277–385 million people live within schistosomiasis-endemic regions where river prawns are or were present (out of the 800 million people who are at risk of schistosomiasis). Using a published repository of schistosomiasis studies in sub-Saharan Africa, we compared infection before and after the construction of 14 large dams for people living in: (i) upstream catchments within historical habitats of native prawns, (ii) comparable undammed watersheds, and (iii) dammed catchments beyond the historical reach of migratory prawns. Damming was followed by greater increases in schistosomiasis within prawn habitats than outside prawn habitats. We estimate that one third to one half of the global population-at-risk of schistosomiasis could benefit from restoration of native prawns. Because dams block prawn migrations, our results suggest that prawn extirpation contributes to the sharp increase of schistosomiasis after damming, and points to prawn restoration as an ecological solution for reducing human disease. This article is part of the themed issue ‘Conservation, biodiversity and infectious disease: scientific evidence and policy implications’. PMID:28438916
Risk factors for schistosomiasis transmission among school children in Gwanda district, Zimbabwe.
Nyati-Jokomo, Zibusiso; Chimbari, Moses J
2017-11-01
A nationwide cross sectional schistosomiasis survey conducted in 2011 in 280 primary schools found a prevalence rate of 22.7%. This warranted an intervention with Mass Drug Administration at all schools in line with WHO guidelines. This study aimed to identify risk factors for schistosomiasis transmission among Grade 3 children at two primary schools in Gwanda district. A descriptive cross sectional survey which was part of a larger study on Malaria and Bilharzia in Southern Africa (MABISA) was conducted. Grade 3 children (n=120) attending two purposively selected rural primary schools in Dombo and Ntalale in Gwanda were respondents. Data on socio-demographic characteristics and risk factors which included knowledge and practices were collected using a pretested interviewer administered questionnaire. Of the 120 children, 98 (81.7%) of the children indicated that they did not consistently use the toilet. The other risk factors for schistosomiasis were bathing and swimming in rivers and dams 80 (66.7%), watering the vegetable gardens using unprotected water sources 77 (64.7%) and crossing rivers on their way to school barefooted 31.7%. History of schistosomiasis cases based on self-reporting indicated that of the 9 children 7 were girls. There was poor knowledge of schistosomiasis among the children with 54% of the children indicating that they had never heard about the disease. Misconceptions on the causes of schistosomiasis which included drinking dirty water, mosquitoes and flies as the causes of schistosomiasis were reported by the children. Parents were cited as the least disseminators of information on schistosomiasis with only 4 out of the 120 children having received information from their parents. Frequent contact with unprotected water sources, non-use of the toilet, and lack of information on schistosomiasis could predispose the children to infection. There is need to raise awareness about schistosomiasis in schools and the community to reduce the risk of contracting schistosomiasis due to risky behaviour. Copyright © 2017. Published by Elsevier B.V.
Wang, Ji-sheng; Chen, Jian-feng; Liu, Ya-hong; Song, Liang-liang
2016-02-01
To understand the source of knowledge on schistosomiasis prevention and control and the acceptable degree on different propagation patterns of population in Jingjiang City after schistosomiasis transmission-interrupted, so as to provide the evidence for the production of suitable materials for health education. The permanent residents, floating population as well as the primary school students in Grade 5 and 6 in riverside regions in Jingjiang City were selected as the investigation objects, the information propagation condition and the knowledge source, and the expected propagation patterns were investigated by questionnaires. The popularizing rates on the television, computer and mobile phone of the villagers were 99.81%, 84.16% and 87.78%, respectively. Both the two investigated schools had the independent TV network, broadcast and multimedia, and all the computer classroom could connected to Internet. The main sources on schistosomiasis control of permanent residents and floating population were folders and the exhibition board (62.0% and 40.5% respectively), the substantial material (42.0% and 33.5% respectively) and TV (40.5% and 36.0% respectively), while those of the students were video CD (100%), substantial material (99.5%) and folders and the exhibition boards (84.2%). The propagation ways with high acceptable degrees among the residents and floating population were substantial material, folders and the exhibition boards and short messages by mobile phone, while those among the students were video CD, substantial material, folders and the exhibition boards. The material on health education should be targeted to the demands of the different populations and their condition of information propagation, in addition, the Internet material should be developed and the communicational channels should be broaden.
Zhou, Sha; Jin, Xin; Li, Yalin; Li, Wei; Chen, Xiaojun; Xu, Lei; Zhu, Jifeng; Xu, Zhipeng; Zhang, Yang; Liu, Feng; Su, Chuan
2016-01-01
Background More than 220 million people worldwide are chronically infected with schistosomes, causing severe disease or even death. The major pathological damage occurring in schistosomiasis is attributable to the granulomatous inflammatory response and liver fibrosis induced by schistosome eggs. The inflammatory response is tightly controlled and parallels immunosuppressive regulation, constantly maintaining immune homeostasis and limiting excessive immunopathologic damage in important host organs. It is well known that the activation of programmed death 1 (PD-1) signaling causes a significant suppression of T cell function. However, the roles of PD-1 signaling in modulating CD4+ T cell responses and immunopathology during schistosome infection, have yet to be defined. Methodology/Principal Findings Here, we show that PD-1 is upregulated in CD4+ T cells in Schistosoma japonicum (S. japonicum)-infected patients. We also show the upregulation of PD-1 expression in CD4+ T cells in the spleens, mesenteric lymph nodes, and livers of mice with S. japonicum infection. Finally, we found that the blockade of PD-1 signaling enhanced CD4+ T helper 2 (Th2) cell responses and led to more severe liver immunopathology in mice with S. japonicum infection, without a reduction of egg production or deposition in the host liver. Conclusions/Significance Overall, our study suggests that PD-1 signaling is specifically induced to control Th2-associated inflammatory responses during schistosome infection and is beneficial to the development of PD-1-based control of liver immunopathology. PMID:27792733
Nyandwi, E; Veldkamp, A; Amer, S; Karema, C; Umulisa, I
2017-10-25
Schistosomiasis mansoni constitutes a significant public health problem in Rwanda. The nationwide prevalence mapping conducted in 2007-2008 revealed that prevalence per district ranges from 0 to 69.5% among school children. In response, mass drug administration campaigns were initiated. However, a few years later some additional small-scale studies revealed the existence of areas of high transmission in districts formerly classified as low endemic suggesting the need for a more accurate methodology for identification of hotspots. This study investigated if confirmed cases of schistosomiasis recorded at health facility level can be used to, next to existing prevalence data, detect geographically more accurate hotspots of the disease and its associated risk factors. A GIS-based spatial and statistical analysis was carried out. Confirmed cases, recorded at primary health facilities level, were combined with demographic data to calculate incidence rates for each of 367 health facility service area. Empirical Bayesian smoothing was used to deal with rate instability. Incidence rates were compared with prevalence data to identify their level of agreement. Spatial autocorrelation of the incidence rates was analyzed using Moran's Index, to check if spatial clustering occurs. Finally, the spatial relationship between schistosomiasis distribution and potential risk factors was assessed using multiple regression. Incidence rates for 2007-2008 were highly correlated with prevalence values (R 2 = 0.79), indicating that in the case of Rwanda incidence data can be used as a proxy for prevalence data. We observed a focal distribution of schistosomiasis with a significant spatial autocorrelation (Moran's I > 0: 0,05-0.20 and p ≤ 0,05), indicating the occurrence of hotspots. Regarding risk factors, it was identified that the spatial pattern of schistosomiasis is significantly associated with wetland conditions and rice cultivation. In Rwanda the high density of health facilities and the standardized microscopic laboratory diagnostic allow the derived data to be used to complement prevalence studies to identify hotspots of schistosomiasis and its associated risk factors. This type of information, in turn, can support disease control interventions and monitoring.
Kulinkina, Alexandra V; Walz, Yvonne; Koch, Magaly; Biritwum, Nana-Kwadwo; Utzinger, Jürg; Naumova, Elena N
2018-06-04
Schistosomiasis is a water-related neglected tropical disease. In many endemic low- and middle-income countries, insufficient surveillance and reporting lead to poor characterization of the demographic and geographic distribution of schistosomiasis cases. Hence, modeling is relied upon to predict areas of high transmission and to inform control strategies. We hypothesized that utilizing remotely sensed (RS) environmental data in combination with water, sanitation, and hygiene (WASH) variables could improve on the current predictive modeling approaches. Schistosoma haematobium prevalence data, collected from 73 rural Ghanaian schools, were used in a random forest model to investigate the predictive capacity of 15 environmental variables derived from RS data (Landsat 8, Sentinel-2, and Global Digital Elevation Model) with fine spatial resolution (10-30 m). Five methods of variable extraction were tested to determine the spatial linkage between school-based prevalence and the environmental conditions of potential transmission sites, including applying the models to known human water contact locations. Lastly, measures of local water access and groundwater quality were incorporated into RS-based models to assess the relative importance of environmental and WASH variables. Predictive models based on environmental characterization of specific locations where people contact surface water bodies offered some improvement as compared to the traditional approach based on environmental characterization of locations where prevalence is measured. A water index (MNDWI) and topographic variables (elevation and slope) were important environmental risk factors, while overall, groundwater iron concentration predominated in the combined model that included WASH variables. The study helps to understand localized drivers of schistosomiasis transmission. Specifically, unsatisfactory water quality in boreholes perpetuates reliance of surface water bodies, indirectly increasing schistosomiasis risk and resulting in rapid reinfection (up to 40% prevalence six months following preventive chemotherapy). Considering WASH-related risk factors in schistosomiasis prediction can help shift the focus of control strategies from treating symptoms to reducing exposure.
[Epidemiological investigation on confirmed cases of schistosomiasis in Hubei Province].
Yan-Yan, Chen; Shun-Xiang, Cai; Guo, Li; Ying, Xiao; Xiao-Wei, Shan; Juan, Zhang; Jian-Bing, Liu
2016-05-10
To grasp the distribution and epidemiology of confirmed cases of schistosomiasis in Hubei Province, so as to provide the evidence for promoting the prevention and control work. The confirmed cases of schistosomiasis in Hubei Province from 2010 to 2014 were epidemiologically investigated, and the prevalence characteristics and main influencing factors were analyzed. A total of 10 102 confirmed cases from 2010 to 2014 were surveyed. There were 1 062 local infected patients, accounting for 10.51% and including 354 repeated infections and 17 newly infected. There were 290 foreigninfected patients, accounting for 2.87%, with 206 repeated infection cases and 84 newly infected. There were 8 750 historical patients, including 2 229 patients who leaked the former schistosomiasis investigations, accounting for 22.06%; 570 patients missed treatment, accounting for 5.64%; 3 640 patients were treated with non-standard therapy, accounting for 36.03%; 2 311 patients were treated with poor medication efficacy, accounting for 22.88%. The multivariate non-conditional Logistic regression, targeting at confirmed cases in 2014, showed that, for the leaking investigations, the potential risk factors included the age, educational level, and latrine renovation ( b >0, OR >1), the protective factors were the times of previous treatment, cattle feeding in villager team, and Oncomelania hupensis snails in surroundings ( b <0, OR <1); for the treatment-missing, the age, educational level, snails in the surroundings of residence were risk factors ( b <0, OR <1); for the substandard treatment, the risk factors included the occupation and snails in the surroundings of residence ( b >0, OR >1), and the educational level and snails in the own field were protective factors ( b <0, OR <1). The epidemiological investigation on the confirmed cases of schistosomiasis could grasp the epidemic factors so as to improve the management and carry out the scientific control.
The situation of hepatosplenic schistosomiasis in Brazil today.
Andrade, Z A
1998-01-01
Specific chemotherapy against schistosomiasis together with environmental changes occurring in endemic areas of Brazil are causing a revolution in the clinico-pathological presentation of the disease when comparing to date from 10 to 15 years ago. To update the subject, an inquiry was made among the most experienced Brazilian investigators in this field. They agree that a decrease of about 50 to 70% in prevalence, and an even higher decrease in incidence are taking place in Brazil today. The prevalence of schistosome-infection has decreased in some areas and increased in other, with spreading sometimes occurring to peri-urban regions, indicating that schistosomiasis control depends on the application of multiple measures. General clinical and pathological manifestations related to hepatosplenic disease, such as ascites, gastric hemorrhages, big-spleen syndrome, cor pulmonale, glomerulopathy, etc. are also less severe nowadays than they used to be in the past.
Schistosomiasis: Geospatial Surveillance and Response Systems in Southeast Asia
NASA Astrophysics Data System (ADS)
Malone, John; Bergquist, Robert; Rinaldi, Laura; Xiao-nong, Zhou
2016-10-01
Geographic information system (GIS) and remote sensing (RS) from Earth-observing satellites offer opportunities for rapid assessment of areas endemic for vector-borne diseases including estimates of populations at risk and guidance to intervention strategies. This presentation deals with GIS and RS applications for the control of schistosomiasis in China and the Philippines. It includes large-scale risk mapping including identification of suitable habitats for Oncomelania hupensis, the intermediate host snail of Schistosoma japonicum. Predictions of infection risk are discussed with reference to ecological transformations and the potential impact of climate change and the potential for long-term temperature increases in the North as well as the impact on rivers, lakes and water resource developments. Potential integration of geospatial mapping and modeling in schistosomiasis surveillance and response systems in Asia within Global Earth Observation System of Systems (GEOSS) guidelines in the health societal benefit area is discussed.
Lo, Nathan C; Gurarie, David; Yoon, Nara; Coulibaly, Jean T; Bendavid, Eran; Andrews, Jason R; King, Charles H
2018-01-23
Schistosomiasis is a parasitic disease that affects over 240 million people globally. To improve population-level disease control, there is growing interest in adding chemical-based snail control interventions to interrupt the lifecycle of Schistosoma in its snail host to reduce parasite transmission. However, this approach is not widely implemented, and given environmental concerns, the optimal conditions for when snail control is appropriate are unclear. We assessed the potential impact and cost-effectiveness of various snail control strategies. We extended previously published dynamic, age-structured transmission and cost-effectiveness models to simulate mass drug administration (MDA) and focal snail control interventions against Schistosoma haematobium across a range of low-prevalence (5-20%) and high-prevalence (25-50%) rural Kenyan communities. We simulated strategies over a 10-year period of MDA targeting school children or entire communities, snail control, and combined strategies. We measured incremental cost-effectiveness in 2016 US dollars per disability-adjusted life year and defined a strategy as optimally cost-effective when maximizing health gains (averted disability-adjusted life years) with an incremental cost-effectiveness below a Kenya-specific economic threshold. In both low- and high-prevalence settings, community-wide MDA with additional snail control reduced total disability by an additional 40% compared with school-based MDA alone. The optimally cost-effective scenario included the addition of snail control to MDA in over 95% of simulations. These results support inclusion of snail control in global guidelines and national schistosomiasis control strategies for optimal disease control, especially in settings with high prevalence, "hot spots" of transmission, and noncompliance to MDA. Copyright © 2018 the Author(s). Published by PNAS.
Yoon, Nara; Coulibaly, Jean T.; Bendavid, Eran; Andrews, Jason R.; King, Charles H.
2018-01-01
Schistosomiasis is a parasitic disease that affects over 240 million people globally. To improve population-level disease control, there is growing interest in adding chemical-based snail control interventions to interrupt the lifecycle of Schistosoma in its snail host to reduce parasite transmission. However, this approach is not widely implemented, and given environmental concerns, the optimal conditions for when snail control is appropriate are unclear. We assessed the potential impact and cost-effectiveness of various snail control strategies. We extended previously published dynamic, age-structured transmission and cost-effectiveness models to simulate mass drug administration (MDA) and focal snail control interventions against Schistosoma haematobium across a range of low-prevalence (5–20%) and high-prevalence (25–50%) rural Kenyan communities. We simulated strategies over a 10-year period of MDA targeting school children or entire communities, snail control, and combined strategies. We measured incremental cost-effectiveness in 2016 US dollars per disability-adjusted life year and defined a strategy as optimally cost-effective when maximizing health gains (averted disability-adjusted life years) with an incremental cost-effectiveness below a Kenya-specific economic threshold. In both low- and high-prevalence settings, community-wide MDA with additional snail control reduced total disability by an additional 40% compared with school-based MDA alone. The optimally cost-effective scenario included the addition of snail control to MDA in over 95% of simulations. These results support inclusion of snail control in global guidelines and national schistosomiasis control strategies for optimal disease control, especially in settings with high prevalence, “hot spots” of transmission, and noncompliance to MDA. PMID:29301964
Coltart, Cordelia E M; Chew, Anastasia; Storrar, Neill; Armstrong, Margaret; Suff, Natalie; Morris, Leila; Chiodini, Peter L; Whitty, Christopher J M
2015-03-01
Schistosomiasis in returning travellers is one of the most common imported tropical infections with potentially serious complications, which are preventable if diagnosed early. A review was undertaken of consecutive cases of schistosomiasis presenting at the Hospital for Tropical Diseases, London, UK from 1997 to 2012. All 1020 schistosomiasis cases were from Africa and Schistosoma haematobium was the predominant species in those with microscopy confirmed schistosomiasis (74.2%, 204/252). The number of cases of imported schistosomiasis is decreasing steadily as a proportion of travellers seen. The majority of cases were in travellers originating from non-endemic settings (81.8%, 707/864). The most common symptom was of genitourinary complaints (22.6%, 230/1020), predominantly haematuria (17.8%, 181/1020); 36.1% (368) of cases were asymptomatic. Overall 42% had eosinophilia, and 62% of ova positive S. haematobium cases had haematuria on urine dip. Thus, no single screening tool was sufficient to identify or rule out schistosomiasis when used alone. Serology testing was a more sensitive tool in travellers than in other patients (p=0.007). The prevalence of schistosomiasis in presenting travellers is decreasing. The predominant presenting species has shifted from S. mansoni to S. haematobium. No single test can reliably diagnose schistosomiasis, with eosinophilia and urine dip having low sensitivity. Clinicians need to continue to undertake a wide spectrum of diagnostic tests to ensure cases of schistosomiasis are not missed. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Steinmann, Peter; Keiser, Jennifer; Bos, Robert; Tanner, Marcel; Utzinger, Jürg
2006-07-01
An estimated 779 million people are at risk of schistosomiasis, of whom 106 million (13.6%) live in irrigation schemes or in close proximity to large dam reservoirs. We identified 58 studies that examined the relation between water resources development projects and schistosomiasis, primarily in African settings. We present a systematic literature review and meta-analysis with the following objectives: (1) to update at-risk populations of schistosomiasis and number of people infected in endemic countries, and (2) to quantify the risk of water resources development and management on schistosomiasis. Using 35 datasets from 24 African studies, our meta-analysis showed pooled random risk ratios of 2.4 and 2.6 for urinary and intestinal schistosomiasis, respectively, among people living adjacent to dam reservoirs. The risk ratio estimate for studies evaluating the effect of irrigation on urinary schistosomiasis was in the range 0.02-7.3 (summary estimate 1.1) and that on intestinal schistosomiasis in the range 0.49-23.0 (summary estimate 4.7). Geographic stratification showed important spatial differences, idiosyncratic to the type of water resources development. We conclude that the development and management of water resources is an important risk factor for schistosomiasis, and hence strategies to mitigate negative effects should become integral parts in the planning, implementation, and operation of future water projects.
Spatiotemporal Patterns of Schistosomiasis-Related Deaths, Brazil, 2000–2011
Martins-Melo, Francisco Rogerlândio; Pinheiro, Marta Cristhiany Cunha; Ramos, Alberto Novaes; Alencar, Carlos Henrique; Bezerra, Fernando Schemelzer de Moraes
2015-01-01
We analyzed spatiotemporal patterns of 8,756 schistosomiasis-related deaths in Brazil during 2000–2011 and identified high-risk clusters of deaths, mainly in highly schistosomiasis-endemic areas along the coast of Brazil’s Northeast Region. Schistosomiasis remains a neglected public health problem with a high number of deaths in disease-endemic and emerging focal areas. PMID:26401716
SATAYATHUM, SUDTIDA A.; MUCHIRI, ERIC M.; OUMA, JOHN H.; WHALEN, CHRISTOPHER C.; KING, CHARLES H.
2010-01-01
Urinary schistosomiasis remains a significant burden for Africa and the Middle East. Success of regional control strategies will depend, in part, on what influence local environmental and behavioral factors have on individual risk for primary infection and/or reinfection. Based on experience in a multi-year (1984–1992), school-based Schistosoma haematobium control program in Coast Province, Kenya, we examined risk for infection outcomes as a function of age, sex, pretreatment morbidity, treatment regimen, water contact, and residence location, with the use of life tables and Cox proportional-hazards analysis. After adjustment, location of residence, age less than 12 years, pretreatment hematuria, and incomplete treatment were the significant independent predictors of infection, whereas sex and frequency of water contact were not. We conclude that local physical features and age-related factors play a predominant role in S. haematobium transmission in this setting. In large population-based control programs, treatment allocation strategies may need to be tailored to local conditions on a village-by-village basis. PMID:16837713
Jin, Huang; Chun-Lian, Tang; Zu-Wu, Tu; Li, Tang; Ke-Hui, Zhang; Qian, Li; Jun, Ye
2018-04-18
To prepare freeze-drying control materials of IgG antibody against Schistosoma japonicum for detection kits. The serum samples of schistosomiasis patients from endemic areas and normal people without history of schistosome infection or contact with infested water in Hubei Province were collected. All the sera were detected by the method approved by China Food and Drug Administration and selected for preparation of quality control samples. Totally twelve positive quality control materials, ten negative quality control materials, and one sensitive and one precision quality control materials were screened. According to the positive serum level, the positive degrees of quality control materials were divided into strong, medium and weak levels. The stability could be valid for one year. The freeze-drying quality control materials of IgG antibody against S. japonicum for detection kits are prepared. They are easy to use and have good stability, and therefore, they may meet the requirement of quality control for the detection of schistosomiasis diagnostics kits.
Research gaps for three main tropical diseases in the People’s Republic of China
2013-01-01
This scoping review analyzes the research gaps of three diseases: schistosomiasis japonica, malaria and echinococcosis. Based on available data in the P.R. China, we highlight the gaps between control capacity and prevalence levels, and between diagnostic/drug development and population need for treatment at different stages of the national control programme. After reviewing the literature from 848 original studies and consultations with experts in the field, the gaps were identified as follows. Firstly, the malaria research gaps include (i) deficiency of active testing in the public community and no appropriate technique to evaluate elimination, (ii) lack of sensitive diagnostic tools for asymptomatic patients, (iii) lack of safe drugs for mass administration. Secondly, gaps in research of schistosomiasis include (i) incongruent policy in the implementation of integrated control strategy for schistosomiasis, (ii) lack of effective tools for Oncomelania sp. snail control, (iii) lack of a more sensitive and cheaper diagnostic test for large population samples, (iv) lack of new drugs in addition to praziquantel. Thirdly, gaps in research of echinococcosis include (i) low capacity in field epidemiology studies, (ii) lack of sanitation improvement studies in epidemic areas, (iii) lack of a sensitivity test for early diagnosis, (iv) lack of more effective drugs for short-term treatment. We believe these three diseases can eventually be eliminated in mainland China if all the research gaps are abridged in a short period of time. PMID:23895635
Testicular Schistosomiasis Mimicking Malignancy in a Child: A Case Report.
Ekenze, Sebastian O; Modekwe, Victor O; Nzegwu, Martin A; Ekpemo, Samuel C; Ezomike, Uchechukwu O
2015-08-01
Schistosomiasis is an important communicable disease in the developing world. However, testicular schistosomiasis is an extremely rare condition. We report a case of testicular schistosomiasis mimicking testicular tumour in a 13 year old who presented with huge unilateral testicular mass. The dilemma encountered in the diagnosis and treatment of this child is presented to highlight the need for high index of suspicion of this pathology in children with testicular mass presenting from schistosomiasis-endemic areas. © The Author [2015]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Kabore, Achille; Biritwum, Nana-Kwadwo; Downs, Philip W.; Soares Magalhaes, Ricardo J.; Zhang, Yaobi; Ottesen, Eric A.
2013-01-01
Background Mapping the distribution of schistosomiasis is essential to determine where control programs should operate, but because it is impractical to assess infection prevalence in every potentially endemic community, model-based geostatistics (MBG) is increasingly being used to predict prevalence and determine intervention strategies. Methodology/Principal Findings To assess the accuracy of MBG predictions for Schistosoma haematobium infection in Ghana, school surveys were evaluated at 79 sites to yield empiric prevalence values that could be compared with values derived from recently published MBG predictions. Based on these findings schools were categorized according to WHO guidelines so that practical implications of any differences could be determined. Using the mean predicted values alone, 21 of the 25 empirically determined ‘high-risk’ schools requiring yearly praziquantel would have been undertreated and almost 20% of the remaining schools would have been treated despite empirically-determined absence of infection – translating into 28% of the children in the 79 schools being undertreated and 12% receiving treatment in the absence of any demonstrated need. Conclusions/Significance Using the current predictive map for Ghana as a spatial decision support tool by aggregating prevalence estimates to the district level was clearly not adequate for guiding the national program, but the alternative of assessing each school in potentially endemic areas of Ghana or elsewhere is not at all feasible; modelling must be a tool complementary to empiric assessments. Thus for practical usefulness, predictive risk mapping should not be thought of as a one-time exercise but must, as in the current study, be an iterative process that incorporates empiric testing and model refining to create updated versions that meet the needs of disease control operational managers. PMID:23505584
Savaya Alkalay, Amit; Rosen, Ohad; Sokolow, Susanne H.; Faye, Yacinthe P. W.; Faye, Djibril S.; Aflalo, Eliahu D.; Jouanard, Nicolas; Zilberg, Dina; Huttinger, Elizabeth; Sagi, Amir
2014-01-01
Early malacological literature suggests that the outbreak of schistosomiasis, a parasitic disease transmitted by aquatic snails, in the Senegal River basin occurred due to ecological changes resulting from the construction of the Diama dam. The common treatment, the drug praziquantel, does not protect from the high risk of re-infection due to human contact with infested water on a daily basis. The construction of the dam interfered with the life cycle of the prawn Macrobrachium vollenhovenii by blocking its access to breeding grounds in the estuary. These prawns were demonstrated to be potential biological control agents, being effective predators of Schistosoma-susceptible snails. Here, we propose a responsible restocking strategy using all-male prawn populations which could provide sustainable disease control. Male prawns reach a larger size and have a lower tendency to migrate than females. We, therefore, expect that periodic restocking of all-male juveniles will decrease the prevalence of schistosomiasis and increase villagers' welfare. In this interdisciplinary study, we examined current prawn abundance along the river basin, complemented with a retrospective questionnaire completed by local fishermen. We revealed the current absence of prawns upriver and thus demonstrated the need for restocking. Since male prawns are suggested to be preferable for bio-control, we laid the molecular foundation for production of all-male M. vollenhovenii through a complete sequencing of the insulin-like androgenic gland-encoding gene (IAG), which is responsible for sexual differentiation in crustaceans. We also conducted bioinformatics and immunohistochemistry analyses to demonstrate the similarity of this sequence to the IAG of another Macrobrachium species in which neo-females are produced and their progeny are 100% males. At least 100 million people at risk of schistosomiasis are residents of areas that experienced water management manipulations. Our suggested non-breeding sustainable model of control—if proven successful—could prevent re-infections and thus prove useful throughout the world. PMID:25166746
Controlled Release Applications of Organometals.
ERIC Educational Resources Information Center
Thayer, John S.
1981-01-01
Reviews two classes of controlled release organometals: (1) distributional, to distribute bioactive materials to control a certain target organism; and (2) protective, to protect surface or interior of some structure from attach by organisms. Specific examples are given including a discussion of controlled release for schistosomiasis. (SK)
Dawaki, Salwa; Al-Mekhlafi, Hesham M.; Ithoi, Init; Ibrahim, Jamaiah; Abdulsalam, Awatif M.; Ahmed, Abdulhamid; Sady, Hany; Nasr, Nabil A.; Atroosh, Wahib M.
2015-01-01
Background Schistosomiasis is one of the most common neglected tropical diseases, especially in the developing countries in Africa, Asia and South America, with Nigeria having the greatest number of cases of schistosomiasis worldwide. This community-based study aims to evaluate the knowledge, attitude and practices (KAP) regarding schistosomiasis among rural Hausa communities in Kano State, Nigeria. Methods A cross-sectional study was carried out among 551 participants from Hausa communities in five local government areas in Kano State, North Central Nigeria. Demographic, socioeconomic and environmental information as well as KAP data were collected using a pre-tested questionnaire. Moreover, faecal and urine samples were collected and examined for the presence of Schistosoma mansoni and S. haematobium eggs respectively. Results The overall prevalence of schistosomiasis was 17.8%, with 8.9% and 8.3% infected with S. mansoni and S. haematobium respectively, and 0.5% had co-infection of both species. Moreover, 74.5% of the participants had prior knowledge about schistosomiasis with 67.0% of them how it is transmitted and 63.8% having no idea about the preventive measures. Three-quarters of the respondents considered schistosomiasis a serious disease while their practices to prevent infections were still inadequate, with only 34.7% of them seeking treatment from clinics/hospitals. Significant associations between the KAP and age, gender, education and employment status were reported. Multiple logistic regression analysis revealed that age, gender, history of infection and educational level of the respondents were the most important factors significantly associated with the KAP on schistosomiasis among this population. Conclusions Schistosomiasis is still prevalent among Hausa communities in Nigeria and participants’ knowledge about the disease was poor. Mass drug administration, community mobilization and health education regarding the cause, transmission and prevention of schistosomiasis and education about good personal and sanitary hygiene practices should be considered in order to significantly reduce the prevalence and morbidity of infection within these communities. PMID:26606264
Dawaki, Salwa; Al-Mekhlafi, Hesham M; Ithoi, Init; Ibrahim, Jamaiah; Abdulsalam, Awatif M; Ahmed, Abdulhamid; Sady, Hany; Nasr, Nabil A; Atroosh, Wahib M
2015-01-01
Schistosomiasis is one of the most common neglected tropical diseases, especially in the developing countries in Africa, Asia and South America, with Nigeria having the greatest number of cases of schistosomiasis worldwide. This community-based study aims to evaluate the knowledge, attitude and practices (KAP) regarding schistosomiasis among rural Hausa communities in Kano State, Nigeria. A cross-sectional study was carried out among 551 participants from Hausa communities in five local government areas in Kano State, North Central Nigeria. Demographic, socioeconomic and environmental information as well as KAP data were collected using a pre-tested questionnaire. Moreover, faecal and urine samples were collected and examined for the presence of Schistosoma mansoni and S. haematobium eggs respectively. The overall prevalence of schistosomiasis was 17.8%, with 8.9% and 8.3% infected with S. mansoni and S. haematobium respectively, and 0.5% had co-infection of both species. Moreover, 74.5% of the participants had prior knowledge about schistosomiasis with 67.0% of them how it is transmitted and 63.8% having no idea about the preventive measures. Three-quarters of the respondents considered schistosomiasis a serious disease while their practices to prevent infections were still inadequate, with only 34.7% of them seeking treatment from clinics/hospitals. Significant associations between the KAP and age, gender, education and employment status were reported. Multiple logistic regression analysis revealed that age, gender, history of infection and educational level of the respondents were the most important factors significantly associated with the KAP on schistosomiasis among this population. Schistosomiasis is still prevalent among Hausa communities in Nigeria and participants' knowledge about the disease was poor. Mass drug administration, community mobilization and health education regarding the cause, transmission and prevention of schistosomiasis and education about good personal and sanitary hygiene practices should be considered in order to significantly reduce the prevalence and morbidity of infection within these communities.
Wu, Xiaoying; Ren, Jianwei; Gao, Zulu; Xu, Yun; Xie, Huiqun; Li, Tingfang; Cheng, Yanhua; Hu, Fei; Liu, Hongyun; Gong, Zhihong; Liang, Jinyi; Shen, Jia; Liu, Zhen; Wu, Feng; Sun, Xi; Niu, Zhongzheng; Ning, An
2017-04-01
China still has more than 30,000 patients of advanced schistosomiasis while new cases being reported consistently. D-dimer is a fibrin degradation product. As ascites being the dominating symptom in advanced schistosomiasis, the present study aimed to explore a prediction model of ascites with D-dimer and other clinical easy-achievable indicators. A case-control study nested in a prospective cohort was conducted in schistosomiasis-endemic area of southern China. A total of 291 patients of advanced schistosomiasis were first investigated in 2013 and further followed in 2014. Information on clinical history, physical examination, and abdominal ultrasonography, including the symptom of ascites was repeatedly collected. Result showed 44 patients having ascites. Most of the patients' ascites were confined in the kidney area with median area of 20 mm 2 . The level of plasma D-dimer and pertinent liver function indicators were measured at the initial investigation in 2013. Compared with those without ascites, cases with ascites had significantly higher levels of D-dimer (0.71±2.44 μg/L vs 0.48±2.12 μg/L, P =0.005), as well ALB (44.5 vs 46.2, g/L) and Type IV collagen (50.04 vs 44.50 μg/L). Receiver operating characteristic curve analyses indicated a moderate predictive value of D-dimer by its own area under curve (AUC) of 0.64 (95% CI: 0.54-0.73) and the cutoff value as 0.81 μg/L. Dichotomized by the cutoff level, D-dimer along with other categorical variables generated a prediction model with AUC of 0.76 (95% CI: 0.68-0.89). Risks of patients with specific characteristics in the prediction model were summarized. Our study suggests that the plasma D-dimer level is a reliable predictor for incident ascites in advanced schistosomiasis japonica patients.
Wu, Xiaoying; Ren, Jianwei; Gao, Zulu; Xu, Yun; Xie, Huiqun; Li, Tingfang; Cheng, Yanhua; Hu, Fei; Liu, Hongyun; Gong, Zhihong; Liang, Jinyi; Shen, Jia; Liu, Zhen; Wu, Feng; Sun, Xi; Niu, Zhongzheng; Ning, An
2017-01-01
China still has more than 30,000 patients of advanced schistosomiasis while new cases being reported consistently. D-dimer is a fibrin degradation product. As ascites being the dominating symptom in advanced schistosomiasis, the present study aimed to explore a prediction model of ascites with D-dimer and other clinical easy-achievable indicators. A case-control study nested in a prospective cohort was conducted in schistosomiasis-endemic area of southern China. A total of 291 patients of advanced schistosomiasis were first investigated in 2013 and further followed in 2014. Information on clinical history, physical examination, and abdominal ultrasonography, including the symptom of ascites was repeatedly collected. Result showed 44 patients having ascites. Most of the patients’ ascites were confined in the kidney area with median area of 20 mm2. The level of plasma D-dimer and pertinent liver function indicators were measured at the initial investigation in 2013. Compared with those without ascites, cases with ascites had significantly higher levels of D-dimer (0.71±2.44 μg/L vs 0.48±2.12 μg/L, P=0.005), as well ALB (44.5 vs 46.2, g/L) and Type IV collagen (50.04 vs 44.50 μg/L). Receiver operating characteristic curve analyses indicated a moderate predictive value of D-dimer by its own area under curve (AUC) of 0.64 (95% CI: 0.54–0.73) and the cutoff value as 0.81 μg/L. Dichotomized by the cutoff level, D-dimer along with other categorical variables generated a prediction model with AUC of 0.76 (95% CI: 0.68–0.89). Risks of patients with specific characteristics in the prediction model were summarized. Our study suggests that the plasma D-dimer level is a reliable predictor for incident ascites in advanced schistosomiasis japonica patients. PMID:28506039
Xia, Congcong; Bergquist, Robert; Lynn, Henry; Hu, Fei; Lin, Dandan; Hao, Yuwan; Li, Shizhu; Hu, Yi; Zhang, Zhijie
2017-03-08
The Poyang Lake Region, one of the major epidemic sites of schistosomiasis in China, remains a severe challenge. To improve our understanding of the current endemic status of schistosomiasis and to better control the transmission of the disease in the Poyang Lake Region, it is important to analyse the clustering pattern of schistosomiasis and detect the hotspots of transmission risk. Based on annual surveillance data, at the village level in this region from 2009 to 2014, spatial and temporal cluster analyses were conducted to assess the pattern of schistosomiasis infection risk among humans through purely spatial (Local Moran's I, Kulldorff and Flexible scan statistic) and space-time scan statistics (Kulldorff). A dramatic decline was found in the infection rate during the study period, which was shown to be maintained at a low level. The number of spatial clusters declined over time and were concentrated in counties around Poyang Lake, including Yugan, Yongxiu, Nanchang, Xingzi, Xinjian, De'an as well as Pengze, situated along the Yangtze River and the most serious area found in this study. Space-time analysis revealed that the clustering time frame appeared between 2009 and 2011 and the most likely cluster with the widest range was particularly concentrated in Pengze County. This study detected areas at high risk for schistosomiasis both in space and time at the village level from 2009 to 2014 in Poyang Lake Region. The high-risk areas are now more concentrated and mainly distributed at the river inflows Poyang Lake and along Yangtze River in Pengze County. It was assumed that the water projects including reservoirs and a recently breached dyke in this area were partly to blame. This study points out that attempts to reduce the negative effects of water projects in China should focus on the Poyang Lake Region.
Wang, Shuo; Carlton, Elizabeth J.; Chen, Lin; Liu, Yang; Spear, Robert C.
2013-01-01
Health education is an important component of efforts to control schistosomiasis. In China, while education programmes have been implemented intensively, few articles in recent years in either the Chinese or English literature report randomised, controlled interventions of the impacts on knowledge, attitudes and behaviours .Thus, we designed and carried out a cluster-randomised controlled education intervention trial that targeted 706 adults from rural areas in 28 villages in Sichuan, China. We evaluated the effects of the intervention on five endpoints: (1) schistosomiasis knowledge, (2) attitudes towards infection testing and treatment, (3) use of personal protective equipment (PPE), (4) reducing defecation in the field, and (5) reducing dermal contact with potentially contaminated water sources. The results indicated that people in both the intervention and control groups showed improvement in knowledge, attitudes and reduction in field-defecation in the follow-up surveys. However, there was little evidence that suggested statistically significant differences between the two groups regarding any endpoint. Participation in intervention classes was associated with age, gender, occupation and education level. Our study suggests short-term health education interventions may not be effective in improving schistosomiasis knowledge or in the adoption of health-protective behaviours. This might be partially due to the spontaneous learning process of people subject to repeated surveys and other disease control activities. Considering the difficulties of occupationassociated behaviour change and knowledge reinforcement in general, longer-term education programmes should be considered in the future. PMID:23711611
Opio, Christopher Kenneth; Kazibwe, Francis; Ocama, Ponsiano; Rejani, Lalitha; Belousova, Elena Nikolaevna; Ajal, Paul
2016-01-01
Severe chronic hepatic schistosomiasis is a common cause of episodes upper gastrointestinal bleeding (UGIB) in sub-Saharan Africa (SSA). However, there is paucity of data on clinical epidemiology of episodes of UGIB from rural Africa despite on going public health interventions to control and eliminate schistosomiasis. Through a cross sectional study we profiled lifetime episodes of upper gastrointestinal bleeding and associated factors at a rural primary health facility in sub-Saharan Africa were schistosomiasis is endemic. The main outcome was number of lifetime episodes of UGIB analyzed as count data. From 107 enrolled participants, 323 lifetime episodes of UGIB were reported. Fifty-seven percent experienced ≥ 2 lifetime episodes of UGIB. Ninety-four percent had severe chronic hepatic schistosomiasis and 80% esophageal varices. Alcohol use and viral hepatitis was infrequent. Eighty-eight percent were previously treated with praziquantel and 70% had a history of blood transfusion. No patient had ever had an endoscopy or treatment for prevention of recurrent variceal bleeding. Multivariable analysis identified a cluster of eight clinical factor variables (age ≥ 40, female sex, history of blood transfusion, abdominal collaterals, esophageal varices, pattern x periportal fibrosis, anemia, and thrombocytopenia) significantly associated (P-value < 0.05) with increased probability of experiencing two or more lifetime episodes of UGIB in our study. Upper gastrointestinal bleeding is a common health problem in this part of rural SSA where schistosomiasis is endemic. The clinical profile described is unique and is important for improved case management, and for future research.
Integration of mass drug administration programmes in Nigeria: The challenge of schistosomiasis.
Richards, Frank O.; Eigege, Abel; Miri, Emmanuel S.; Jinadu, M. Y.; Hopkins, Donald R.
2006-01-01
PROBLEM: Annual mass drug administration (MDA) with safe oral anthelminthic drugs (praziquantel, ivermectin and albendazole) is the strategy for control of onchocerciasis, lymphatic filariasis (LF) and schistosomiasis. District health officers seek to integrate treatment activities in areas of overlapping disease endemicity, but they are faced with having to merge different programmatic guidelines. APPROACH: We proceeded through the three stages of integrated MDA implementation: mapping the distribution of the three diseases at district level; tailoring district training and logistics based on the results of the mapping exercises; and implementing community-based annual health education and mass treatment where appropriate. During the process we identified the "know-do" gaps in the MDA guidelines for each disease that prevented successful integration of these programmes. LOCAL SETTING: An integrated programme launched in 1999 in Plateau and Nasarawa States in central Nigeria, where all three diseases were known to occur. RELEVANT CHANGES: Current guidelines allowed onchocerciasis and LF activities to be integrated, resulting in rapid mapping throughout the two states, and states-wide provision of over 9.3 million combined ivermectin-albendazole treatments for the two diseases between 2000 and 2004. In contrast, schistosomiasis activities could not be effectively integrated because of the more restrictive guidelines, resulting in less than half of the two states being mapped, and delivery of only 701,419 praziquantel treatments for schistosomiasis since 1999. LESSONS LEARNED: Integration of schistosomiasis into other MDA programmes would be helped by amended guidelines leading to simpler mapping, more liberal use of praziquantel and the ability to administer praziquantel simultaneously with ivermectin and albendazole. PMID:16917658
Feng, Shu-hua
2015-04-01
To discuss the prevention of schistosomiasis in tourism of lake region. The seasonal distribution of tourism activities and spatial distribution of scenic spots, as well as the coupling between space and temporal of Oncomelania snail distribution and the transmission time of schistosomiasis in Poyang Lake region were analyzed. The travel preference of schistosomiasis susceptible population was surveyed by questionnaires and interviews. There were couplings of space and temporal between tourism activities in Poyang Lake region and transmission time of schistosomiasis as well as space distribution of snails, respectively. The most popular tourism items were Shuishangrenjia (overwater household) and fishing folk culture with property of participation and experience. The suggestion is to establish health records of tourists, carry out health education of schistosomiasis, and enhance the management of tourism and activities of tourists.
Sousa-Figueiredo, José Carlos; Gamboa, Dina; Pedro, João Mário; Fançony, Cláudia; Langa, António Justino; Soares Magalhães, Ricardo J.; Stothard, J. Russell; Nery, Susana Vaz
2012-01-01
Background Malaria, schistosomiasis and geohelminth infection are linked to maternal and child morbidity and mortality in sub-Saharan Africa. Knowing the prevalence levels of these infections is vital to guide governments towards the implementation of successful and cost-effective disease control initiatives. Methodology/Principal Findings A cross-sectional study of 1,237 preschool children (0–5 year olds), 1,142 school-aged children (6–15 year olds) and 960 women (>15 year olds) was conducted to understand the distribution of malnutrition, anemia, malaria, schistosomiasis (intestinal and urinary) and geohelminths in a north-western province of Angola. We used a recent demographic surveillance system (DSS) database to select and recruit suitable households. Malnutrition was common among children (23.3% under-weight, 9.9% wasting and 32.2% stunting), and anemia was found to be a severe public health problem (i.e., >40%). Malaria prevalence was highest among preschool children reaching 20.2%. Micro-hematuria prevalence levels reached 10.0% of preschool children, 16.6% of school-aged children and 21.7% of mothers. Geohelminth infections were common, affecting 22.3% of preschool children, 31.6% of school-aged children and 28.0% of mothers. Conclusions Here we report prevalence levels of malaria, schistosomiasis and geohelminths; all endemic in this poorly described area where a DSS has been recently established. Furthermore we found evidence that the studied infections are associated with the observed levels of anemia and malnutrition, which can justify the implementation of integrated interventions for the control of these diseases and morbidities. PMID:22493664
Schistosomiasis vaccine development: approaches and prospects.
Bergquist, N R
1995-01-01
Mounting evidence for acquired immunity to schistosomiasis in humans supports the case for immunological intervention. On the other hand, rapid reinfection poses a threat to younger age groups due to the slow maturation of natural resistance. However, rational approaches, based on advances in immunology and molecular biology, have substantially increased the odds of producing an effective vaccine. Since the parasite cannot replicate in the human host and serious morbidity generally occurs only after a relatively long period of heavy worm burden, complete protection against infection is not essential. The chances of success would increase if more than one of the various host/parasite interphases were targeted, for example reducing morbidity through decreased worm loads as well as through suppression of egg production. Several promising schistosome antigens have now reached an advanced phase of development and are currently undergoing independent confirmatory testing according to a standardized protocol. A few molecules are being contemplated for scaled-up production but, so far, only one has reached the stage of industrial manufacture and safety testing. Since schistosomiasis cannot realistically be controlled by a single approach, vaccination is envisaged to be implemented in conjunction with other means of control, notably chemotherapy.
Kjetland, Eyrun Floerecke; Kurewa, Edith Nyaradzai; Ndhlovu, Patricia D; Midzi, Nicholas; Gwanzura, Lovemore; Mason, Peter R; Gomo, Exnevia; Sandvik, Leiv; Mduluza, Takafira; Friis, Henrik; Gundersen, Svein Gunnar
2008-12-01
To examine the association between schistosomiasis and reproductive tract symptoms. A cross-sectional study was conducted in a Schistosoma haematobium-endemic area of rural Zimbabwe. A total of 483 permanently resident adult women of Mupfure Ward aged 20-49 were interviewed and examined clinically, each providing three consecutive urine samples. Logistic regression analysis was used to control for sexually transmitted diseases (STDs). Women with genital sandy patches had significantly more genital itch (P = 0.009) and perceived their discharge as abnormal (P = 0.003). Eighty percent of the women who had genital itch, yellow discharge, and childhood or current waterbody contact had sandy patches. Fifty-two percent of the women with genital sandy patches did not have detectable S. haematobium ova in urine. Genital schistosomiasis was associated with stress incontinence and pollakisuria, but not with menstrual irregularities, current or previous ulcers, or tumours. Genital schistosomiasis may be a differential diagnosis to the STDs in women who have been exposed to fresh water in endemic areas. Because of the chronic nature of the disease in adults, we suggest to pay special attention to the prevention of morbidity.
Hua, Ming-gui; Jin, Hua-zhong; Liu, Jian-hua; Duan, Hong-mei; Xu, Xin-mini
2015-08-01
To investigate the schistosomiasis epidemic situation changes after its transmission interrupted in Lufeng County in 1986, so as to provide the evidence for formulating the interventions for schistosomiasis elimination. The surveillance of Oncomelania hupensis snail was performed by the systematic sampling, environmental sampling and special environmental comprehensive survey methods. The surveillance of human population was carried out by the sero logical screening method, and the positives were re-examined with the stool hatching method. The surveillance of livestock was performed by the plastic cup of pipe jacking hatching method. The living snails were detected in Lufeng County from 1987 to 2007 except in 1988 and 1994. The two import buffalo infected with schistosomes were detected in 2001 and ni local infected livestock were found. Since 2004, the comprehensive measures, including the social control strategy and surviv al snail elimination, were carried out, and no snails were detected and no schistosome infected persons or livestock were found for 7 consecutive years since 2008. The achievement of schistosomiasis transmission interrupted ha been consolidated in Lufeng County, but most of the historical snail environments have not been modified and there are stil snail breeding conditions. Therefore, we should continue to carry out the snail surveillance.
Guimarães, Ricardo J P S; Freitas, Corina C; Dutra, Luciano V; Scholte, Ronaldo G C; Amaral, Ronaldo S; Drummond, Sandra C; Shimabukuro, Yosio E; Oliveira, Guilherme C; Carvalho, Omar S
2010-07-01
This paper analyses the associations between Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) on the prevalence of schistosomiasis and the presence of Biomphalaria glabrata in the state of Minas Gerais (MG), Brazil. Additionally, vegetation, soil and shade fraction images were created using a Linear Spectral Mixture Model (LSMM) from the blue, red and infrared channels of the Moderate Resolution Imaging Spectroradiometer spaceborne sensor and the relationship between these images and the prevalence of schistosomiasis and the presence of B. glabrata was analysed. First, we found a high correlation between the vegetation fraction image and EVI and second, a high correlation between soil fraction image and NDVI. The results also indicate that there was a positive correlation between prevalence and the vegetation fraction image (July 2002), a negative correlation between prevalence and the soil fraction image (July 2002) and a positive correlation between B. glabrata and the shade fraction image (July 2002). This paper demonstrates that the LSMM variables can be used as a substitute for the standard vegetation indices (EVI and NDVI) to determine and delimit risk areas for B. glabrata and schistosomiasis in MG, which can be used to improve the allocation of resources for disease control.
Schistosomiasis of the appendix in Maiduguri.
Gali, B M; Nggada, H A; Eni, E U
2006-07-01
We retrospectively studied 27 histologically diagnosed cases of schistosomiasis of the appendix at the University of Maiduguri Teaching Hospital between January 1994 and December 2003. Of 1183 cases of appendices histologically examined, schistosomiasis was seen in 27 (2.3%).
Huang, Jinbai; Luo, Jing; Peng, Jie; Yang, Tao; Zheng, Huanghua; Mao, Chunping
2017-11-01
Background Diffusion-weighted imaging (DWI) was introduced into clinical use some years ago. However, its use in the diagnosis of cerebral schistosomiasis has not been reported. Purpose To investigate the ability of the apparent diffusion coefficient (ADC) value of DWI in the diagnosis of cerebral schistosomiasis, and to differentiate it from brain high-grade gliomas and metastasis. Material and Methods Conventional brain MRI with pre-contrast, post-contrast, and DWI was performed on 50 cases of cerebral schistosomiasis, high-grade glioma, and brain metastasis. The ADC values of the three lesions, the proximal and the distal perifocal edema were measured. In order to remove the individual difference effect of ADC values, relative ADC (rADC) values were calculated through dividing the ADC value of the lesion area by that of the contralateral normal white matter. rADC values were used to evaluate the differences among cerebral schistosomiasis, brain high-grade gliomas, and metastasis. Results rADC of cerebral schistosomiasis was significantly lower than rADC of brain metastasis ( P < 0.05), without any significant differences when compared with high-grade gliomas. rADC of proximal perifocal edema in cerebral schistosomiasis was significantly higher than in high-grade gliomas ( P < 0.010), but not different compared with brain metastasis. Conclusion DWI examination with ADC values of lesions and proximal perifocal edema might be helpful in the exact diagnosis of cerebral schistosomiasis.
NASA Astrophysics Data System (ADS)
Liu, Zhaoyan; Li, Chuanrong; Tang, Lingli; Zhou, Xiaonong; Ma, Lingling
2014-11-01
Schistosomiasis is a parasitic disease that menaces human health. In terms of impact, this disease is second only to malaria as the most devastating parasitic disease. Oncomelania hupensis (snail) is the unique intermediate host of schistosoma, so monitoring and controlling of the number of snail is key to reduce the risk of schistosomiasis transmission. Remote sensing technology can real-timely access the large-scale environmental factors related to snail breeding and reproduction, and can also provide the efficient information to determine the location, area, and spread tendency of snail. Based on the T-S (Takagi-Sugeno) fuzzy information theory, a quantitative remote sensing monitoring model of snail has been developed in previous wok. In a case study, this paper will take Xinmin beach, Gaoyou Lake as new research area, carry out 20 years (1990 - 2010) dynamic monitoring, to further validate the effectiveness of the T-S Fuzzy RS snail monitoring model.
NASA Astrophysics Data System (ADS)
Liu, Zhaoyan; Li, Chuanrong; Tang, Lingli; Zhou, Xiaonong; Ma, Lingling
2014-11-01
Schistosomiasis is a parasitic disease that menaces human health. In terms of impact, this disease is second only to malaria as the most devastating parasitic disease. Oncomelania hupensis (snail) is the unique intermediate host of schistosoma, so monitoring and controlling of the number of snail is key to reduce the risk of schistosomiasis transmission. Remote sensing technology can real-timely access the large-scale environmental factors related to snail breeding and reproduction, and can also provide the efficient information to determine the location, area, and spread tendency of snail. Based on the T-S (Takagi-Sugeno) fuzzy information theory, a quantitative remote sensing monitoring model of snail has been developed in previous wok. In a case study, this paper will take Xinmin beach, Gaoyou Lake as new research area, carry out 20 years (1990 - 2010) dynamic monitoring, to further validate the effectiveness of the T-S Fuzzy RS snail monitoring model.
Hanna, Laila S; Medhat, Amina M; Abdel-Menem, Hanan A
2003-04-01
In Egypt, schistosomiasis is still a major public health problem and praziquantel is the drug of choice for its treatment, whereas diazinon is globally used as an insecticide for controlling pests. They adversely affect the environment. Therefore, the authors studied the effect of 1/20 LD50 diazinon given orally to healthy and Schistosoma mansoni infected mice for 5 successive days up to 9 and 17 weeks coupled with a therapeutic dose (2 x 500 mg/kg Bwt) of praziquantel, 2 weeks before sacrificing. The results showed that non significant differences were obtained from total proteins, albumin, globulins, and albumin/globulin ratio. However, significant differences were revealed from alpha1-, alpha2-, beta1-, beta2-, and gamma-globubins in addition to plasma ceruloplasmin. Diazinon changed the levels of alpha2-, beta1-, and gamma-globubins, while diazinon coupled with schistosomiasis affected the levels of most studied parameters. Consequently, exposure to insecticides should be avoided specially in the rural areas where schistosomiasis is still endemic.
Yang, Guo-Jing; Vounatsou, Penelope; Zhou, Xiao-Nong; Utzinger, Jürg; Tanner, Marcel
2005-01-01
Geographic information system (GIS) and remote sensing (RS) technologies offer new opportunities for rapid assessment of endemic areas, provision of reliable estimates of populations at risk, prediction of disease distributions in areas that lack baseline data and are difficult to access, and guidance of intervention strategies, so that scarce resources can be allocated in a cost-effective manner. Here, we focus on the epidemiology and control of schistosomiasis in China and review GIS and RS applications to date. These include mapping prevalence and intensity data of Schistosoma japonicum at a large scale, and identifying and predicting suitable habitats for Oncomelania hupensis, the intermediate host snail of S. japonicum, at a small scale. Other prominent applications have been the prediction of infection risk due to ecological transformations, particularly those induced by floods and water resource developments, and the potential impact of climate change. We also discuss the limitations of the previous work, and outline potential new applications of GIS and RS techniques, namely quantitative GIS, WebGIS, and utilization of emerging satellite information, as they hold promise to further enhance infection risk mapping and disease prediction. Finally, we stress current research needs to overcome some of the remaining challenges of GIS and RS applications for schistosomiasis, so that further and sustained progress can be made to control this disease in China and elsewhere.
Moyo, V B; Changadeya, W; Chiotha, S; Sikawa, D
2016-03-01
This study was designed to determine the prevalence of and risk factors for schistosomiasis among a group of preschool children in Malawi. Schistosomiasis burden among preschoolers in Malawi is not well documented in the literature. This study used field research (in the form of a snail survey), laboratory work (urinalysis and microscopy for parasite identification), and questionnaire-guided interviews to determine the prevalence of and risk factors for urinary schistosomiasis among children, aged between 6 and 60 months, in Malengachanzi, Nkhotakota District, Malawi. Urinary schistosomiasis prevalence among preschool children was 13%. Of the factors evaluated, only age (P = 0.027) was statistically significantly associated with urinary schistosomiasis risk. Four-year-old preschool children were five times more likely to contract urinary schistosomiasis than twoyear-old children (odds ratio [OR] = 5.255; 95% confidence interval [CI] = 1.014-27.237; P = 0.048). Increased contact with infested water among older children likely explains much of their increased risk. Infestation was evidenced by the presence of infected Bulinus globosus snails in the water contact points surveyed. Multiple regression analysis showed that visiting water contact sites daily (OR = 0.898, 95% CI = 0.185-4.350, P = 0.894), bathing in these sites (OR = 9.462, 95% CI = 0.036-0.00, P = 0.430) and lack of knowledge, among caregivers, regarding the causes of urinary schistosomiasis (OR = 0.235, 95% CI = 0.005-1.102, P = 0.066) posed statistically insignificant risk increases for preschoolers contracting urinary schistosomiasis. Urinary schistosomiasis was prevalent among preschool children in Malengachanzi, Nkhotakota District. Contact with infested water puts these children and the general population at risk of infection and reinfection. Inclusion of preschool children in treatment programmes should be considered imperative, along with safe treatment guidelines. To prevent infection, the population in the area should be provided with health education and safe alternative water sources.
Gazzinelli, Maria Flávia; Lobato, Lucas; Andrade, Gisele; Matoso, Leonardo Ferreira; Diemert, David J; Gazzinelli, Andréa
2016-10-01
To evaluate the effectiveness of two teaching strategies, both guided by the concept of dialogicity, on adolescents' knowledge about schistosomiasis and adherence to diagnostic fecal testing. Two teaching strategies related to schistosomiasis were developed, an educational video and group conversation, which were tested in two groups of students aged 10-15 years old. Before and after the intervention, a questionnaire was applied to assess participants' knowledge about schistosomiasis and, after the intervention, two fecal samples were requested from each participant. Comparisons were performed by paired t- and McNemar tests. Both strategies resulted in statistically significant improvements in knowledge between the pre- and post-tests. Students who watched the video had a higher return rate of fecal samples and percentage of correct questionnaire answers, mainly on questions about schistosomiasis infection. Teaching strategies based on dialogue favored the construction of concepts about schistosomiasis that can influence the adoption of positives attitudes related to health. Using teaching strategies based on the concept of dialogicity can favor the increase of knowledge of school age children about schistosomiasis and can influence behavioral change related to health. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Gazzinelli, Maria Flávia; Lobato, Lucas; Andrade, Gisele; Matoso, Leonardo Ferreira; Diemert, David J.; Gazzinelli, Andréa
2016-01-01
Objective To evaluate the effectiveness of two teaching strategies, both guided by the concept of dialogicity, on adolescents’ knowledge about schistosomiasis and adherence to diagnostic fecal testing. Methods Two teaching strategies related to schistosomiasis were developed, an educational video and group conversation, which were tested in two groups of students aged 10–15 years old. Before and after the intervention, a questionnaire was applied to assess participants' knowledge about schistosomiasis and, after the intervention, two fecal samples were requested from each participant. Comparisons were performed by paired t- and McNemar tests. Results Both strategies resulted in statistically significant improvements in knowledge between the pre- and post-tests. Students who watched the video had a higher return rate of fecal samples and percentage of correct questionnaire answers, mainly on questions about schistosomiasis infection. Conclusion teaching strategies based on dialogue favored the construction of concepts about schistosomiasis that can influence the adoption of positives attitudes related to health. Practical Implications Using teaching strategies based on the concept of dialogicity can favor the increase of knowledge of school age children about schistosomiasis and can influence behavioral change related to health. PMID:27180618
Discriminating acute from chronic human schistosomiasis mansoni.
Beck, Lílian; Van-Lüme, Daniele S M; Souza, Joelma R; Domingues, Ana L C; Favre, Tereza; Abath, Frederico G C; Montenegro, Silvia M L
2008-01-01
Specific immunoglobulin (IgA, IgG and IgM) responses to different antigen targets (soluble eggs antigen--SEA, soluble worm adult protein--SWAP and keyhole limpet hole--KLH) were measured by enzyme linked immunosorbent assay (ELISA) in patients with acute and chronic schistosomiasis, as well as patients without schistosomiasis. SEA IgA and KLH IgM presented high discriminatory powers to distinguish acute from chronic schistosomiasis, with calculated areas under the curve (AUCs) of 0.88 and 0.82, respectively, obtained from receiver operating characteristic (ROC) curve. On the other hand, these tests, particularly SEA IgA were not useful to distinguish schistosomiasis (including the acute and chronic forms) from individuals without this disease, but infected with other intestinal parasites (Ascaris lumbricoides, Trichuris trichiura and hookworm). By contrast, SWAP IgG and SEA IgG were able to discriminate schistosomiasis patients from healthy individuals and patients infected with other parasites (AUCs of 0.96 and 0.85, respectively). Thus, it is possible to use a combination of serological tests, such as SEA IgA and SWAP IgG, to simultaneously establish the diagnosis of schistosomiasis and discriminate the acute from the chronic forms of the disease.
Dutra, Walderez O; Correa-Oliveira, Rodrigo; Dunne, David; Cecchini, Luiza Fosenca; Fraga, Lúcia; Roberts, Morven; Soares-Silveira, Alda Maria; Webster, Michelle; Yssel, Hans; Gollob, Kenneth J
2002-07-06
Human resistance to re-infection with S. mansoni is correlated with high levels of anti-soluble adult worm antigens (SWAP) IgE. Although it has been shown that IL-4 and IL-5 are crucial in establishing IgE responses in vitro, the active in vivo production of these cytokines by T cells, and the degree of polarization of Th2 vs. Th0 in human schistosomiasis is not known. To address this question, we determined the frequency of IL-4 and IFN-gamma or IL-5 and IL-2 producing lymphocytes from schistosomiasis patients with high or low levels of IgE anti-SWAP. Our analysis showed that high and low IgE-producers responded equally to schistosomiasis antigens as determined by proliferation. Moreover, patients from both groups displayed similar percentages of circulating lymphocytes. However, high IgE-producers had an increased percentage of activated CD4+ T cells as compared to the low IgE-producers. Moreover, intracellular cytokine analysis, after short-term stimulation with anti-CD3/CD28 mAbs, showed that IgE high-producers display an increase in the percentage of T lymphocytes expressing IL-4 and IL-5 as compared to IgE low-responders. A coordinate control of the frequency of IL-4 and IL-5 producing lymphocytes in IgE high, but not IgE low-responders, was observed. High IgE phenotype human schistosomiasis patients exhibit a coordinate regulation of IL-4 and IL-5 producing cells and the lymphocyte derived IL-4 comes from true polarized Th2 like cells, in the absence of measurable Th0 cells as measured by co-production of IL-4 and IFN-gamma.
Al-Shehri, Hajri; Stanton, Michelle C; LaCourse, James E; Atuhaire, Aaron; Arinaitwe, Moses; Wamboko, Aida; Adriko, Moses; Kabatereine, Narcis B; Stothard, J Russell
2016-12-01
Water-borne parasitic diseases associated with poverty still blight the lives of African school children. In Uganda, intestinal schistosomiasis is still common along the shoreline of Lake Albert, despite ongoing control, and co-infection with giardiasis and malaria is poorly described. To shed light on putative interactions between diseases, a prospective cross-sectional parasitological survey was undertaken in five primary schools. Stool samples from 254 school children, aged 5-10 years, were examined by microscopy and rapid diagnostic tests (RDTs), with additional real-time PCR assays for detection of Giardia DNA. A finger-prick blood sample was also taken from each child and tested for malaria, and haemoblobin levels measured. Assocations between diseases and anaemia were assessed. Intestinal schistosomiasis (46.5%), giardiasis (41.6%) and malaria (56.2%) were common, and a quarter of children were anaemic (<115 g/L). Up to 87.0% of children were excreting Giardia DNA and the prevalence of heavy infection by real-time PCR (Ct≤19) was 19.5%, being positively associated with light, moderate and heavy egg-patent schistosomiasis, as well as with anaemia. In this setting, an extensive burden of giardiasis was revealed with heavy intensity infections associated with egg-patent intestinal schistosomiasis and anaemia. To improve child health, greater attention on giardiasis is needed along with exploring joined-up actions across diseases that promote better water hygiene and sanitation measures. © The Author 2016. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Dutra, Walderez O; Correa-Oliveira, Rodrigo; Dunne, David; Cecchini, Luiza Fosenca; Fraga, Lúcia; Roberts, Morven; Soares-Silveira, Alda Maria; Webster, Michelle; Yssel, Hans; Gollob, Kenneth J
2002-01-01
Background Human resistance to re-infection with S. mansoni is correlated with high levels of anti-soluble adult worm antigens (SWAP) IgE. Although it has been shown that IL-4 and IL-5 are crucial in establishing IgE responses in vitro, the active in vivo production of these cytokines by T cells, and the degree of polarization of Th2 vs. Th0 in human schistosomiasis is not known. To address this question, we determined the frequency of IL-4 and IFN-γ or IL-5 and IL-2 producing lymphocytes from schistosomiasis patients with high or low levels of IgE anti-SWAP. Results Our analysis showed that high and low IgE-producers responded equally to schistosomiasis antigens as determined by proliferation. Moreover, patients from both groups displayed similar percentages of circulating lymphocytes. However, high IgE-producers had an increased percentage of activated CD4+ T cells as compared to the low IgE-producers. Moreover, intracellular cytokine analysis, after short-term stimulation with anti-CD3/CD28 mAbs, showed that IgE high-producers display an increase in the percentage of T lymphocytes expressing IL-4 and IL-5 as compared to IgE low-responders. A coordinate control of the frequency of IL-4 and IL-5 producing lymphocytes in IgE high, but not IgE low-responders, was observed. Conclusions High IgE phenotype human schistosomiasis patients exhibit a coordinate regulation of IL-4 and IL-5 producing cells and the lymphocyte derived IL-4 comes from true polarized Th2 like cells, in the absence of measurable Th0 cells as measured by co-production of IL-4 and IFN-γ. PMID:12100735
da Silva, Rubens Antonio; de Carvalho, Maria Esther; Zacharias, Fabiana; de Lima, Valquíria R; Teles, Horacio M S
2002-01-01
A rather high prevalence of mansoni schistosomiasis has been observed in some localities of Bananal, State of São Paulo, during the past decade. The highest prevalence of schistosomiasis was found in the Palha District; it was thus considered adequate for an evaluation of public awareness of the risks involved in acquiring schistosomiasis, a likely outcome of certain behavior patterns. We interviewed 542 district-dwellers. The 5-to-39 age-group constituted 65.5% of the whole sample. Concerning the infection, 69.2% had hearsay information; 46.1% know the infection; 69.6% know how it is acquired; 31.5% know about the symptoms and 57.1% know what can be done to avoid infection; 17.7% declared to have acquired the infection at least once in their lifetime; 62.3% reported total or partial immersion in collections of water of Bananal, once or twice a week, 53.9% of these for bathing or fishing. Although most (91.7%) households have treated running water, are connected to the sewage network or have septic tanks, 9% of the people interviewed use to defecate on the field. It became clear that the educational messages aimed at this population had not been adequate, having failed to fulfil any expectations. The local people received only piecemeal and subjective information about their problem. The control of schistosomiasis requires an integrated practice, which includes the analysis of macro-determinant factors, such as basic sanitation, habitation, education and health care. In short, we require a multidisciplinary vision of the mechanisms of transmission of the infection, which depends upon adequate planning and well trained personnel, intent on their educational work, to attain satisfactory results.
Serological approaches for the diagnosis of schistosomiasis - A review.
Hinz, Rebecca; Schwarz, Norbert G; Hahn, Andreas; Frickmann, Hagen
2017-02-01
Schistosomiasis is a common disease in endemic areas of Sub-Saharan Africa, South America and Asia. It is rare in Europe, mainly imported from endemic countries due to travelling or human migration. Available methods for the diagnosis of schistosomiasis comprise microscopic, molecular and serological approaches, with the latter detecting antigens or antibodies associated with Schistosoma spp. infection. The serological approach is a valuable screening tool in low-endemicity settings and for travel medicine, though the interpretation of any diagnostic results requires knowledge of test characteristics and a patient's history. Specific antibody detection by most currently used assays is only possible in a relatively late stage of infection and does not allow for the differentiation of acute from previous infections for therapeutic control or the discrimination between persisting infection and re-infection. Throughout the last decades, new target antigens have been identified, and assays with improved performance and suitability for use in the field have been developed. For numerous assays, large-scale studies are still required to reliably characterise assay characteristics alone and in association with other available methods for the diagnosis of schistosomiasis. Apart from S. mansoni, S. haematobium and S. japonicum, for which most available tests were developed, other species of Schistosoma that occur less frequently need to be taken into account. This narrative review describes and critically discusses the results of published studies on the evaluation of serological assays that detect antibodies against different Schistosoma species of humans. It provides insights into the diagnostic performance and an overview of available assays and their suitability for large-scale use or individual diagnosis, and thus sets the scene for serological diagnosis of schistosomiasis and the interpretation of results. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
Leblanc, Claire; Pham, Luu-Ly; Mariani, Patricia; Titomanlio, Luigi; El Ghoneimi, Alaa; Paris, Luc; Escoda, Simon; Lottmann, Henri; Toubiana, Julie; Paugam, André; Ulinski, Tim; Bouchaud, Olivier; Brun, Sophie; Izri, Arezki; Faye, Albert; De Pontual, Loïc
2017-12-01
The objective of this retrospective study is to describe imported schistosomiasis in children in the Paris region between 2010 and 2015. Forty children with a diagnosis of schistosomiasis were included. Thirty-seven (93%) had a chronic urinary form with hematuria. The lost-to-follow up rate for the second consultation was 25%. The diagnosis and management of imported schistosomiasis must be improved-notably by raising awareness among clinicians and providing families with more information.
The microbiome in urogenital schistosomiasis and induced bladder pathologies
Adebayo, Adewale S.; Survayanshi, Mangesh; Bhute, Shrikanth; Agunloye, Atinuke M.; Isokpehi, Raphael D.; Shouche, Yogesh S.
2017-01-01
Background Human schistosomiasis is a highly prevalent neglected tropical disease (NTD) caused by Schistosoma species. Research on the molecular mechanisms influencing the outcomes of bladder infection by Schistosoma haematobium is urgently needed to develop new diagnostics, therapeutics and infection prevention strategies. The objective of the research study was to determine the microbiome features and changes in urine during urogenital schistosomiasis and induced bladder pathologies. Methodology Seventy participants from Eggua, southwestern Nigeria provided morning urine samples and were screened for urogenital schistosomiasis infection and bladder pathologies in a cross-sectional study. Highthroughput NGS sequencing was carried out, targeting the 16S V3 region. Filtered reads were processed and analyzed in a bioinformatics pipeline. Principal findings The study participants (36 males and 34 females, between ages 15 and 65) were categorized into four groups according to status of schistosomiasis infection and bladder pathology. Data analytics of the next-generation sequencing reads revealed that Proteobacteria and Firmicutes dominated and had influence on microbiome structure of both non-infected persons and persons with urogenital schistosomiasis. Furthermore, gender and age influenced taxa abundance independent of infection or bladder pathology. Several taxa distinguished urogenital schistosomiasis induced bladder pathologies from urogenital schistosomiasis infection alone and from healthy persons, including known immune-stimulatory taxa such as Fusobacterium, Sphingobacterium and Enterococcus. Some of these significant taxa, especially Sphingobacterium were projected as markers of infection, while several genera including potentially beneficial taxa such as Trabulsiella and Weissella, were markers of the non-infected. Finally, expected changes in protein functional categories were observed to relate to cellular maintenance and lipid metabolism. Conclusion The urinary microbiome is a factor to be considered in developing biomarkers, diagnostic tools, and new treatment for urogenital schistosomiasis and induced bladder pathologies. PMID:28793309
Turner, Hugo C; Truscott, James E; Bettis, Alison A; Farrell, Sam H; Deol, Arminder K; Whitton, Jane M; Fleming, Fiona M; Anderson, Roy M
2017-04-28
The majority of schistosomiasis control programmes focus on targeting school-aged children. Expanding the use of community-wide mass treatment to reach more adults is under consideration. However, it should be noted that this would require a further increase in programmatic resources, international aid, and commitment for the provision of praziquantel. Consequently, it is important to understand (i) where a change of strategy would have the greatest benefit, and (ii) how generalisable the conclusions of field trials and analytical studies based on mathematical models investigating the impact of community-wide mass treatment, are to a broad range of settings. In this paper, we employ a previously described deterministic fully age-structured schistosomiasis transmission model and evaluate the benefit of community-wide mass treatment both in terms of controlling morbidity and eliminating transmission for Schistosoma mansoni, across a wide range of epidemiological settings and programmatic scenarios. This included variation in the baseline relative worm pre-control burden in adults, the overall level of transmission in defined settings, choice of effectiveness metric (basing morbidity calculations on prevalence or intensity), the level of school enrolment and treatment compliance. Community-wide mass treatment was found to be more effective for controlling the transmission of schistosome parasites than using a school-based programme only targeting school-aged children. However, in the context of morbidity control, the potential benefit of switching to community-wide mass treatment was highly variable across the different scenarios analysed. In contrast, for areas where the goal is to eliminate transmission, the projected benefit of community-wide mass treatment was more consistent. Whether community-wide mass treatment is appropriate will depend on the local epidemiological setting (i.e. the relative pre-control burden in adults and transmission intensity), and whether the goal is morbidity control or eliminating transmission. This has important implications regarding the generalisability of cost-effectiveness analyses of schistosomiasis interventions. Our results indicate that areas with poor school-enrolment/coverage could benefit more from community-wide treatment of praziquantel and should potentially be prioritised for any change in strategy. This work highlights the importance of not over-generalising conclusions and policy in this area, but of basing decisions on high quality epidemiological data and quantitative analyses of the impact of interventions in a range of settings.
Braae, Uffe Christian; Magnussen, Pascal; Harrison, Wendy; Ndawi, Benedict; Lekule, Faustin; Johansen, Maria Vang
2016-09-01
Taenia solium is found throughout sub-Saharan Africa and co-endemic with schistosomiasis in many regions. Taenia solium leads to taeniosis and neurocysticercosis - the leading cause of preventable epilepsy globally. This study aimed to assess the effects of the National Schistosomiasis Control Programme on prevalence of taeniosis and porcine cysticercosis over a four year period in Tanzania. School-based mass drug administration (MDA) of praziquantel was carried out based on schistosomiasis endemicity. Four human and five porcine cross-sectional surveys were carried out from 2012 to 2015 in Mbozi and Mbeya district in Tanzania. Three rounds of school-based MDA of praziquantel were delivered in Mbozi and two in Mbeya. The prevalence of taeniosis and porcine cysticercosis was estimated annually. Stool samples were collected from humans and prevalence of taeniosis estimated by copro-Ag-ELISA. Blood samples from pigs were collected to estimate cysticercosis prevalence by Ag-ELISA. "Track-and-treat" of taeniosis cases was carried out after each survey. In total 12082 stool samples and 4579 porcine serum samples were collected. Significantly fewer children (≤ 15) from Mbozi were infected throughout the study than children from Mbeya who showed a significant decrease in copro-Ag prevalence after the first treatment only. During the final survey in Mbozi the prevalence of taeniosis in adults (1.8%) was significantly lower (p = 0.031, OR 0.40, CI: 0.17-0.89), compared to baseline (4.1%). The prevalence of porcine cysticercosis (8%) had also dropped significantly (p = 0.002, OR 0.49, CI: 0.32-0.76) in this district compared to baseline (13%), whereas no significant difference was seen in Mbeya compared to baseline. The study suggests that three rounds of MDA targeting schistosomiasis in school-aged children combined with 'track-and-treat' contributed to a reduction in prevalence of T. solium in this population, and also had a spillover effect on adults in treated areas as well as reducing the prevalence of T. solium in the intermediate pig host population. Elimination of T. solium in this area would require a One Health approach.
Julé, Amélie M; Vaillant, Michel; Lang, Trudie A; Guérin, Philippe J; Olliaro, Piero L
2016-06-01
Schistosomiasis control mainly relies on preventive chemotherapy with praziquantel (PZQ) distributed through mass drug administration. With a target of 260 million treatments yearly, reliably assessing and monitoring efficacy is all-important. Recommendations for treatment and control of schistosomiasis are supported by systematic reviews and meta-analyses of aggregated data, which however also point to limitations due to heterogeneity in trial design, analyses and reporting. Some such limitations could be corrected through access to individual participant-level data (IPD), which facilitates standardised analyses. A systematic literature review was conducted to identify antischistosomal drug efficacy studies performed since 2000; including electronic searches of the Cochrane Infectious Diseases Group specialised register and the Cochrane Library, PubMed, CENTRAL and Embase; complemented with a manual search for articles listed in past reviews. Antischistosomal treatment studies with assessment of outcome within 60 days post-treatment were eligible. Meta-data, i.e. study-level characteristics (Schistosoma species, number of patients, drug administered, country, etc.) and efficacy parameters were extracted from published documents to evaluate the scope of an individual-level data sharing platform. Out of 914 documents screened, 90 studies from 26 countries were included, enrolling 20,517 participants infected with Schistosoma spp. and treated with different PZQ regimens or other drugs. Methodologies varied in terms of diagnostic approaches (number of samples and test repeats), time of outcome assessment, and outcome measure (cure rate or egg reduction rate, as an arithmetic or geometric mean), making direct comparison of published data difficult. This review describes the landscape of schistosomiasis clinical research. The volume of data and the methodological and reporting heterogeneity identified all indicate that there is scope for an individual participant-level database, to allow for standardised analyses.
NASA Astrophysics Data System (ADS)
Perez-Saez, Javier; Bertuzzo, Enrico; Frohelich, Jean-Marc; Mande, Theophile; Ceperley, Natalie; Sou, Mariam; Yacouba, Hamma; Maiga, Hamadou; Sokolow, Susanne; De Leo, Giulio; Casagrandi, Renato; Gatto, Marino; Mari, Lorenzo; Rinaldo, Andrea
2015-04-01
We study the spatial geography of schistosomiasis in the african context of Burkina Faso by means of a spatially explicit model of disease dynamics and spread. The relevance of our work lies in its ability to describe quantitatively a geographic stratification of the disease burden capable of reproducing important spatial differences, and drivers/controls of disease spread. Among the latters, we consider specifically the development and management of water resources which have been singled out empirically as an important risk factor for schistosomiasis. The model includes remotely acquired and objectively manipulated information on the distributions of population, infrastructure, elevation and climatic drivers. It also includes a general description of human mobility and addresses a first-order characterization of the ecology of the intermediate host of the parasite causing the disease based on maximum entropy learning of relevant environmenal covariates. Spatial patterns of the disease were analyzed about their disease-free equilibrium by proper extraction and mapping of suitable eigenvectors of the Jacobian matrix subsuming all stability properties of the system. Human mobility was found to be a primary control of both pathogen invasion success and of the overall distribution of disease burden. The effects of water resources development were studied by accounting for the (prior and posterior) average distances of human settlements from water bodies that may serve as suitable habitats to the intermediate host of the parasite. Water developments, in combination with human mobility, were quantitatively related to disease spread into regions previously nearly disease-free and to large-scale empirical incidence patterns. We concluded that while the model still needs refinements based on field and epidemiological evidence, the framework proposed provides a powerful tool for large-scale, long-term public health planning and management of schistosomiasis.
Ramamoorthi, Roopa; Graef, Katy M; Dent, Jennifer
2015-01-01
Schistosomiasis, one of 17 diseases deemed to be neglected by the World Health Organization, has received little attention from the biopharmaceutical industry. Due to this, only a handful of drugs have been developed to treat schistosomiasis, with only one, praziquantel, used in most endemic regions. Growing concern over resistance coupled with praziquantel's incomplete efficacy across all stages of the Schistosoma platyhelminth life cycle highlights the urgent need for new drugs. The WIPO Re:Search consortium is a platform whereupon biopharmaceutical company compounds are being repurposed to efficiently and cost-effectively develop new drugs for neglected diseases such as schistosomiasis. This article summarizes recent clinical-stage efforts to identify new antischistosomals and highlights biopharmaceutical company compounds with potential for repurposing to treat schistosomiasis.
Rosser, A; Rollinson, D; Forrest, M; Webster, B L
2015-09-04
Accurate diagnosis of urogenital schistosomiasis is vital for surveillance/control programs. Amplification of schistosome DNA in urine by PCR is sensitive and specific but requires infrastructure, financial resources and skilled personnel, often not available in endemic areas. Recombinase Polymerase Amplification (RPA) is an isothermal DNA amplification/detection technology that is simple, rapid, portable and needs few resources. Here a Schistosoma haematobium RPA assay was developed and adapted so that DNA amplicons could be detected using oligochromatographic Lateral Flow (LF) strips. The assay successfully amplified S. haematobium DNA at 30-45 °C in 10 mins and was sensitive to a lower limit of 100 fg of DNA. The assay was also successful with the addition of crude urine, up to 5% of the total reaction volume. Cross amplification occurred with other schistosome species but not with other common urine microorganisms. The LF-RPA assay developed here can amplify and detect low levels of S. haematobium DNA. Reactions are rapid, require low temperatures and positive reactions are interpreted using lateral flow strips, reducing the need for infrastructure and resources. This together with an ability to withstand inhibitors within urine makes RPA a promising technology for further development as a molecular diagnostic tool for urogenital schistosomiasis.
Lothe, Andrea; Zulu, Nqobile; Øyhus, Arne Olav; Kjetland, Eyrun Floerecke; Taylor, Myra
2018-05-25
Schistosomiasis, a neglected tropical disease caused by parasites that infest open water sources such as rivers and dams may increase susceptibility to HIV. Mass-treatment with praziquantel tablets, recommended by the World Health Organization reduces the prevalence of schistosomiasis. The goal in endemic areas is 75% treatment participation in every treatment round (e.g. yearly). However, in rural Ugu district, KwaZulu-Natal, South-Africa there was low participation among pupils in a Department of Health Mass-Treatment Campaign for schistosomiasis. Nested in a large study on schistosomiasis the study was conducted in 2012 over 4 months using qualitative methods with the Health Belief Model as the conceptual framework. Purposive sampling was done. Focus Group Discussions were undertaken at six schools in grades 10-12. Individual in-depth interviews were held with one teacher and two pupils at each school. In addition three traditional healers and a community health worker were interviewed. The severity of schistosomiasis was not recognised and neither was the pupils' susceptibility. Barriers to treatment included confusing S, haematobium symptoms with sexually transmitted infections, teasing and stigma. Increased knowledge, health literacy for treatment, and correct understanding about the severity of schistosomiasis may provide cues to action. The study indicates that comprehensive information may increase pupil participation in mass-treatment and decrease schistosomiasis prevalence. This study was registered with clinicaltrials.gov registry database and the registration number is NCT01154907 30 June 2011.
Knowledge, Attitudes, and Practices Related to Schistosomiasis Among Children in Northern Senegal.
Frigerio, Simona; Bert, Fabrizio; Clari, Marco; Di Fine, Giovanni; Riva, Susanna; Bergese, Ilaria; Diouf, Samba Gueye; Alvaro, Rosaria; Buonomo, Ersilia
Schistosomiasis is a highly prevalent parasitic disease in Senegal. The early symptoms are hematuria and dysuria. Children's comprehension of the disease is fundamental to preventing the infection. The aim of this study was to investigate the knowledge attitudes, and practices related to schistosomiasis among schoolchildren in 2 rural villages in Northern Senegal and to evaluate their impact on the disease. A cross-sectional study was conducted. Data about children's knowledge of schistosomiasis, behavior, and preventive measures were collected through a questionnaire. Questionnaire responses from 575 schoolchildren were analyzed. Correct answers about risky behavior for schistosomiasis were associated with early symptoms (P = 0.010). Wearing shoes and washing hands with soap were associated with not having hematuria and dysuria (P = 0.007 and 0.049, respectively). Playing in rivers was associated with the aforementioned symptoms (P < 0.001). Children who had good knowledge of schistosomiasis reportedly did not have symptoms (P = 0.002). A logistic regression model showed that female sex (odds ratio = 0.35; P = 0.01) and attending a primary school (odds ratio = 0.13; P < 0.001) were significant predictors of a lower risk of the early symptoms of urinary schistosomiasis. This study revealed that the level of knowledge among children in North Senegal about the causes, transmission, prevention, and treatment of schistosomiasis warrants implementing educational intervention. Copyright © 2016 Icahn School of Medicine at Mount Sinai. Published by Elsevier Inc. All rights reserved.
Kalinda, Chester; Chimbari, Moses; Mukaratirwa, Samson
2017-01-13
Climate change has been predicted to increase the global mean temperature and to alter the ecological interactions among organisms. These changes may play critical roles in influencing the life history traits of the intermediate hosts (IHs). This review focused on studies and disease models that evaluate the potential effect of temperature rise on the ecology of IH snails and the development of parasites within them. The main focus was on IH snails of schistosome parasites that cause schistosomiasis in humans. A literature search was conducted on Google Scholar, EBSCOhost and PubMed databases using predefined medical subject heading terms, Boolean operators and truncation symbols in combinations with direct key words. The final synthesis included nineteen published articles. The studies reviewed indicated that temperature rise may alter the distribution, optimal conditions for breeding, growth and survival of IH snails which may eventually increase the spread and/or transmission of schistosomiasis. The literature also confirmed that the life history traits of IH snails and their interaction with the schistosome parasites are affected by temperature and hence a change in climate may have profound outcomes on the population size of snails, parasite density and disease epidemiology. We concluded that understanding the impact of temperature on the growth, fecundity and survival of IH snails may broaden the knowledge on the possible effects of climate change and hence inform schistosomiasis control programmes.
Chang, Howard; Li, Qunna; Hoover, Christopher M.; Wilke, Thomas; Clewing, Catharina; Carlton, Elizabeth J.; Liang, Song; Lu, Ding; Zhong, Bo; Remais, Justin V.
2016-01-01
Background While the dispersal of hosts and vectors—through active or passive movement—is known to facilitate the spread and re-emergence of certain infectious diseases, little is known about the movement ecology of Oncomelania spp., intermediate snail host of the parasite Schistosoma japonicum, and its consequences for the spread of schistosomiasis in East and Southeast Asia. In China, despite intense control programs aimed at preventing schistosomiasis transmission, there is evidence in recent years of re-emergence and persistence of infection in some areas, as well as an increase in the spatial extent of the snail host. A quantitative understanding of the dispersal characteristics of the intermediate host can provide new insights into the spatial dynamics of transmission, and can assist public health officials in limiting the geographic spread of infection. Methodology/Principal findings Oncomelania hupensis robertsoni snails (n = 833) were sampled from 29 sites in Sichuan, China, genotyped, and analyzed using Bayesian assignment to estimate the rate of recent snail migration across sites. Landscape connectivity between each site pair was estimated using the geographic distance distributions derived from nine environmental models: Euclidean, topography, incline, wetness, land use, watershed, stream use, streams and channels, and stream velocity. Among sites, 14.4% to 32.8% of sampled snails were identified as recent migrants, with 20 sites comprising >20% migrants. Migration rates were generally low between sites, but at 8 sites, over 10% of the overall host population originated from one proximal site. Greater landscape connectivity was significantly associated with increased odds of migration, with the minimum path distance (as opposed to median or first quartile) emerging as the strongest predictor across all environmental models. Models accounting for land use explained the largest proportion of the variance in migration rates between sites. A greater number of irrigation channels leading into a site was associated with an increase in the site’s propensity to both attract and retain snails. Conclusions/Significance Our findings have important implications for controlling the geographic spread of schistosomiasis in China, through improved understanding of the dispersal capacity of the parasite’s intermediate host. PMID:27977674
Head, Jennifer R; Chang, Howard; Li, Qunna; Hoover, Christopher M; Wilke, Thomas; Clewing, Catharina; Carlton, Elizabeth J; Liang, Song; Lu, Ding; Zhong, Bo; Remais, Justin V
2016-12-01
While the dispersal of hosts and vectors-through active or passive movement-is known to facilitate the spread and re-emergence of certain infectious diseases, little is known about the movement ecology of Oncomelania spp., intermediate snail host of the parasite Schistosoma japonicum, and its consequences for the spread of schistosomiasis in East and Southeast Asia. In China, despite intense control programs aimed at preventing schistosomiasis transmission, there is evidence in recent years of re-emergence and persistence of infection in some areas, as well as an increase in the spatial extent of the snail host. A quantitative understanding of the dispersal characteristics of the intermediate host can provide new insights into the spatial dynamics of transmission, and can assist public health officials in limiting the geographic spread of infection. Oncomelania hupensis robertsoni snails (n = 833) were sampled from 29 sites in Sichuan, China, genotyped, and analyzed using Bayesian assignment to estimate the rate of recent snail migration across sites. Landscape connectivity between each site pair was estimated using the geographic distance distributions derived from nine environmental models: Euclidean, topography, incline, wetness, land use, watershed, stream use, streams and channels, and stream velocity. Among sites, 14.4% to 32.8% of sampled snails were identified as recent migrants, with 20 sites comprising >20% migrants. Migration rates were generally low between sites, but at 8 sites, over 10% of the overall host population originated from one proximal site. Greater landscape connectivity was significantly associated with increased odds of migration, with the minimum path distance (as opposed to median or first quartile) emerging as the strongest predictor across all environmental models. Models accounting for land use explained the largest proportion of the variance in migration rates between sites. A greater number of irrigation channels leading into a site was associated with an increase in the site's propensity to both attract and retain snails. Our findings have important implications for controlling the geographic spread of schistosomiasis in China, through improved understanding of the dispersal capacity of the parasite's intermediate host.
Standley, Claire J; Adriko, Moses; Besigye, Fred; Kabatereine, Narcis B; Stothard, Russell J
2011-03-01
The Sesse Islands, in the Ugandan portion of Lake Victoria, have long been considered a low transmission zone for intestinal schistosomiasis. Based on observations of high prevalence of Schistosoma mansoni infection in the northern-most islands of this archipelago, a follow-up survey was conducted to ascertain whether transmission was endemic to this island group, combining parasitological and malacological surveys. Prevalence of intestinal schistosomiasis was again observed to be high, as was intensity of infections which, combined with low reported incidence of treatment, suggests that chemotherapy-based control initiatives are not being maximally effective in this region as high levels of population movement between islands and districts are confounding. The local disease transmission was confirmed by the observations of high abundance of Biomphalaria, as well as field-caught snails shedding S. mansoni cercariae. DNA sequencing of 12 cercariae revealed common mitochondrial cox1 haplotypes, as well as, novel ones, consistent with the high genetic diversity of this parasite in Lake Victoria. Intestinal schistosomiasis is firmly endemic in parts of the Sesse Islands and more broadly, this island group provides an insight into the future challenges to be faced by the Ugandan National Control Programme in regularly reaching these rather remote, inaccessible and largely itinerant communities.
Stothard, J Russell; French, Michael D; Khamis, I Simba; Basáñez, María-Gloria; Rollinson, David
2009-10-01
As part of a 4-year control programme beginning in 2003 and entitled Piga Vita Kichocho, around 140,000 school-aged children on Unguja Island, Zanzibar were treated annually with a combination of praziquantel and albendazole. To provide information on the impact of this intervention, a subset of children, originating from 24 sentinel schools, were monitored in 2004, 2005 and 2006 using both parasitological and behavioural questionnaire methods. Overall, prevalence of urinary schistosomiasis fell by 52%, intensity by 55% and gross haematuria by 82%. There was a positive and statistically significant correlation between areas of elevated disease prevalence and areas of predicted high transmission based upon local occurrence of the permissive intermediate snail host. In areas of low transmission, urinary schistosomiasis was greatly reduced, but, by contrast, other intervention strategies are needed to complement and synergise with chemotherapy in high transmission areas. Whereas significant reductions were documented in the prevalence of both Trichuris trichiura and hookworm, prevalence of Ascaris lumbricoides significantly increased over the monitoring period. Through a detailed analysis of named child records, evidence of predisposition to helminth (re)infection and individual bias towards polyparasitism was detected, highlighting the often overlapping distribution of these parasites within the school-aged child.
An economic evaluation of the national schistosomiasis control programme in China from 1992 to 2000.
Zhou, Xiao-Nong; Wang, Li-Ying; Chen, Ming-Gang; Wang, Tian-Ping; Guo, Jia-Gang; Wu, Xiao-Hua; Jiang, Qing-Wu; Zheng, Jiang; Chen, Xian-Yi
2005-01-01
The World Bank Loan Project, by far the largest effort in China for schistosomiasis control since control activities were initiated in the mid 1950s, was carried out for a 9-year period commencing in 1992 in the 8 provinces where Schistosoma japonicum remained endemic when the project started. To evaluate its impact, a retrospective economic evaluation was done in 2001. Six representative counties, i.e. Huarong in Hunan province, Qianjiang in Hubei province, Yugan in Jiangxi province, Tongling in Anhui province, Xichang in Sichuan province and Dali in Yunnan province, were selected for the study. The total financial input in these counties from 1992 to 2000 was RMB Yuan 90.334 million with the World Bank loan accounting for 40.9%. Control efforts resulted in reduction of human prevalence rates in the six counties from 0.7-9.0% in 1992 to 0.1-2.7% in 2000. With regard to S. japonicum infection in bovines, a high reduction was observed in Qianjiang, and smaller decreases were noted in four counties, while there was an increase in Dali. In general, the areas infested by the intermediate host snail fluctuated around the initial level. The net benefit-cost ratio was 6.20, which means that this project gained US$ 6.20 for every dollar spent. The correlation coefficients of the net benefit-cost ratio to the human and bovine infection rates at the beginning of the project were 0.55 and 0.66, respectively. It is conceivable that further progress in schistosomiasis control is an important feature for sustained growth of the local economy, particularly in areas where control of the disease has been most challenging.
Acka, Cinthia A.; Raso, Giovanna; N'Goran, Eliézer K.; Tschannen, Andres B.; Bogoch, Isaac I.; Séraphin, Essane; Tanner, Marcel; Obrist, Brigit; Utzinger, Jürg
2010-01-01
Background In the developing world where parasitic worm infections are pervasive, preventive chemotherapy is the key strategy for morbidity control. However, local knowledge, attitudes, and practices (KAP) of parasitic worms are poorly understood, although such information is required for prevention and sustainable control. Methods We carried out KAP surveys in two rural communities of Côte d'Ivoire that were subjected to school-based and community-based research and control activities. We used qualitative and quantitative methods. The former included observations, in-depth interviews with key informants, and focus group discussions with school children and adults. Quantitative methods consisted of a structured questionnaire administered to household heads. Principal Findings Access to clean water was lacking in both communities and only a quarter of the households had functioning latrines. There was a better understanding of soil-transmitted helminthiasis than intestinal schistosomiasis, but community-based rather than school-based interventions appeared to improve knowledge of schistosomiasis. In the villages with community-based interventions, three-quarters of household interviewees knew about intestinal schistosomiasis compared to 14% in the village where school-based interventions were implemented (P<0.001). Whereas two-thirds of respondents from the community-based intervention village indicated that the research and control project was the main source of information, only a quarter of the respondents cited the project as the main source. Conclusions/Significance Preventive chemotherapy targeting school-aged children has limitations, as older population segments are neglected, and hence lack knowledge about how to prevent and control parasitic worm infections. Improved access to clean water and sanitation is necessary, along with health education to make a durable impact against helminth infections. PMID:21200423
Acute schistosomiasis in European students returning from fieldwork at Lake Tanganyika, Tanzania.
Steiner, Florian; Ignatius, Ralf; Friedrich-Jaenicke, Barbara; Dieckmann, Sebastian; Harms, Gundel; Poppert, Sven; Mockenhaupt, Frank P
2013-01-01
Schistosomiasis is common in many African regions and poses a risk for travelers and the local population. So far, schistosomiasis in travelers or expatriates returning from the Tanzanian bank of Lake Tanganyika has not been reported. We report a group of students who sought treatment with signs of acute schistosomiasis after having returned from Lake Tanganyika, Tanzania. Information as to travel and exposure as well as clinical and laboratory data were collected. Schistosomiasis was diagnosed in 8 of 16 students from Berlin, Germany, who had returned from a 2- to 3-month stay of fieldwork in Kigoma District at Lake Tanganyika, Tanzania. All 16 students reported frequent freshwater exposure at the lake. Six patients showed signs of acute schistosomiasis and had fever, and some of them also had cough, weakness, headache, or abdominal pain. Eosinophilia was present in five of the six symptomatic individuals. Notably, two serologically enzyme-linked immunosorbent assay (ELISA)-positive individuals did not report or present with symptoms or abnormal laboratory parameters. Schistosoma mansoni eggs were found in one symptomatic and one asymptomatic individual each. Blood and stool samples from the other eight individuals who were equally exposed to freshwater yielded negative results. This is the first report of an outbreak of acute schistosomiasis imported from the Tanzanian shore of Lake Tanganyika and highlights the risk for travelers and the local population of acquiring the infection in that part of Tanzania. It provides arguments for routine serological screening for schistosomiasis in individuals who had prior freshwater contact in endemic areas, irrespective of symptoms or other laboratory findings. © 2013 International Society of Travel Medicine.
[Schistosomiasis monitoring and its cost in population in Danyang City, 2010-2014].
Zhu, Tao; Jiang, Tao; Shi, Yu-kun; Wang, Juan
2015-12-01
To explore the monitoring method of the infection source of schistosomiasis in the population of the schistosomiasis transmission-interrupted area with Oncomelania hupensis snails. The changes of schistosomiasis among the population were investigated by using the active and passive monitoring methods in Danyang City from 2010 to 2014, and the cost-effectiveness of the two monitoring methods was evaluated. Totally 49,277 persons were detected for schistosomiasis by dipstick dye immunoassay (DDIA) from 2010 to 2014 and 608 cases were positive, and the positive rate was 1.23%. There were no positive persons by etiology detections. The positive rates of active and passive monitoring methods were 1.61% and 1.13%, respectively and there was a significant difference between them (χ² = 15.982, P < 0.05). The average cost per positive case of the active monitoring was higher than that of the passive monitoring without considering the costs of the mobilization and labor. In the schistosomiasis transmission-interrupted area with snails, the active and passive monitoring methods need to be combined in the future.
Sun, Le-Ping; Wang, Wei; Zuo, Yin-Ping; Zhang, Zheng-Qiu; Hong, Qing-Biao; Yang, Guo-Jing; Zhu, Hong-Ru; Liang, You-Sheng; Yang, Hai-Tao
2017-03-22
Schistosomiasis is a global snail-transmitted infectious disease of poverty. Transmission control had been achieved in China in 2015 after the control efforts for over 60 years. Currently, the remaining core regions endemic for Schistosoma japonicum are mainly located in the marshland and lake regions along the Yangtze River basin. During the period from 2001 through 2015, an integrated environmental improvement of the marshlands was carried out through the implementation of industrial, agricultural and resources development projects in Yizheng County along the Yangtze River. S. japonicum infection in humans, livestock and snails was estimated by serology, stool examination, hatching technique and microscopy during the 15-year study period to evaluate the effect of the integrated environmental improvement on control and elimination of schistosomiasis. A 0.05% overall rate of S. japonicum infection was observed in snails during the 15-year study period, and no infected snails were detected since 2012. The overall prevalence of S. japonicum infection was 0.09% in humans during the study period, and no human infection was found since 2012. In addition, only 13 bovines were identified with S. japonicum infection in 2003 during the 15-year study period, and since 2004, no infection was found in livestock. The results of the present study demonstrate that the implementation of industrial, agricultural and water resources development projects, not only alters snail habitats in marshland regions, and promotes local economic development, which appears a win-to-win strategy to block the transmission of S. japonicum and accelerate socio-economic development along the Yangtze River.
Campbell, Suzy J; Biritwum, Nana-Kwadwo; Woods, Geordie; Velleman, Yael; Fleming, Fiona; Stothard, J Russell
2018-01-01
The World Health Organization's (WHO) 2015-2020 Global Strategy on water, sanitation, and hygiene (WASH) and neglected tropical diseases (NTDs) encourages integration, whilst maintaining existing structured NTD investments, and acceleration towards Sustainable Development Goal (SDG) targets. Accordingly, SDG-associated and WASH-NTD indicators have been developed, commencing important intersectoral dialogue, alongside opportunities for future disease-specific refinements. The rationale for soil-transmitted helminthiasis (STH)- and schistosomiasis-specific WASH considerations, and a traffic-light figure, are presented here to indicate where current international definitions may, or may not, suffice. Certain unique aspects in control dynamics and parasitic lifecycles, however, necessitate additional implementation research with more appropriate measurement indicators developed to record programmatic interventions and to define strategic priorities more effectively. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
Yoshitaka Komiya's visits to China and schistosomiasis investigation.
Fan, Ka-Wai
2016-11-24
This article is about a Japanese parasitologist, Yoshitaka Komiya (1900-1976), who was invited to China for a schistosomiasis investigation in 1956. In 1955, Chairman Mao initiated a national campaign to eliminate schistosomiasis, which at that time was still common in southern China, and for this purpose, the People's Republic of China invited Yoshitaka Komiya to China. He published a report based on his observations during this visit. This article aims to explore the meaning of Komiya's visit to the People's Republic of China and his observations about the anti-schistosomiasis campaign. © The Author(s) 2016.
Schistosomiasis in European Travelers and Migrants: Analysis of 14 Years TropNet Surveillance Data.
Lingscheid, Tilman; Kurth, Florian; Clerinx, Jan; Marocco, Stefania; Trevino, Begoña; Schunk, Mirjam; Muñoz, José; Gjørup, Ida E; Jelinek, Tomas; Develoux, Michel; Fry, Graham; Jänisch, Thomas; Schmid, Matthias L; Bouchaud, Olivier; Puente, Sabino; Zammarchi, Lorenzo; Mørch, Kristine; Björkman, Anders; Siikamäki, Heli; Neumayr, Andreas; Nielsen, Henrik; Hellgren, Urban; Paul, Malgorzata; Calleri, Guido; Kosina, Pavel; Myrvang, Bjørn; Ramos, José M; Just-Nübling, Gudrun; Beltrame, Anna; Saraiva da Cunha, José; Kern, Peter; Rochat, Laurence; Stich, August; Pongratz, Peter; Grobusch, Martin P; Suttorp, Norbert; Witzenrath, Martin; Hatz, Christoph; Zoller, Thomas
2017-08-01
Schistosomiasis remains one of the most prevalent parasitic diseases worldwide and the infection is frequently found in travelers and migrants. The European Network for Tropical Medicine and Travel Health conducted a sentinel surveillance study on imported schistosomiasis between 1997 and 2010. This report summarizes epidemiological and clinical data from 1,465 cases of imported schistosomiasis. Direct pathogen detection and serology were the main diagnostic tools applied. Of these, 486 (33%) cases were identified among European travelers, 231 (16%) among long-term expatriates, and 748 (51%) among non-European immigrants. Overall, only 18.6% of travelers had received pretravel advice; 95% of infections were acquired in the African region. On species level, Schistosoma mansoni was identified in 570 (39%) and Schistosoma haematobium in 318 (22%) cases; 57.5% of patients were symptomatic. Acute symptoms were reported in 27% of patients leading to earlier presentation within 3 months. Praziquantel was used in all patients to treat schistosomiasis. Many infections were detected in asymptomatic patients. In 47.4% of asymptomatic patients infection was detected by microscopy and in 39% by serology or antigen testing. Schistosomiasis remains a frequent infection in travelers and migrants to Europe. Travelers should be made aware of the risk of schistosomiasis infection when traveling to sub-Saharan Africa. Posttravel consultations particularly for returning expatriates are useful given the high potential for detecting asymptomatic infections.
Perianal lesions after return from Togo: An isolated cutaneous manifestation of schistosomiasis.
Note, Stéphanie; Vanbrabant, Peter; Soentjens, Patrick
2016-12-01
Isolated perianal lesions in a returned traveller from Togo were observed. Eosinophilia was the lead to schistosomiasis, although no systemic symptoms were reported. This case report of cutaneous schistosomiasis demonstrates the importance of a travel history, especially geographic and exposure features, and treats the differential diagnosis of eosinophilia in a returned traveller with skin lesions.
A new focus of schistosomiasis mansoni in Hayk town, northeastern Ethiopia.
Amsalu, Gashaw; Mekonnen, Zeleke; Erko, Berhanu
2015-02-03
The endemicity of human schistosomiasis has long been established in Ethiopia, and new foci have also been continuously reported.The objective of this study was to determine the transmission and magnitude of schistosomiasis in Hayk area, northeastern Ethiopia. A cross sectional parasitological survey involving 384 school children was conducted for intestinal schistosomiasis between January and March 2010 in two primary schools in Hayk area, northeastern Ethiopia. The stool samples were processed for microscopic examination using Kato-Katz technique. Malacological survey and observation on human water contact activities were also carried out. Snails were checked for schistosome infection by shedding and lab-bred mice were exposed to the cercariae shed from Biomphalaria pfeifferi en masse. Adult Schistosoma mansoni worms were harvested from the mice after 45 days of exposure to the schistosome cercariae. The overall prevalence and intensity of intestinal schistosomiasis among school children in Hayk Number 1 and Hayk Number 2 Primary Schools was found to be 45% and 161 epg, respectively. The prevalence of infection had relationship with age and sex. Males were more infected than females. Children in the age group 15-19 years had the highest infection rate, followed by 10-14 and 5-9 years age group. Schistosome infection in Biomphalaria pfeifferi was 3.2%. Schistosome infection was also established in laboratory-bred mice and adult Schistosoma mansoni worms were harvested. The observed intestinal schistosomiasis with prevalence of 45% among young children, collection of schistosome infected Biomphalaria pfeifferi, and the establishment of lab infection in mice showed that transmission of intestinal schistosomiasis is taking place in the area. Preventive chemotherapy with praziquantel should be immediately put in place to reduce morbidity and interrupt transmission of schistosomiasis in the area.
Kilany, Yasser Fouad; Abou Holw, Sahar A; Abouel-Nour, Mohamed Fathy; Morsy, Ayman T A
2009-12-01
The multifactor outcome of hypoandrogenemia with the impact of oxidative stress induced by glucose intolerance, fascioliasis with or without schistosomiasis and cumulative smoking influence on bone remodeling and the early development of osteoporotic manifestations were studied. The effect on vascular endothelium immune mediated mechanisms and antioxidant capacity were monitored in cases of youth aged selected male smokers involving 20 with hypoandrogenemia who were either subjected to sedentary life style, glucose intolerance fascioliasis hepatic fibrosis (FHF) (G1) or without (G2) and GI after following 6 months therapy (G3). Monitoring of clinical picture and biochemical assessments of osteoporotic indices (osteocolcin, bone alkaline phosphatase, parathyroid hormone, urinary cyclic AMP), hypoandrogenism (dehydroepiandrosterane sulphate or DHEAS & testosterone) glycemic determinant (insulin) immuno-inflammatory response (interleukein-6, tumor necrosis factor alpha, E-selectin, ceruloplasmin) smoking index (serum cotinine), total antioxidant capacity (AOC) and lipid peroxidation (malonedialdehyde) was done before and after 6 months therapeutic program involving supplement of DHEAS, mirazid, chromium picolinate, and megavit zinc alongside smoking cessation and physical exercise daily for at least 30 minutes. Treatment with Mirazid supplied as 10 mg/kg for 6 successive days resulted in 100% cure of fascioliasis whether single or combined with schistosomiasis.
Manzella, Adonis; Borba-Filho, Paulo; Brandt, Carlos T; Oliveira, Keyla
2012-06-01
The purpose of this study was to describe the brain magnetic resonance imaging (MRI) findings in young patients with hepatosplenic schistosomiasis mansoni without overt neurologic manifestations. This study included 34 young persons (age range = 9-25 years) with hepatosplenic schistosomiasis mansoni who had been previously treated. Patients were scanned on a 1.5-T system that included multiplanar pre-contrast and post-contrast sequences, and reports were completed by two radiologists after a consensus review. Twenty (58.8%) patients had MRI signal changes that were believed to be related to schistosomiasis mansoni. Twelve of the 20 patients had small focal hyperintensities on T2WI in the cerebral white matter, and eight patients had symmetric hyperintense basal ganglia on T1WI. There was a high frequency of brain MRI signal abnormalities in this series. Although not specific, these findings may be related to schistosomiasis.
[Analysis of projects of schistosomiasis sponsored by National Science Foundation of China].
Wen-di, Zhou; Liang, Shi; Xue-Dan, Ke; Jie, Wang
2017-07-27
To summarize the present development by analysis of projects in schistosomiasis funded by National Science Foundation of China (NSFC). Based on the ISIS database of NFSC, the projects in the studies of schistosomiasis from 2005 to 2016 were analyzed. The distributions of sponsored numbers, amounts, types, agencies, disciplines and changes in research topics by means of network profiles were described. During the study period, 198 projects were funded by NSFC totally with 76.05 million yuan in which the general and youth projects were main types. The main sponsored agencies were research institutes and medical colleges. The top three fields sponsored were medical pathogenic microbes and infection, veterinary and medical immunology. The funding on schistosomiasis researches has a downward trend, but studies are continuing in depth. In this situation, innovative and interdisciplinary researches need to be encouraged to promote the development of schistosomiasis.
[Land-use and urinary schistosomiasis in Daloa (Côte d'Ivoire)].
Fournet, F; N'Guessan, N A; Cadot, E
2004-02-01
The relation between agricultural land development of inland-valleys and health population has been studied in a town of the Ivorian forest area using urinary schistosomiasis as an indicator. Snails were collected during 4 months in rice fields and water holes used for market gardening of two urban inland-valleys (Batagnihi and Gakognihi). Prevalence of schistosomiasis was evaluated in two districts, Kennedy II and Fadiga, located close to the investigated inland-valleys. Schistosomiasis risk was higher in the Batagnihi where rice cultivation was more developed and prevalence of urinary schistosomiasis was higher in the Kennedy II district which is close to this inland-valley particularly among the Northern migrant people. The Kennedy II population has much more contacts with the inland-valley because of rice cultivation and social status. The higher socio-economic level of the Fadiga population limiting its contacts with the inland-valley can explain this result.
Carlton, Elizabeth J; Liu, Yang; Zhong, Bo; Hubbard, Alan; Spear, Robert C
2015-01-01
Human waste is used as an agricultural fertilizer in China and elsewhere. Because the eggs of many helminth species can survive in environmental media, reuse of untreated or partially treated human waste, commonly called night soil, may promote transmission of human helminthiases. We conducted an open cohort study in 36 villages to evaluate the association between night soil use and schistosomiasis in a region of China where schistosomiasis has reemerged and persisted despite control activities. We tested 2,005 residents for Schistosoma japonicum infection in 2007 and 1,365 residents in 2010 and interviewed heads of household about agricultural practices each study year. We used an intervention attributable ratio framework to estimate the association between night soil use and S. japonicum infection. Night soil use was reported by half of households (56% in 2007 and 46% in 2010). Village night soil use was strongly associated with human S. japonicum infection in 2007. We estimate cessation of night soil use would lead to a 49% reduction in infection prevalence in 2007 (95% CI: 12%, 71%). However, no association between night soil and schistosomiasis was observed in 2010. These inconsistent findings may be due to unmeasured confounding or temporal shifts in the importance of different sources of S. japonicum eggs on the margins of disease elimination. The use of untreated or partially treated human waste as an agricultural fertilizer may be a barrier to permanent reductions in human helminthiases. This practice warrants further attention by the public health community.
Questionnaires for rapid screening of schistosomiasis in sub-Saharan Africa.
Lengeler, Christian; Utzinger, Jürg; Tanner, Marcel
2002-01-01
New initiatives are aiming to reduce the global burden of schistosomiasis, mainly through the large-scale application of chemotherapy. To target chemotherapy effectively, rapid assessment procedures are needed for identifying high-risk communities that are foci for the disease. In this review, we examine the development and validation of simple school questionnaires for screening communities for Schistosoma haematobium and S. mansoni rapidly and inexpensively. The focus is on sub-Saharan Africa, where 85% of the current schistosomiasis burden is concentrated. For more than a decade, the questionnaire approach has been validated in 10 countries, with 133 880 children interviewed in 1282 schools, and with 54 996 children examined for S. haematobium. The questionnaires were well accepted, highly reliable, and of low cost. The success of the questionnaires is explained by the fact that S. haematobium infections were easily perceived through the presence of blood in urine. Evidence from 48 258 children interviewed in 545 schools indicated that reported blood in stools and bloody diarrhoea are valuable indicators for community diagnosis of S. mansoni. However, the diagnostic performance of the questionnaires for S. mansoni was weaker than for S. haematobium, and although these results are encouraging, the questionnaires need additional validation. Recently, questionnaires were extended from community to individual diagnosis and showed considerable promise. Questionnaires are now available for promptly defining the magnitude of schistosomiasis in a large area, which will allow limited resources for morbidity control to be allocated optimally. PMID:11984610
Gurarie, David; King, Charles H; Yoon, Nara; Li, Emily
2016-08-04
Schistosoma parasites sustain a complex transmission process that cycles between a definitive human host, two free-swimming larval stages, and an intermediate snail host. Multiple factors modify their transmission and affect their control, including heterogeneity in host populations and environment, the aggregated distribution of human worm burdens, and features of parasite reproduction and host snail biology. Because these factors serve to enhance local transmission, their inclusion is important in attempting accurate quantitative prediction of the outcomes of schistosomiasis control programs. However, their inclusion raises many mathematical and computational challenges. To address these, we have recently developed a tractable stratified worm burden (SWB) model that occupies an intermediate place between simpler deterministic mean worm burden models and the very computationally-intensive, autonomous agent models. To refine the accuracy of model predictions, we modified an earlier version of the SWB by incorporating factors representing essential in-host biology (parasite mating, aggregation, density-dependent fecundity, and random egg-release) into demographically structured host communities. We also revised the snail component of the transmission model to reflect a saturable form of human-to-snail transmission. The new model allowed us to realistically simulate overdispersed egg-test results observed in individual-level field data. We further developed a Bayesian-type calibration methodology that accounted for model and data uncertainties. The new model methodology was applied to multi-year, individual-level field data on S. haematobium infections in coastal Kenya. We successfully derived age-specific estimates of worm burden distributions and worm fecundity and crowding functions for children and adults. Estimates from the new SWB model were compared with those from the older, simpler SWB with some substantial differences noted. We validated our new SWB estimates in prediction of drug treatment-based control outcomes for a typical Kenyan community. The new version of the SWB model provides a better tool to predict the outcomes of ongoing schistosomiasis control programs. It reflects parasite features that augment and perpetuate transmission, while it also readily incorporates differences in diagnostic testing and human sub-population differences in treatment coverage. Once extended to other Schistosoma species and transmission environments, it will provide a useful and efficient tool for planning control and elimination strategies.
Zheng, Jiang; Gu, Xue-guang; Xu, Yong-long; Ge, Ji-hua; Yang, Xian-xiang; He, Chang-hao; Tang, Chao; Cai, Kai-ping; Jiang, Qing-wu; Liang, You-sheng; Wang, Tian-ping; Xu, Xing-jian; Zhong, Jiu-he; Yuan, Hong-chang; Zhou, Xiao-nong
2002-05-01
To study the relationship between the changes of environment and the transmission of Schistosomiasis japonica after the construction of the Three Gorge Reservoir. On the basis of the predictive data on changes of water level and sediment in the middle and lower reaches of the Yangtze River after the dam construction provided by the Yangtze River Committee on Water Conservancy, corresponding data were collected and analyzed. In order to understand the effects of changes of water level and sediment on Oncomelania hupensis, the intermediate host of Schistosoma japonicum, field surveys and ecologically intimated experiments were done. The prevalence status and factors related to transmission were investigated by epidemiology, medical geography and public health. Positive impact on control of schistosomiasis is that floods in the Yangtze River will occur less and will decrease the dispersal of snails and the chances of infection for humans and animals as well. Snail habitats' beach will be reduced in the flushed area along the Yangtze River. Exploitation of beach and elimination of snails will benefit from the beach's uplift in flushed area. The floods ahead of time in autumn will interfere with the development of snails. Negative impact is that the flushed beaches and migratory settlements at certain altitude may become snail habitats. So the reservoir area will be a potential transmission area of schistosomiasis due to dispersal of infectious resources and Oncomelania snails. The uprising of the water body level may cause the expending of the snail habitats in some places of Jianghan plain during the transition of spring to summer. The destruction of the embankments of the Dongting Lake will be put off by its delayed flush, which causes the beach in a situation of growing reed-grass or grass for a long time that benefits the reproduction of the snails. The chances for schistosome infection to humans and animals will be on the increase, because the water regression occurs ahead of time in the Dongting Lake beach in autumn. The distribution of snails will not be affected by the changes of water level in the lower reaches of the Yangtze River after the dam is built, but the flushed section in Anhui in the recent 80 years are suitable for the snails' development. The environmental changes due to dam construction will not obviously affect the development of snails and the transmission of schistosomiasis in the Poyang Lake area. The construction of the huge dam and the formation of the Three Gorge Reservoir on the Yangtze River may have both positive and negative impact on schistosomiasis transmission and control. Great effort must be made to decrease the negative impact to avoid or, at least, to decrease S. japonicum transmission.
Xu, Xiao-Dan; Xu, Chun-Fang; Dai, Jian-Jun; Qian, Jian-Qing; Pin, Xun
2016-05-01
To examine the platelet count (PC)/spleen diameter (SD) ratio in predicting the presence of esophageal varices (EV) in patients with schistosomiasis liver cirrhosis. A total of 95 consecutive patients with EV induced by schistosomiasis liver cirrhosis were enrolled in this trial. A total of 141 schistosomiasis liver cirrhosis patients without EV were enrolled as controls. All patients were diagnosed by endoscopy. Demographic, laboratory, and Doppler ultrasound parameters were collected and analyzed. Binary logistic regression analysis was carried out to identify independent risk factors associated with EV occurrence. Receiver operating curves were generated to obtain the PC/SD ratio cutoff values for the optimal sensitivity and specificity with respect to EV. The accuracy was increased in diagnosing for EV using the ratio of PC/SD compared with the SD alone [area under the curve: 0.891 95% confidence interval (CI): 0.844-0.928 vs. 0.764 95% CI: 0.705-0.817; P<0.01]. The optimal cutoff value was 1004, with a 77.1% (95% CI: 67.9-84.8%) positive-predictive value and an 89.3% (95% CI: 82.7-94.0%) negative-predictive value. Using a cutoff of 1004, it was determined that 117/141 (83.0%) patients without EV could avoid undergoing unnecessary endoscopy, whereas 14/95 (14.7%) patients with EV would be misdiagnosed. In contrast, when the ratio was set at 909, the positive-predictive and negative-predictive values were 79.5% (95% CI: 69.5-87.4%) and 83.1% (95% CI: 76.1-88.8%), respectively. A ratio of 909 would accurately predict the absence of EV in 123/141 (87.2%) patients; however, 24/95 (25.3%) patients with EV would miss the necessary screening endoscopy. The ratio of PC/SD was a useful marker in predicting the presence of EV in patients with schistosomiasis liver cirrhosis.
Sturrock, Hugh J W; Gething, Pete W; Ashton, Ruth A; Kolaczinski, Jan H; Kabatereine, Narcis B; Brooker, Simon
2011-09-01
In schistosomiasis control, there is a need to geographically target treatment to populations at high risk of morbidity. This paper evaluates alternative sampling strategies for surveys of Schistosoma mansoni to target mass drug administration in Kenya and Ethiopia. Two main designs are considered: lot quality assurance sampling (LQAS) of children from all schools; and a geostatistical design that samples a subset of schools and uses semi-variogram analysis and spatial interpolation to predict prevalence in the remaining unsurveyed schools. Computerized simulations are used to investigate the performance of sampling strategies in correctly classifying schools according to treatment needs and their cost-effectiveness in identifying high prevalence schools. LQAS performs better than geostatistical sampling in correctly classifying schools, but at a cost with a higher cost per high prevalence school correctly classified. It is suggested that the optimal surveying strategy for S. mansoni needs to take into account the goals of the control programme and the financial and drug resources available.
Molluscicide for the control of schistosomiasis in irrigation schemes: a study in Southern Rhodesia.
Shiff, C J; Clarke, V de V; Evans, A C; Barnish, G
1973-01-01
The development of large areas of irrigation farming in the south-eastern lowveld of Southern Rhodesia has produced the risk of severe transmission of schistosomiasis over an extent of some 30 000 ha. Control measures instituted by the Ministry of Health were primarily directed against the large and widely distributed snail populations by using molluscicides. The chemical was applied to the irrigation water by drip-feed methods once every 6-8 months. The drains, however, were treated routinely by pairs of rangers searching for snails and applying chemical where they were found. The efficacy of control operations has been assessed by longitudinal studies in children free from infection to determine the incidence of infection. The results indicate that transmission of both Schistosoma haematobium and S. mansoni has been reduced to a level below that measured in areas of the country where irrigation is not practised. The total annual cost for this work was US$ 54 800-55 500.
King, Charles H.; Sutherland, Laura J.; Bertsch, David
2015-01-01
Background Programs for schistosomiasis control are advancing worldwide, with many benefits noted in terms of disease reduction. Yet risk of reinfection and recurrent disease remain, even in areas with high treatment coverage. In the search for means to better prevent new Schistosoma infections, attention has returned to an older strategy for transmission control, i.e., chemical mollusciciding, to suppress intermediate host snail species responsible for S. mansoni and S. haematobium transmission. The objective of this systematic review and meta-analysis was to summarize prior experience in molluscicide-based control of Bulinus and Biomphalaria spp. snails, and estimate its impact on local human Schistosoma infection. Methodology/Principal Findings The review was registered at inception with PROSPERO (CRD42013006869). Studies were identified by online database searches and hand searches of private archives. Eligible studies included published or unpublished mollusciciding field trials performed before January 2014 involving host snails for S. mansoni or S. haematobium, with a primary focus on the use of niclosamide. Among 63 included papers, there was large variability in terms of molluscicide dosing, and treatment intervals varied from 3–52 weeks depending on location, water source, and type of application. Among 35 studies reporting on prevalence, random effects meta-analysis indicated that, on average, odds of infection were reduced 77% (OR 0.23, CI95% 0.17, 0.31) during the course of mollusciciding, with increased impact if combined with drug therapy, and progressively greater impact over time. In 17 studies reporting local incidence, risk of new infection was reduced 64% (RR 0.36 CI95% 0.25, 0.5), but additional drug treatment did not appear to influence incidence effects. Conclusion/Significance While there are hurdles to implementing molluscicide control, its impact on local transmission is typically strong, albeit incomplete. Based on past experience, regular focal mollusciciding is likely to contribute significantly to the move toward elimination of schistosomiasis in high risk areas. PMID:26709922
Odhiambo, Gladys O; Musuva, Rosemary M; Odiere, Maurice R; Mwinzi, Pauline N
2016-09-15
The Community Directed Intervention (CDI) strategy has been used to conduct various health interventions in Africa, including control of Neglected Tropical Diseases (NTDs). Although the CDI approach has shown good results in the control of onchocerciasis and lymphatic filariasis with respect to treatment coverage using community drug distributors, its utility in the control of schistosomiasis among urban poor is yet to be established. Using a longitudinal qualitative study, we explored the experiences, opportunities, challenges as well as recommendations of Community Health Workers (CHWs) after participation in annual mass drug administration (MDA) activities for schistosomiasis using the CDI approach in an urban setting. Unstructured open-ended group discussions were conducted with CHWs after completion of annual MDA activities. Narratives were obtained from CHWs using a digital audio recorder during the group discussions, transcribed verbatim and translated into English where applicable. Thematic decomposition of data was done using ATLAS.ti. software, and themes explored using the principle of interpretative phenomenological analysis (IPA). From the perspective of the CHWs, opportunities for implementing CDI in urban settings, included the presence of CHWs, their supervisory structures and their knowledge of intervention areas, and opportunity to integrate MDA with other health interventions. Several challenges were mentioned with regards to implementing MDA using the CDI strategy among them lack of incentives, fear of side effects, misconceptions regarding treatment and mistrust, difficulties working in unsanitary environmental conditions, insecurity, and insufficient time. A key recommendation in promoting more effective MDA using the CDI approach was allocation of more time to the exercise. Findings from this study support the feasibility of using CDI for implementing MDA for schistosomiasis in informal settlements of urban areas. Extensive community sensitization and provision of incentives may help address the aforementioned challenges associated with implementing MDA using the CDI strategy. Opportunities highlighted in this study may be of value to other programmes that may be considering the adoption of the CDI strategy for rolling out interventions in the urban setting.
Human anthelminthic vaccines: Rationale and challenges.
Hotez, Peter J; Strych, Ulrich; Lustigman, Sara; Bottazzi, Maria Elena
2016-06-24
Helminth infections are the most common afflictions of humankind, affecting almost every single person living in profound poverty. Through mass drug administration (MDA) we have seen sharp declines in the global prevalence of some helminth infections, including lymphatic filariasis, onchocerciasis, and ascariasis. However, since 1990, there has been no appreciable decrease in the global prevalence of hookworm infection, schistosomiasis, or food-borne trematodiases. Through the activities of a non-profit product development partnerships and two research institutes, a total of five human anthelmintic vaccines for hookworm infection (two) and schistosomiasis (three) have advanced from discovery through manufacture and are now in Phase 1 clinical testing. At least three additional antigens, including two for onchocerciasis and one for schistosomiasis, are also advancing through preclinical development with the intention of moving into the clinic soon. These preventive human anthelmintic vaccines could be used as stand-alone technologies administered to infants as part of the Expanded Program on Immunization (EPI), or together with anthelmintic drugs in programs linked to MDA. Significant hurdles though could hinder the advancement of these vaccines into later-stage clinical and product development and licensure. They include the absence of a major pharma partner (and the resultant access to adjuvants and industrial scale manufacturing expertise), an uncharted roadmap for how to introduce anthelmintic vaccines into appropriate health systems, uncertain global access and regulatory strategies that might need to rely on developing country vaccine manufacturers and national regulatory authorities, and the lack of innovative financing schemes. However, the public health and economic benefits of introducing these vaccines could be massive and therefore deserve international attention and support. Copyright © 2016 Elsevier Ltd. All rights reserved.
2009-01-01
Background Renal tract involvement is implicated in both early and late schistosomiasis leading to increased disease burden. Despite there being good estimates of disease burden due to renal tract disease secondary to schistosomiasis at the global level, it is often difficult to translate these estimates into local communities. The aim of this study was to assess the burden of urinary tract pathology and morbidity due to schistosomiasis in Zanzibar and identify reliable clinical predictors of schistosomiasis associated renal disease. Methods A cross-sectional comparison of Ungujan men and women living within either high or low endemic areas for urinary schistosomiasis was conducted. Using urine analysis with reagent strips, parasitological egg counts, portable ultrasonography and a qualitative case-history questionnaire. Data analysis used single and multiple predictor variable logistic regression. Results One hundred and sixty people were examined in the high endemic area (63% women and 37% men), and 101 people in the low endemic area (61% women and 39% men). In the high endemic area, egg-patent schistosomiasis and urinary tract pathology were much more common (p = 1 × 10-3, 8 × 10-6, respectively) in comparison with the low endemic area. Self-reported frothy urine, self-reported haematuria, dysuria and urgency to urinate were associated with urinary tract pathology (p = 1.8 × 10-2, p = 1.1 × 10-4, p = 1.3 × 10-6, p = 1.1 × 10-7, respectively) as assessed by ultrasonography. In a multi-variable logistic regression model, self-reporting of schistosomiasis in the past year, self-reporting of urgency to urinate and having an egg-positive urine sample were all independently associated with detectable urinary tract abnormality, consistent with schistosomiasis-specific disease. Having two or more of these features was moderately sensitive (70%) as a predictor for urinary tract abnormality with high specificity (92%). Conclusion Having two out of urgency to urinate, self reporting of previous infections and detection of eggs in the urine were good proxy predictors of urinary tract abnormality as detected by ultrasound. PMID:19943968
Lyons, Beatrice; Stothard, Russel; Rollinson, David; Khamis, Simba; Simai, Khamis A; Hunter, Paul R
2009-11-29
Renal tract involvement is implicated in both early and late schistosomiasis leading to increased disease burden. Despite there being good estimates of disease burden due to renal tract disease secondary to schistosomiasis at the global level, it is often difficult to translate these estimates into local communities. The aim of this study was to assess the burden of urinary tract pathology and morbidity due to schistosomiasis in Zanzibar and identify reliable clinical predictors of schistosomiasis associated renal disease. A cross-sectional comparison of Ungujan men and women living within either high or low endemic areas for urinary schistosomiasis was conducted. Using urine analysis with reagent strips, parasitological egg counts, portable ultrasonography and a qualitative case-history questionnaire. Data analysis used single and multiple predictor variable logistic regression. One hundred and sixty people were examined in the high endemic area (63% women and 37% men), and 101 people in the low endemic area (61% women and 39% men). In the high endemic area, egg-patent schistosomiasis and urinary tract pathology were much more common (p = 1 x 10-3, 8 x 10-6, respectively) in comparison with the low endemic area. Self-reported frothy urine, self-reported haematuria, dysuria and urgency to urinate were associated with urinary tract pathology (p = 1.8 x 10-2, p = 1.1 x 10-4, p = 1.3 x 10-6, p = 1.1 x 10-7, respectively) as assessed by ultrasonography. In a multi-variable logistic regression model, self-reporting of schistosomiasis in the past year, self-reporting of urgency to urinate and having an egg-positive urine sample were all independently associated with detectable urinary tract abnormality, consistent with schistosomiasis-specific disease. Having two or more of these features was moderately sensitive (70%) as a predictor for urinary tract abnormality with high specificity (92%). Having two out of urgency to urinate, self reporting of previous infections and detection of eggs in the urine were good proxy predictors of urinary tract abnormality as detected by ultrasound.
Chen, Yinbo; Liu, Zhuo; Qian, Jun; Feng, Haiyang; Li, Dechuan; Fan, Yongtian
2016-01-01
To investigate the expression difference of DNA mismatch repair gene hMLH1 and hMSH2 between schistosomiasis-associated colorectal cancer and sporadic colorectal cancer. Clinical and pathological data of colorectal cancer patients receiving operations in Zhejiang Cancer Hospital between January 2008 and December 2010 were retrospectively analyzed. Patients were divided into schistosomiasis group(n=80) and sporadic group (n=258) according to the preoperative history and pathologic results. Pathological specimens were collected and tissue chips were made to analyze the expression of hMLH1 and hMSH2 by immunohistochemistr. Compared with sporadic group, older age [(62.2 ± 9.6) year vs. (57.2 ± 11.7) year, P=0.000)], lower platelet level [(197.0 ± 59.6) × 10(9)/L vs. (217.0 ± 84.3) × 10(9)/L, P=0.02] and lower WBC level [(5.9 ± 1.9) × 10(9)/L vs. (6.6 ± 2.8) × 10(9)/L, P=0.02] were found in schistosomiasis group. Ratio of low differentiation-undifferentiation tumor was significantly higher in schistosomiasis group [44.2% (34/77) vs. 4.9% (12/247), P<0.05]. Lower positive rate of hMLH1 expression [77.5% (62/80) vs. 98.1% (253/258), P=0.000] and hMSH2 expression [75.0% (60/80) vs. 95.3% (246/258), P=0.000] was found in schistosomiasis group compared with sporadic group. Concurrent schistosomiasis was one of the risk factors of hMLH1/hMSH2 deficiency (RR: 0.913, 95% CI: 0.836-0.997, P=0.043), but not an independent factor (RR: 0.951, 95% CI: 0.867-1.043, P=0.286). Schistosomiasis is associated with lower positive expression of hMLH1 and hMSH2, which indicates that hMLH1/hMSH2 deficiency may be a potential mechanism of schistosomiasis inducing carcinogenesis of colorectal cancer.
Tchuem Tchuenté, Louis-Albert; Dongmo Noumedem, Calvine; Ngassam, Pierre; Kenfack, Christian Mérimé; Gipwe, Nestor Feussom; Dankoni, Esther; Tarini, Ann; Zhang, Yaobi
2013-12-23
The previous nationwide mapping of schistosomiasis and soil-transmitted helminthiasis (STH) in Cameroon was conducted 25 years ago. Based on its results, mass drug administration (MDA) of praziquantel was limited to the three northern regions and few health districts in the southern part of Cameroon. In 2010, we started the process of updating the disease distribution in order to improve the control strategies. Three of the ten regions of Cameroon were mapped in 2010 and the data were published. In 2011, surveys were conducted in four additional regions, i.e. Littoral, North-West, South and South-West. Parasitological surveys were conducted in March 2011 in selected schools in all 65 health districts of the four targeted regions, using appropriate research methodologies, i.e. Kato-Katz and urine filtration. The results showed significant variation of schistosomiasis and STH prevalence between schools, villages, districts and regions. Schistosoma haematobium was the most prevalent schistosome species, with an overall prevalence of 3.2%, followed by S. mansoni (3%) and S. guineensis (1.2%). The overall prevalence of schistosomiasis across the four regions was 7.4% (95% CI: 6.7-8.3%). The prevalence for Ascaris lumbricoides was 19.5% (95% CI: 18.3-20.7%), Trichuris trichiura 18.9% (95% CI: 17.7-20.1%) and hookworms 7.6% (95% CI: 6.8-8.4%), with an overall STH prevalence of 32.5% (95% CI: 31.1-34.0%) across the four regions. STH was more prevalent in the South region (52.8%; 95% CI: 48.0-57.3%), followed by the South-West (46.2%; 95% CI: 43.2-49.3%), the North-West (35.9%; 95% CI: 33.1-38.7%) and the Littoral (13.0%; 95% CI: 11.3-14.9%) regions. In comparison to previous data in 1985-87, the results showed an increase of schistosomiasis transmission in several health districts, whereas there was a significant decline of STH infections. Based on the prevalence data, the continuation of annual or bi-annual MDA for STH is recommended, as well as an extension of praziquantel in identified moderate and high risk communities for schistosomiasis.
2013-01-01
Background The previous nationwide mapping of schistosomiasis and soil-transmitted helminthiasis (STH) in Cameroon was conducted 25 years ago. Based on its results, mass drug administration (MDA) of praziquantel was limited to the three northern regions and few health districts in the southern part of Cameroon. In 2010, we started the process of updating the disease distribution in order to improve the control strategies. Three of the ten regions of Cameroon were mapped in 2010 and the data were published. In 2011, surveys were conducted in four additional regions, i.e. Littoral, North-West, South and South-West. Methods Parasitological surveys were conducted in March 2011 in selected schools in all 65 health districts of the four targeted regions, using appropriate research methodologies, i.e. Kato-Katz and urine filtration. Results The results showed significant variation of schistosomiasis and STH prevalence between schools, villages, districts and regions. Schistosoma haematobium was the most prevalent schistosome species, with an overall prevalence of 3.2%, followed by S. mansoni (3%) and S. guineensis (1.2%). The overall prevalence of schistosomiasis across the four regions was 7.4% (95% CI: 6.7-8.3%). The prevalence for Ascaris lumbricoides was 19.5% (95% CI: 18.3-20.7%), Trichuris trichiura 18.9% (95% CI: 17.7-20.1%) and hookworms 7.6% (95% CI: 6.8-8.4%), with an overall STH prevalence of 32.5% (95% CI: 31.1-34.0%) across the four regions. STH was more prevalent in the South region (52.8%; 95% CI: 48.0-57.3%), followed by the South-West (46.2%; 95% CI: 43.2-49.3%), the North-West (35.9%; 95% CI: 33.1-38.7%) and the Littoral (13.0%; 95% CI: 11.3-14.9%) regions. Conclusions In comparison to previous data in 1985–87, the results showed an increase of schistosomiasis transmission in several health districts, whereas there was a significant decline of STH infections. Based on the prevalence data, the continuation of annual or bi-annual MDA for STH is recommended, as well as an extension of praziquantel in identified moderate and high risk communities for schistosomiasis. PMID:24365046
NASA Astrophysics Data System (ADS)
McCandless, M.; Ibaraki, M.; Shum, C.; Lee, H.; Liang, S.
2008-12-01
Schistosomiasis is the second-most prevalent tropical disease after malaria affecting two-hundred million people annually world-wide; it shortens lifespan on average by ten years in endemic areas and no vaccine exists. The current control methods of human host chemotherapy and application of molluscicides to the environment do not break the disease transmission cycle. Schistosomiasis transmission in southern China involves an amphibious intermediate host snail for which hydrology is a key factor because the adults need moist vegetation while the juveniles are fully aquatic. Thus, hydrology is a key factor in schistosomiasis transmission and understanding its role can inform control measures. Our objective is to integrate hydrologic, ecologic, and other environmental factors to determine the changes in available snail habitat through space and time. We use radar altimetry measurements to determine water level every 35 days when the Envisat (Environmental Satellite) passes over the lake. The radar altimetry readings have been calibrated to levels from in-situ gauging stations and will support remote analysis of disease transmission potential without the need for gauging station data. A geographic information system was used to combine key factors including water level, topography, and air temperature data to identify areas of available snail habitat. In order to accomplish this, we conducted three steps including: delineating the watershed, specifying potential snail habitat areas through topography and air temperature classification, and calculating the intersection between potential snail habitat and non-flooded areas in the watershed. Statistical analyses of total available habitat area are also conducted. These maps and statistics analyses can be used by public health agencies to monitor snail habitat trends over time. Coupling remote sensing of water levels with a geographic information system model will continue to be important as the hydrology of the lake changes due to the completion of the upstream Three Gorges Dam project.
Vaillant, Michel; Lang, Trudie A.; Guérin, Philippe J.; Olliaro, Piero L.
2016-01-01
Background Schistosomiasis control mainly relies on preventive chemotherapy with praziquantel (PZQ) distributed through mass drug administration. With a target of 260 million treatments yearly, reliably assessing and monitoring efficacy is all-important. Recommendations for treatment and control of schistosomiasis are supported by systematic reviews and meta-analyses of aggregated data, which however also point to limitations due to heterogeneity in trial design, analyses and reporting. Some such limitations could be corrected through access to individual participant-level data (IPD), which facilitates standardised analyses. Methodology A systematic literature review was conducted to identify antischistosomal drug efficacy studies performed since 2000; including electronic searches of the Cochrane Infectious Diseases Group specialised register and the Cochrane Library, PubMed, CENTRAL and Embase; complemented with a manual search for articles listed in past reviews. Antischistosomal treatment studies with assessment of outcome within 60 days post-treatment were eligible. Meta-data, i.e. study-level characteristics (Schistosoma species, number of patients, drug administered, country, etc.) and efficacy parameters were extracted from published documents to evaluate the scope of an individual-level data sharing platform. Principal findings Out of 914 documents screened, 90 studies from 26 countries were included, enrolling 20,517 participants infected with Schistosoma spp. and treated with different PZQ regimens or other drugs. Methodologies varied in terms of diagnostic approaches (number of samples and test repeats), time of outcome assessment, and outcome measure (cure rate or egg reduction rate, as an arithmetic or geometric mean), making direct comparison of published data difficult. Conclusions This review describes the landscape of schistosomiasis clinical research. The volume of data and the methodological and reporting heterogeneity identified all indicate that there is scope for an individual participant-level database, to allow for standardised analyses. PMID:27347678
Schistosomiasis: Traverers in Africa.
Strohmayer, Jeremy; Matthews, Ian; Locke, Robert
2016-01-01
Schistosomiasis is a parasitic infection acquired through freshwater exposure in the tropics. It is an infection that can have devastating implications to military personnel if it is not recognized and treated, especially later in life. While there is an abundance of information available about schistosomiasis in endemic populations, the information on nonendemic populations, such as deployers, is insufficient. Definitive studies for this population are lacking, but there are actions that can and should be taken to prevent infection and to treat patients. This literary review presents a case study, reviews basic science, and explores the information available about schistosomiasis in nonendemic populations. Specifically, the authors provide recommendations for the prevention, diagnosis, and postexposure management in military personnel. 2016.
Health education and community participation in the control of urinary schistosomiasis in Ghana.
Aryeetey, M E; Aholu, C; Wagatsuma, Y; Bentil, G; Nkrumah, F K; Kojima, S
1999-06-01
To study the role of health education and community participation for the provision of facilities necessary for the control of urinary schistosomiasis in southern Ghana. Health education facilitates community participation in the provision of facilities for the control of bilharzia. Three rural communities drained by the Densu river in southern Ghana. Individuals aged 14 years and above formed groups of 10-12 persons by age, sex, ethnic and educational background; 15-16 groups were formed. Based on existing structures, one community received active, another passive health education and the third had no education. All three communities received chemotherapy. Study was carried out in three phases: pre-intervention phase--during which baseline data on residents' knowledge, attitude, beliefs and perception about bilharzia were collected using focus group discussions (FGD) prior to the second phase, intervention. Another FGD was held after 18 months to evaluate the intervention--third phase. This study suggests that most community members were aware of schistosomiasis but not as a disease. Before the health education, some residents believed bilharzia was a sign of manhood while others attributed the red colour of the urine to the red colour of a variety of sugar cane eaten in the area. After the health education, residents in the three areas constructed hand-dug wells. In addition, those who received active health education constructed two toilets for the schools and weeded the banks of the rivers. Residents also associated the disease with the water snail. Health education was useful in changing community perception on bilharzia.
Gujral, L; Vaz, R G
2000-01-01
To assess the prevalence and identify levels of information and risk behavior associated with vesical schistosomiasis, a cross-sectional study was conducted in October-November 1996, involving students from 3 primary schools in the Primeiro de Junho health district in Maputo, Mozambique. Epidemiological interviews and urine samples were taken from 434 male and female students from grades 2 through 5, randomly selected. Estimated prevalence was 11.3% (49/434). Highest prevalence was in the age group ( 15 years old, and the highest intensity of infection among the 10-14-year age group, with 204 eggs/10 ml urine. Approximately 18.9% had heard of schistosomiasis, and of these, only 19.5% (16/82) knew how the disease is manifested. Approximately 50% of the students reported frequent water contacts with potential sources of schistosomiasis. The study shows that vesical schistosomiasis is a public health problem among students in this health district.
Guo, J; Booth, M; Jenkins, J; Wang, H; Tanner, M
1998-12-01
The World Bank Loan Project for schistosomiasis in China commenced field activities in 1992. In this paper, we describe disease control strategies for levels of different endemicity, and estimate unit costs and total expenditure of screening, treatment (cattle and humans) and snail control for 8 provinces where Schistosoma japonicum infection is endemic. Overall, we estimate that more than 21 million US dollars were spent on field activities during the first three years of the project. Mollusciciding (43% of the total expenditure) and screening (28% of the total) are estimated to have the most expensive field activities. However, despite the expense of screening, a simple model predicts that selective chemotherapy could have been cheaper than mass chemotherapy in areas where infection prevalence was higher than 15%, which was the threshold for mass chemotherapy intervention. It is concluded that considerable cost savings could be made in the future by narrowing the scope of snail control activities, redefining the threshold infection prevalence for mass chemotherapy, defining smaller administrative units, and developing rapid assessment tools.
Maluil, Samuel; Stevens, Rom A
2016-11-01
Schistosomiasis is a known risk after exposure to freshwater in tropical parts of the world. In March 2014, 28 off-duty U.S. service members went on a water adventure in the Nile River in Jinja, Uganda. In April 2014, 10 of the 28 service members returned for a second water adventure. Twelve weeks after freshwater exposure, schistosomiasis enzyme-linked immunosorbent assay testing was performed. Twenty-five percent had elevated Schistosomiasis mansoni immunoglobulin G (7 positive of 28 exposed); all had negative pre-exposure serology. The serology-positive service members were treated with oral praziquantel 60 mg/kg in divided doses. Our report is the first schistosomiasis report among U.S. service members deployed to Africa since World War II. The absence of reports among U.S. service members and several reports among deployed foreign military units and tourists in sub-Saharan Africa suggest a lack of postexposure testing. We recommend schistosomiasis testing of prior and future U.S. military units deployed to sub-Saharan Africa with fresh water exposure. Unit commanders and medical personnel should discourage unnecessary fresh water contact in sub-Saharan Africa. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.
PREVALENCE AND RISK FACTORS OF SCHISTOSOMIASIS AMONG HAUSA COMMUNITIES IN KANO STATE, NIGERIA
DAWAKI, Salwa; AL-MEKHLAFI, Hesham Mahyoub; ITHOI, Init; IBRAHIM, Jamaiah; ABDULSALAM, Awatif Mohammed; AHMED, Abdulhamid; SADY, Hany; ATROOSH, Wahib Mohammed; AL-AREEQI, Mona Abdullah; ELYANA, Fatin Nur; NASR, Nabil Ahmed; SURIN, Johari
2016-01-01
SUMMARY Schistosomiasis remains one of the most prevalent neglected tropical diseases especially in Nigeria which has the greatest number of infected people worldwide. A cross-sectional study was conducted among 551 participants from Kano State, North Central Nigeria. Fecal samples were examined for the presence of Schistosoma mansoni eggs using the formalin-ether sedimentation method while the urine samples were examined using the filtration technique for the presence of S. haematobium eggs. Demographic, socioeconomic and environmental information was collected using a pre-validated questionnaire. The overall prevalence of schistosomiasis was 17.8%, with 8.9% and 8.3% infected with S. mansoni and S. haematobium, respectively and 0.5% presenting co-infection with both species. The multiple logistic regression analysis revealed that age < 18 years (OR = 2.13; 95% CI; 1.34- 3.41), presence of infected family members (OR = 3.98; 95% CI; 2.13-7.46), and history of infection (OR = 2.87; 95% CI; 1.87- 4.56) were the significant risk factors associated with schistosomiasis in these communities. In conclusion, this study revealed that schistosomiasis is still prevalent among Hausa communities in Nigeria. Mass drug administration, health education and community mobilization are imperative strategies to significantly reduce the prevalence and morbidity of schistosomiasis in these communities. PMID:27410914
Utzinger, J.; N'Goran, E. K.; Ossey, Y. A.; Booth, M.; Traoré, M.; Lohourignon, K. L.; Allangba, A.; Ahiba, L. A.; Tanner, M.; Lengeler, C.
2000-01-01
The distribution of schistosomiasis is focal, so if the resources available for control are to be used most effectively, they need to be directed towards the individuals and/or communities at highest risk of morbidity from schistosomiasis. Rapid and inexpensive ways of doing this are needed, such as simple school questionnaires. The present study used such questionnaires in an area of western Côte d'Ivoire where Schistosoma mansoni is endemic; correctly completed questionnaires were returned from 121 out of 134 schools (90.3%), with 12,227 children interviewed individually. The presence of S. mansoni was verified by microscopic examination in 60 randomly selected schools, where 5047 schoolchildren provided two consecutive stool samples for Kato-Katz thick smears. For all samples it was found that 54.4% of individuals were infected with S. mansoni. Moreover, individuals infected with S. mansoni reported "bloody diarrhoea", "blood in stools" and "schistosomiasis" significantly more often than uninfected children. At the school level, Spearman rank correlation analysis showed that the prevalence of S. mansoni significantly correlated with the prevalence of reported bloody diarrhoea (P = 0.002), reported blood in stools (P = 0.014) and reported schistosomiasis (P = 0.011). Reported bloody diarrhoea and reported blood in stools had the best diagnostic performance (sensitivity: 88.2%, specificity: 57.7%, positive predictive value: 73.2%, negative predictive value: 78.9%). The study, which is probably the largest of its kind ever undertaken in Africa, revealed a moderate diagnostic performance of questionnaires for identifying individuals and/or communities at high risk from S. mansoni. PMID:10812739
[Investigation on field feces in schistosomiasis endemic areas in Jingzhou City].
Tian, Ke-qing; Wang, Jia-song; He, Liang-cai; Peng, You-xin
2014-04-01
To understand the status of field feces in Jingzhou City, so as to provide the evidence for improving the control measures to interrupt the transmission routes of schistosomiasis. The distribution of field feces was investigated in 27 schistosomiasis endemic villages in Gong' an, Jianli, Jiangling, Honghu and Shishou counties (cities) from 2010 to 2012. The schistosome positive status of the field feces was surveyed with the hatching method. There were 1366 field feces and the average density was 0.0892 feces per 100 square meters in this survey. The cattle feces, human feces, dog feces and elk feces respectively accounted for 99.71%, 0.07%, 0.15% and 0.07% in the survey. The infection rates of the field feces were 1.46% and 2.42% in the channels and bottomlands, respectively (P > 0.05). The average rate of infected field feces was 3.21% in 2010, 0.36% in 2011, and 1.60% in 2012, and the difference between 2010 and 2012 was not statistically significant (P > 0.05). The main field feces come from cattle, and the main distribution of infected field feces is in channels and bottom-lands. Therefore, the management of cattle and treatment of field feces should be strengthened.
Chura-Chambi, Rosa M; Nakajima, Erika; de Carvalho, Roberta R; Miyasato, Patricia A; Oliveira, Sergio C; Morganti, Ligia; Martins, Elizabeth A L
2013-12-01
Schistosomiasis is an important parasitic disease, with about 240 million people infected worldwide. Humans and animals can be infected, imposing an enormous social and economic burden. The only drug available for chemotherapy, praziquantel, does not control reinfections, and an efficient vaccine for prophylaxis is still missing. However, the tegumental protein Sm29 of Schistosoma mansoni was shown to be a promising antigen to compose an anti-schistosomiasis vaccine. Though, recombinant Sm29 is expressed in Escherichia coli as insoluble inclusion bodies requiring an efficient process of refolding, thus, hampering its production in large scale. We present in this work studies to refold the recombinant Sm29 using high hydrostatic pressure, a mild condition to dissociate aggregated proteins, leading to refolding on a soluble conformation. Our studies resulted in high yield of rSm29 (73%) as a stably soluble and structured protein. The refolded antigen presented protective effect against S. mansoni development in immunized mice. We concluded that the refolding process by application of high hydrostatic pressure succeeded, and the procedure can be scaled-up, allowing industrial production of Sm29. Copyright © 2013 Elsevier B.V. All rights reserved.
Is praziquantel therapy safe during pregnancy?
Adam, Ishag; Elwasila, El Taib; Homeida, Mamoun
2004-09-01
Schistosomiasis control programmes are generally based on mass distribution of praziquantel (PZQ). This approach has been further strengthened by studies that demonstrated reduction in schistosomiasis-related morbidity following regular use of PZQ. Many women were excluded from this therapy when pregnant. Since a high degree of parity is achieved in many schistosomiasis-endemic regions, excluded women often miss treatment and consequently the beneficial effect of this therapy. This study investigated the effect of PZQ therapy on pregnancy in the Gezira region of Sudan. As part of the Blue Nile Health Project, more than 320,000 individuals received annual treatment with PZQ from 1980 to 1990. The present study reviewed the treatment records of all women between 1990 and 1995 in four villages. Eighty-eight of 637 women interviewed had received PZQ during their pregnancy. The outcome and the effect of PZQ therapy on their offspring were compared with a group of 549 women who had not received the drug during pregnancy. There were no significant differences between the two groups in the rate of abortion or preterm deliveries. No congenital abnormalities were noted by clinical examination in any of the babies born to either group. This retrospective study suggested that PZQ therapy is safe during pregnancy.
Hua, Hai-Yong; Wang, Wei; Cao, Guo-Qun; Tang, Feng; Liang, You-Sheng
2013-09-11
Human Schistosoma haematobium infection that causes urinary schistosomiasis occurs in Africa and the eastern Mediterranean, and China is only endemic for S. japonicum. In this report, we reported an imported case with S. haematobium infection returning from Angola to Shaanxi Province, northwestern China, where S. japonicum is not endemic. The case was misdiagnosed as ureteral calculus, invasive urothelial carcinoma and eosinophilic cystitis in several hospitals, and was finally diagnosed by means of serological assay followed by microscopic examination of the urine sediment. The patient was then treated with praziquantel, and a satisfactory outcome was obtained. As S. haematobium is not indigenous to China, most Chinese doctors and medical technicians are unfamiliar with this introduced parasitic disease, therefore, they need to increase the awareness of its existence when they encounter persons who have visited or resided in endemic areas, and the techniques for detection of the parasite, so as to reduce the misdiagnosis. In addition, health education should be given to those who will go to the endemic areas to improve their knowledge and awareness on prevention and control of schistosomiasis haematobia, thereby reducing the risk of exposure to the infested freshwater.
Feng, Y; Liu, L; Xia, S; Xu, J-F; Bergquist, R; Yang, G-J
2016-01-01
With the goal set to eliminate schistosomiasis nationwide by 2020, The People's Republic of China has initiated the surveillance-response stage to identify remaining sources of infection and potential pockets from where the disease could reemerge. Shifting the focus from classical monitoring and evaluation to rapid detection and immediate response, this approach requires modelling to bridge the surveillance and response components. We review here studies relevant to schistosomiasis modelling in a Chinese surveillance-response system with the expectation to achieve a practically useful understanding of the current situation and potential future study directions. We also present useful experience that could tentatively be applied in other endemic regions in the world. Modelling is discussed at length as it plays an essential role, both with regard to the intermediate snail host and in the definitive, mammal hosts. Research gaps with respect to snail infection, animal hosts and sectoral research cooperation are identified and examined against the prevailing background of ecosystem and socioeconomic changes with a focus on coexisting challenges and opportunities in a situation with increasing financial constraints. Copyright © 2016 Elsevier Ltd. All rights reserved.
1979-06-10
L. ......... ... ..D.. . C .. . . . .. . . 1 .. . .. ...... A COLIPhRATIVE STUDY OF Ti-M PRDVAIL-NC., .4D MORBIDITY OF SCHISTOSOMIASIS HA.SMATOBIUI...morbidity of 1 haematobium and b\\mansoni infection were compared in Egyptian children in matched age groups. The relationship of the prevalence to the...dating back to the ancient " gyptian period 1 . The ecological concept of schistosomiasis sugaests that in most endemic areas men and women of all
Schistosomiasis-an endemic parasitic waterborne disease.
Drudge-Coates, Lawrence; Turner, Bruce
Schistosomiasis (or bilharzia) is a chronic waterborne disease caused by parasitic worms or schistosoma in the tropics and sub tropics. Five main species exist, and common to all is its transmission to humans as a result of exposure to infested fresh water, into which the cercariae of the parasite are released by freshwater snails. With the rise of tourism and travel, more people are travelling to countries where schistosomiasis is a risk. Schistosoma haematobium is responsible for urogenital schistosomiasis, in which manifestations range from acute hypersensitivity reactions to bladder disease in the detection of which the nurse cystoscopist can have a significant role. Treatment is highly effective, and the diagnosis should be considered in individuals with possible clinical illness who have travelled to or lived in endemic areas.
Potential effects of Cramoll 1,4 lectin on murine Schistosomiasis mansoni.
Melo, Cristiane Moutinho Lagos de; de Lima, Amanda Lucena Rosendo; Beltrão, Eduardo Isidoro Carneiro; Cavalcanti, Carmelita C Bezerra; de Melo-Júnior, Mário Ribeiro; Montenegro, Silvia Maria L; Coelho, Luana Cassandra B Barroso; Correia, Maria Tereza dos Santos; Carneiro-Leão, Ana Maria dos Anjos
2011-05-01
Cratylia mollis is a natural forage plant from the Northeast of Brazil. C. mollis seed lectin (Cramoll) containing molecular forms 1 and 4 (Cramoll 1,4) has shown anti-inflammatory and wound-healing activities. This work analyzed the effect of Cramoll 1,4 on experimental schistosomiasis in mice. Experimental groups (n=15/group) were composed of female albino Swiss mice, which were subcutaneously and caudally infected with Schistosoma mansoni (BH strain, 100 cercariae/mouse) and were treated with an intraperitoneal dose after infection as follows: (1) Cramoll 1,4 (50 mg kg(-1) single dose - after 40 days of infection), (2) Cramoll 1,4 (7 mg kg(-1) daily dose - for 7 days after infection) and control (untreated mice). Mice were sacrificed 8 weeks after infection and adult worms were recovered from the portal-hepatic system. Livers were fixed in 10% (v/v) formaldehyde/0.15M NaCl and tissue sections were processed for haematoxilin and Masson's trichrome stainings. Mice infected subcutaneously harboured no or very few worms and hence the effect of Cramoll 1,4 could not be assessed. Results (P≤0.05) were obtained with Cramoll 1,4 using the two treatments, with reduction of: egg excretion (79 and 80%), adult worm recovery (71 and 79%) and liver granulomas (40 and 73.5%) in relation to control. This study showed the potential anti-helminthic activity of Cramoll 1,4 when tested against Schistosomiasis mansoni infection in mice. Copyright © 2011 Elsevier B.V. All rights reserved.
Zhang, Hui-Juan; Zhu, Rong; Wu, Cheng-Guo; Guo, Jia-Gang
2007-06-01
To investigate the changes in natural ecology and social environment after the construction of the dam in the Three Gorges Reservoir area, and to understand the social behavior status and education backgrounds of the local residents, and to analyze the potential impact of these factors on schistosomiasis spreading. Data of nature and social economy after the construction of the dam in the Three Gorge area were collected, and a cross-sectional study with questionnaire survey on information including social demographic characteristics, people's production and life style, knowledge about schistosomiasis was conducted among natives, emigrations. After the construction of the dam, as the stream became slower, the water-level fluctuating zone on the bank of the reservoir was formed. The main source of drinking water and daily life activity are mainly depends on the river supplying (accounting about 68.7% and 75.8%, respectively); due to the needs of farming, washing cloths and vegetables, 45.6% of resident had a close contact with river water. People with away-from-home employment among emigrations were increased from 5.7% to 18.7%. The proportion of using hygienic lavatory was 88.6%. The main source of water for drinking and daily life among emigrations was tap water (85.4% and 87.0%). The residents had no awareness about the health hazard for schistosomiasis, with less health information The natural environment of reservoir areas and the life style are risk factors for the spread of schistosomiasis. The improved sanitation condition and the economy construction after the construction of the dam is propitious to keeping away from the introduction of schistosomiasis. However, people with away-from-home employment among emigrations are still at risk of schistosomiasis.
Tchouanguem, Huguette Nguedie; Fouelifack, Florent Ymele; Keugoung, Basile; Fouelifa, Loic Dongmo; Moyou, Roger Somo
2016-01-01
Schistosomiasis, the second endemic parasitic infection in the world, is a parasitosis caused by trematodes from the genus Schistosoma. Our study aims to assess the prevalence of different species of schistosomes (Schistosoma mansoni, haematobium and intercalatum) among schoolchildren and to identify risk factors, clinical signs of schistosomiasis, and schistosomiasis intermediate host snails in stagnant water. We conducted a cross sectional study over a three months period. The study consisted of sociodemographic and clinical data recording, collection of stool samples and urine, molluscan research and treatment of positive students for other helminths. Laboratory tests were performed at the Medical Research Institute and the study of Medicinal Plants in Yaounde where stool samples and urine were examined using KATO KATZ and centrifugation technique respectively, and shellfish species were determined by a malacologist. A total of 400 students aged between 8-16 years, 223 (55.7%) girls and 177 (44.3%) boys attending 4 elementary school were enrolled in the study. The social survey revealed that 154 students out of 400 (or 38.5%) were in contact with the river water at least once a week, 58% from around noon. All students had at least one symptom of schistosomiasis although nonspecific and dominated by abdominal pain in 72% of cases (n = 288 of 400). Biologically, no schistosomiasis eggs were detected. Cercaria releasing rate was negative in the 100 watery species found. The Santchou health area is not an active outbreak of schistosomiasis, but remains a risk area because of rice cultivation and stagnant water. The intensification of health education campaigns among the general population would delay the onset of this infection in the locality.
Carvalho, O S; Massara, C L; Guerra, H L; Campos, Y R; Caldeira, R L; Chaves, A; Katz, N
1998-01-01
This study was conducted to assess the presence of schistosomiasis mansoni in the "Noroeste de Minas" mesoregion, an area considered non-endemic. A malacologic survey and parasitologic stool examinations were undertaken in 13 municipalities of the mesoregion. A sample of 3,283 primary school students was submitted to fecal examination by the Kato-Katz method. A total of 3,627 planorbids was collected and examined. The molluscs were identified as Biomphalaria straminea in seven municipalities (Unaí, Bonfinópolis de Minas, Paracatu, Jaão Pinheiro, Vazante, Lagamar and Lagoa Grande) and as Biomphalaria peregrina in one (Presidente Olegário). All planorbids were negative for Schistosoma mansoni. Four students were diagnosed with schistosomiasis in the municipalities of Buritis, Formoso, Paracatu and Unaí, but none of these cases was considered autochthonous. The data obtained indicate that the "Noroeste de Minas" mesoregion continues to be non-endemic for schistosomiasis mansoni, although the presence of intermediate hosts associated with parasitized individuals emphasizes the need for epidemiological surveillance of schistosomiasis in this mesoregion.
Recent advances in proteomic applications for schistosomiasis research: potential clinical impact.
Sotillo, Javier; Doolan, Denise; Loukas, Alex
2017-02-01
Schistosomiasis is a neglected tropical disease affecting hundreds of millions of people worldwide. Recent advances in the field of proteomics and the development of new and highly sensitive mass spectrometers and quantitative techniques have provided new tools for advancing the molecular biology, cell biology, diagnosis and vaccine development for public health threats such as schistosomiasis. Areas covered: In this review we describe the latest advances in research that utilizes proteomics-based tools to address some of the key challenges to developing effective interventions against schistosomiasis. We also provide information about the potential of extracellular vesicles to advance the fight against this devastating disease. Expert commentary: Different proteins are already being tested as vaccines against schistosomiasis with promising results. The re-analysis of the Schistosoma spp. proteomes using new and more sensitive mass spectrometers as well as better separation approaches will help identify more vaccine targets in a rational and informed manner. In addition, the recent development of new proteome microarrays will facilitate characterisation of novel markers of infection as well as new vaccine and diagnostic candidate antigens.
... fever Images Swimmer's itch Antibodies References Bustinduy AL, King CH. Schistosomiasis. In: Farrar J, Hotez PJ, Junghanss ... commercial use must be authorized in writing by ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer ...
Environmental management: a re-emerging vector control strategy.
Ault, S K
1994-01-01
Vector control may be accomplished by environmental management (EM), which consists of permanent or long-term modification of the environment, temporary or seasonal manipulation of the environment, and modifying or changing our life styles and practices to reduce human contact with infective vectors. The primary focus of this paper is EM in the control of human malaria, filariasis, arboviruses, Chagas' disease, and schistosomiasis. Modern EM developed as a discipline based primarily in ecologic principles and lessons learned from the adverse environmental impacts of rural development projects. Strategies such as the suppression of vector populations through the provision of safe water supplies, proper sanitation, solid waste management facilities, sewerage and excreta disposal systems, water manipulation in dams and irrigation systems, vector diversion by zooprophylaxis, and vector exclusion by improved housing, are discussed with appropriate examples. Vectors of malaria, filariasis, Chagas' disease, and schistosomiasis have been controlled by drainage or filling aquatic breeding sites, improved housing and sanitation, the use of expanded polystyrene beads, zooprophylaxis, or the provision of household water supplies. Community participation has been effective in the suppression of dengue vectors in Mexico and the Dominican Republic. Alone or combined with other vector control methods, EM has been proven to be a successful approach to vector control in a number of places. The future of EM in vector control looks promising.
Hotez, Peter J.; Savioli, Lorenzo; Fenwick, Alan
2012-01-01
The neglected tropical diseases (NTDs) are highly endemic but patchily distributed among the 20 countries and almost 400 million people of the Middle East and North Africa (MENA) region, and disproportionately affect an estimated 65 million people living on less than US$2 per day. Egypt has the largest number of people living in poverty of any MENA nation, while Yemen has the highest prevalence of people living in poverty. These two nations stand out for having suffered the highest rates of many NTDs, including the soil-transmitted nematode infections, filarial infections, schistosomiasis, fascioliasis, leprosy, and trachoma, although they should be recognized for recent measures aimed at NTD control. Leishmaniasis, especially cutaneous leishmaniasis, is endemic in Syria, Iran, Iraq, Libya, Morocco, and elsewhere in the region. Both zoonotic (Leishmania major) and anthroponotic (Leishmania tropica) forms are endemic in MENA in rural arid regions and urban regions, respectively. Other endemic zoonotic NTDs include cystic echinococcosis, fascioliasis, and brucellosis. Dengue is endemic in Saudi Arabia, where Rift Valley fever and Alkhurma hemorrhagic fever have also emerged. Great strides have been made towards elimination of several endemic NTDs, including lymphatic filariasis in Egypt and Yemen; schistosomiasis in Iran, Morocco, and Oman; and trachoma in Morocco, Algeria, Iran, Libya, Oman, Saudi Arabia, Tunisia, and the United Arab Emirates. A particularly noteworthy achievement is the long battle waged against schistosomiasis in Egypt, where prevalence has been brought down by regular praziquantel treatment. Conflict and human and animal migrations are key social determinants in preventing the control or elimination of NTDs in the MENA, while local political will, strengthened international and intersectoral cooperative efforts for surveillance, mass drug administration, and vaccination are essential for elimination. PMID:22389729
Kabatereine, Narcis B; Standley, Claire J; Sousa-Figueiredo, Jose C; Fleming, Fiona M; Stothard, J Russell; Talisuna, Ambrose; Fenwick, Alan
2011-12-13
It is widely advocated that integrated strategies for the control of neglected tropical diseases (NTDs) are cost-effective in comparison to vertical disease-specific programmes. A prerequisite for implementation of control interventions is the availability of baseline data of prevalence, including the population at risk and disease overlap. Despite extensive literature on the distribution of schistosomiasis on the mainland in Uganda, there has been a knowledge gap for the prevalence of co-infections with malaria, particularly for island communities in Lake Victoria. In this study, nine lakeshore and island districts were surveyed for the prevalence of NTDs and malaria, as well as educational and health infrastructure. A total of 203 communities were surveyed, including over 5000 school-age children. Varying levels of existing health infrastructure were observed between districts, with only Jinja District regularly treating people for NTDs. Community medicine distributors (CMD) were identified and trained in drug delivery to strengthen capacity. Prevalence levels of intestinal schistosomiasis and soil-transmitted helminthiasis were assessed via Kato-Katz thick smears of stool and malaria prevalence determined by microscopy of fingerprick blood samples. Prevalence levels were 40.8%, 26.04% and 46.4%, respectively, while the prevalence of co-infection by Schistosoma mansoni and Plasmodium spp. was 23.5%. Socio-economic status was strongly associated as a risk factor for positive infection status with one or more of these diseases. These results emphasise the challenges of providing wide-scale coverage of health infrastructure and drug distribution in remote lakeshore communities. The data further indicate that co-infections with malaria and NTDs are common, implying that integrated interventions for NTDs and malaria are likely to maximize cost-effectiveness and sustainability of disease control efforts.
2011-01-01
Background It is widely advocated that integrated strategies for the control of neglected tropical diseases (NTDs) are cost-effective in comparison to vertical disease-specific programmes. A prerequisite for implementation of control interventions is the availability of baseline data of prevalence, including the population at risk and disease overlap. Despite extensive literature on the distribution of schistosomiasis on the mainland in Uganda, there has been a knowledge gap for the prevalence of co-infections with malaria, particularly for island communities in Lake Victoria. In this study, nine lakeshore and island districts were surveyed for the prevalence of NTDs and malaria, as well as educational and health infrastructure. Results A total of 203 communities were surveyed, including over 5000 school-age children. Varying levels of existing health infrastructure were observed between districts, with only Jinja District regularly treating people for NTDs. Community medicine distributors (CMD) were identified and trained in drug delivery to strengthen capacity. Prevalence levels of intestinal schistosomiasis and soil-transmitted helminthiasis were assessed via Kato-Katz thick smears of stool and malaria prevalence determined by microscopy of fingerprick blood samples. Prevalence levels were 40.8%, 26.04% and 46.4%, respectively, while the prevalence of co-infection by Schistosoma mansoni and Plasmodium spp. was 23.5%. Socio-economic status was strongly associated as a risk factor for positive infection status with one or more of these diseases. Conclusions These results emphasise the challenges of providing wide-scale coverage of health infrastructure and drug distribution in remote lakeshore communities. The data further indicate that co-infections with malaria and NTDs are common, implying that integrated interventions for NTDs and malaria are likely to maximize cost-effectiveness and sustainability of disease control efforts. PMID:22166365
Schistosomiasis elimination by 2020 or 2030?
Fenwick, Alan; Jourdan, Peter
2016-06-01
Schistosomiasis has been a public health burden in a number of countries across the globe for centuries and probably beyond. The World Health Organization and partners are currently preparing to move towards elimination of this disease. However, given the historical challenges and barriers to ridding areas of this water-borne parasite infection, we question whether the current targets for eliminating schistosomiasis as a global health problem can be achieved. Copyright © 2016 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.
2014-01-01
Background Manson’s schistosomiasis continues to be a severe public health problem in Brazil, where thousands of people live under the risk of contracting this parasitosis. In the Northeast of Brazil, schistosomiasis has expanded from rural areas to the coast of Pernambuco State, where the intermediate host is Biomphalaria glabrata snails. This study aims at presenting situational analyses on schistosomiasis at the coastal locality of Porto de Galinhas, Pernambuco, Brazil, by determining the risk factors relating to its occurrence from the epidemiological and spatial perspectives. Methods In order to gather prevalence data, a parasitological census surveys were conducted in 2010 in the light of the Kato-Katz technique. Furthermore, malacological surveys were also conducted in the same years so as to define the density and infection rates of the intermediate host. Lastly, socioeconomic-behavioral survey was also conducted to determine the odds ratio for infection by Schistosoma mansoni. Based on these data, spatial analyses were done, resulting in maps of the risk of disease transmission. To predict the risk of schistosomiasis occurrence, a multivariate logistic regression was performed using R 2.13 software. Results Based on prevalence, malacological and socioeconomic-behavioural surveys, it was identified a prevalence of 15.7% in the investigated population (2,757 individuals). Due to the malacological survey, 36 breeding sites were identified, of which 11 were classified as foci of schistosomiasis transmission since they pointed out snails which were infected by Schistosoma mansoni. Overall, 11,012 snails (Biomphalaria glabrata) were collected. The multivariate regression model identified six explanatory variables of environmental, socioeconomic and demographic nature. Spatial sweep analysis by means of the Bernoulli method identified one statistically significant cluster in Salinas (RR = 2.2; p-value < 0.000), the district with the highest occurrence of cases. Conclusions Based on the resulting information from this study, the epidemiological dimensions of this disease are significant and severe, within the scenario of schistosomiasis in Pernambuco state. The risk factors which were identified in the predictive model made it clear that the environmental and social conditions influence on the schistosomiasis occurrences. PMID:24559264
Lv, Chao; Hong, Yang; Fu, Zhiqiang; Lu, Ke; Cao, Xiaodan; Wang, Tao; Zhu, Chuangang; Li, Hao; Xu, Rui; Jia, Bingguang; Han, Qian; Dou, Xuefeng; Shen, Yuanxi; Zhang, Zuhang; Zai, Jinli; Feng, Jintao; Lin, Jiaojiao
2016-03-09
Schistosomiasis is a huge threat to human and animal health. Apart from bovines, goats play an important role in the transmission of schistosomiasis in some endemic areas of China. An accessible, quality-assured goat schistosomiasis diagnostic technique is needed. Recently, our laboratory identified two recombinant diagnostic antigens, SjPGM and SjRAD23 via an immuno-proteomic method. The application of these two recombinant antigens to develop a higher sensitivity and specificity technique for the sheep schistosomiasis diagnosis is urgently needed. Epitopes of SjPGM and SjRAD23 were predicted and three polypeptides, two from SjRAD23 and one from SjPGM, were selected. Recombinant plasmids containing two to three DNA sequences encoding predicted polypeptides or large hydrophilic region of Sj23 (LHD-Sj23) were constructed and expressed. Eight recombinant schistosome antigens including four multi-epitope proteins and four recombinant single-molecule antigens as well as SEA, were assessed by ELISA in 91 sera from schistosome-infected goats, 44 sera from non-infected goats, 37 sera from Orientobilharzia-infected goats, and 12 from Haemonchus contortus-infected goats. ELISA tests showed that three multi-epitope proteins had higher sensitivity than the four single-molecule antigens (rSjRAD23, rSjPGM, rBSjRAD23-1, rBSj23) and the multi-epitope protein rBSjPGM-BSjRAD23-1-BSj23 had the highest sensitivity (97.8 %, 89/91) and maintained good specificity (100 %, 44/44) as well as low cross-reactivity with haemonchosis (8.33 %, 3/12) and orientobilharziasis (13.51 %, 5/37) in the diagnosis of goat schistosomiasis. In contrast, when SEA was applied as a diagnosis antigen, it had 100 % (91/91) sensitivity, 75 % (33/44) specificity, 25 and 83.78 % cross-reactivity with haemonchosis (3/12) and orientobilharziasis (31/37), respectively. The application of recombinant multi-epitope proteins may increase the sensitivity of diagnosis technique and retain high specificity of single-molecule antigens for schistosomiasis, and the recombinant antigen rBSjPGM-BSjRAD23-1-BSj23 has the potential to be used as a diagnosis antigen for goat schistosomiasis.
Dida, Gabriel O.; Gelder, Frank B.; Anyona, Douglas N.; Matano, Ally-Said; Abuom, Paul O.; Adoka, Samson O.; Ouma, Collins; Kanangire, Canisius K.; Owuor, Phillip O.; Ofulla, Ayub V. O.
2014-01-01
We purposively selected 39 sampling sites along the Mara River and its two perennial tributaries of Amala and Nyangores and sampled snails. In addition, water physicochemical parameters (temperature, turbidity, dissolved oxygen, conductivity, alkalinity, salinity and pH) were taken to establish their influence on the snail abundance and habitat preference. Out of the 39 sites sampled, 10 (25.6%) had snails. The snail species encountered included Biomphalaria pfeifferi Krauss – the intermediate host of Schistosoma mansoni Sambon, Bulinus africanus – the intermediate host of Schistosoma haematobium, and Lymnaea natalensis Krauss – the intermediate host of both Fasciola gigantica and F. hepatica Cobbold. Ceratophallus spp., a non-vector snail was also encountered. Most (61.0%) of the snails were encountered in streamside pools. Schistosomiasis-transmitting host snails, B. pfeifferi and B. africanus, were fewer than fascioliasis-transmitting Lymnaea species. All the four different snail species were found to be attached to different aquatic weeds, with B. pfeifferi accounting for over half (61.1%) of the snails attached to the sedge, followed by B. africanus and Lymnaea spp., accounting for 22.2 and 16.7%, respectively. Ceratophallus spp. were non-existent in sedge. The results from this preliminary study show that snails intermediate hosts of schistosomiasis and fascioliasis exists in different habitats, in few areas along the Mara River, though their densities are still low to have any noticeable impacts on disease transmission in case they are infected. The mere presence of the vector snails in these focal regions calls for their immediate control and institution of proper regulations, management, and education among the locals that can help curtail the spread of the snails and also schistosomiasis and fascioliasis within the Mara River basin. PMID:25405008
Raso, Giovanna; Essé, Clémence; Dongo, Kouassi; Ouattara, Mamadou; Zouzou, Fabien; Hürlimann, Eveline; Koffi, Veronique A; Coulibaly, Gaoussou; Mahan, Virginie; Yapi, Richard B; Koné, Siaka; Coulibaly, Jean Tenena; Meïté, Aboulaye; Guéhi-Kabran, Marie-Claire; Bonfoh, Bassirou; N'Goran, Eliézer Kouakou; Utzinger, Jürg
2018-06-12
The global strategy to control helminthiases (schistosomiasis and soil-transmitted helminthiasis) emphasizes preventive chemotherapy. However, in the absence of access to clean water, improved sanitation, and adequate hygiene, reinfection after treatment can occur rapidly. Integrated approaches might be necessary to sustain the benefits of preventive chemotherapy and make progress toward interruption of helminthiases transmission. The aim of this study was to assess and quantify the effect of an integrated control package that consists of preventive chemotherapy, community-led total sanitation, and health education on soil-transmitted helminthiasis, schistosomiasis, intestinal protozoa infection, and diarrhea in rural Côte d'Ivoire. In a first step, a community health education program was developed that includes an animated cartoon to promote improved hygiene and health targeting school-aged children, coupled with a health education theater for the entire community. In a second step, a cluster randomized trial was implemented in 56 communities of south-central Côte d'Ivoire with 4 intervention arms: (1) preventive chemotherapy; (2) preventive chemotherapy plus community-led total sanitation; (3) preventive chemotherapy plus health education; and (4) all 3 interventions combined. Before implementation of the aforementioned interventions, a baseline parasitologic, anthropometric, and hygiene-related knowledge, attitudes, practices, and beliefs survey was conducted. These surveys were repeated 18 and 39 months after the baseline cross-sectional survey to determine the effect of different interventions on helminth and intestinal protozoa infection, nutritional indicators, and knowledge, attitudes, practices, and beliefs. Monitoring of diarrhea was done over a 24-month period at 2-week intervals, starting right after the baseline survey. Key results from this cluster randomized trial will shed light on the effect of integrated approaches consisting of preventive chemotherapy, community-led total sanitation, and health education against infections with soil-transmitted helminths, schistosomes, an intestinal protozoa and prevention of diarrhea in a rural part of Côte d'Ivoire. The research provided new insights into the acceptability, strengths, and limitations of an integrated community-based control package targeting helminthiases, intestinal protozoa infections, and diarrhea in rural communities of Côte d'Ivoire. In the longer term, the study will allow determining the effect of the integrated control approach on infection patterns with parasitic worms and intestinal protozoa, diarrheal incidence, anthropometric measures, and hygiene-related knowledge, attitudes, practices, and beliefs. International Standard Randomized Controlled Trial Number (ISRCTN): 53102033; http://www.isrctn.com/ISRCTN53102033 (Archived by WebCite at http://www.webcitation.org/6wpnXEiHo). RR1-10.2196/9166. ©Giovanna Raso, Clémence Essé, Kouassi Dongo, Mamadou Ouattara, Fabien Zouzou, Eveline Hürlimann, Veronique A Koffi, Gaoussou Coulibaly, Virginie Mahan, Richard B Yapi, Siaka Koné, Jean Tenena Coulibaly, Aboulaye Meïté, Marie-Claire Guéhi-Kabran, Bassirou Bonfoh, Eliézer Kouakou N'Goran, Jürg Utzinger. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 12.06.2018.
The Tao survivorship of schistosomes: implications for schistosomiasis control.
Cai, Pengfei; Gobert, Geoffrey N; You, Hong; McManus, Donald P
2016-06-01
Schistosomiasis, caused by blood flukes of the genus Schistosoma, is a major public health problem which contributes substantially to the economic and financial burdens of many nations in the developing world. An array of survival strategies, such as the unique structure of the tegument which acts as a major host-parasite interface, immune modulation mechanisms, gene regulation, and apoptosis and self-renewal have been adopted by schistosome parasites over the course of long-term evolution with their mammalian definitive hosts. Recent generation of complete schistosome genomes together with numerous biological, immunological, high-throughput "-omics" and gene function studies have revealed the Tao or strategies that schistosomes employ not only to promote long-term survival, but also to ensure effective life cycle transmission. New scenarios for the future control of this important neglected tropical disease will present themselves as our understanding of these Tao increases. Copyright © 2016 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Deng, Wangping; Xu, Bin; Hu, Haiyan; Li, Jianyong; Hu, Wei; Song, Shiping; Feng, Zheng; Fan, Chunhai
2013-05-01
Schistosomiasis control remains to be an important and challenging task in the world. However, lack of quick, simple, sensitive and specific sero-diagnostic test is still a hurdle in the control practice. The commonly employed enzyme-linked immuno-sorbent assay (ELISA) relies on the native soluble egg antigen (SEA) that is limited in supply. Here we developed an electrochemical immunosensor array (ECISA) assay with an interfacial co-assembly strategy. A recombinant Schistosoma japonicum (Sj) calcium-binding protein (SjE16) was used as a principal antigen, while the SEA as a minor, co-assembling agent, with a ratio of 8:1 (SjE16: SEA, Sj16EA), which was co-immobilized on a disposable 16-channel screen-printed carbon electrode array. A portable electrochemical detector was employed to detect antibodies in serum samples. The sensitivity of ECISA reached 100% with minimal cross-reactions. Therefore, we have demonstrated that this rapid, sensitive and specific ECISA technique has the potential to perform large-scale on-site screening of Sj infection.
Assaré, Rufin K.; Tian-Bi, Yves-Nathan T.; Yao, Patrick K.; N’Guessan, Nicaise A.; Ouattara, Mamadou; Yapi, Ahoua; Coulibaly, Jean T.; Meïté, Aboulaye; Hürlimann, Eveline; Knopp, Stefanie; Utzinger, Jürg; N’Goran, Eliézer K.
2016-01-01
Background The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) has launched several large-scale trials to determine the best strategies for gaining and sustaining control of schistosomiasis and transitioning toward elimination. In Côte d’Ivoire, a 5-year cluster-randomized trial is being implemented in 75 schools to sustain the control of schistosomiasis mansoni. We report Schistosoma mansoni infection levels in children one year after the initial school-based treatment (SBT) with praziquantel and compare with baseline results to determine the effect of the intervention. Methodology The baseline cross-sectional survey was conducted in late 2011/early 2012 and the first follow-up in May 2013. Three consecutive stool samples were collected from 9- to 12-year-old children in 75 schools at baseline and 50 schools at follow-up. Stool samples were subjected to duplicate Kato-Katz thick smears. Directly observed treatment (DOT) coverage of the SBT was assessed and the prevalence and intensity of S. mansoni infection compared between baseline and follow-up. Principal Findings The S. mansoni prevalence in the 75 schools surveyed at baseline was 22.1% (95% confidence interval (CI): 19.5–24.4%). The DOT coverage was 84.2%. In the 50 schools surveyed at baseline and one year after treatment, the overall prevalence of S. mansoni infection decreased significantly from 19.7% (95% CI: 18.5–20.8%) to 12.8% (95% CI: 11.9–13.8%), while the arithmetic mean S. mansoni eggs per gram of stool (EPG) among infected children slightly increased from 92.2 EPG (95% CI: 79.2–105.3 EPG) to 109.3 EPG (95% CI: 82.7–135.9 EPG). In two of the 50 schools, the prevalence increased significantly, despite a DOT coverage of >75%. Conclusions/Significance One year after the initial SBT, the S. mansoni prevalence had decreased. Despite this positive trend, an increase was observed in some schools. Moreover, the infection intensity among S. mansoni-infected children was slightly higher at the 1-year follow-up compared to the baseline situation. Our results emphasize the heterogeneity of transmission dynamics and provide a benchmark for the future yearly follow-up surveys of this multi-year SCORE intervention study. PMID:26789749
2011-01-01
Background Less is known about mass drug administration [MDA] for neglected tropical diseases [NTDs] than is suggested by those so vigorously promoting expansion of the approach. This paper fills an important gap: it draws upon local level research to examine the roll out of treatment for two NTDs, schistosomiasis and soil-transmitted helminths, in Uganda. Methods Ethnographic research was undertaken over a period of four years between 2005-2009 in north-west and south-east Uganda. In addition to participant observation, survey data recording self-reported take-up of drugs for schistosomiasis, soil-transmitted helminths and, where relevant, lymphatic filariasis and onchocerciasis was collected from a random sample of at least 10% of households at study locations. Data recording the take-up of drugs in Ministry of Health registers for NTDs were analysed in the light of these ethnographic and social survey data. Results The comparative analysis of the take-up of drugs among adults revealed that although most long term residents have been offered treatment at least once since 2004, the actual take up of drugs for schistosomiasis and soil-transmitted helminths varies considerably from one district to another and often also within districts. The specific reasons why MDA succeeds in some locations and falters in others relates to local dynamics. Issues such as population movement across borders, changing food supply, relations between drug distributors and targeted groups, rumours and conspiracy theories about the 'real' purpose of treatment, subjective experiences of side effects from treatment, alternative understandings of affliction, responses to social control measures and historical experiences of public health control measures, can all make a huge difference. The paper highlights the need to adapt MDA to local circumstances. It also points to specific generalisable issues, notably with respect to health education, drug distribution and more effective use of existing public health legislation. Conclusion While it has been an achievement to have offered free drugs to so many adults, current standard practices of monitoring, evaluation and delivery of MDA for NTDs are inconsistent and inadequate. Efforts to integrate programmes have exacerbated the difficulties. Improved assessment of what is really happening on the ground will be an essential step in achieving long-term overall reduction of the NTD burden for impoverished communities. PMID:21211001
The hidden epidemic of schistosomiasis in recent African immigrants and asylum seekers to Italy.
Beltrame, Anna; Buonfrate, Dora; Gobbi, Federico; Angheben, Andrea; Marchese, Valentina; Monteiro, Geraldo Badona; Bisoffi, Zeno
2017-08-01
The prevalence of schistosomiasis among recent refugees from sub-Saharan Africa in Italy is unknown. This is a retrospective review of African immigrants screened at Centre for Tropical Diseases of Negrar from March 2014 to February 2016. Of the 373 immigrants tested, 34% were positive at least at one schistosomiasis test. The proportion of positive ELISA serology was 103/373 (27.6%). At microscopy, infected subjects were 65/373 (17.4%), (51% Schistosoma haematobium, 38% Schistosoma mansoni, 11% both). CCA antigen for S. mansoni was positive in 47/373 individuals (12.6%). We found a particularly high positivity rate in subjects from Mali (72.1%) and Ivory Coast (48%). This "hidden epidemic" of schistosomiasis cannot be longer neglected, considering the risk of severe complications, and the effective and inexpensive treatment available.
Kosinski, Karen Claire; Kulinkina, Alexandra V; Abrah, Akua Frimpomaa Atakora; Adjei, Michael N; Breen, Kara Marie; Chaudhry, Hafsa Myedah; Nevin, Paul E; Warner, Suzanne H; Tendulkar, Shalini Ahuja
2016-04-14
Surface water contaminated with human waste may transmit urogenital schistosomiasis (UGS). Water-related activities that allow skin exposure place people at risk, but public health practitioners know little about why some communities with access to improved water infrastructure have substantial surface water contact with infectious water bodies. Community-based mixed-methods research can provide critical information about water use and water infrastructure improvements. Our mixed-methods study assessed the context of water use in a rural community endemic for schistosomiasis. Eighty-seven (35.2 %) households reported using river water but not borehole water; 26 (10.5 %) reported using borehole water but not river water; and 133 (53.8 %) households reported using both water sources. All households are within 1 km of borehole wells, but tested water quality was poor in most wells. Schistosomiasis is perceived by study households (89.3 %) to be a widespread problem in the community, but perceived schistosomiasis risk fails to deter households from river water usage. Hematuria prevalence among schoolchildren does not differ by household water use preference. Focus group data provides context for water preferences. Demand for improvements to water infrastructure was a persistent theme; however, roles and responsibilities with respect to addressing community water and health concerns are ill-defined. Collectively, our study illustrates how complex attitudes towards water resources can affect which methods will be appropriate to address schistosomiasis.
Norseth, Hanne M.; Ndhlovu, Patricia D.; Kleppa, Elisabeth; Randrianasolo, Bodo S.; Jourdan, Peter M.; Roald, Borghild; Holmen, Sigve D.; Gundersen, Svein G.; Bagratee, Jayanthilall; Onsrud, Mathias; Kjetland, Eyrun F.
2014-01-01
Background Schistosoma (S.) haematobium is a neglected tropical disease which may affect any part of the genital tract in women. Female genital schistosomiasis (FGS) may cause abnormal vaginal discharge, contact bleeding, genital tumours, ectopic pregnancies and increased susceptibility to HIV. Symptoms may mimic those typical of sexually transmitted infections (STIs) and women with genital schistosomiasis may be incorrectly diagnosed. An expert consensus meeting suggested that the following findings by visual inspection should serve as proxy indicators for the diagnosis of schistosomiasis of the lower genital tract in women from S. haematobium endemic areas: sandy patches appearing as (1) single or clustered grains or (2) sandy patches appearing as homogenous, yellow areas, or (3) rubbery papules. In this atlas we aim to provide an overview of the genital mucosal manifestations of schistosomiasis in women. Methodology/Principal findings Photocolposcopic images were captured from women, between 1994 and 2012 in four different study sites endemic for S. haematobium in Malawi, Zimbabwe, South Africa and Madagascar. Images and specimens were sampled from sexually active women between 15 and 49 years of age. Colposcopic images of other diseases are included for differential diagnostic purposes. Significance This is the first atlas to present the clinical manifestations of schistosomiasis in the lower female genital tract. It will be freely available for online use, downloadable as a presentation and for print. It could be used for training purposes, further research, and in clinical practice. PMID:25412334
Norseth, Hanne M; Ndhlovu, Patricia D; Kleppa, Elisabeth; Randrianasolo, Bodo S; Jourdan, Peter M; Roald, Borghild; Holmen, Sigve D; Gundersen, Svein G; Bagratee, Jayanthilall; Onsrud, Mathias; Kjetland, Eyrun F
2014-01-01
Schistosoma (S.) haematobium is a neglected tropical disease which may affect any part of the genital tract in women. Female genital schistosomiasis (FGS) may cause abnormal vaginal discharge, contact bleeding, genital tumours, ectopic pregnancies and increased susceptibility to HIV. Symptoms may mimic those typical of sexually transmitted infections (STIs) and women with genital schistosomiasis may be incorrectly diagnosed. An expert consensus meeting suggested that the following findings by visual inspection should serve as proxy indicators for the diagnosis of schistosomiasis of the lower genital tract in women from S. haematobium endemic areas: sandy patches appearing as (1) single or clustered grains or (2) sandy patches appearing as homogenous, yellow areas, or (3) rubbery papules. In this atlas we aim to provide an overview of the genital mucosal manifestations of schistosomiasis in women. Photocolposcopic images were captured from women, between 1994 and 2012 in four different study sites endemic for S. haematobium in Malawi, Zimbabwe, South Africa and Madagascar. Images and specimens were sampled from sexually active women between 15 and 49 years of age. Colposcopic images of other diseases are included for differential diagnostic purposes. This is the first atlas to present the clinical manifestations of schistosomiasis in the lower female genital tract. It will be freely available for online use, downloadable as a presentation and for print. It could be used for training purposes, further research, and in clinical practice.
Koroma, Joseph B; Peterson, Jen; Gbakima, Aiah A; Nylander, Francis E; Sahr, Foday; Soares Magalhães, Ricardo J; Zhang, Yaobi; Hodges, Mary H
2010-11-23
A national baseline mapping of schistosomiasis and soil-transmitted helminthiasis (STH) was performed in Sierra Leone. The aim was to provide necessary tools for the Ministry of Health and Sanitation to plan the intervention strategies in the national integrated control program on neglected tropical diseases according to the World Health Organization (WHO) guidelines for preventative chemotherapy (PCT) and for future monitoring and evaluation. 53 primary schools were randomly selected through a two-staged random sampling throughout the country. Approximately one hundred children aged 5-16 years of age were systematically selected from each school and their stool samples examined in a field laboratory. A total of 5,651 samples were examined. Data were analyzed with multivariable logistic regression models using model-based geostatistics. Spatial analysis predicted that S. mansoni infection was positively associated with population density and elevation and that there was a large cluster of high risk of S. mansoni infection (prevalence >70%) in the north and most of the eastern areas of the country, in line with the observed prevalence in Kono (63.8-78.3%), Koinadugu (21.6-82.1%), Kailahun (43.5-52.6%), Kenema (6.1-68.9%) and Tonkolili (0-57.3%). Hookworm infection was negatively associated with population density and land surface temperature, and was high across Sierra Leone with a large cluster of high infection risk (prevalence >70%) in the north-eastern part of the country. Remarkably low prevalence of Ascaris lumbricoides (7.2%) and Trichuris trichiura (3.3%) was recorded when compared with results published in the 1990s. Results justify PCT for schistosomiasis for school age children and at-risk adults every year in high-risk communities in five districts and every two years in moderate-risk communities in one more district. The high prevalence of STH, particularly hookworm, coupled with widespread anemia according to a national report in Sierra Leone, suggests all but one district justifying biannual PCT for STH for pre-school children, school age children, and at-risk adults. PCT for STH in the remaining district, Kono is justified annually.
Koroma, Joseph B.; Peterson, Jen; Gbakima, Aiah A.; Nylander, Francis E.; Sahr, Foday; Soares Magalhães, Ricardo J.; Zhang, Yaobi; Hodges, Mary H.
2010-01-01
Background A national baseline mapping of schistosomiasis and soil-transmitted helminthiasis (STH) was performed in Sierra Leone. The aim was to provide necessary tools for the Ministry of Health and Sanitation to plan the intervention strategies in the national integrated control program on neglected tropical diseases according to the World Health Organization (WHO) guidelines for preventative chemotherapy (PCT) and for future monitoring and evaluation. Methodology/Principal Findings 53 primary schools were randomly selected through a two-staged random sampling throughout the country. Approximately one hundred children aged 5–16 years of age were systematically selected from each school and their stool samples examined in a field laboratory. A total of 5,651 samples were examined. Data were analyzed with multivariable logistic regression models using model-based geostatistics. Spatial analysis predicted that S. mansoni infection was positively associated with population density and elevation and that there was a large cluster of high risk of S. mansoni infection (prevalence >70%) in the north and most of the eastern areas of the country, in line with the observed prevalence in Kono (63.8–78.3%), Koinadugu (21.6–82.1%), Kailahun (43.5–52.6%), Kenema (6.1–68.9%) and Tonkolili (0–57.3%). Hookworm infection was negatively associated with population density and land surface temperature, and was high across Sierra Leone with a large cluster of high infection risk (prevalence >70%) in the north-eastern part of the country. Remarkably low prevalence of Ascaris lumbricoides (7.2%) and Trichuris trichiura (3.3%) was recorded when compared with results published in the 1990s. Conclusions/Significance Results justify PCT for schistosomiasis for school age children and at-risk adults every year in high-risk communities in five districts and every two years in moderate-risk communities in one more district. The high prevalence of STH, particularly hookworm, coupled with widespread anemia according to a national report in Sierra Leone, suggests all but one district justifying biannual PCT for STH for pre-school children, school age children, and at-risk adults. PCT for STH in the remaining district, Kono is justified annually. PMID:21124881
Schistosomiasis in the Gorgol Valley of Mauritania
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jobin, W.R.; Negron-Aponte, H.; Michelson, E.H.
1976-07-01
Schistosomiasis may be increasing in West Africa due to the development of water-resource projects which were given a strong impetus by the disastrous Sahelian drought. This report concerns the existing epidemiology of schistosomiasis in West Africa for the Fourth Region of Mauritania, along the Gorgol River. In this area two reservoirs are proposed, to supply a new rice irrigation system. During May and November 1974, field surveys were made to determine the prevalence and intensity of schistosomiasis, and the relevant species of snails. The surveys were made as a basis for designing the irrigation systems to minimize transmission. The onlymore » snails found in the area were two species of Bulinus; therefore, the human population was tested for Schistosoma haematobium. A high prevalence of schistosomiasis was found in M'Bout, the town nearest the proposed reservoir at Foum Gleita. Prevalence rates were lowest in Kaedi near the confluence of the Gorgol and Senegal rivers. During the period between the first and second survey the incidence rate among children in M'Bout became very high (68%), probably because of increased water contact related to the rains that broke the long drought in August 1974.« less
Predation of schistosomiasis vector snails by ostracoda (crustacea)
Sohn, I.G.; Kornicker, L.S.
1972-01-01
An ostracod species of Cypretta is an effective predator in laboratory experiments on 1- to 3-day-old Biomphalaria glabrata, a vector snail of the blood fluke that causes the tropical and subtropical disease schistosomiasis.
Zhao, Bo; Wang, Yan-Yan; Cao, Yun; Zhang, Hui-Qin; Zhu, Xing-Quan; He, Yong-Kang; Xia, Chao-Ming
2015-01-01
Background Schistosomiasis has decreased significantly in prevalence and intensity of infection in China, thus more accurate and sensitive methods are desperately needed for the further control of schistosomiasis. The present work aimed to assess the utility of the loop-mediated isothermal amplification (LAMP) for detection of light intensity infection or false-negative patients and patients post-treatment, targeting the highly repetitive retrotransposon SjR2 of Schistosoma japonicum. Methodology/ Principal Findings LAMP was first assessed in rabbits with low intensity infection (EPG<10). Then 110 patient sera from Hunan Province, China, and 47 sera after treatment by praziquantel were used to evaluate the diagnostic validity of LAMP. Meanwhile, 42 sera from healthy individuals in a non-endemic area, and 60 sera from "healthy” residents who were identified as being negative for feces examination and immuno-methods in an endemic area were also examined. The results showed that LAMP could detect S. japonicum DNA in sera from rabbits at 3rd day post-infection. Following administration of praziquantel, the S. japonicum DNA in rabbit sera became negative at 10 weeks post-treatment. Of 110 sera from patients, LAMP showed 95.5% sensitivity, and even for 41 patients with less than 10 EPG, the sensitivity of LAMP still reached to 95.1%. For 47 patients after treatment, the negative conversion rate of S. japonicum DNA in patient sera increased from 23.4%, 61.7% to 83.0% at 3 months, 6 months and 9 months post-treatment, respectively. No false-positive result was obtained for 42 human sera from non-endemic area, while for the 60 “healthy” individuals from endemic area, 10 (16.7%) individuals were positive by LAMP, which suggested that these individuals might be false-negative patients. Conclusions/ Significance The present study demonstrated that the LAMP assay is sensitive, specific, and affordable, which would help reduce schistosomiasis transmission through targeted treatment of individuals, particularly for those with negative stool examinations who may yet remain infected. The LAMP assay may provide a potential tool to support schistosomiasis control and elimination strategies. PMID:25874964
Xu, Jing; Guan, Zhi-Xun; Zhao, Bo; Wang, Yan-Yan; Cao, Yun; Zhang, Hui-Qin; Zhu, Xing-Quan; He, Yong-Kang; Xia, Chao-Ming
2015-04-01
Schistosomiasis has decreased significantly in prevalence and intensity of infection in China, thus more accurate and sensitive methods are desperately needed for the further control of schistosomiasis. The present work aimed to assess the utility of the loop-mediated isothermal amplification (LAMP) for detection of light intensity infection or false-negative patients and patients post-treatment, targeting the highly repetitive retrotransposon SjR2 of Schistosoma japonicum. LAMP was first assessed in rabbits with low intensity infection (EPG<10). Then 110 patient sera from Hunan Province, China, and 47 sera after treatment by praziquantel were used to evaluate the diagnostic validity of LAMP. Meanwhile, 42 sera from healthy individuals in a non-endemic area, and 60 sera from "healthy" residents who were identified as being negative for feces examination and immuno-methods in an endemic area were also examined. The results showed that LAMP could detect S. japonicum DNA in sera from rabbits at 3rd day post-infection. Following administration of praziquantel, the S. japonicum DNA in rabbit sera became negative at 10 weeks post-treatment. Of 110 sera from patients, LAMP showed 95.5% sensitivity, and even for 41 patients with less than 10 EPG, the sensitivity of LAMP still reached to 95.1%. For 47 patients after treatment, the negative conversion rate of S. japonicum DNA in patient sera increased from 23.4%, 61.7% to 83.0% at 3 months, 6 months and 9 months post-treatment, respectively. No false-positive result was obtained for 42 human sera from non-endemic area, while for the 60 "healthy" individuals from endemic area, 10 (16.7%) individuals were positive by LAMP, which suggested that these individuals might be false-negative patients. The present study demonstrated that the LAMP assay is sensitive, specific, and affordable, which would help reduce schistosomiasis transmission through targeted treatment of individuals, particularly for those with negative stool examinations who may yet remain infected. The LAMP assay may provide a potential tool to support schistosomiasis control and elimination strategies.
Sandwich mapping of schistosomiasis risk in Anhui Province, China.
Hu, Yi; Bergquist, Robert; Lynn, Henry; Gao, Fenghua; Wang, Qizhi; Zhang, Shiqing; Li, Rui; Sun, Liqian; Xia, Congcong; Xiong, Chenglong; Zhang, Zhijie; Jiang, Qingwu
2015-06-03
Schistosomiasis mapping using data obtained from parasitological surveys is frequently used in planning and evaluation of disease control strategies. The available geostatistical approaches are, however, subject to the assumption of stationarity, a stochastic process whose joint probability distribution does not change when shifted in time. As this is impractical for large areas, we introduce here the sandwich method, the basic idea of which is to divide the study area (with its attributes) into homogeneous subareas and estimate the values for the reporting units using spatial stratified sampling. The sandwich method was applied to map the county-level prevalence of schistosomiasis japonica in Anhui Province, China based on parasitological data collected from sample villages and land use data. We first mapped the county-level prevalence using the sandwich method, then compared our findings with block Kriging. The sandwich estimates ranged from 0.17 to 0.21% with a lower level of uncertainty, while the Kriging estimates varied from 0 to 0.97% with a higher level of uncertainty, indicating that the former is more smoothed and stable compared to latter. Aside from various forms of reporting units, the sandwich method has the particular merit of simple model assumption coupled with full utilization of sample data. It performs well when a disease presents stratified heterogeneity over space.
Schistosoma mansoni cercariae swim efficiently by exploiting an elastohydrodynamic coupling
NASA Astrophysics Data System (ADS)
Krishnamurthy, Deepak; Katsikis, Georgios; Bhargava, Arjun; Prakash, Manu
2017-03-01
The motility of many parasites is critical for infecting their host, as exemplified in the transmission cycle of the parasite Schistosoma mansoni. In its human infectious stage, submillimetre-scale forms of the parasite known as cercariae swim in freshwater and infect humans by penetrating the skin. This infection causes schistosomiasis, a disease comparable to malaria in global socio-economic impact. Given that cercariae do not feed and hence have a lifetime of around 12 hours, efficient motility is crucial for schistosomiasis transmission. Despite this, a first-principles understanding of how cercariae swim is lacking. Combining biological experiments, a novel theoretical model and its robotic realization, we show that cercariae use their forked tail to swim against gravity using a novel swimming gait, described here as a `T-swimmer gait'. During this gait, cercariae beat their tail periodically while maintaining an increased flexibility near their posterior and anterior ends. This flexibility allows an interaction between fluid drag and bending resistance--an elastohydrodynamic coupling, to naturally break time-reversal symmetry and enable locomotion at small length scales. Finally, we find that cercariae maintain this flexibility at an optimal regime for efficient swimming. We anticipate that our work sets the ground for linking the swimming of cercariae to disease transmission, and could potentially enable explorations of novel strategies for schistosomiasis control and prevention.
Perez-Saez, Javier; Mari, Lorenzo; Bertuzzo, Enrico; Casagrandi, Renato; Sokolow, Susanne H.; De Leo, Giulio A.; Mande, Theophile; Ceperley, Natalie; Froehlich, Jean-Marc; Sou, Mariam; Karambiri, Harouna; Yacouba, Hamma; Maiga, Amadou; Gatto, Marino; Rinaldo, Andrea
2015-01-01
We study the geography of schistosomiasis across Burkina Faso by means of a spatially explicit model of water-based disease dynamics. The model quantitatively addresses the geographic stratification of disease burden in a novel framework by explicitly accounting for drivers and controls of the disease, including spatial information on the distributions of population and infrastructure, jointly with a general description of human mobility and climatic/ecological drivers. Spatial patterns of disease are analysed by the extraction and the mapping of suitable eigenvectors of the Jacobian matrix subsuming the stability of the disease-free equilibrium. The relevance of the work lies in the novel mapping of disease burden, a byproduct of the parametrization induced by regional upscaling, by model-guided field validations and in the predictive scenarios allowed by exploiting the range of possible parameters and processes. Human mobility is found to be a primary control at regional scales both for pathogen invasion success and the overall distribution of disease burden. The effects of water resources development highlighted by systematic reviews are accounted for by the average distances of human settlements from water bodies that are habitats for the parasite’s intermediate host. Our results confirm the empirical findings about the role of water resources development on disease spread into regions previously nearly disease-free also by inspection of empirical prevalence patterns. We conclude that while the model still needs refinements based on field and epidemiological evidence, the proposed framework provides a powerful tool for large-scale public health planning and schistosomiasis management. PMID:26513655
2012-01-01
Background In Brazil, schistosomiasis mansoni infection is an endemic disease that mainly affects the country’s rural populations who carry out domestic and social activities in rivers and water accumulations that provide shelter for the snails of the disease. The process of rural migration to urban centers and the disorderly occupation of natural environments by these populations from endemic areas have favored expansion of schistosomiasis to locations that had been considered to be disease-free. Based on environmental changes that have occurred in consequent to an occupation and urbanization process in the locality of Porto de Galinhas, the present study sought to identify the relationship between those chances, measure by remote-sensing techniques, and establish a new endemic area for schistosomiasis on the coast of Pernambuco State - Brazil. Methods To gather prevalence data, two parasitological census surveys were conducted (2000 and 2010) using the Kato-Katz technique. Two malacological surveys were also conducted in the same years in order to define the density and infection rate of the intermediate host. Based on these data, spatial analyses were done, resulting in maps of the risk of disease transmission. To ascertain the environmental changes that have occurred at the locality, images from the QuickBird satellite were analyzed, thus resulting in land use maps. Results Over this 10-year period, the foci of schistosomiasis became more concentrated in the Salinas district. This area was considered to be at the greatest risk of schistosomiasis transmission and had the highest prevalence rates over this period. The study illustrated that this was the area most affected by the environmental changes resulting from the disorderly urbanization process, which gave rise to unsanitary environments that favored the establishment and maintenance of foci of schistosomiasis transmission, thereby consolidating the process of expansion and endemization of this parasitosis. PMID:23164247
Zhou, Huan; He, Yongkang; Ohtsuka, Ryutaro
2005-01-01
Based on nutritional and parasitological examinations of 389 children aged 10-13 years in five primary schools in the schistosomiasis endemic Dongting Lake region of China, the causal factors of their retarded growth, represented by height, weight, mid-upper arm circumference and body mass index, were investigated. Among the four parasites, schistosomiasis infection due to Schistosoma japonicum played a significant role, with higher rates in girls than in boys. Praziquantel treatment of schistosomiasis decreased the infection rate and improved the children's growth. For dietary intake factors, the contribution of protein to total energy intake, which was lower in girls than in boys, had the greatest effect on the growth patterns. The sex difference in growth retardation is judged to be attributable to the traditional norms, such as girls spending more time in infested environments and gender discrimination in food distribution.
Baaten, Gijs G; Sonder, Gerard J; van Gool, Tom; Kint, Joan A; van den Hoek, Anneke
2011-04-05
This study prospectively assessed the occurrence of clinical and subclinical schistosomiasis, strongyloidiasis, filariasis, and toxocariasis, and the screening value of eosinophilia in adult short-term travelers to helminth-endemic countries. Visitors of a pre-travel health advice centre donated blood samples for serology and blood cell count before and after travel. Samples were tested for eosinophilia, and for antibodies against schistosomiasis, strongyloidiasis, filariasis, and toxocariasis. Previous infection was defined as seropositivity in pre- and post-travel samples. Recent infection was defined as a seroconversion. Symptoms of parasitic disease were recorded in a structured diary. Previous infection was found in 112 of 1207 subjects: schistosomiasis in 2.7%, strongyloidiasis in 2.4%, filariasis in 3.4%, and toxocariasis in 1.8%. Recent schistosomiasis was found in 0.51% of susceptible subjects at risk, strongyloidiasis in 0.25%, filariasis in 0.09%, and toxocariasis in 0.08%. The incidence rate per 1000 person-months was 6.4, 3.2, 1.1, and 1.1, respectively. Recent infections were largely contracted in Asia. The positive predictive value of eosinophilia for diagnosis was 15% for previous infection and 0% for recent infection. None of the symptoms studied had any positive predictive value. The chance of infection with schistosomiasis, strongyloidiasis, filariasis, and toxocariasis during one short-term journey to an endemic area is low. However, previous stay leads to a cumulative risk of infection. Testing for eosinophilia appeared to be of no value in routine screening of asymptomatic travelers for the four helminthic infections. Findings need to be replicated in larger prospective studies.
Ferreira, Rita de Cassia dos Santos; Montenegro, Silvia Maria Lucena; Domingues, Ana Lucia Coutinho; Bandeira, Angela Pontes; Silveira, Carlos Antonio da Mota; Leite, Luiz Arthur Calheiros; Pereira, Clara de Almeida; Fernandes, Izolda Moura; Mertens, Alessandra Brainer; Almeida, Milena Oliveira
2014-05-21
It is suggested that interleukin (IL)-13 and transforming growth factor (TGF)-beta play a role in the pulmonary vascular changes found in animal models of schistosomiasis. The aim of this study was to assess and compare the serum levels of total TGF-beta and IL-13 of patients with schistosomiasis with pulmonary arterial hypertension (PAH) and patients with schistosomiasis without PAH. 34 patients from the schistosomiasis outpatient clinic of the Hospital das Clinicas, Recife, Pernambuco, Brazil, without PAH assessed by echocardiography and 34 patients from the Reference Centre of Pulmonary Hypertension of Pronto Socorro Cardiológico de Pernambuco, Recife, Brazil with PAH, confirmed by right heart catheterization, were enrolled on the study. Both groups presented with schistosomal periportal fibrosis after abdominal ultrasound. Serum levels of TGF-beta1 and IL-13 were determined by ELISA. Student t test to independent samples, Mann-Whitney test to nonparametric variables, Pearson correlation test for correlation analyses and Fisher Chi-squared test to compare categorical analyses were used. The median value of TGF-beta1 was significantly higher in patients with PAH (22496.9 pg/ml, interquartile range [IR] 15936.7 - 32087.8) than in patients without PAH (13629.9 pg/ml, IR: 10192.2- 22193.8) (p = 0.006). There was no difference in the median value of IL-13 in the group with Sch-PAH compared to patients without Sch-PAH (p > 0.05). Our results suggest that TGF-beta possibly plays a role in the pathogenesis of schistosomiasis-associated PAH.
Review of Parasitic Zoonoses in Egypt
Youssef, Ahmed I.; Uga, Shoji
2014-01-01
This review presents a comprehensive picture of the zoonotic parasitic diseases in Egypt, with particular reference to their relative prevalence among humans, animal reservoirs of infection, and sources of human infection. A review of the available literature indicates that many parasitic zoonoses are endemic in Egypt. Intestinal infections of parasitic zoonoses are widespread and are the leading cause of diarrhea, particularly among children and residents of rural areas. Some parasitic zoonoses are confined to specific geographic areas in Egypt, such as cutaneous leishmaniasis and zoonotic babesiosis in the Sinai. Other areas have a past history of a certain parasitic zoonoses, such as visceral leishmaniasis in the El-Agamy area in Alexandria. As a result of the implementation of control programs, a marked decrease in the prevalence of other zoonoses, such as schistosomiasis and fascioliasis has been observed. Animal reservoirs of parasitic zoonoses have been identified in Egypt, especially in rodents, stray dogs and cats, as well as vectors, typically mosquitoes and ticks, which constitute potential risks for disease transmission. Prevention and control programs against sources and reservoirs of zoonoses should be planned by public health and veterinary officers based on reliable information from systematic surveillance. PMID:24808742
[Successive ectopic pregnancies associated with tubal shistosomiasis in a French traveler].
Laroche, Justine; Mottet, Nicolas; Malincenco, Marianna; Gay, Catherine; Royer, Pierre Yves; Riethmuller, Didier
2016-01-01
Schistosomiasis is the second endemic parasitic disease in the world and is a common cause of urogenital infections. Ectopic pregnancies due to tubal obstruction by schistosoma's eggs are usually reported in Africa. Schistosomiasis also affects travelers but infection of the female genital tract is less frequently described. We report an unusual clinical case of two successive ectopic pregnancies with tubal schistosomiasis in a French woman, seven years after a travel to Mali. The first event was discovered after histologic examination of salpingectomy and the second event required a controlateral salpingotomy with an injection of methotrexate, two months later.
Gashaw, Fikru; Aemero, Mulugeta; Legesse, Mengistu; Petros, Beyene; Teklehaimanot, Tilahun; Medhin, Girmay; Berhe, Nega; Mekonnen, Yalemtsehay; Erko, Berhanu
2015-10-31
Schistosomiasis is endemic in Ethiopia and previously unknown transmission foci have been reported from time to time in different parts of the country. Further surveys are required in areas where endemicity of the disease is not known to cover them with control program if transmission is taking place. This study, therefore, aims to assess the magnitude of schistosomiasis mansoni and soil-transmitted helminthiasis in Maksegnit and Enfranz Towns, northwestern Ethiopia. Cross-sectional parasitological and malacological surveys were conducted in three schools found in Maksegnit and Enfranz Towns. Stool specimens were collected from 550 randomly selected school children (age range 5 to 17 years) and processed for microscopic examination using Kato-Katz method (single smear per stool sample). Malacological survey was conducted in Gumara and Garno Rivers found in the study areas. Biomphalaria pfeifferi snails collected from the two rivers were individually exposed to artificial light in order to induce cercarial shedding. Laboratory-bred Swiss albino mice were exposed to the cercariae and definite identification of the schistosome species was made based on morphology. The overall prevalence of S. mansoni infection was found to be 49%; however, it varied by schools, with Selam having 60.7%, and Maksegnit Number 1 and 2 having 45.8 and 39.6%, respectively. The respective mean intensity of S. mansoni infection among school children in Selam, Maksegnit Number 1 and Maksegnit Number 2 Schools were 243, 194 and 183 eggs per gram of stool (epg). In all the study areas there was no difference in prevalence of S. mansoni infection in relation to age, however, the prevalence varied by sex, with males having highest prevalence (54.5% vs 44.1%) (p = 0.012). Adult S. mansoni worms were harvested from mice exposed to cercariae shed from B. pfeifferi on the 6(th) week post-exposure. The prevalence of Ascaris lumbricoides single infection was 16.5% while its co-infection with S. mansoni was 18.2%. Infections of young children, findings of schistosome infected snails, establishment of mice infection and harvesting adult worms from the lab-bred mice confirm that autochthonous transmission is taking place in the study areas. Hence, preventive chemotherapy with praziquantel should be put in place, complemented with other measures such as provision of sanitary facilities and health education, to control morbidity and transmission of schistosomiasis and soil-transmitted helminthiasis in the study areas.
Wichmann, Dominic; Poppert, Sven; Von Thien, Heidrun; Clerinx, Joannes; Dieckmann, Sebastian; Jensenius, Mogens; Parola, Philippe; Richter, Joachim; Schunk, Mirjam; Stich, August; Zanger, Philipp; Burchard, Gerd D; Tannich, Egbert
2013-01-30
Acute schistosomiasis constitutes a rare but serious condition in individuals experiencing their first prepatent Schistosoma infection. To circumvent costly and time-consuming diagnostics, an early and rapid diagnosis is required. So far, classic diagnostic tools such as parasite microscopy or serology lack considerable sensitivity at this early stage of Schistosoma infection. To validate the use of a blood based real-time polymerase chain reaction (PCR) test for the detection of Schistosoma DNA in patients with acute schistosomiasis who acquired their infection in various endemic regions we conducted a European-wide prospective study in 11 centres specialized in travel medicine and tropical medicine. Patients with a history of recent travelling to schistosomiasis endemic regions and freshwater contacts, an episode of fever (body temperature ≥38.5°C) and an absolute or relative eosinophil count of ≥700/μl or 10%, were eligible for participation. PCR testing with DNA extracted from serum was compared with results from serology and microscopy. Of the 38 patients with acute schistosomiasis included into the study, PCR detected Schistosoma DNA in 35 patients at initial presentation (sensitivity 92%). In contrast, sensitivity of serology (enzyme immunoassay and/or immunofluorescence assay) or parasite microscopy was only 70% and 24%, respectively. For the early diagnosis of acute schistosomiasis, real-time PCR for the detection of schistosoma DNA in serum is more sensitive than classic diagnostic tools such as serology or microscopy, irrespective of the region of infection. Generalization of the results to all Schistosoma species may be difficult as in the study presented here only eggs of S. mansoni were detected by microscopy. A minimum amount of two millilitre of serum is required for sufficient diagnostic accuracy.
Ferreira, Fernanda Teixeira; Fidelis, Thiago André; Pereira, Thiago Almeida; Otoni, Alba; Queiroz, Leonardo Campos; Amâncio, Frederico Figueiredo; Antunes, Carlos Maurício; Lambertucci, José Roberto
2017-01-01
The Kato-Katz technique is the standard diagnostic test for Schistosoma mansoni infection in rural areas. However, the utility of this method is severely limited by the day-to-day variability in host egg excretion in the stool. In high-transmission areas, the point-of-care circulating cathodic antigen (POC-CCA) urine assay has proven to be a reliable test. However, investigations of the reliability of the POC-CCA assay in low-transmission regions are under way. This study aimed to evaluate the sensitivity and specificity of the POC-CCA assay and the morbidity of schistosomiasis in a low-endemic area in Brazil. Pains City is a low-transmission zone for schistosomiasis. A total of 300 subjects aged 7-76 years were randomly selected for the POC-CCA cassette test. For S. mansoni diagnosis, three stool samples on six slides were compared with one urine sample for each subject. The sensitivity and specificity in the absence of a gold standard were calculated using latent class analysis. Clinical examinations and abdominal ultrasounds were performed in 181 volunteers to evaluate morbidity associated with schistosomiasis. The sensitivity and specificity of the Kato-Katz technique were 25.6% and 94.6%, respectively. By contrast, the sensitivity and specificity of the POC-CCA assay were 68.1% and 72.8%, respectively. Hepatosplenic schistosomiasis was diagnosed in two patients (1.1%). Overall, the POC-CCA urine assay proved to be a useful test for diagnosing S. mansoni in a low-endemic area in Brazil. Severe clinical forms of schistosomiasis can be present even in such low-endemic areas.
Epidemiology and Control of Malaria, Leishmaniasis and Schistosomiasis in Brazil
1991-02-15
using a 22 gauge needle. The aspirates were inoculated onto NNN media overlaid with 0.9% NaCl with Gentamyacin and . Penicillin /Streptomyosin, and...13-16. 2. Chulay JD, Oster CN, McGreevy PB, Hendricks LD, Kreutzer RD, 1988. American cutaneous leishmaniasis. Rev Soc Brasileira Med Trop 21 165-72
Montresor, Antonio
2017-01-01
Every year, in endemic countries, several million individuals are given anthelminthic drugs in the context of preventive chemotherapy programmes for morbidity control of schistosomiasis and soil-transmitted helminthiasis. The capacity of accurately evaluating the efficacy of the drugs used as well as the health impact produced by treatment is of utmost importance for the appropriate planning and implementation of these interventions. The cure rate is an indicator of drug efficacy that was originally developed for assessing the clinical efficacy of antibiotics on selected bacterial diseases. Over time, this indicator has also been widely applied to anthelminthic drugs and consequently used to monitor and evaluate preventive chemotherapy interventions. In the author's opinion, however, measurement of cure rate provides information of limited usefulness in the context of helminth control programmes. The present article analyses the peculiarities of helminth infections and those of the drugs used in preventive chemotherapy, explaining the reasons why the cure rate is not an adequate indicator in this specific public health context. PMID:21612808
Health Data Publications No. 30. Burma (Union of Burma)
1966-01-01
Toxoplasmosis 40 Mycotic Infections 40 Helminthiasis 40 Filaria sis 41 Dracontiasis 41 Bilharziasis (Schistosomiasis) 42 Fascioliasis 42 Paragonimiasis 42...schistosomiasis is acquired in Burma. Fascioliasis Infection with the trematode Fasciola hepatica has been found in Burma and is of importance in at least
Carvalho, Omar S; Scholte, Ronaldo G C; Guimarães, Ricardo J P S; Freitas, Corina C; Drummond, Sandra C; Amaral, Ronaldo S; Dutra, Luciano V; Oliveira, Guilherme; Massara, Cristiano L; Enk, Martin J
2010-07-01
Geographical Information System (GIS) is a tool that has recently been applied to better understand spatial disease distributions. Using meteorological, social, sanitation, mollusc distribution data and remote sensing variables, this study aimed to further develop the GIS technology by creating a model for the spatial distribution of schistosomiasis and to apply this model to an area with rural tourism in the Brazilian state of Minas Gerais (MG). The Estrada Real, covering about 1,400 km, is the largest and most important Brazilian tourism project, involving 163 cities in MG with different schistosomiasis prevalence rates. The model with three variables showed a R(2) = 0.34, with a standard deviation of risk estimated adequate for public health needs. The main variables selected for modelling were summer vegetation, summer minimal temperature and winter minimal temperature. The results confirmed the importance of Remote Sensing data and the valuable contribution of GIS in identifying priority areas for intervention in tourism regions which are endemic to schistosomiasis.
NASA Astrophysics Data System (ADS)
Marie, Tiphanie; Yesou, Herve; Huber, Claire; De Fraipont, Paul; Uribe, Carlos; Lacaux, Jean-Pierre; Lafaye, Murielle; Lai, Xijun; Desnos, Yves-Louis
2013-01-01
This paper present the method used to determine the areas where schistosomiasis transmission is the higher. A primary work was necessary to this study: identification of potential presence of schistosomiasis japonicum’s vector in Poyang lakeshore area (Jiangxi Province, P.R. China). Results obtained from its first work were crossing with the most risky human activities and with villages to elaborate a level of transmission risk. The first parameter determined concern fishing, which was identified like the most risky activity for schistosomiasis transmission, and fish traps were digitalized using a very high resolution ALOS data. The second parameter is about the risky areas for buffalo grazing, and vector potential presence areas were crossed with village proximity to determine the most risky areas for human transmission. The third parameter built is a level of risk for each village digitalized around Poyang Lake, taking into account the proximity and level of potential presence of vector’s areas.
Guyatt, H. L.; Brooker, S.; Kihamia, C. M.; Hall, A.; Bundy, D. A.
2001-01-01
OBJECTIVE: To determine the impact of deworming on anaemia as part of a large-scale school-based anthelmintic treatment programme in the Tanga Region of the United Republic of Tanzania. METHODS: Both the reduction in the prevalence of anaemia and the cost per case prevented were taken into consideration. Cross-sectional studies involved parasitological examination and anaemia evaluation before and at 10 months and 15 months after schoolchildren were dewormed. FINDINGS: Baseline studies indicated that the prevalence of anaemia (haemoglobin < 110 g/l) was high (54%) among schoolchildren, particularly those with high intensities of hookworm and schistosomiasis. Attributable fraction analysis suggested that hookworm and schistosomiasis were responsible for 6% and 15% of anaemia cases, respectively. Fifteen months after deworming with albendazole and praziquantel the prevalence of anaemia was reduced by a quarter and that of moderate-to-severe anaemia (haemoglobin <90 g/l) was reduced by nearly a half. The delivery of these anthelmintics through the school system was achieved at the relatively low cost of US$ 1 per treated child. The cost per anaemia case prevented by deworming schoolchildren was in the range US$ 6-8, depending on the haemoglobin threshold used. CONCLUSIONS: The results suggested that deworming programmes should be included in public health strategies for the control of anaemia in schoolchildren where there are high prevalences of hookworm and schistosomiasis. PMID:11545325
STOTHARD, J. RUSSELL; SOUSA-FIGUEIREDO, JOSÉ C.; BETSON, MARTHA; GREEN, HELEN K.; SETO, EDMUND Y. W.; GARBA, AMADOU; SACKO, MOUSSA; MUTAPI, FRANCISCA; VAZ NERY, SUSANA; AMIN, MUTAMAD A.; MUTUMBA-NAKALEMBE, MARGARET; NAVARATNAM, ANNALAN; FENWICK, ALAN; KABATEREINE, NARCIS B.; GABRIELLI, ALBIS F.; MONTRESOR, ANTONIO
2011-01-01
SUMMARY Where very young children come into contact with water containing schistosome cercariae, infections occur and schistosomiasis can be found. In high transmission environments, where mothers daily bathe their children with environmentally drawn water, many infants and preschool-aged children have schistosomiasis. This ‘new’ burden, inclusive of co-infections with Schistosoma haematobium and Schistosoma mansoni, is being formally explored as infected children are not presently targeted to receive praziquantel (PZQ) within current preventive chemotherapy campaigns. Thus an important PZQ treatment gap exists whereby infected children might wait up to 4–5 years before receiving first treatment in school. International treatment guidelines, set within national treatment platforms, are presently being modified to provide earlier access to medication(s). Although detailed pharmacokinetic studies are needed, to facilitate pragmatic dosing in the field, an extended ‘dose pole’ has been devised and epidemiological monitoring has shown that administration of PZQ (40 mg/kg), in either crushed tablet or liquid suspension, is both safe and effective in this younger age-class; drug efficacy, however, against S. mansoni appears to diminish after repeated rounds of treatment. Thus use of PZQ should be combined with appropriate health education/water hygiene improvements for both child and mother to bring forth a more enduring solution. PMID:21861945
Magalhães, Ricardo J Soares; Salamat, Maria Sonia; Leonardo, Lydia; Gray, Darren J; Carabin, Hélène; Halton, Kate; McManus, Donald P; Williams, Gail M; Rivera, Pilarita; Saniel, Ofelia; Hernandez, Leda; Yakob, Laith; McGarvey, Stephen; Clements, Archie
2015-01-01
Schistosoma japonicum infection is believed to be endemic in 28 of the 80 provinces of The Philippines and the most recent data on schistosomiasis prevalence have shown considerable variability between provinces. In order to increase the efficient allocation of parasitic disease control resources in the country, we aimed to describe the small-scale spatial variation in S. japonicum prevalence across The Philippines, quantify the role of the physical environment in driving the spatial variation of S. japonicum, and develop a predictive risk map of S. japonicum infection. Data on S. japonicum infection from 35,754 individuals across the country were geolocated at the barangay level and included in the analysis. The analysis was then stratified geographically for the regions of Luzon, the Visayas and Mindanao. Zero-inflated binomial Bayesian geostatistical models of S. japonicum prevalence were developed and diagnostic uncertainty was incorporated. Results of the analysis show that in the three regions, males and individuals aged ≥ 20 years had significantly higher prevalence of S. japonicum compared with females and children < 5 years. The role of the environmental variables differed between regions of The Philippines. Schistosoma japonicum infection was widespread in the Visayas whereas it was much more focal in Luzon and Mindanao. This analysis revealed significant spatial variation in the prevalence of S. japonicum infection in The Philippines. This suggests that a spatially targeted approach to schistosomiasis interventions, including mass drug administration, is warranted. When financially possible, additional schistosomiasis surveys should be prioritized for areas identified to be at high risk but which were under-represented in our dataset. PMID:25128879
Soares Magalhães, Ricardo J; Salamat, Maria Sonia; Leonardo, Lydia; Gray, Darren J; Carabin, Hélène; Halton, Kate; McManus, Donald P; Williams, Gail M; Rivera, Pilarita; Saniel, Ofelia; Hernandez, Leda; Yakob, Laith; McGarvey, Stephen; Clements, Archie
2014-11-01
Schistosoma japonicum infection is believed to be endemic in 28 of the 80 provinces of The Philippines and the most recent data on schistosomiasis prevalence have shown considerable variability between provinces. In order to increase the efficient allocation of parasitic disease control resources in the country, we aimed to describe the small-scale spatial variation in S. japonicum prevalence across The Philippines, quantify the role of the physical environment in driving the spatial variation of S. japonicum, and develop a predictive risk map of S. japonicum infection. Data on S. japonicum infection from 35,754 individuals across the country were geo-located at the barangay level and included in the analysis. The analysis was then stratified geographically for the regions of Luzon, the Visayas and Mindanao. Zero-inflated binomial Bayesian geostatistical models of S. japonicum prevalence were developed and diagnostic uncertainty was incorporated. Results of the analysis show that in the three regions, males and individuals aged ⩾20years had significantly higher prevalence of S. japonicum compared with females and children <5years. The role of the environmental variables differed between regions of The Philippines. Schistosoma japonicum infection was widespread in the Visayas whereas it was much more focal in Luzon and Mindanao. This analysis revealed significant spatial variation in the prevalence of S. japonicum infection in The Philippines. This suggests that a spatially targeted approach to schistosomiasis interventions, including mass drug administration, is warranted. When financially possible, additional schistosomiasis surveys should be prioritised for areas identified to be at high risk but which were under-represented in our dataset. Copyright © 2014 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.
Leslie, Jacqueline; Garba, Amadou; Oliva, Elisa Bosque; Barkire, Arouna; Tinni, Amadou Aboubacar; Djibo, Ali; Mounkaila, Idrissa; Fenwick, Alan
2011-10-01
In 2004 Niger established a large scale schistosomiasis and soil-transmitted helminths control programme targeting children aged 5-14 years and adults. In two years 4.3 million treatments were delivered in 40 districts using school based and community distribution. Four districts were surveyed in 2006 to estimate the economic cost per district, per treatment and per schistosomiasis infection averted. The study compares the costs of treatment at start up and in a subsequent year, identifies the allocation of costs by activity, input and organisation, and assesses the cost of treatment. The cost of delivery provided by teachers is compared to cost of delivery by community distributers (CDD). The total economic cost of the programme including programmatic, national and local government costs and international support in four study districts, over two years, was US$ 456,718; an economic cost/treatment of $0.58. The full economic delivery cost of school based treatment in 2005/06 was $0.76, and for community distribution was $0.46. Including only the programme costs the figures are $0.47 and $0.41 respectively. Differences at sub-district are more marked. This is partly explained by the fact that a CDD treats 5.8 people for every one treated in school. The range in cost effectiveness for both direct and direct and indirect treatments is quantified and the need to develop and refine such estimates is emphasised. The relative cost effectiveness of school and community delivery differs by country according to the composition of the population treated, the numbers targeted and treated at school and in the community, the cost and frequency of training teachers and CDDs. Options analysis of technical and implementation alternatives including a financial analysis should form part of the programme design process.
Silva, José Damião da; Pinheiro, Marta Cristhiany Cunha; Sousa, Mariana Silva; Gomes, Vivian da Silva; Castro, Issis Maria Nogueira de; Ramos, Alberto Novaes; Bezerra, Fernando Schemelzer de Moraes
2017-01-01
The development of the São Francisco River Integration Project [Projeto de Integração do Rio São Francisco (PISF)] in the State of Ceará, Brazil, has resulted in environmental and socioeconomic changes with potential risks to public health. We aimed to determine the presence of Schistosoma mansoni infections in schoolchildren (aged 7-14 years) and workers from the construction site in an area under the direct influence of the PISF in the municipality of Brejo Santo-CE, to aid in the prevention and control of schistosomiasis. We conducted a cross-sectional study using two S. mansoni-detection methods: detection of S. mansoni eggs by the Kato-Katz parasitological method in stool samples (assessed in triplicate for each sample) and S. mansoni circulating cathodic antigen by the point-of-care immunochromatographic rapid test (POC-CCA) in urine. In general, the positivity rates for S. mansoni detection were 1.9% (2/106) among schoolchildren and 2.9% (4/138) among workers. No child had evidence of S. mansoni eggs in their stools; 1.9% tested positive by the POC-CCA method. Among workers, two (1.4%) tested positive by the Kato-Katz test and three (2.2%) by the POC-CCA test. If the POC-CCA test results that were scored as traces were considered negative, then the positivity rates dropped to 0.9% and 0.7% for schoolchildren and workers, respectively. The active transmission of schistosomiasis in a region covered by the PISF was recognized, reinforcing the necessity to consolidate surveillance and control actions, as well as structural sanitation measures to reverse the social determinants of the disease.
Effect of artemether on cytokine profile and egg induced pathology in murine schistosomiasis mansoni
Madbouly, Neveen A.; Shalash, Ibraheem R.; El Deeb, Somaya O.; El Amir, Azza M.
2014-01-01
Artemether (ART), the methylated derivative of artemisinin, is an efficacious antimalarial drug that also displays antischistosomal properties. This study was designed to evaluate the immunomodulatory action of a single intramuscular dose (50 mg/kg body weight) of ART in comparison with PZQ treatment (42 days PI). ART administration was 7, 14, 21 and 45 days PI. ART effect was studied parasitologically, histopathologically and immunologically. It was found that maximum effect was reached when ART treatment interfered with 14 or 21 days old schistosomula. ART treatment 14 or 21 days PI was associated with shift from Th2 to Th1 predominancy (decrease in IL-4 and upgrading of serum IFN-γ levels). In conclusion, ART is a promising drug in control of schistosomiasis mansoni due to its reductive effect on worm burden and its role in improvement of hepatic granulomatous lesions. PMID:26644922
Schistosomiasis Breeding Environment Situation Analysis in Dongting Lake Area
NASA Astrophysics Data System (ADS)
Li, Chuanrong; Jia, Yuanyuan; Ma, Lingling; Liu, Zhaoyan; Qian, Yonggang
2013-01-01
Monitoring environmental characteristics, such as vegetation, soil moisture et al., of Oncomelania hupensis (O. hupensis)’ spatial/temporal distribution is of vital importance to the schistosomiasis prevention and control. In this study, the relationship between environmental factors derived from remotely sensed data and the density of O. hupensis was analyzed by a multiple linear regression model. Secondly, spatial analysis of the regression residual was investigated by the semi-variogram method. Thirdly, spatial analysis of the regression residual and the multiple linear regression model were both employed to estimate the spatial variation of O. hupensis density. Finally, the approach was used to monitor and predict the spatial and temporal variations of oncomelania of Dongting Lake region, China. And the areas of potential O. hupensis habitats were predicted and the influence of Three Gorges Dam (TGB)project on the density of O. hupensis was analyzed.
Balahbib, Abdelaali; Amarir, Fatima; Corstjens, Paul L A M; de Dood, Claudia J; van Dam, Govert J; Hajli, Amina; Belhaddad, Meryem; El Mansouri, Bouchra; Sadak, Abderrahim; Rhajaoui, Mohamed; Adlaoui, El Bachir
2017-04-06
After alleged stop of transmission of schistosomiasis and further down the line in post elimination settings, sensitive tools are required to monitor infection status to prevent potential re-emergence. In Rahala, where transmission cycle of Schistosoma haematobium is interrupted since 2004 but where 30% of snails are still infected by S. bovis, potential human S. bovis infection can't be excluded. As methods based on egg-counts do not provide the required sensitivity, antibody or antigen assays are envisaged as the most appropriate tools for this type of monitoring. In this pilot study, the performances of three assays were compared: two commercially available antibody tests (ELISA and haemagglutination format) indicating exposure, and an antigen test (lateral flow strip format) demonstrating active infection. All 37 recruited study participants resided in Rahala (Akka, province Tata, Morocco). Participants had been diagnosed and cured from schistosomiasis in the period between 1983 and 2003. In 2015 these asymptomatic participants provided fresh clinical samples (blood and urine) for analysis with the aforementioned diagnostics tests. No eggs were identified in the urine of the 37 participants. The haemagglutination test indicated 6 antibody positives whereas the ELISA indicated 28 antibody positives, one indecisive and one false positive. ELISA and haemagglutination results matched for 18 individuals, amongst which 5 out of 6 haemagglutination positives. With the antigen test (performed on paired serum and urine samples), serum from two participants (cured 21 and 32 years ago) indicated the presence of low levels of the highly specific Schistosoma circulating anodic antigen (CAA), demonstrating low worm level infections (less than 5 pg/ml corresponding to probably single worm pair). One tested also CAA positive with urine. ELISA indicated the presence of human anti-Schistosoma antibodies in these two CAA positive cases, haemagglutination results were negative. To prevent reemergence of schistosomiasis in Morocco current monitoring programs require specific protocols that include testing of antibody positives for active infection by the UCP-LF CAA test, the appropriate diagnostic tool to identify Schistosoma low grade infections in travelers, immigrants and assumed cured cases. The test is genus specific will also identify infections related to S. bovis.
Hammam, Olfat; Wishahi, Mohamed; Hindawi, All; Mosaad, Maha; Akl, Maha; Khalil, Heba; Al Ganzoury, Hossam; Badawy, Mohamed; Elesaily, Khaled
2014-12-01
HER2 is an oncogene encoding a type 1 tyrosine kinase growth factor receptor and the role of HER2 in the development of numerous types of human cancer is still understood and correlates with clinical outcome, poor prognosis, it is a predictor factor for poor response to chemotherapy. HER2 overexpression is associated with reduced disease free and overall survival. Patients who have HER2 negative expression have a poor prognosis. The aim of the present study is to explore the accuracy of detection of expression of HER2 protein by two different techniques of immunohistochemistry (IHC) and gene amplification by fluorescent in situ hybridization (FISH). The two techniques were applied to sixty two patients that included different cell types of carcinoma of the bladder, benign bilharzial lesions and control. Characteristics of the 62 patients are: 10 chronic cystitis, 19 squamous cell carcinoma (SCC) with schistosomiasis, 33 urothelial carcinoma (UC) schistosomal and non-schistosomal, ten healthy individuals without schistosomiasis served as controls. Gene amplification of HER2 was done using FISH and protein expression of HER2 by IHC. The study was applied on archival data of formalin-fixed paraffin embedded tissues and patient clinical data and follow up for 5 years. Overexpression of HER2 protein was found in 30/52 (57.7%). Fourteen cases had score of 2+, and sixteen cases had score of 3+. Using FISH technique it showed more accurate detection of HER2 gene as those fourteen cases who had score of 2+ had been found to be 5 out of 14 were positive for gene over expression, the other sixteen who had score of 3+ all were positive for gene amplification. HER2 protein and gene was found to be significantly overexpressed in carcinoma of the bladder in both cell types SCC and UC with or without schistosomiasis compared to the benign lesions and control groups (P <0.01) by both techniques. There is significant increase in expression of HER2 protein and gene in SCC compared to UC (P< 0.01). In UC overexpression of HER2 protein and gene was evident in all stages Ta, T1, T2-4. HER2 protein and gene overexpressed in different grades of UC. In SCC HER2 protein and gene had overexpression in different stages and grades.
Ndeffo Mbah, Martial L.; Kjetland, Eyrun F.; Atkins, Katherine E.; Poolman, Eric M.; Orenstein, Evan W.; Meyers, Lauren Ancel; Townsend, Jeffrey P.; Galvani, Alison P.
2013-01-01
Epidemiological studies from sub-Saharan Africa show that genital infection with Schistosoma haematobium may increase the risk for HIV infection in young women. Therefore, preventing schistosomiasis has the potential to reduce HIV transmission in sub-Saharan Africa. We developed a transmission model of female genital schistosomiasis and HIV infections that we fit to epidemiological data of HIV and female genital schistosomiasis prevalence and coinfection in rural Zimbabwe. We used the model to evaluate the cost-effectiveness of a multifaceted community-based intervention for preventing schistosomiasis and, consequently, HIV infections in rural Zimbabwe, from the perspective of a health payer. The community-based intervention combined provision of clean water, sanitation, and health education (WSH) with administration of praziquantel to school-aged children. Considering variation in efficacy between 10% and 70% of WSH for reducing S. haematobium transmission, our model predicted that community-based intervention is likely to be cost-effective in Zimbabwe at an aggregated WSH cost corresponding to US $725–$1,000 per individual over a 20-y intervention period. These costs compare favorably with empirical measures of WSH provision in developing countries, indicating that integrated community-based intervention for reducing the transmission of S. haematobium is an economically attractive strategy for reducing schistosomiasis and HIV transmission in sub-Saharan Africa that would have a powerful impact on averting infections and saving lives. PMID:23589884
Decline in transmission of schistosomiasis mansoni in Oman.
Al Abaidani, Idris; Al-Abri, Seif; Shaban, Mahmoud; Ghugey, Satish L; Al Kathery, Salem; Al-Mashikhi, Khalid; Garba, Amadou; Gabrielli, Albis Francesco
2016-12-12
Intestinal schistosomiasis due to Schistosoma mansoni was first reported in Oman in 1979. We describe the trend in parasitological and serological prevalence of human infection with S. mansoni in the endemic area over the period 1982-2014, and the compliance of data generated by the national monitoring and evaluation system with schistosomiasis elimination criteria set by the Ministry of Health of Oman. Parasitological and serological assessments were carried out on population (mainly children) living in the area at risk for schistosomiasis in Dhofar, the country's only endemic Governorate, for a period of over 30 years. Kato-Katz thick smear and Indirect Haemagglutination Assay were the techniques employed. Data indicate a progressive decline in prevalence of S. mansoni throughout the 1980s and the 1990s, a recrudescence in the early 2000s, and a more marked decrease following the implementation of six rounds of mass treatment with praziquantel from 2007 to 2013. Latest parasitological prevalence (2011) was 0%, while latest serological prevalence (2014) was 0.11%. Transmission of schistosomiasis has reached very low levels in Oman. Elimination criteria established by the Ministry of Health of Oman (parasitological prevalence ≤ 1% and serological prevalence ≤ 5%) have been met since 2008. Further investigations are required to assess whether interruption of transmission has been achieved in some or all foci, in view of the establishment of a formal verification process under the auspices of WHO.
Phillips, David Alexander; Ferreira, José Antonio; Ansah, Deidra; Teixeira, Herica Sa; Kitron, Uriel; Filippis, Thelma de; Alcântara, Marcelo H de; Fairley, Jessica K
2017-04-01
Despite public health efforts to reduce the global burden of leprosy, gaps remain in the knowledge surrounding transmission of infection. Helminth co-infections have been associated with a shift towards the lepromatous end of the disease spectrum, potentially increasing transmission in co-endemic areas. Using this biologically plausible association, we conducted a geographic information systems (GIS) study to investigate the spatial associations of schistosomiasis and leprosy in an endemic area of Minas Gerais (MG), Brazil. Data on new cases of Mycobacterium leprae and Schistosoma mansoni infections from 2007-2014 were retrieved from the Brazilian national notifiable diseases information system for seven municipalities in and surrounding Vespasiano, MG. A total of 139 cases of leprosy and 200 cases of schistosomiasis were mapped to a municipality level. For one municipality, cases were mapped to a neighborhood level and a stratified analysis was conducted to identify spatial associations. A relative risk of 6.80 [95% confidence interval (CI) 1.46 - 31.64] of leprosy was found in neighborhoods with schistosomiasis. Incidence rates of leprosy increased with corresponding incidence rates of schistosomiasis, and the temporal trends of both infections were similar. The associations found in this project support the hypothesis that helminth infections may influence the transmission of leprosy in co-endemic areas.
Comparison of non-schistosomal rectosigmoid cancer and schistosomal rectosigmoid cancer.
Feng, Hao; Lu, Ai-Guo; Zhao, Xue-Wei; Han, Ding-Pei; Zhao, Jing-Kun; Shi, Lei; Schiergens, Tobias S; Lee, Serene M L; Zhang, Wen-Peng; Thasler, Wolfgang E
2015-06-21
To compare the clinicopathological features of patients with non-schistosomal rectosigmoid cancer and schistosomal rectosigmoid cancer. All the patients with rectosigmoid carcinoma who underwent laparoscopic radical surgical resection in the Shanghai Minimally Invasive Surgical Center at Ruijin Hospital affiliated to Shanghai Jiao-Tong University between October 2009 and October 2013 were included in this study. Twenty-six cases of colonic schistosomiasis diagnosed through colonoscopy and pathological examinations were collected. Symptoms, endoscopic findings and clinicopathological characteristics were evaluated retrospectively. There were no significant differences between patients with and without schistosomiasis in gender, age, CEA, CA19-9, preoperative biopsy findings or postoperative pathology. Patients with rectosigmoid schistosomiasis had a significantly higher CA-125 level and a larger proportion of these patients were at an early tumor stage (P = 0.003). Various morphological characteristics of schistosomiasis combined with rectosigmoid cancer could be found by colonoscopic examination: 46% were fungating mass polyps, 23% were congestive and ulcerative polyps, 23% were cauliflower-like masses, 8% were annular masses. Only 27% of the patients were diagnosed with rectal carcinoma preoperatively after the biopsy. Computed tomography (CT) scans showed thickened intestinal walls combined with linear and tram-track calcifications in 26 patients. Rectosigmoid carcinoma combined with schistosomiasis is associated with higher CA-125 values and early tumor stages. CA-125 and CT scans have a reasonable sensitivity for the accurate diagnosis.
The social and economic context and determinants of schistosomiasis japonica.
Huang, Yi-Xin; Manderson, Lenore
2005-01-01
A variety of biological and social factors govern schistosomiasis japonica in China. Social factors include those at a national and regional level, such as policies and patterns of development, which impact on local economic activities, and affect community, household and personal risk factors of infection. Drawing on research conducted in China, we illustrate how social structural and related factors influence individual risk and prevalence of infection. At a macro-level, political changes have occurred resulting in the shift from collective to family-based production, leading to clustering of infection in families. Industrialization and urbanization, and associated increased population mobility, have also influenced patterns of transmission and infection. Types of activities and local production patterns determine the exposure of individuals to schistosome-infested water sources. Fishermen have the most frequent water contact, aquatic workers the second and farmers the third; the relative risk of Schistosoma japonicum infection follows the same order. Among farmers, human infection is significantly related to agricultural production in rice fields infested with the intermediate host snail, and to rates of the infection in livestock. Risk of S. japonicum infection is also influenced by the domestic environment, including both the location of the house in relation to snail-colonized water sources, access to safe water, and improved sanitation. Household wealth and income determine family ability to provide and maintain safe water and sanitation, while determining or interacting with other variables. At an individual level, sex, age, educational level and ethnicity are all associated with different patterns of water use and water contact behaviour thereby affecting infection rates. Schistosomiasis impairs the growth and nutrition of children and the physical work capacity of adults, and so affects economic development. Given this, we note the importance of further research and social and contextual aspects of schistosomiasis infection in order to develop and sustain sound control strategies.
Zhou, Xiao-Nong; Xu, Jing; Chen, Hong-Gen; Wang, Tian-Ping; Huang, Xi-Bao; Lin, Dan-Dan; Wang, Qi-Zhi; Tang, Li; Guo, Jia-Gang; Wu, Xiao-Hua; Feng, Ting; Chen, Jia-Xu; Guo, Jian; Chen, Shao-Hong; Li, Hao; Wu, Zhong-Dao; Peeling, Rosanna W.
2011-01-01
Background Appropriate diagnostics to monitor disease trends and assess the effectiveness and impact of interventions are essential for guiding treatment strategies at different thresholds of schistosomiasis transmission and for certifying elimination. Field validation of these assays is urgently needed before they can be adopted to support policy decisions of the national programme for control and elimination of schistosomiasis in P.R. China. We compared the efficacy and utility of different immunoassays in guiding control strategies and monitoring the endemic status of S. japonicum infections towards elimination. Methodology/Principal Findings A cross-sectional survey was conducted in seven villages with different transmission intensities settings to assess the performance and utility of three immunoassays, e.g., an indirect hemagglutination assay (IHA_JX), an enzyme linked immunosorbent assay (ELISA_SZ), and a dot immunogold filtration assay (DIGFA_SH). 6,248 individuals aged 6–65 years old who gave consent and supplied their stool and blood samples were included for data analysis. Results showed that ELISA_SZ performed significantly higher sensitivity (95.45%, 95%CI: 92.94–97.97%) than IHA_JX (87.59%, 95%CI: 83.51–91.49%) and DIGFA_SH (79.55%, 95%CI: 74.68–84.41%), especially in subgroups with very low infection intensity. The specificity of ELISA_SZ, IHA_JX, DIGFA_SH in 6–9 year olds with occasional exposure was nearly 90%. DIGFA_SH performed the highest screening efficacy for patients among three assays with overall positive predicative value of 13.07% (95%CI: 11.42–14.72%). We found a positive correlation of antibody positive rate of IHA_JX with results of stool examination in age strata (r = 0.70, P<0.001). Seropositivity of IHA_JX in children aged 6–9 years old showed an excellent correlation with prevalence of schistosome infection in the seven communities (r = 0.77, P<0.05). Conclusions/Significance Studies suggest that ELISA_SZ could be used to guide selective chemotherapy in moderate or low endemic regions. IHA_JX could be used to as a surveillance tool and for certifying elimination of schistosomiasis through monitoring children as a sentinel population. PMID:22206024
van der Werf, Marieke J; Mbaye, Amadou; Sow, Seydou; Gryseels, Bruno; de Vlas, Sake J
2002-01-01
A project to improve integrated control of schistosomiasis in the primary health care system of northern Senegal was implemented from February 1995 until September 1999, shortly after a Schistosoma mansoni outbreak. The activities included additional training of doctors and nurses in symptom-based treatment and making praziquantel (PZQ) available for an affordable price. To investigate staff performance and the availability and costs of diagnostic materials and PZQ at the end of this intervention project. We performed structured interviews with staff from 55 health care facilities in five districts. Respondents from 23 health care facilities reported both S. haematobium and S. mansoni in the coverage area, 32 reported only S. haematobium and three only S. mansoni. The average cost to patients for consultation, diagnosis, treatment and transportation to a referral health care facility was approximately 1.60 Euro. Fifty-seven per cent of the health care facilities with reported S. haematobium in the coverage area treated patients presenting with haematuria on symptoms; 56% of the health care facilities with reported S. mansoni in the coverage area treated patients presenting with blood in stool on symptoms. Thirteen per cent performed a diagnostic test for patients presenting with haematuria and 12% for patients presenting with blood in stool. The remainder, approximately one-third of the health care facilities, referred their patients to another facility for a diagnostic test. Implementation of symptom-based treatment in all health care facilities will reduce the total costs by 0.43 Euro (29%) for patients infected with S. haematobium and 0.78 Euro (46%) for patients infected with S. mansoni. Of the 53 health care facilities with schistosomiasis in their area, 37 had PZQ in stock of which 33 (88%) sold PZQ for the recommended retail price of 0.15 Euro per tablet (or 0.60 Euro per course of four tablets) or lower. Four years after the start of the intervention project, patients presenting with schistosomiasis related symptoms can generally expect proper diagnosis and treatment at all levels of the health care system in Northern Senegal, either at the initial visited health care facility or after referral. However, a further reduction of the total costs of treatment is still possible by a better implementation of symptom-based treatment and further reduction of the costs of PZQ.