These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Mediational Effects of Self-Efficacy Dimensions in the Relationship between Knowledge of Dengue and Dengue Preventive Behaviour with Respect to Control of Dengue Outbreaks: A Structural Equation Model of a Cross-Sectional Survey  

PubMed Central

Background Dengue fever is endemic in Malaysia, with frequent major outbreaks in urban areas. The major control strategy relies on health promotional campaigns aimed at encouraging people to reduce mosquito breeding sites close to people's homes. However, such campaigns have not always been 100% effective. The concept of self-efficacy is an area of increasing research interest in understanding how health promotion can be most effective. This paper reports on a study of the impact of self-efficacy on dengue knowledge and dengue preventive behaviour. Methods and Findings We recruited 280 adults from 27 post-outbreak villages in the state of Terengganu, east coast of Malaysia. Measures of health promotion and educational intervention activities and types of communication during outbreak, level of dengue knowledge, level and strength of self-efficacy and dengue preventive behaviour were obtained via face-to-face interviews and questionnaires. A structural equation model was tested and fitted the data well (?2?=?71.659, df?=?40, p?=?0.002, RMSEA?=?0.053, CFI?=?0.973, TLI?=?0.963). Mass media, local contact and direct information-giving sessions significantly predicted level of knowledge of dengue. Level and strength of self-efficacy fully mediated the relationship between knowledge of dengue and dengue preventive behaviours. Strength of self-efficacy acted as partial mediator in the relationship between knowledge of dengue and dengue preventive behaviours. Conclusions To control and prevent dengue outbreaks by behavioural measures, health promotion and educational interventions during outbreaks should now focus on those approaches that are most likely to increase the level and strength of self-efficacy. PMID:24086777

Isa, Affendi; Loke, Yoon K.; Smith, Jane R.; Papageorgiou, Alexia; Hunter, Paul R.

2013-01-01

2

Dengue Prevention  

MedlinePLUS

... 4 RT-PCR Assay Case Definition Dengue Panel Project Education/Training Patient Education & Training Media Resources Dengue Clinical Case Management (DCCM) Publications and Related Links Dengue Branch Dengue ...

3

Lessons learned from previous dengue outbreaks  

PubMed Central

Dengue is an important tropical infection caused by an arbovirus dengue. As a mosquito borne infection, this disease is widely spread in several tropical endemic countries. Millions of world populations are at risk for this arboviral infection. Each year, thousands of dengue infections are reported and there are several death cases. Each year, the outbreaks of dengue emerge in several countries and this implies the global importance of this infection. Fighting with dengue outbreak is important in public health. In this specific chapter, the author discussed lessons learned from previous dengue outbreaks.

Wiwanitkit, Viroj

2014-01-01

4

Effects of a Five-Year Citywide Intervention Program To Control Aedes aegypti and Prevent Dengue Outbreaks in Northern Argentina  

PubMed Central

Background Dengue has propagated widely through the Americas. Most countries have not been able to maintain permanent larval mosquito control programs, and the long-term effects of control actions have rarely been documented. Methodology The study design was based on a before-and-after citywide assessment of Aedes aegypti larval indices and the reported incidence of dengue in Clorinda, northeastern Argentina, over 2003–2007. Interventions were mainly based on focal treatment with larvicides of every mosquito developmental site every four months (14 cycles), combined with limited source reduction efforts and ultra-low-volume insecticide spraying during emergency operations. The program conducted 120,000 house searches for mosquito developmental sites and 37,000 larvicide applications. Principal Findings Random-effects regression models showed that Breteau indices declined significantly in nearly all focal cycles compared to pre-intervention indices clustered by neighborhood, after allowing for lagged effects of temperature and rainfall, baseline Breteau index, and surveillance coverage. Significant heterogeneity between neighborhoods was revealed. Larval indices seldom fell to 0 shortly after interventions at the same blocks. Large water-storage containers were the most abundant and likely to be infested. The reported incidence of dengue cases declined from 10.4 per 10,000 in 2000 (by DEN-1) to 0 from 2001 to 2006, and then rose to 4.5 cases per 10,000 in 2007 (by DEN-3). In neighboring Paraguay, the reported incidence of dengue in 2007 was 30.6 times higher than that in Clorinda. Conclusions Control interventions exerted significant impacts on larval indices but failed to keep them below target levels during every summer, achieved sustained community acceptance, most likely prevented new dengue outbreaks over 2003–2006, and limited to a large degree the 2007 outbreak. For further improvement, a shift is needed towards a multifaceted program with intensified coverage and source reduction efforts, lids or insecticide-treated covers to water-storage containers, and a broad social participation aiming at long-term sustainability. PMID:19399168

Gurtler, Ricardo E.; Garelli, Fernando M.; Coto, Hector D.

2009-01-01

5

Severe dengue outbreak in Yunnan, China, 2013.  

PubMed

In recent decades, the impact of dengue has increased both geographically and in intensity, and this disease is now a threat to approximately half of the world's population. An unexpected large outbreak of dengue fever was reported in Xishuangbanna Dai Autonomous Prefecture, Yunnan Province, China, in 2013. This was the first autochthonous outbreak with a significant proportion of severe dengue cases in mainland China in a decade. According to the 2009 World Health Organization guidelines, half of the 136 laboratory confirmed cases during the epidemic were severe dengue. The clinical presentation included severe haemorrhage (such as massive vaginal and gastrointestinal bleeding), severe plasma leakage (such as pleural effusion, ascites, or hypoproteinaemia), and organ involvement (such as myocarditis and lung impairment); 21 cases eventually deteriorated to shock. During this outbreak, all severe cases occurred in adults, among whom about 43% had co-morbid conditions. Nucleic acid detection and virus isolation confirmed dengue virus serotype 3 (DENV-3) to be the pathogenic agent of this outbreak. Phylogenetic analyses of envelope gene sequences showed that these DENV-3 isolates belonged to genotype II. This finding is of great importance to understand the circulation of DENV and predict the risk of severe disease in mainland China. Here, we provide a brief report of the epidemiology, clinical manifestations, and aetiology of this dengue fever outbreak, and characterize DENV strains isolated from clinical specimens. PMID:25107464

Zhang, Fu-Chun; Zhao, Hui; Li, Li-Hua; Jiang, Tao; Hong, Wen-Xin; Wang, Jian; Zhao, Ling-Zhai; Yang, Hui-Qin; Ma, De-Hong; Bai, Chun-Hai; Shan, Xi-Yun; Deng, Yong-Qiang; Qin, Cheng-Feng

2014-10-01

6

Cost of dengue outbreaks: literature review and country case studies  

PubMed Central

Background Dengue disease surveillance and vector surveillance are presumed to detect dengue outbreaks at an early stage and to save – through early response activities – resources, and reduce the social and economic impact of outbreaks on individuals, health systems and economies. The aim of this study is to unveil evidence on the cost of dengue outbreaks. Methods Economic evidence on dengue outbreaks was gathered by conducting a literature review and collecting information on the costs of recent dengue outbreaks in 4 countries: Peru, Dominican Republic, Vietnam, and Indonesia. The literature review distinguished between costs of dengue illness including cost of dengue outbreaks, cost of interventions and cost-effectiveness of interventions. Results Seventeen publications on cost of dengue showed a large range of costs from 0.2 Million US$ in Venezuela to 135.2 Million US$ in Brazil. However, these figures were not standardized to make them comparable. Furthermore, dengue outbreak costs are calculated differently across the publications, and cost of dengue illness is used interchangeably with cost of dengue outbreaks. Only one paper from Australia analysed the resources saved through active dengue surveillance. Costs of vector control interventions have been reported in 4 studies, indicating that the costs of such interventions are lower than those of actual outbreaks. Nine papers focussed on the cost-effectiveness of dengue vaccines or dengue vector control; they do not provide any direct information on cost of dengue outbreaks, but their modelling methodologies could guide future research on cost-effectiveness of national surveillance systems. The country case studies – conducted in very different geographic and health system settings - unveiled rough estimates for 2011 outbreak costs of: 12 million US$ in Vietnam, 6.75 million US$ in Indonesia, 4.5 million US$ in Peru and 2.8 million US$ in Dominican Republic (all in 2012 US$). The proportions of the different cost components (vector control; surveillance; information, education and communication; direct medical and indirect costs), as percentage of total costs, differed across the respective countries. Resources used for dengue disease control and treatment were country specific. Conclusions The evidence so far collected further confirms the methodological challenges in this field: 1) to define technically dengue outbreaks (what do we measure?) and 2) to measure accurately the costs in prospective field studies (how do we measure?). Currently, consensus on the technical definition of an outbreak is sought through the International Research Consortium on Dengue Risk Assessment, Management and Surveillance (IDAMS). Best practice guidelines should be further developed, also to improve the quality and comparability of cost study findings. Modelling the costs of dengue outbreaks and validating these models through field studies should guide further research. PMID:24195519

2013-01-01

7

Outbreak of Dengue and Chikungunya Fevers, Toamasina, Madagascar, 2006  

PubMed Central

An outbreak of dengue-like syndrome occurred in Toamasina from January through March 2006. Dengue type l or chikungunya viruses were detected in 38 of 55 patients sampled. Aedes albopictus was the only potential vector collected. Of 4,242 randomly selected representative residents interviewed retrospectively, 67.5% reported a dengue-like syndrome during this period. PMID:18598641

Ratsitorahina, Mahery; Harisoa, Julie; Ratovonjato, Jocelyn; Biacabe, Sophie; Reynes, Jean-Marc; Zeller, Herve; Raoelina, Yolande; Talarmin, Antoine; Soares, Jean Louis

2008-01-01

8

Effects of a Five-Year Citywide Intervention Program To Control Aedes aegypti and Prevent Dengue Outbreaks in Northern Argentina  

Microsoft Academic Search

BackgroundDengue has propagated widely through the Americas. Most countries have not been able to maintain permanent larval mosquito control programs, and the long-term effects of control actions have rarely been documented.MethodologyThe study design was based on a before-and-after citywide assessment of Aedes aegypti larval indices and the reported incidence of dengue in Clorinda, northeastern Argentina, over 2003–2007. Interventions were mainly

Ricardo E. Gürtler; Fernando M. Garelli; Héctor D. Coto

2009-01-01

9

The History of Dengue Outbreaks in the Americas  

PubMed Central

Dengue is a viral disease usually transmitted by Aedes aegypti mosquitoes. Dengue outbreaks in the Americas reported in medical literature and to the Pan American Health Organization are described. The outbreak history from 1600 to 2010 was categorized into four phases: Introduction of dengue in the Americas (1600–1946); Continental plan for the eradication of the Ae. aegypti (1947–1970) marked by a successful eradication of the mosquito in 18 continental countries by 1962; Ae. aegypti reinfestation (1971–1999) caused by the failure of the mosquito eradication program; Increased dispersion of Ae. aegypti and dengue virus circulation (2000–2010) characterized by a marked increase in the number of outbreaks. During 2010 > 1.7 million dengue cases were reported, with 50,235 severe cases and 1,185 deaths. A dramatic increase in the number of outbreaks has been reported in recent years. Urgent global action is needed to avoid further disease spread. PMID:23042846

Brathwaite Dick, Olivia; San Martin, Jose L.; Montoya, Romeo H.; del Diego, Jorge; Zambrano, Betzana; Dayan, Gustavo H.

2012-01-01

10

Factors Associated with Larval Control Practices in a Dengue Outbreak Prone Area  

PubMed Central

In order to reduce the risk of dengue outbreak recurrence in a dengue outbreak prone area, the members of the community need to sustain certain behavior to prevent mosquito from breeding. Our study aims to identify the factors associated with larval control practices in this particular community. A cross-sectional study involves 322 respondents living in a dengue outbreak prone area who were interviewed using a pretested questionnaire. The level of knowledge about Aedes mosquitoes, dengue transmission, its symptoms, and personal preventive measures ranges from fair to good. The level of attitude towards preventive measures was high. However, reported level of personal larval control practices was low (33.2%). Our multiple logistic regression analysis showed that only those with a good level of attitude towards personal preventive measure and frequent attendance to health campaigns were significantly associated with the good larval control practices. We conclude that, in a dengue outbreak prone area, having a good attitude towards preventive measures and frequent participation in health campaigns are important factors to sustain practices on larval control. PMID:25309602

Mohamad, Mariam; Selamat, Mohamad Ikhsan; Ismail, Zaliha

2014-01-01

11

Myanmar Dengue Outbreak Associated with Displacement of Serotypes 2, 3, and 4 by Dengue 1  

PubMed Central

In 2001, Myanmar (Burma) had its largest outbreak of dengue—15,361 reported cases of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS), including 192 deaths. That year, 95% of dengue viruses isolated from patients were serotype 1 viruses belonging to two lineages that had diverged from an earlier, now extinct, lineage sometime before 1998. The ratio of DHF to DSS cases in 2001 was not significantly different from that in 2000, when 1,816 cases of DHF/DSS were reported and dengue 1 also was the most frequently isolated serotype. However, the 2001 ratio was significantly higher than that in 1998 (also an outbreak year) and in 1999, when all four serotypes were detected and serotypes 1, 2, and 3 were recovered in similar numbers. The large number of clinical cases in 2001 may have been due, in part, to a preponderance of infections with dengue 1 viruses. PMID:15200847

Thu, Hlaing Myat; Lowry, Kym; Myint, Thein Thein; Shwe, Than Nu; Han, Aye Maung; Khin, Kyu Kyu; Thant, Kyaw Zin; Thein, Soe

2004-01-01

12

Outbreak of dengue Fever in central china, 2013.  

PubMed

In 2013, the first dengue fever (DF) outbreak in central China was reported in the central of Henan province, northern temperate regions, although they have been sequentially recorded in Southern China. 106 suspected DF cases were reported and 73 patients were confirmed dengue virus type 3 (DEN-3) infections. 62/392 (15.8%) local health persons showed DEN antibodies positive. To this day Henan is the northernmost province in China which has been reported about outbreak of DF and what is important is that it warns us the endemic range of DF has been expanded geographically in China. PMID:25374022

Huang, Xue Yong; Ma, Hong Xia; Wang, Hai Feng; DU, Yan Hua; Su, Jia; Li, Xing Le; Tang, Xiao Yan; Ma, Hong Peng; Zu, Bing Can; Zhang, Qiao Hong; Chen, Hao Min; Xu, Bian Li

2014-11-01

13

Eco-epidemiological analysis of dengue infection during an outbreak of dengue fever, India  

PubMed Central

Background This study was designed to find out a relationship of dengue infection with climatic factors such as rainfall, temperature and relative humidity during the dengue fever epidemic in the year 2003. Blood samples were collected from 1550 patients experiencing a febrile illness clinically consistent with dengue infection. Serological confirmation of Dengue Infection was done using Dengue Duo IgM and IgG Rapid Strip test (Pan Bio, Australia), which detected dengue-specific antibodies. Monthly data of total rainfall, temperature and relative humidity for the year 2003 was obtained from Meteorological Department of Delhi, New Delhi and retrospectively analyzed. Results Out of 1550 suspected cases, 893 cases (57.36%) were confirmed as serologically positive. The difference between numbers of serologically positive cases during different months was significant (p < 0.05). Larger proportions of serologically positive cases were observed among adults. Outbreak coincided mainly with the post monsoon period of subnormal rainfall. The difference between serologically positive cases as compared to serologically negative ones in post monsoon period was significantly higher (p < 0.001). The difference in the rainfall and temperature between three seasonal periods was significant (p < 0.05). Conclusion This prospective study highlighted rain, temperature and relative humidity as the major and important climatic factors, which could alone or collectively be responsible for an outbreak. More studies in this regard could further reveal the correlation between the climatic changes and dengue outbreaks, which would help in making the strategies and plans to forecast any outbreak in future well in advance. PMID:15831102

Chakravarti, Anita; Kumaria, Rajni

2005-01-01

14

Dengue  

MedlinePLUS

Dengue is an infection caused by a virus. You can get it if an infected mosquito bites you. Dengue does not spread from person to person. It ... the world. Outbreaks occur in the rainy season. Dengue is rare in the United States. Symptoms include ...

15

Detecting and Responding to a Dengue Outbreak: Evaluation of Existing Strategies in Country Outbreak Response Planning  

PubMed Central

Background. Dengue outbreaks are occurring with increasing frequency and intensity. Evidence-based epidemic preparedness and effective response are now a matter of urgency. Therefore, we have analysed national and municipal dengue outbreak response plans. Methods. Thirteen country plans from Asia, Latin America and Australia, and one international plan were obtained from the World Health Organization. The information was transferred to a data analysis matrix where information was extracted according to predefined and emerging themes and analysed for scope, inconsistencies, omissions, and usefulness. Findings. Outbreak response planning currently has a considerable number of flaws. Outbreak governance was weak with a lack of clarity of stakeholder roles. Late timing of responses due to poor surveillance, a lack of combining routine data with additional alerts, and lack of triggers for initiating the response weakened the functionality of plans. Frequently an outbreak was not defined, and early response mechanisms based on alert signals were neglected. There was a distinct lack of consideration of contextual influences which can affect how an outbreak detection and response is managed. Conclusion. A model contingency plan for dengue outbreak prediction, detection, and response may help national disease control authorities to develop their own more detailed and functional context specific plans. PMID:24222774

Kroeger, Axel; Runge-Ranzinger, Silvia; O'Dempsey, Tim

2013-01-01

16

Outbreak of dengue in Mumbai and predictive markers for dengue shock syndrome.  

PubMed

An alarming rise of dengue has been seen in Mumbai during the post-monsoon season. We undertook this prospective study in the pediatric wards and pediatric intensive care unit of B. J. Wadia Hospital for Children between 27 August 2003 and 10 October 2003 to determine the clinical features, laboratory abnormalities, and outcome of children affected with dengue and to determine the predictive markers for dengue shock syndrome. Fifty-one suspected dengue cases were tested for positivity of dengue by determination of dengue IgM antibodies by ELISA test. These positive cases were analysed for common clinical features, laboratory derangements, and outcome. Patients were subdivided into three subgroups: dengue fever (DF), dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS) as per WHO classification. Predictive markers for DSS were also determined. Thirty-nine patients had a positive dengue IgM titre, 20 patients had DHF, 18 patients had DSS, and one patient had DF The mean age of presentation was 4.9 years. Fever, hepatomegaly, vomiting, bleeding tendencies, erythematous rash, thrombocytopenia, elevated liver enzymes, and deranged PT and PTT were the predominant clinical and laboratory features. Predictive markers for DSS were younger age at onset, altered sensorium, paralytic ileus, and significantly deranged PT. Patients with DSS also had a longer recovery period and required more supportive management in the form of component therapy and ionotropic support. All three patients who died belonged to the DSS subgroup with case fatality rate for DSS being 16.6 per cent. None of the patients in the DHF or DF subgroup died. Endemicity of dengue fever is on the rise in Mumbai with increased incidence among children. Appropriate investigations, strict monitoring and prompt supportive management can reduce mortality in dengue. Predictive markers of DSS can reduce the mortality if promptly treated. Also prevention of transmission by mosquito control and maintaining water sanitation is required to effectively control this epidemic. PMID:15510763

Shah, Ira; Deshpande, G C; Tardeja, P N

2004-10-01

17

Molecular investigations of dengue virus during outbreaks in Orissa state, Eastern India from 2010 to 2011.  

PubMed

Dengue is one of the most important arboviral diseases in India. Orissa state in Eastern India reported the first dengue outbreak in 2010, followed by extensive outbreaks in 2011, affecting large number of people. Detailed entomological, serological and phylogenetic investigations were performed in mosquitoes and patients serum collected from dengue virus (DENV) affected areas of Orissa. The combination of DENV specific IgM capture-ELISA and reverse-transcription PCR (RT-PCR) detected high DENV positivity in serum samples. DENV was detected in mosquitoes reared from field caught pupae by RT-PCR, which confirmed the vertical transmission of DENV that may have an important role in the recurrence of dengue outbreaks. Phylogenetic analyses revealed the circulation of Indian lineage of DENV-2 (genotype-IV) and DENV-3 (genotype-III) in vectors and patients serum in Orissa from 2010 to 2011, DENV-2 being the prevailing serotype. Selection analyses within the C-prM region showed that the emergence of DENV-2 and DENV-3 in Orissa was constrained by purifying selection which suggested the role of ecological factors like mosquito density and behavior in the recurrent outbreaks. Aedes albopictus was found to be the most abundant vector in the areas surveyed, followed by Aedes aegypti. Indoor breeding spots (earthen pots) were most abundant, with high pupal productivity (38.50) and contributed maximum Aedes species in the affected areas. The DENV infection rate estimated by maximum likelihood estimate (MLE) was high for indoor breeding Aedes (4.87; 95% CI: 1.82, 10.78) in comparison to outdoor breeding Aedes (1.55; 95% CI: 0.09, 7.55). The high MLE in Ae. albopictus (4.72; 95% CI: 1.94, 9.80) in comparison to Ae. aegypti (1.55; 95% CI: 0.09, 7.54) indicated that Ae. albopictus was the main DENV vector responsible for the outbreaks. The results indicated the circulation of two virulent serotypes of DENV in Orissa, mainly by Ae. albopictus with the implication for implementation of intradomecile vector control measures to prevent the spread of dengue. PMID:23523598

Das, Biswadeep; Das, Mumani; Dwibedi, Bhagirathi; Kar, Santanu K; Hazra, Rupenangshu K

2013-06-01

18

Detection of Saint Louis encephalitis virus in dengue-suspected cases during a dengue 3 outbreak.  

PubMed

Arboviruses are frequently associated with outbreaks in humans and represent a serious public health problem. Among the Brazilian arboviruses, Mayaro virus, Dengue virus (DENV), Yellow Fever virus, Rocio virus, Saint Louis Encephalitis virus (SLEV), and Oropouche virus are responsible for most of human cases. All these arboviruses usually produce undistinguishable acute febrile illness, especially in the acute phase of infection. In this study we investigated the presence of arboviruses in sera of 519 patients presenting acute febrile illness, during a dengue outbreak in São José do Rio Preto City (São Paulo, Brazil). A multiplex-nested RT-polymerase chain reaction assay was applied to detect and identify the main Brazilian arboviruses (Flavivirus, Alphavirus, and Orthobunyavirus genera). The molecular analysis showed that 365 samples were positive to DENV-3, 5 to DENV-2, and 8 to SLEV. Among the positive samples, one coinfection was detected between DENV-2 and DENV-3. The phylogenetic analysis of the SLEV envelope gene indicated that the virus circulating in city is related to lineage V strains. These results indicated that during that large DENV-3 outbreak in 2006, different arboviruses cocirculated causing human disease. Thus, it is necessary to have an efficient surveillance system to control the dissemination of these arboviruses in the population. PMID:20645866

Terzian, Ana Carolina Bernardes; Mondini, Adriano; Bronzoni, Roberta Vieira de Moraes; Drumond, Betânia Paiva; Ferro, Bianca Piovezan; Cabrera, Eliana Márcia Sotello; Figueiredo, Luis Tadeu Moraes; Chiaravalloti-Neto, Francisco; Nogueira, Maurício Lacerda

2011-03-01

19

On the analysis of effectiveness in mass application of mosquito repellent for dengue disease prevention  

NASA Astrophysics Data System (ADS)

Dengue disease has been known as one of dangerous vector-borne diseases and become serious threat in many tropical countries. With no vaccine and antiviral available until nowadays, and frequent appearance of extraordinary dengue outbreaks, many governments are forced to declare national problem for dengue. At this moment, the only method available to prevent dengue disease transmission is to combat the disease-carrying mosquitoes as well as to reduce the contact between human and mosquitoes. The fast growing dengue transmission in many countries in recent years indicates that the mosquito control programs are far from successful. The use of mosquito repellent is one possible instrument which could be used as an effective mass treatment to prevent the dengue outbreak during endemic period. Here in this paper a Susceptible-Infectious-Recovered (S-I-R) dengue transmission model with repellent mass treatment is being applied to portions of children and adult compartments. Analysis of the basic reproductive ratio (Ro) of the model is done. It is shown, with reasonable choices of portions of treated children and adults, in combination with reduction of mosquito population, the basic reproductive ratio can be significantly reduced and occurrence of endemic can be avoided. Numerical simulations are shown for various treatment scenarios.

Aldila, D.; Soewono, E.; Nuraini, N.

2012-05-01

20

Exploring the origin and potential for spread of the 2013 dengue outbreak in Luanda, Angola  

PubMed Central

Introduction Dengue in Africa is underreported. Simultaneous reports of travellers with dengue returning from Luanda, Angola, to six countries on four continents suggest that a major dengue outbreak is currently occurring in Angola, South West Africa. Methods To identify the origin of the imported dengue virus, we sequenced the virus from Angola and investigated the interconnectivity via air travel between dengue-endemic countries and Angola. Results and Conclusion Our analyses show that the Angola outbreak was most likely caused by an endemic virus strain that had been circulating in West Africa for many years. We also show that Portugal and South Africa are most likely at the highest risk of importation of dengue from Angola due to the large number of air passengers between Angola and these countries. PMID:23911088

Sessions, October M.; Khan, Kamran; Hou, Yan'an; Meltzer, Eyal; Quam, Mikkel; Schwartz, Eli; Gubler, Duane J.; Wilder-Smith, Annelies

2013-01-01

21

Notes from the field: School reporting of a dengue outbreak--St. Croix, U.S. Virgin Islands, 2012.  

PubMed

Dengue is endemic in the U.S. Virgin Islands, but no outbreaks have been reported since 2005. In November 2012, a school nurse in St. Croix reported suspected dengue in 27 (7%) of 369 students and staff members to the Virgin Islands Department of Health (VIDOH) and the CDC Dengue Branch in Puerto Rico. Four of 12 patient specimens sent to the CDC Dengue Branch for diagnostic testing were confirmed as dengue. Although VIDOH had observed an increase in passive dengue reporting, reliable baseline case counts were unavailable for comparison. An investigation was begun to determine the incidence of recent dengue virus (DENV) infection in schools and islandwide. PMID:23466437

2013-03-01

22

A data-driven epidemiological prediction method for dengue outbreaks using local and remote sensing data  

PubMed Central

Background Dengue is the most common arboviral disease of humans, with more than one third of the world’s population at risk. Accurate prediction of dengue outbreaks may lead to public health interventions that mitigate the effect of the disease. Predicting infectious disease outbreaks is a challenging task; truly predictive methods are still in their infancy. Methods We describe a novel prediction method utilizing Fuzzy Association Rule Mining to extract relationships between clinical, meteorological, climatic, and socio-political data from Peru. These relationships are in the form of rules. The best set of rules is automatically chosen and forms a classifier. That classifier is then used to predict future dengue incidence as either HIGH (outbreak) or LOW (no outbreak), where these values are defined as being above and below the mean previous dengue incidence plus two standard deviations, respectively. Results Our automated method built three different fuzzy association rule models. Using the first two weekly models, we predicted dengue incidence three and four weeks in advance, respectively. The third prediction encompassed a four-week period, specifically four to seven weeks from time of prediction. Using previously unused test data for the period 4–7 weeks from time of prediction yielded a positive predictive value of 0.686, a negative predictive value of 0.976, a sensitivity of 0.615, and a specificity of 0.982. Conclusions We have developed a novel approach for dengue outbreak prediction. The method is general, could be extended for use in any geographical region, and has the potential to be extended to other environmentally influenced infections. The variables used in our method are widely available for most, if not all countries, enhancing the generalizability of our method. PMID:23126401

2012-01-01

23

Characteristics of a dengue outbreak in a remote pacific island chain - republic of the marshall islands, 2011-2012.  

PubMed

Dengue is a potentially fatal acute febrile illness caused by four mosquito-transmitted dengue viruses (DENV-1-4). Although dengue outbreaks regularly occur in many regions of the Pacific, little is known about dengue in the Republic of the Marshall Islands (RMI). To better understand dengue in RMI, we investigated an explosive outbreak that began in October 2011. Suspected cases were reported to the Ministry of Health, serum specimens were tested with a dengue rapid diagnostic test (RDT), and confirmatory testing was performed using RT-PCR and IgM ELISA. Laboratory-positive cases were defined by detection of DENV nonstructural protein 1 by RDT, DENV nucleic acid by RT-PCR, or anti-DENV IgM antibody by RDT or ELISA. Secondary infection was defined by detection of anti-DENV IgG antibody by ELISA in a laboratory-positive acute specimen. During the four months of the outbreak, 1,603 suspected dengue cases (3% of the RMI population) were reported. Of 867 (54%) laboratory-positive cases, 209 (24%) had dengue with warning signs, six (0.7%) had severe dengue, and none died. Dengue incidence was highest in residents of Majuro and individuals aged 10-29 years, and ?95% of dengue cases were experiencing secondary infection. Only DENV-4 was detected by RT-PCR, which phylogenetic analysis demonstrated was most closely related to a virus previously identified in Southeast Asia. Cases of vertical DENV transmission, and DENV/Salmonella Typhi and DENV/Mycobacterium leprae co-infection were identified. Entomological surveys implicated water storage containers and discarded tires as the most important development sites for Aedes aegypti and Ae. albopictus, respectively. Although this is the first documented dengue outbreak in RMI, the age groups of cases and high prevalence of secondary infection demonstrate prior DENV circulation. Dengue surveillance should continue to be strengthened in RMI and throughout the Pacific to identify and rapidly respond to future outbreaks. PMID:25268134

Sharp, Tyler M; Mackay, Andrew J; Santiago, Gilberto A; Hunsperger, Elizabeth; Nilles, Eric J; Perez-Padilla, Janice; Tikomaidraubuta, Kinisalote S; Colon, Candimar; Amador, Manuel; Chen, Tai-Ho; Lalita, Paul; Muñoz-Jordán, Jorge L; Barrera, Roberto; Langidrik, Justina; Tomashek, Kay M

2014-01-01

24

Characteristics of a Dengue Outbreak in a Remote Pacific Island Chain – Republic of the Marshall Islands, 2011–2012  

PubMed Central

Dengue is a potentially fatal acute febrile illness caused by four mosquito-transmitted dengue viruses (DENV-1–4). Although dengue outbreaks regularly occur in many regions of the Pacific, little is known about dengue in the Republic of the Marshall Islands (RMI). To better understand dengue in RMI, we investigated an explosive outbreak that began in October 2011. Suspected cases were reported to the Ministry of Health, serum specimens were tested with a dengue rapid diagnostic test (RDT), and confirmatory testing was performed using RT-PCR and IgM ELISA. Laboratory-positive cases were defined by detection of DENV nonstructural protein 1 by RDT, DENV nucleic acid by RT-PCR, or anti-DENV IgM antibody by RDT or ELISA. Secondary infection was defined by detection of anti-DENV IgG antibody by ELISA in a laboratory-positive acute specimen. During the four months of the outbreak, 1,603 suspected dengue cases (3% of the RMI population) were reported. Of 867 (54%) laboratory-positive cases, 209 (24%) had dengue with warning signs, six (0.7%) had severe dengue, and none died. Dengue incidence was highest in residents of Majuro and individuals aged 10–29 years, and ?95% of dengue cases were experiencing secondary infection. Only DENV-4 was detected by RT-PCR, which phylogenetic analysis demonstrated was most closely related to a virus previously identified in Southeast Asia. Cases of vertical DENV transmission, and DENV/Salmonella Typhi and DENV/Mycobacterium leprae co-infection were identified. Entomological surveys implicated water storage containers and discarded tires as the most important development sites for Aedes aegypti and Ae. albopictus, respectively. Although this is the first documented dengue outbreak in RMI, the age groups of cases and high prevalence of secondary infection demonstrate prior DENV circulation. Dengue surveillance should continue to be strengthened in RMI and throughout the Pacific to identify and rapidly respond to future outbreaks. PMID:25268134

Sharp, Tyler M.; Mackay, Andrew J.; Santiago, Gilberto A.; Hunsperger, Elizabeth; Nilles, Eric J.; Perez-Padilla, Janice; Tikomaidraubuta, Kinisalote S.; Colon, Candimar; Amador, Manuel; Chen, Tai-Ho; Lalita, Paul; Muñoz-Jordán, Jorge L.; Barrera, Roberto; Langidrik, Justina; Tomashek, Kay M.

2014-01-01

25

The 2012 Madeira Dengue Outbreak: Epidemiological Determinants and Future Epidemic Potential  

PubMed Central

Dengue, a vector-borne viral disease of increasing global importance, is classically associated with tropical and sub-tropical regions around the world. Urbanisation, globalisation and climate trends, however, are facilitating the geographic spread of its mosquito vectors, thereby increasing the risk of the virus establishing itself in previously unaffected areas and causing large-scale epidemics. On 3 October 2012, two autochthonous dengue infections were reported within the Autonomous Region of Madeira, Portugal. During the following seven months, this first ‘European’ dengue outbreak caused more than 2000 local cases and 81 exported cases to mainland Europe. Here, using an ento-epidemiological mathematical framework, we estimate that the introduction of dengue to Madeira occurred around a month before the first official cases, during the period of maximum influx of airline travel, and that the naturally declining temperatures of autumn were the determining factor for the outbreak's demise in early December 2012. Using key estimates, together with local climate data, we further propose that there is little support for dengue endemicity on this island, but a high potential for future epidemic outbreaks when seeded between May and August—a period when detection of imported cases is crucial for Madeira's public health planning. PMID:25144749

Lourenco, Jose; Recker, Mario

2014-01-01

26

Ongoing outbreak of dengue serotype-3 in Solomon Islands, January to May 2013  

PubMed Central

Methods Enhanced dengue surveillance was implemented in the capital, Honiara, and in the provinces. This included training health staff on dengue case definitions, data collection and reporting. Vector surveillance was also conducted. Results From 3 January to 15 May 2013, 5254 cases of suspected dengue were reported (101.8 per 10 000 population), including 401 hospitalizations and six deaths. The median age of cases was 20 years (range zero to 90), and 86% were reported from Honiara. Both Aedes aegyti and Aedes albopictus were identified in Honiara. Outbreak response measures included clinical training seminars, vector control activities, implementation of diagnostic and case management protocols and a public communication campaign. Discussion This was the first large dengue outbreak documented in Solomon Islands. Factors that may have contributed to this outbreak include a largely susceptible population, the presence of a highly efficient dengue vector in Honiara, a high-density human population with numerous breeding sites and favourable weather conditions for mosquito proliferation. Although the number of cases has plateaued since 1 April, continued enhanced nationwide surveillance and response activities are necessary. PMID:24319611

Joshua, Cynthia; Sio, Alison; Shortus, Matthew; Dalipanda, Tenneth; Durski, Kara; Musto, Jennie; Puiahi, Elliot; Dofai, Alfred; Aaskov, John; Cao-Lormeau, Van Mai; Musso, Didier; Dutta, Nick; Fleisch, Juliet; Nilles, Eric

2013-01-01

27

Outbreak of viral hemorrhagic fever caused by dengue virus type 3 in Al-Mukalla, Yemen  

PubMed Central

Background Investigations were conducted by the authors to explore an outbreak of viral hemorrhagic fever (VHF) reported in 2010 from Al-Mukalla city, the capital of Hadramout in Yemen. Methods From 15–17 June 2010, the outbreak investigation period, specimens were obtained within 7?days after onset of illness of 18 acutely ill patients hospitalized with VHF and 15 household asymptomatic contacts of 6 acute cases. Additionally, 189 stored sera taken from acutely ill patients with suspected VHF hospitalized in the preceding 12?months were obtained from the Ministry of Health of Yemen. Thus, a total of 222 human specimens were collected; 207 specimens from acute cases and 15 specimens from contacts. All samples were tested with RT-PCR for dengue (DENV), Alkhumra (ALKV), Rift Valley Fever (RVFV), Yellow Fever (YFV), and Chikungunya (CHIKV) viruses. Samples were also tested for DENV IgM, IgG, and NS1-antigen. Medical records of patients were reviewed and demographic, clinical, and laboratory data was collected. Results Of 207 patients tested, 181 (87.4%) patients were confirmed to have acute dengue with positive dengue NS1-antigen (97 patients, 46.9%) and/or IgM (163 patients, 78.7%). Of the 181 patients with confirmed dengue, 100 (55.2%) patients were IgG-positive. DENV RNA was detected in 2 (1%) patients with acute symptoms; both samples were molecularly typed as DENV type 3. No other VHF viruses were detected. For the 15 contacts tested, RT-PCR tests for the five viruses were negative, one contact was dengue IgM positive, and another one was dengue IgG positive. Of the 181 confirmed dengue patients, 120 (66.3%) patients were males and the median age was 24?years. The most common manifestations included fever (100%), headache (94.5%), backache (93.4%), malaise (88.4%), arthralgia (85.1%), myalgia (82.3%), bone pain (77.9%), and leukopenia (76.2%). Two (1.1%) patients died. Conclusions DENV-3 was confirmed to be the cause of an outbreak of VHF in Al-Mukalla. It is important to use both IgM and NS1-antigen tests to confirm acute dengue particularly under the adverse field conditions, where proper storage and transportation of specimens are missing, which substantially reduce the sensitivity of the RT-PCR for detecting DENV RNA. PMID:23497142

2013-01-01

28

Lessons Learned during Dengue Outbreaks in the United States, 2001–2011  

PubMed Central

Since 2001, three autochthonous dengue fever outbreaks have occurred in the United States: in Hawaii (2001); Brownsville, Texas (2005); and southern Florida (2009–2011). We sought to characterize and describe the response to these outbreaks from the perspectives of public health and vector control officials. By conducting a medical literature review through PubMed and news media searches through Google, we identified persons involved in managing each outbreak; 26 persons then participated in qualitative, semistructured interviews. After analyzing the 3 outbreaks, we found the following prominent themes in the response efforts: timely detection of illness; communication of up-to-date, correct information; and development of a rapid response that engages the community. We therefore recommend that public health authorities involve the clinical and laboratory community promptly, provide accurate information, and engage the local community in vector control and case identification and reporting. PMID:22469195

Sell, Tara Kirk; Bouri, Nidhi; Franco, Crystal

2012-01-01

29

Dengue Outbreak in a Hilly State of Arunachal Pradesh in Northeast India  

PubMed Central

Dengue has been reported from plains as well as hilly regions of India including some parts of Northeast India. In July-August 2012, outbreak of fever with unknown origin (FUO) indicative of Dengue was reported in Pasighat, East Siang district of Arunachal Pradesh (AP) state. Serum samples (n = 164) collected from patients from Health Training and Research Centre General Hospital, Pasighat, were tested for NS1 antigen and IgM antibodies. NS1-positive samples were analyzed by RT-PCR assay and entomological surveys were carried out. The majority of suspected cases reported NS1 antigen positivity. Females and young adults were mostly affected. The majority of the amplified NS1-positive samples showed Dengue serotype 3 infection. Aedes (Stegomyia) albopictus, known as semiurban breeding mosquitoes, was the only potential vector species identified from the affected areas of Pasighat which single handedly contributed to the outbreak. Thus, the present work identifies Dengue as an emerging arboviral infection in hilly state of AP along with a looming risk of its spread to neighbouring areas. PMID:24587732

Khan, Siraj A.; Dutta, Prafulla; Topno, Rashmee; Soni, Monika; Mahanta, Jagadish

2014-01-01

30

Molecular detection of Mayaro virus during a dengue outbreak in the state of Mato Grosso, Central-West Brazil  

PubMed Central

Mayaro virus (MAYV) is frequently reported in Pan-Amazonia. The aim of this study was to investigate the circulation of alphaviruses during a dengue outbreak in the state of Mato Grosso, Brazil. Serum samples from dengue-suspected patients were subjected to multiplex semi-nested reverse transcriptase polymerase chain reaction for 11 flaviviruses and five alphaviruses, to nucleotide sequencing and to viral isolation. MAYV was detected in 15 (2.5%) of 604 patients. Twelve were co-infected with dengue virus 4, which was isolated from 10 patients. The molecular detection of MAYV in dengue-suspected patients suggests that other arboviruses may be silently circulating during dengue outbreaks in Brazil. PMID:25141284

Zuchi, Nayara; Heinen, Letícia Borges da Silva; dos Santos, Marcelo Adriano Mendes; Pereira, Fernanda Carla; Slhessarenko, Renata Dezengrini

2014-01-01

31

Dengue Virus Immunoglobulin M Detection in a Reference Laboratory Setting during the 2010 Dengue Virus Outbreak on Caribbean Islands ?  

PubMed Central

A large outbreak of dengue virus (DV) infections occurred on Caribbean islands during 2010, with cases peaking during the second half of the year. In conjunction with the outbreak, we observed an unprecedented spike in the number of sera submitted for DV antibody testing between June and December 2010, with a concomitant increase in the number of IgM-positive specimens, indicative of acute DV infection. Analysis of the place of residence of the IgM-positive patients identified from June to December of 2010 revealed that 58.1% were residents of Caribbean islands (Puerto Rico and the U.S. Virgin Islands), whereas 40.6% were residents of the U.S. mainland or Hawaii. The U.S. residents represented 42 states plus the District of Columbia, but most (53%) were from just 3 states (California, Florida, and New York). In comparison to the Caribbean IgM-positive patient group, the U.S. IgM-positive patient group contained proportionately more adults 21 to 60 years old and fewer individuals <21 years old. These findings indicate that the 2010 Caribbean DV outbreak affected many U.S. residents (mostly adults, presumably travelers) from diverse geographic areas and emphasize the potential for a viremic DV-infected returning traveler to spark a local DV outbreak by introducing DV into a community with competent mosquito vectors. PMID:21613462

Prince, Harry E.; Matud, Jose L.; Lieberman, Jay M.

2011-01-01

32

Dengue and Severe Dengue  

MedlinePLUS

... outbreaks through its collaborating network of laboratories; provides technical support and guidance to countries for the effective management of dengue outbreaks; supports countries to improve their reporting systems and capture the true burden of the disease; ...

33

Sharing experiences: towards an evidence based model of dengue surveillance and outbreak response in Latin America and Asia  

PubMed Central

Background The increasing frequency and intensity of dengue outbreaks in endemic and non-endemic countries requires a rational, evidence based response. To this end, we aimed to collate the experiences of a number of affected countries, identify strengths and limitations in dengue surveillance, outbreak preparedness, detection and response and contribute towards the development of a model contingency plan adaptable to country needs. Methods The study was undertaken in five Latin American (Brazil, Colombia, Dominican Republic, Mexico, Peru) and five in Asian countries (Indonesia, Malaysia, Maldives, Sri Lanka, Vietnam). A mixed-methods approach was used which included document analysis, key informant interviews, focus-group discussions, secondary data analysis and consensus building by an international dengue expert meeting organised by the World Health Organization, Special Program for Research and Training in Tropical Diseases (WHO-TDR). Results Country information on dengue is based on compulsory notification and reporting (“passive surveillance”), with laboratory confirmation (in all participating Latin American countries and some Asian countries) or by using a clinical syndromic definition. Seven countries additionally had sentinel sites with active dengue reporting, some also had virological surveillance. Six had agreed a formal definition of a dengue outbreak separate to seasonal variation in case numbers. Countries collected data on a range of warning signs that may identify outbreaks early, but none had developed a systematic approach to identifying and responding to the early stages of an outbreak. Outbreak response plans varied in quality, particularly regarding the early response. The surge capacity of hospitals with recent dengue outbreaks varied; those that could mobilise additional staff, beds, laboratory support and resources coped best in comparison to those improvising a coping strategy during the outbreak. Hospital outbreak management plans were present in 9/22 participating hospitals in Latin-America and 8/20 participating hospitals in Asia. Conclusions Considerable variation between countries was observed with regard to surveillance, outbreak detection, and response. Through discussion at the expert meeting, suggestions were made for the development of a more standardised approach in the form of a model contingency plan, with agreed outbreak definitions and country-specific risk assessment schemes to initiate early response activities according to the outbreak phase. This would also allow greater cross-country sharing of ideas. PMID:23800243

2013-01-01

34

Preventing extinction and outbreaks in chaotic populations  

E-print Network

Interactions in ecological communities are inherently nonlinear and can lead to complex population dynamics including irregular fluctuations induced by chaos. Chaotic population dynamics can exhibit violent oscillations with extremely small or large population abundances that might cause extinction and recurrent outbreaks, respectively. We present a simple method that can guide management efforts to prevent crashes, peaks, or any other undesirable state. At the same time, the irregularity of the dynamics can be preserved when chaos is desirable for the population. The control scheme is easy to implement because it relies on time series information only. The method is illustrated by two examples: control of crashes in the Ricker map and control of outbreaks in a stage-structured model of the flour beetle Tribolium. It turns out to be effective even with few available data and in the presence of noise, as is typical for ecological settings.

Frank M. Hilker; Frank H. Westerhoff

2006-06-30

35

Dengue Prevention and 35 Years of Vector Control in Singapore  

PubMed Central

After a 15-year period of low incidence, dengue has reemerged in Singapore in the past decade. We identify potential causes of this resurgence. A combination of lowered herd immunity, virus transmission outside the home, an increase in the age of infection, and the adoption of a case-reactive approach to vector control contribute to the increased dengue incidence. Singapore's experience with dengue indicates that prevention efforts may not be sustainable. For renewed success, Singapore needs to return to a vector control program that is based on carefully collected entomologic and epidemiologic data. Singapore's taking on a leadership role in strengthening disease surveillance and control in Southeast Asia may also be useful in reducing virus importation. PMID:16707042

Goh, Kee-Tai; Gubler, Duane J.

2006-01-01

36

No clinical or biological difference between Chikungunya and Dengue Fever during the 2010 Gabonese outbreak  

PubMed Central

Chikungunya (CHIKV) and Dengue (DENV) viruses, both arboviruses, have caused multiple outbreaks worldwide. Their clinical features are poorly described in Africa and there is no comparative study, although Chikungunya is considered as a dengue-like disease. We conducted a comparative study of clinical and biological data from CHIKV and DENV positive patients during the 2010 Gabonese outbreak. Patients consulting with general symptoms and having laboratory confirmation for CHIKV or DENV were included. Clinical and biological data were recorded. Statistical analyses were performed using Epi Info. A P value < 0.05 was considered significant. In all, 270 CHIKV+, 53 DENV+ and 20 co-infected patients were included in the study. Headaches, hemorrhage, leukopenia and lymphopenia were significantly (P respectively 0.01, 0.001, 0.02 and 0.001) more frequent in DENV+ patients than in CHIKV+. There was no additive effect of the two viruses.These clinical and hematological disorders are non specific and cannot assist for the differential diagnosis. These diseases are clinically indistinguishable, and need for laboratory confirmation. PMID:24470935

Nkoghe, Dieudonne; Kassa, Roland Fabrice Kassa; Bisvigou, Ulrich; Caron, Melanie; Grard, Gilda; Leroy, Eric Maurice

2012-01-01

37

Seroprevalence of Antibodies against Chikungunya, Dengue, and Rift Valley Fever Viruses after Febrile Illness Outbreak, Madagascar  

PubMed Central

In October 2009, two–3 months after an outbreak of a febrile disease with joint pain on the eastern coast of Madagascar, we assessed serologic markers for chikungunya virus (CHIKV), dengue virus (DENV), and Rift Valley fever virus (RVFV) in 1,244 pregnant women at 6 locations. In 2 eastern coast towns, IgG seroprevalence against CHIKV was 45% and 23%; IgM seroprevalence was 28% and 5%. IgG seroprevalence against DENV was 17% and 11%. No anti-DENV IgM was detected. At 4 locations, 450–1,300 m high, IgG seroprevalence against CHIKV was 0%–3%, suggesting CHIKV had not spread to higher inland-altitudes. Four women had IgG against RVFV, probably antibodies from a 2008 epidemic. Most (78%) women from coastal locations with CHIKV-specific IgG reported joint pain and stiffness; 21% reported no symptoms. CHIKV infection was significantly associated with high bodyweight. The outbreak was an isolated CHIKV epidemic without relevant DENV co-transmission. PMID:23092548

Girmann, Mirko; Randriamampionona, Njary; Bialonski, Alexandra; Maus, Deborah; Krefis, Anne Caroline; Njarasoa, Christine; Rajanalison, Jeanne Fleury; Ramandrisoa, Herly Daniel; Randriarison, Maurice Lucien; May, Jurgen; Schmidt-Chanasit, Jonas; Rakotozandrindrainy, Raphael

2012-01-01

38

Seroprevalence of antibodies against Chikungunya, Dengue, and Rift Valley fever viruses after febrile illness outbreak, Madagascar.  

PubMed

In October 2009, two-3 months after an outbreak of a febrile disease with joint pain on the eastern coast of Madagascar, we assessed serologic markers for chikungunya virus (CHIKV), dengue virus (DENV), and Rift Valley fever virus (RVFV) in 1,244 pregnant women at 6 locations. In 2 eastern coast towns, IgG seroprevalence against CHIKV was 45% and 23%; IgM seroprevalence was 28% and 5%. IgG seroprevalence against DENV was 17% and 11%. No anti-DENV IgM was detected. At 4 locations, 450-1,300 m high, IgG seroprevalence against CHIKV was 0%-3%, suggesting CHIKV had not spread to higher inland-altitudes. Four women had IgG against RVFV, probably antibodies from a 2008 epidemic. Most (78%) women from coastal locations with CHIKV-specific IgG reported joint pain and stiffness; 21% reported no symptoms. CHIKV infection was significantly associated with high bodyweight. The outbreak was an isolated CHIKV epidemic without relevant DENV co-transmission. PMID:23092548

Schwarz, Norbert G; Girmann, Mirko; Randriamampionona, Njary; Bialonski, Alexandra; Maus, Deborah; Krefis, Anne Caroline; Njarasoa, Christine; Rajanalison, Jeanne Fleury; Ramandrisoa, Herly Daniel; Randriarison, Maurice Lucien; May, Jürgen; Schmidt-Chanasit, Jonas; Rakotozandrindrainy, Raphael

2012-11-01

39

The basic reproduction number R0 and effectiveness of reactive interventions during dengue epidemics: the 2002 dengue outbreak in Easter Island, Chile.  

PubMed

We use a stochastic simulation model to explore the effect of reactive intervention strategies during the 2002 dengue outbreak in the small population of Easter Island, Chile. We quantified the effect of interventions on the transmission dynamics and epidemic size as a function of the simulated control intensity levels and the timing of initiation of control interventions. Because no dengue outbreaks had been reported prior to 2002 in Easter Island, the 2002 epidemic provided a unique opportunity to estimate the basic reproduction number R0 during the initial epidemic phase, prior to the start of control interventions. We estimated R0 at 27.2 (95%CI: 14.8, 49.3). We found that the final epidemic size is highly sensitive to the timing of start of interventions. However, even when the control interventions start several weeks after the epidemic onset, reactive intervention efforts can have a significant impact on the final epidemic size. Our results indicate that the rapid implementation of control interventions can have a significant effect in reducing the epidemic size of dengue epidemics. PMID:24245625

Chowell, Gerardo; Fuentes, R; Olea, A; Aguilera, X; Nesse, H; Hyman, J M

2013-01-01

40

Study on Entomological Surveillance and its Significance during a Dengue Outbreak in the District of Tirunelveli in Tamil Nadu, India  

PubMed Central

Objectives To study the significance of entomological surveillance, the house index (HI), container index (CI), and Breteau index (BI) were determined to estimate the degree of a major dengue outbreak in Tirunelveli, Tamil Nadu, India (Latitude: 8°42?N; Longitude: 77°42?E) in May 2012. Methods The HI, CI, and BI were determined in a primary health center (PHC) in the village of Maruthamputhur (Pappakudi taluk, Tirunelveli) by carrying out an antilarval (AL) work that involved door-to-door search for immature stages of Aedes spp. mosquitoes by trained field workers and volunteers. The work of field workers was evaluated by a junior and senior entomologist the following day. Results Before the AL work, the reported numbers of fever cases from Week 1 to 5 in Maruthamputhur were 211, 394, 244, 222, and 144 with two deaths. By contrast, after the AL work, these numbers were considerably reduced and there was no fever-related death (the HI was reduced from 48.2% to 1.6%, the CI from 28.6% to 0.4%, and the BI from 48.2 to 1.6). Conclusion Because no specific medicine and vaccines are available to treat dengue fever and dengue hemorrhagic fever, entomological surveillance and its significance can be used to halt the outbreak of dengue as shown in this study. PMID:24159547

Basker, Parasuraman; Kannan, Pichai; Porkaipandian, Rajagopal Thirugnanasambandam; Saravanan, Sivsankaran; Sridharan, Subramaniam; Kadhiresan, Mahaligam

2013-01-01

41

Unusual and rare manifestations of dengue during a dengue outbreak in a tertiary care hospital in South India.  

PubMed

Dengue is the most rapidly spreading mosquito-borne viral disease in the world, and as a larger proportion of the population is being affected, more unusual manifestations are being reported. Very few studies have documented unusual manifestations of dengue in South India. This prospective study was undertaken from July 2011 to June 2013 to document rare manifestations of dengue fever in 175 hospitalized patients. The clinical diagnosis was confirmed by the detection of NS1Ag, dengue IgM, or IgG by ELISA and/or a RT-PCR and CDC real-time PCR for dengue virus (DENV) RNA. The daily profiles of the hematological and biochemical investigations were followed and recorded. Unusual and rare manifestations of dengue were documented for 115 patients (66 %). Hepatitis was observed in 70 % of the cases. Pleural effusion was seen in 11 %, acute renal failure in 10 %, neurological complications such as encephalitis in 7.4 %, myocarditis in 9 %, and bleeding gastric ulcers in 3.4 % of the cases. DENV serotype 2 was more prevalent in patients with unusual manifestations of dengue in our study. The WHO classification system does not include unusual and rare manifestations; hence, it is essential to be aware of these manifestations and closely monitor them for better clinical management and outcome of patients. PMID:24510171

Neeraja, M; Iakshmi, V; Teja, V D; Lavanya, Vanjari; Priyanka, E N; Subhada, K; Parida, M M; Dash, P K; Sharma, Sashi; Rao, P V L; Reddy, Gopal

2014-07-01

42

Dengue: an emerging disease in Nepal.  

PubMed

Dengue is an acute infectious disease caused by dengue viruses and transmitted by the Aedes species of mosquito. The rapid global spread of the dengue virus into new areas has begun to attract more research attention. A series of dengue fever outbreaks in several districts of Nepal has been recently observed. The evidence of all four serotypes (DEN - 1 - 4) could be a consequence of a sudden resurgence of a more severe dengue disease in Nepal. Health care providers need to become familiar with the disease to prevent or control the possibility of future outbreaks. The clinical features, diagnosis, treatment, epidemiological patterns and challenges of dengue virus infection in Nepal will be discussed here. PMID:22922903

Pun, S B

2011-01-01

43

Optimal Lead Time for Dengue Forecast  

PubMed Central

Background A dengue early warning system aims to prevent a dengue outbreak by providing an accurate prediction of a rise in dengue cases and sufficient time to allow timely decisions and preventive measures to be taken by local authorities. This study seeks to identify the optimal lead time for warning of dengue cases in Singapore given the duration required by a local authority to curb an outbreak. Methodology and Findings We developed a Poisson regression model to analyze relative risks of dengue cases as functions of weekly mean temperature and cumulative rainfall with lag times of 1–5 months using spline functions. We examined the duration of vector control and cluster management in dengue clusters >?=?10 cases from 2000 to 2010 and used the information as an indicative window of the time required to mitigate an outbreak. Finally, we assessed the gap between forecast and successful control to determine the optimal timing for issuing an early warning in the study area. Our findings show that increasing weekly mean temperature and cumulative rainfall precede risks of increasing dengue cases by 4–20 and 8–20 weeks, respectively. These lag times provided a forecast window of 1–5 months based on the observed weather data. Based on previous vector control operations, the time needed to curb dengue outbreaks ranged from 1–3 months with a median duration of 2 months. Thus, a dengue early warning forecast given 3 months ahead of the onset of a probable epidemic would give local authorities sufficient time to mitigate an outbreak. Conclusions Optimal timing of a dengue forecast increases the functional value of an early warning system and enhances cost-effectiveness of vector control operations in response to forecasted risks. We emphasize the importance of considering the forecast-mitigation gaps in respective study areas when developing a dengue forecasting model. PMID:23110242

Hii, Yien Ling; Rocklov, Joacim; Wall, Stig; Ng, Lee Ching; Tang, Choon Siang; Ng, Nawi

2012-01-01

44

Dengue among United Nations mission in Haiti personnel, 1995: implications for preventive medicine.  

PubMed

The incidence of dengue infections has been increasing in the Caribbean, and cases have been identified among successive deployments of multinational peacekeepers to Haiti (1994-1997). In the absence of an effective vaccine or chemoprophylaxis to prevent dengue fever, vector-control operations and use of personal protection measures to prevent arthropod bites are the most effective means of limiting disease transmission. During our 5-month deployment as part of the United Nations Mission in Haiti, 79 cases of recent dengue fever were identified among 249 patients (32%) presenting with febrile illness to the 86th Combat Support Hospital. Further investigation revealed low unit readiness to perform standard vector-control activities and poor individual adherence to measures to prevent arthropod bites. Command enforcement of existing field preventive medicine doctrine is essential to prevent casualties caused by dengue, other arthropod-borne infections, and nuisance arthropod bites during military deployments. PMID:10226460

Gambel, J M; Drabick, J J; Swalko, M A; Henchal, E A; Rossi, C A; Martinez-Lopez, L

1999-04-01

45

Immunization coverage required to prevent outbreaks of dog rabies  

Microsoft Academic Search

WHO recommends that 70% of dogs in a population should be immunized to eliminate or prevent outbreaks of rabies. This critical percentage (pc) has been established empirically from observations on the relationship between vaccination coverage and rabies incidence in dog populations around the world. Here, by contrast, we estimate pc by using epidemic theory, together with data available from four

Paul G. Coleman; Christopher Dye

1996-01-01

46

Preventing dengue through mobile phones: evidence from a field experiment in Peru.  

PubMed

Dengue is the most rapidly spreading mosquito-borne viral disease in the world (WHO, 2009). During the last two decades, the dramatic rise in the number of dengue infections has been particularly evident in Latin American and the Caribbean countries. This paper examines the experimental evidence of the effectiveness of mobile phone technology in improving households' health preventive behavior in dengue-endemic areas. The main results suggest that repeated exposure to health information encourages households' uptake of preventive measures against dengue. As a result, the Breteau Index in treatment households, an objective measure of dengue risk transmission, is 0.10 standard deviations below the mean of the control group, which shows a reduction in the number of containers per household that test positive for dengue larvae. The estimates also show marginally significant effects of the intervention on self-reported dengue symptoms. Moreover, we use a multiple treatment framework that randomly assigns households to one of the four treatment groups in order to analyze the impacts of framing on health behavior. Different variants emphasized information on monetary and non-monetary benefits and costs. The main results show no statistical differences among treatment groups. PMID:24681813

Dammert, Ana C; Galdo, Jose C; Galdo, Virgilio

2014-05-01

47

Community participation in the prevention and control of dengue: the patio limpio strategy in Mexico  

PubMed Central

Community participation is vital to prevent and control the spread of dengue in Latin America. Initiatives such as the integrated management strategy for dengue prevention and control (IMS-Dengue) and integrated vector management (IVM) incorporate social mobilisation and behavioural change at the community level as part of a wider strategy to control dengue. These strategies aim to improve the efficacy, cost-effectiveness, environmental impact and sustainability of vector control strategies. Community empowerment is a key aspect of the strategy as it allows the local population to drive eradication of the disease in their environment. Through the patio limpio campaign, the concept of community participation has been employed in Mexico to raise awareness of the consequences of dengue. Patio limpio consists of training local people to identify, eliminate, monitor and evaluate vector breeding sites systematically in households under their supervision. A community participation programme in Guerrero State found that approximately 54% were clean and free of breeding sites. Households that were not visited and assessed had a 2·4-times higher risk of developing dengue than those that were. However, after a year, only 30% of trained households had a clean backyard. This emphasises the need for a sustainable process to encourage individuals to maintain efforts in keeping their environment free of dengue. PMID:22668443

Tapia-Conyer, Roberto; Mendez-Galvan, Jorge; Burciaga-Zuniga, Pierre

2012-01-01

48

Community participation in the prevention and control of dengue: the patio limpio strategy in Mexico.  

PubMed

Community participation is vital to prevent and control the spread of dengue in Latin America. Initiatives such as the integrated management strategy for dengue prevention and control (IMS-Dengue) and integrated vector management (IVM) incorporate social mobilisation and behavioural change at the community level as part of a wider strategy to control dengue. These strategies aim to improve the efficacy, cost-effectiveness, environmental impact and sustainability of vector control strategies. Community empowerment is a key aspect of the strategy as it allows the local population to drive eradication of the disease in their environment. Through the patio limpio campaign, the concept of community participation has been employed in Mexico to raise awareness of the consequences of dengue. patio limpio consists of training local people to identify, eliminate, monitor and evaluate vector breeding sites systematically in households under their supervision. A community participation programme in Guerrero State found that approximately 54% were clean and free of breeding sites. Households that were not visited and assessed had a 2·4-times higher risk of developing dengue than those that were. However, after a year, only 30% of trained households had a clean backyard. This emphasises the need for a sustainable process to encourage individuals to maintain efforts in keeping their environment free of dengue. PMID:22668443

Tapia-Conyer, Roberto; Méndez-Galván, Jorge; Burciaga-Zúñiga, Pierre

2012-05-01

49

Dengue Outbreaks in High-Income Area, Kaohsiung City, Taiwan, 2003-2009  

PubMed Central

Kaohsiung City, a modern metropolis of 1.5 million persons, has been the focus of dengue virus activity in Taiwan for several decades. The aim of this study was to provide a temporal and spatial description of dengue virus epidemiology in Kaohsiung City by using data for all laboratory-confirmed dengue cases during 2003–2009. We investigated age- and sex-dependent incidence rates and the spatiotemporal patterns of all cases confirmed through passive or active surveillance. Elderly persons were at particularly high risk for dengue virus–related sickness and death. Of all confirmed cases, ?75% were detected through passive surveillance activities; case-patients detected through active surveillance included immediate family members, neighbors, and colleagues of confirmed case-patients. Changing patterns of case clustering could be due to the effect of unmeasured environmental and demographic factors. PMID:23017369

Schi?ler, Karin L.; Jepsen, Martin R.; Ho, Chi-Kung; Li, Shu-Hua; Konradsen, Flemming

2012-01-01

50

Effect of community participation on household environment to mitigate dengue transmission in Thailand.  

PubMed

Due to the absence of dengue vaccination, vector control is the only measure to prevent dengue outbreaks. The key element of dengue prevention is to eliminate vector habitats. Clean household environment, preventive behaviors of household members and community participation in dengue prevention and control are key successful elements. This study aimed to investigate the associations between environmental factors, dengue knowledge, perception and preventive behaviors of household and collaboration of community members and household risk of dengue by using mixed methods. One dengue epidemic province was selected from each region of Thailand including Bangkok. Two districts, one from the highest and another from the lowest dengue incidence areas, were selected from those provinces. The household leaders, community members, and local authorities in highest dengue incidence areas were interviewed by using questionnaire and through group interviews. The environment of each selected household was observed. Of 4,561 households, 194 were reported having dengue case(s) in the past year and that outdoor solid waste disposal significantly influenced household risk of dengue (OR=1.62; 95% CI=1.16-2.29). In contrast, having gardening areas reduced dengue risk at household level by 32%. High level of community participation in dengue prevention and control in uninfected areas and the information from local authorities and community members reconfirmed that community participation was the key factor against dengue outbreaks. Sustainable process of encouraging community members to eliminate vector breeding sites such as outdoor solid waste disposal is likely to lead to an achievement in dengue prevention and control. PMID:24862055

Suwannapong, N; Tipayamongkholgul, M; Bhumiratana, A; Boonshuyar, C; Howteerakul, N; Poolthin, S

2014-03-01

51

Return of Epidemic Dengue in the United States: Implications for the Public Health Practitioner  

PubMed Central

Conditions that facilitate sustained dengue transmission exist in the United States, and outbreaks have occurred during the past decade in Texas, Hawaii, and Florida. More outbreaks can also be expected in years to come. To combat dengue, medical and public health practitioners in areas with mosquito vectors that are competent to transmit the virus must be aware of the threat of reemergent dengue, and the need for early reporting and control to reduce the impact of dengue outbreaks. Comprehensive dengue control includes human and vector surveillance, vector management programs, and community engagement efforts. Public health, medical, and vector-control communities must collaborate to prevent and control disease spread. Policy makers should understand the role of mosquito abatement and community engagement in the prevention and control of the disease. PMID:22547856

Bouri, Nidhi; Sell, Tara Kirk; Franco, Crystal; Adalja, Amesh A.; Henderson, D.A.; Hynes, Noreen A.

2012-01-01

52

75 FR 34146 - Draft Guideline for the Prevention and Control of Norovirus Gastroenteritis Outbreaks in...  

Federal Register 2010, 2011, 2012, 2013

...AND HUMAN SERVICES Centers for Disease Control and Prevention Draft Guideline for the Prevention and Control of Norovirus Gastroenteritis Outbreaks...Settings AGENCY: Centers for Disease Control and Prevention (CDC), Department...

2010-06-16

53

Management of animal botulism outbreaks: from clinical suspicion to practical countermeasures to prevent or minimize outbreaks.  

PubMed

Botulism is a severe neuroparalytic disease that affects humans, all warm-blooded animals, and some fishes. The disease is caused by exposure to toxins produced by Clostridium botulinum and other botulinum toxin-producing clostridia. Botulism in animals represents a severe environmental and economic concern because of its high mortality rate. Moreover, meat or other products from affected animals entering the food chain may result in a public health problem. To this end, early diagnosis is crucial to define and apply appropriate veterinary public health measures. Clinical diagnosis is based on clinical findings eliminating other causes of neuromuscular disorders and on the absence of internal lesions observed during postmortem examination. Since clinical signs alone are often insufficient to make a definitive diagnosis, laboratory confirmation is required. Botulinum antitoxin administration and supportive therapies are used to treat sick animals. Once the diagnosis has been made, euthanasia is frequently advisable. Vaccine administration is subject to health authorities' permission, and it is restricted to a small number of animal species. Several measures can be adopted to prevent or minimize outbreaks. In this article we outline all phases of management of animal botulism outbreaks occurring in wet wild birds, poultry, cattle, horses, and fur farm animals. PMID:23971806

Anniballi, Fabrizio; Fiore, Alfonsina; Löfström, Charlotta; Skarin, Hanna; Auricchio, Bruna; Woudstra, Cédric; Bano, Luca; Segerman, Bo; Koene, Miriam; Båverud, Viveca; Hansen, Trine; Fach, Patrick; Tevell Aberg, Annica; Hedeland, Mikael; Olsson Engvall, Eva; De Medici, Dario

2013-09-01

54

A phylogenetic analysis using full-length viral genomes of South American dengue serotype 3 in consecutive Venezuelan outbreaks reveals novel NS5 mutation  

PubMed Central

Dengue virus currently causes 50-100 million infections annually. Comprehensive knowledge about the evolution of Dengue in response to selection pressure is currently unavailable, but would greatly enhance vaccine design efforts. In the current study, we sequenced 187 new dengue virus serotype 3(DENV-3) genotype III whole genomes isolated from Asia and the Americas. We analyzed them together with previously-sequenced isolates to gain a more detailed understanding of the evolutionary adaptations existing in this prevalent American serotype. In order to analyze the phylogenetic dynamics of DENV-3 during outbreak periods; we incorporated datasets of 48 and 11 sequences spanning two major outbreaks in Venezuela during 2001 and 2007-2008 respectively. Our phylogenetic analysis of newly sequenced viruses shows that subsets of genomes cluster primarily by geographic location, and secondarily by time of virus isolation. DENV-3 genotype III sequences from Asia are significantly divergent from those from the Americas due to their geographical separation and subsequent speciation. We measured amino acid variation for the E protein by calculating the Shannon entropy at each position between Asian and American genomes. We found a cluster of 7 amino acid substitutions having high variability within E protein domain III, which has previously been implicated in serotype-specific neutralization escape mutants. No novel mutations were found in the E protein of sequences isolated during either Venezuelan outbreak. Shannon entropy analysis of the NS5 polymerase mature protein revealed that a G374E mutation, in a region that contributes to interferon resistance in other flaviviruses by interfering with JAK-STAT signaling was present in both the Asian and American sequences from the 2007-2008 Venezuelan outbreak, but was absent in the sequences from the 2001 Venezuelan outbreak. In addition to E, several NS5 amino acid changes were unique to the 2007-2008 epidemic in Venezuela and may give additional insight into the adaptive response of DENV-3 at the population level. PMID:21964598

Schmidt, DJ; Pickett, BE; Camacho, D; Comach, G; Xhaja, K; Lennon, NJ; Rizzolo, K; de Bosch, N; Becerra, A; Nogueira, ML; Mondini, A; da Silva, EV; Vasconcelos, PF; Munoz-Jordan, JL; Santiago, GA; Ocazionez, R; Gehrke, L; Lefkowitz, EJ; Birren, BW; Henn, MR; Bosch, I

2013-01-01

55

A phylogenetic analysis using full-length viral genomes of South American dengue serotype 3 in consecutive Venezuelan outbreaks reveals a novel NS5 mutation.  

PubMed

Dengue virus currently causes 50-100 million infections annually. Comprehensive knowledge about the evolution of Dengue in response to selection pressure is currently unavailable, but would greatly enhance vaccine design efforts. In the current study, we sequenced 187 new dengue virus serotype 3 (DENV-3) genotype III whole genomes isolated from Asia and the Americas. We analyzed them together with previously-sequenced isolates to gain a more detailed understanding of the evolutionary adaptations existing in this prevalent American serotype. In order to analyze the phylogenetic dynamics of DENV-3 during outbreak periods; we incorporated datasets of 48 and 11 sequences spanning two major outbreaks in Venezuela during 2001 and 2007-2008, respectively. Our phylogenetic analysis of newly sequenced viruses shows that subsets of genomes cluster primarily by geographic location, and secondarily by time of virus isolation. DENV-3 genotype III sequences from Asia are significantly divergent from those from the Americas due to their geographical separation and subsequent speciation. We measured amino acid variation for the E protein by calculating the Shannon entropy at each position between Asian and American genomes. We found a cluster of seven amino acid substitutions having high variability within E protein domain III, which has previously been implicated in serotype-specific neutralization escape mutants. No novel mutations were found in the E protein of sequences isolated during either Venezuelan outbreak. Shannon entropy analysis of the NS5 polymerase mature protein revealed that a G374E mutation, in a region that contributes to interferon resistance in other flaviviruses by interfering with JAK-STAT signaling was present in both the Asian and American sequences from the 2007-2008 Venezuelan outbreak, but was absent in the sequences from the 2001 Venezuelan outbreak. In addition to E, several NS5 amino acid changes were unique to the 2007-2008 epidemic in Venezuela and may give additional insight into the adaptive response of DENV-3 at the population level. PMID:21964598

Schmidt, D J; Pickett, B E; Camacho, D; Comach, G; Xhaja, K; Lennon, N J; Rizzolo, K; de Bosch, N; Becerra, A; Nogueira, M L; Mondini, A; da Silva, E V; Vasconcelos, P F; Muñoz-Jordán, J L; Santiago, G A; Ocazionez, R; Gehrke, L; Lefkowitz, E J; Birren, B W; Henn, M R; Bosch, I

2011-12-01

56

Beyond compliance: environmental health problem solving, interagency collaboration, and risk assessment to prevent waterborne disease outbreaks  

Microsoft Academic Search

A systems approach to environmental health problem solving was used to investigate two waterborne norovirus outbreaks in Wyoming and can serve in the development of improved prevention strategies. An interagency collaboration to prevent waterborne disease involving local, state, and federal partners was designed to coordinate response to outbreak investigations. Improved risk assessment and reporting procedures were also integrated to ensure

Joslyn D Cassady; Charles Higgins; Hugh M Mainzer; Scott A Seys; John Sarisky; Myfanwy Callahan; Karl J Musgrave

2006-01-01

57

Knowledge, perceptions, and practices with respect to the prevention of dengue in a mid-Pacific coastal village of Costa Rica.  

PubMed

Dengue fever is the fastest spreading, most prevalent and deadly arthropod-borne viral disease worldwide, present in over 125 countries. In 2013, Costa Rica is experiencing the highest number of Dengue infections since the virus's reintroduction to the country in 1993. This study evaluated the Dengue-related knowledge of 320 community members, and polled opinions on how to better educate and mobilize the community on Dengue prevention in Quebrada Ganado, Costa Rica during March-May, 2013. In addition, property inspections were used to find relationships between knowledge or opinions and presence ofAedes breeding sites. Results showed that while citizens knew the virus is transmitted by mosquitoes that reproduce near water, they lacked knowledge on Aedes habits and confused it with other mosquitoes. Eighty-one percent of respondents assumed some responsibility for dengue prevention. Suggestions for improved education included consistent and continual information on the risks and dangers dengue poses to an individual. Characteristics relating to households with more positive breeding sites were: lower education level, higher prevalence of dengue infections in the household, lesser knowledge of dengue symptoms, a lower rating on the dangers of dengue and a lower rating on the importance of preventative actions. While a range of prevention methods are implemented, active community involvement is highly important for successful Dengue prevention. Continual evaluation is necessary to make more immediate, long-term behavioral societal changes, and to maximize the economic resources spent on Dengue prevention. PMID:25412518

Egedus, Victoria L; Ortega, José Morales; Obando, Anabelle Alfaro

2014-09-01

58

NS1 Antigen Capture ELISA an Effective Method for Diagnosis of Early Dengue Infection - Report of an Outbreak at Angul District, Odisha, India  

PubMed Central

Background: An outbreak of dengue infection occurred in Angul district of Odisha in the month of August & September, 2011. The study was undertaken to detect NS1 antigen positivity among the study population, to compare IgM capture ELISA with NS1 antigen detection for diagnosis of dengue and to identify the predominant genotype of Dengue virus responsible for the outbreak. Materials and Methods: Total 1020 serum samples were collected from clinically suspected cases of dengue from the outbreak. All were subjected for NS1 antigen detection, 92 were selected based on their clinical severity of illness (fever, rash, bleeding manifestation, arthralgia) for further study of IgM ELISA and platelet count and 148 NS1 positive samples were selected from different Blocks of Anugul district for RT-PCR at NIV, Pune, India. Results: Five hundred and thirteen (50.2%) samples were positive for NS1 antigen (highly significant p-value <0.0001, C.I - 95%) with 88% positivity during 1-5 days. The NS1 Ag positivity was peaked to 86.9% on days 3 to 5 (Sensitivity & NPV - 100% each) & declined to 6.2% during 6-10 days with a low sensitivity of 7.14% but 100% specificity & PPV. However, the IgM antibody positivity was 81.2% on days 6 to 10 and 87.5% after 10 days (Sensitivity- 100%, Specificity-13.33%,PPV-7.14% & NPV - 100%). RT-PCR resulted 32.4% positivity (6- DEN1, 39 - DEN 2 & 3- DEN 3) among which 20% were in IgM +ve & 68% in IgM -ve cases. Conclusion: Therefore, early diagnosis of dengue could be mainly by NS1 antigen detection whereas Ig M ELISA is a better tool during the later stage of infection &RT-PCR is more effective in IgM -ve cases.The predominant genotype responsible for the outbreak was found to be DEN-2.

Mahapatra, Dharitri; Sarangi, Gitanjali; Paty, Bimoch Projna; Das, Padma; Chayani, Nirupama

2014-01-01

59

Outbreak!  

NSDL National Science Digital Library

Outbreak! is an online, interactive educational game that helps students and teachers learn and evaluate clinical microbiology skills. When the game was used in introductory microbiology laboratories, qualitative evaluation by students showed very positiv

Smith, Geoffrey B.; Clark, Sherri

2004-09-01

60

Dengue fever mimicking acute appendicitis: A case report?  

PubMed Central

INTRODUCTION Dengue fever is an acute viral disease, which usually presents as a mild febrile illness. Patients with severe disease present with dengue haemorrhagic fever or dengue toxic shock syndrome. Rarely, it presents with abdominal symptoms mimicking acute appendicitis. We present a case of a male patient presenting with right iliac fossa pain and suspected acute appendicitis that was later diagnosed with dengue fever following a negative appendicectomy. PRESENTATION OF CASE A 13-year old male patient presented with fever, localized right-sided abdominal pain and vomiting. Abdominal ultrasound was not helpful and appendicectomy was performed due to worsening abdominal signs and an elevated temperature. A normal appendix with enlarged mesenteric nodes was found at surgery. Complete blood count showed thrombocytopenia with leucopenia. Dengue fever was now suspected and confirmed by IgM enzyme-linked immunosorbent assay against dengue virus. DISCUSSION This unusual presentation of dengue fever mimicking acute appendicitis should be suspected during viral outbreaks and in patients with atypical symptoms and cytopenias on blood evaluation in order to prevent unnecessary surgery. CONCLUSION This case highlights the occurrence of abdominal symptoms and complications that may accompany dengue fever. Early recognition of dengue fever mimicking acute appendicitis will avoid non-therapeutic operation and the diagnosis may be aided by blood investigations indicating a leucopenia, which is uncommon in patients with suppurative acute appendicitis. PMID:24096347

Mcfarlane, M.E.C.; Plummer, J.M.; Leake, P.A.; Powell, L.; Chand, V.; Chung, S.; Tulloch, K.

2013-01-01

61

Epidemic dengue transmission in southern Sumatra, Indonesia  

Microsoft Academic Search

An outbreak of dengue fever (DF), dengue haemorrhagic fever (DHF), and dengue shock syndrome (DSS) in the city of Palembang, south Sumatra, Indonesia was investigated to (i) validate epidemic occurrence, (ii) confirm dengue virus aetiology and associated serotype(s), (iii) provide a demonstrable measure of community impact, and (iv) identify causative relationship (if any) with climatic El Niño Southern Oscillation (ENSO)

Andrew Lee Corwin; Ria Purwita Larasati; Michael J. Bangs; Suharyono Wuryadi; Sumarjati Arjoso; Nono Sukri; Erlin Listyaningsih; Sri Hartati; Rozali Namursa; Zarkasih Anwar; Surya Chandra; Benny Loho; Holani Ahmad; James R. Campbell; Kevin R. Porter

2001-01-01

62

Forecast of Dengue Incidence Using Temperature and Rainfall  

PubMed Central

Introduction An accurate early warning system to predict impending epidemics enhances the effectiveness of preventive measures against dengue fever. The aim of this study was to develop and validate a forecasting model that could predict dengue cases and provide timely early warning in Singapore. Methodology and Principal Findings We developed a time series Poisson multivariate regression model using weekly mean temperature and cumulative rainfall over the period 2000–2010. Weather data were modeled using piecewise linear spline functions. We analyzed various lag times between dengue and weather variables to identify the optimal dengue forecasting period. Autoregression, seasonality and trend were considered in the model. We validated the model by forecasting dengue cases for week 1 of 2011 up to week 16 of 2012 using weather data alone. Model selection and validation were based on Akaike's Information Criterion, standardized Root Mean Square Error, and residuals diagnoses. A Receiver Operating Characteristics curve was used to analyze the sensitivity of the forecast of epidemics. The optimal period for dengue forecast was 16 weeks. Our model forecasted correctly with errors of 0.3 and 0.32 of the standard deviation of reported cases during the model training and validation periods, respectively. It was sensitive enough to distinguish between outbreak and non-outbreak to a 96% (CI?=?93–98%) in 2004–2010 and 98% (CI?=?95%–100%) in 2011. The model predicted the outbreak in 2011 accurately with less than 3% possibility of false alarm. Significance We have developed a weather-based dengue forecasting model that allows warning 16 weeks in advance of dengue epidemics with high sensitivity and specificity. We demonstrate that models using temperature and rainfall could be simple, precise, and low cost tools for dengue forecasting which could be used to enhance decision making on the timing, scale of vector control operations, and utilization of limited resources. PMID:23209852

Hii, Yien Ling; Zhu, Huaiping; Ng, Nawi; Ng, Lee Ching; Rocklov, Joacim

2012-01-01

63

CD8+ T cells prevent antigen-induced antibody-dependent enhancement of dengue disease in mice.  

PubMed

Dengue virus (DENV) causes pathologies ranging from the febrile illness dengue fever to the potentially lethal severe dengue disease. A major risk factor for developing severe dengue disease is the presence of subprotective DENV-reactive Abs from a previous infection (or from an immune mother), which can induce Ab-dependent enhancement of infection (ADE). However, infection in the presence of subprotective anti-DENV Abs does not always result in severe disease, suggesting that other factors influence disease severity. In this study we investigated how CD8(+) T cell responses influence the outcome of Ab-mediated severe dengue disease. Mice were primed with aluminum hydroxide-adjuvanted UV-inactivated DENV prior to challenge with DENV. Priming failed to induce robust CD8(+) T cell responses, and it induced nonneutralizing Ab responses that increased disease severity upon infection. Transfer of exogenous DENV-activated CD8(+) T cells into primed mice prior to infection prevented Ab-dependent enhancement and dramatically reduced viral load. Our results suggest that in the presence of subprotective anti-DENV Abs, efficient CD8(+) T cell responses reduce the risk of Ab-mediated severe dengue disease. PMID:25217165

Zellweger, Raphaël M; Eddy, William E; Tang, William W; Miller, Robyn; Shresta, Sujan

2014-10-15

64

Dengue viral infections  

PubMed Central

Dengue viral infections are one of the most important mosquito borne diseases in the world. They may be asymptomatic or may give rise to undifferentiated fever, dengue fever, dengue haemorrhagic fever (DHF), or dengue shock syndrome. Annually, 100 million cases of dengue fever and half a million cases of DHF occur worldwide. Ninety percent of DHF subjects are children less than 15 years of age. At present, dengue is endemic in 112 countries in the world. No vaccine is available for preventing this disease. Early recognition and prompt initiation of appropriate treatment are vital if disease related morbidity and mortality are to be limited. This review outlines aspects of the epidemiology of dengue infections, the dengue virus and its mosquito vector, clinical features and pathogenesis of dengue infections, and the management and control of these infections. PMID:15466994

Malavige, G; Fernando, S; Fernando, D; Seneviratne, S

2004-01-01

65

Use of Insecticide-Treated School Uniforms for Prevention of Dengue in Schoolchildren: A Cost-Effectiveness Analysis  

PubMed Central

Background Dengue-related illness is a leading cause of hospitalization and death, particularly among children. Practical, acceptable and affordable measures are urgently needed to protect this age group. Schools where children spend most of their day is proposed as an ideal setting to implement preventive strategies against day-biting Aedes mosquitoes. The use of insecticide-treated school uniforms is a promising strategy currently under investigation. Methods Using a decision-analytic model, we evaluated the cost-effectiveness of the use of insecticide-treated school uniforms for prevention of dengue, compared with a “do-nothing” alternative, in schoolchildren from the societal perspective. We explored how the potential economic value of the intervention varied under various scenarios of intervention effectiveness and cost, as well as dengue infection risk in school-aged children, using data specific to Thailand. Results At an average dengue incidence rate of 5.8% per year in school-aged children, the intervention was cost-effective (ICER?$16,440) in a variety of scenarios when the intervention cost per child was $5.3 or less and the intervention effectiveness was 50% or higher. In fact, the intervention was cost saving (ICER<0) in all scenarios in which the intervention cost per child was $2.9 or less per year and the intervention effectiveness was 50% or higher. The results suggested that this intervention would be of no interest to Thai policy makers when the intervention cost per child was $10.6 or higher per year regardless of intervention effectiveness (ICER>$16,440). Conclusions Our results present the potential economic value of the use of insecticide-treated uniforms for prevention of dengue in schoolchildren in a typical dengue endemic setting and highlight the urgent need for additional research on this intervention. PMID:25247556

Tozan, Yesim; Ratanawong, Pitcha; Louis, Valerie R.; Kittayapong, Pattamaporn; Wilder-Smith, Annelies

2014-01-01

66

Myanmar Migrant Woman Caretakers on Prevention of Dengue fever: A Study on Knowledge, Attitude and Practices in Tak Province, Thailand  

Microsoft Academic Search

A cross-sectional survey was conducted to assess the knowledge, attitudes about, and practices to prevent, dengue fever among Myanmar migrant woman caretakers in Mae Sot District, Tak Province, Thailand during January 2004. In total, 307 households out of 1,014 Myanmar migrant households in Mae Sot District were selected using systematic random sampling. One woman caretaker per household was interviewed using

Hmwe Hmwe Kyu; Myint Thu; Marc Van der Putten

67

Large Outbreak Caused by Methicillin Resistant Staphylococcus pseudintermedius ST71 in a Finnish Veterinary Teaching Hospital - From Outbreak Control to Outbreak Prevention  

PubMed Central

Introduction The purpose of this study was to describe a nosocomial outbreak caused by methicillin resistant Staphylococcus pseudintermedius (MRSP) ST71 SCCmec II-III in dogs and cats at the Veterinary Teaching Hospital of the University of Helsinki in November 2010 – January 2012, and to determine the risk factors for acquiring MRSP. In addition, measures to control the outbreak and current policy for MRSP prevention are presented. Methods Data of patients were collected from the hospital patient record software. MRSP surveillance data were acquired from the laboratory information system. Risk factors for MRSP acquisition were analyzed from 55 cases and 213 controls using multivariable logistic regression in a case-control study design. Forty-seven MRSP isolates were analyzed by pulsed field gel electrophoresis and three were further analyzed with multi-locus sequence and SCCmec typing. Results Sixty-three MRSP cases were identified, including 27 infections. MRSPs from the cases shared a specific multi-drug resistant antibiogram and PFGE-pattern indicated clonal spread. Four risk factors were identified; skin lesion (OR?=?6.2; CI95% 2.3–17.0, P?=?0.0003), antimicrobial treatment (OR?=?3.8, CI95% 1.0–13.9, P?=?0.0442), cumulative number of days in the intensive care unit (OR?=?1.3, CI95% 1.1–1.6, P?=?0.0007) or in the surgery ward (OR?=?1.1, CI95% 1.0–1.3, P?=?0.0401). Tracing and screening of contact patients, enhanced hand hygiene, cohorting and barrier nursing, as well as cleaning and disinfection were used to control the outbreak. To avoid future outbreaks and spread of MRSP a search-and-isolate policy was implemented. Currently nearly all new MRSP findings are detected in screening targeted to risk patients on admission. Conclusion Multidrug resistant MRSP is capable of causing a large outbreak difficult to control. Skin lesions, antimicrobial treatment and prolonged hospital stay increase the probability of acquiring MRSP. Rigorous control measures were needed to control the outbreak. We recommend the implementation of a search-and-isolate policy to reduce the burden of MRSP. PMID:25333798

Gronthal, Thomas; Moodley, Arshnee; Nykasenoja, Suvi; Junnila, Jouni; Guardabassi, Luca; Thomson, Katariina; Rantala, Merja

2014-01-01

68

Clinical, Molecular, and Epidemiological Analysis of Dengue Cases during a Major Outbreak in the Midwest Region of Minas Gerais, Brazil  

PubMed Central

This study aims to perform the first molecular and clinical-epidemiological analysis of dengue cases in Divinopolis, MG, Brazil. Data from 4,110 cases of dengue were accessed and 190 clinical samples were collected for molecular analyses. In this study, 2.7% of the men and 3.0% of the women were admitted to hospital. There was no association between gender and hospital admission. The symptoms observed in this study are according to the Health Ministry, but fever was present in 82.2% and not in 100% of cases. The chance of hospital admission was 1.55 higher in patients with any kind of bleeding (334) and 2.4% of individuals without bleeding were also hospitalized due to other warning signs. In the molecular analyses, 23% of the samples were positive for DENV. DENV-2 and DENV-3 were identified in 2010, DENV-3 in 2011, DENV-1 in 2012, and DENV-1 and DENV-4 in 2013. DENV detection was possible in samples with only one day of symptoms. This first report of dengue data in Divinópolis provided more insight into the viral types and effects of disease in the city, confirming the need for caution in assessing cases of suspected dengue and for revision of the criteria proposed by the Health Ministry to classify cases of the disease. PMID:25120572

Braga, Juliana Cristina Duarte; da Silva, Leandro Cesar; Tiburcio, Jacqueline Domingues; Silva, Mirna de Abreu e; Pereira, Lailah Horacio Sales; Dutra, Karina Rocha; Ferreira, Jaqueline Maria Siqueira; Lopes, Debora de Oliveira; dos Santos, Luciana Lara

2014-01-01

69

Beyond compliance: environmental health problem solving, interagency collaboration, and risk assessment to prevent waterborne disease outbreaks  

PubMed Central

A systems approach to environmental health problem solving was used to investigate two waterborne norovirus outbreaks in Wyoming and can serve in the development of improved prevention strategies. An interagency collaboration to prevent waterborne disease involving local, state, and federal partners was designed to coordinate response to outbreak investigations. Improved risk assessment and reporting procedures were also integrated to ensure better availability of necessary data. Public health entities should implement sustainable intersectoral interventions to prevent waterborne disease that not only improve regulatory compliance but also have a positive impact on community health outcomes. Collaborative preventive health and water system protection activities should receive priority attention for implementation in state and local jurisdictions. PMID:16840755

Cassady, Joslyn D; Higgins, Charles; Mainzer, Hugh M; Seys, Scott A; Sarisky, John; Callahan, Myfanwy; Musgrave, Karl J

2006-01-01

70

Time series analysis of dengue incidence in Guadeloupe, French West Indies: Forecasting models using climate variables as predictors  

PubMed Central

Background During the last decades, dengue viruses have spread throughout the Americas region, with an increase in the number of severe forms of dengue. The surveillance system in Guadeloupe (French West Indies) is currently operational for the detection of early outbreaks of dengue. The goal of the study was to improve this surveillance system by assessing a modelling tool to predict the occurrence of dengue epidemics few months ahead and thus to help an efficient dengue control. Methods The Box-Jenkins approach allowed us to fit a Seasonal Autoregressive Integrated Moving Average (SARIMA) model of dengue incidence from 2000 to 2006 using clinical suspected cases. Then, this model was used for calculating dengue incidence for the year 2007 compared with observed data, using three different approaches: 1 year-ahead, 3 months-ahead and 1 month-ahead. Finally, we assessed the impact of meteorological variables (rainfall, temperature and relative humidity) on the prediction of dengue incidence and outbreaks, incorporating them in the model fitting the best. Results The 3 months-ahead approach was the most appropriate for an effective and operational public health response, and the most accurate (Root Mean Square Error, RMSE = 0.85). Relative humidity at lag-7 weeks, minimum temperature at lag-5 weeks and average temperature at lag-11 weeks were variables the most positively correlated to dengue incidence in Guadeloupe, meanwhile rainfall was not. The predictive power of SARIMA models was enhanced by the inclusion of climatic variables as external regressors to forecast the year 2007. Temperature significantly affected the model for better dengue incidence forecasting (p-value = 0.03 for minimum temperature lag-5, p-value = 0.02 for average temperature lag-11) but not humidity. Minimum temperature at lag-5 weeks was the best climatic variable for predicting dengue outbreaks (RMSE = 0.72). Conclusion Temperature improves dengue outbreaks forecasts better than humidity and rainfall. SARIMA models using climatic data as independent variables could be easily incorporated into an early (3 months-ahead) and reliably monitoring system of dengue outbreaks. This approach which is practicable for a surveillance system has public health implications in helping the prediction of dengue epidemic and therefore the timely appropriate and efficient implementation of prevention activities. PMID:21658238

2011-01-01

71

Preventing diseases and outbreaks at child care centers using an education, evaluation, and inspection method.  

PubMed

From 2005 to 2008, Washoe County, Nevada, child care centers experienced an increase in illnesses from communicable disease outbreaks. The number of ill children and caregivers from these outbreaks went from 26 in 2005 to 266 in 2008, an increase of 923%. A clear need to reverse this trend existed. Therefore, in 2009 Washoe County strengthened its regulations for child care facilities by adding numerous communicable disease prevention standards. In addition, in 2009 a two-year education, evaluation, and inspection program was implemented at Washoe County child care centers. Following the implementation of this program, a decline occurred in the number of illnesses. The number of ill children and caregivers from outbreaks went from 266 in 2008 to 13 in 2011, a decrease of 95%. PMID:24683935

Wagner, Jordan; Clodfelter, Sharon

2014-03-01

72

Prevention of Dengue Fever: An Exploratory School-Community Intervention Involving Students Empowered as Change Agents  

ERIC Educational Resources Information Center

Background: Dengue fever and dengue hemorrhagic fever (DF/DHF) are epidemic and endemic in tropical and subtropical countries including Sri Lanka. Numerous structural and community interventions have been shown to be effective in interrupting the life cycle of mosquitoes that transmit DF/DHF; however, these interventions are not always implemented…

Jayawardene, Wasantha P.; Lohrmann, David K.; YoussefAgha, Ahmed H.; Nilwala, Dayani C.

2011-01-01

73

The Prevalence and Endemic Nature of Dengue Infections in Guangdong, South China: An Epidemiological, Serological, and Etiological Study from 2005-2011  

PubMed Central

Objectives Frequent outbreaks of dengue are considered to be associated with an increased risk for endemicity of the disease. The occurrence of a large number of indigenous dengue cases in consecutive years indicates the possibility of a changing dengue epidemic pattern in Guangdong, China. Methods To have a clear understanding of the current dengue epidemic, a retrospective study of epidemiological profile, serological response, and virological features of dengue infections from 2005–2011 was conducted. Case data were collected from the National Notifiable Infectious Diseases Reporting Network. Serum samples were collected and prepared for serological verification and etiological confirmation. Incidence, temporal and spatial distribution, and the clinical manifestation of dengue infections were analyzed. Pearson's Chi-Square test was used to compare incidences between different age groups. A seroprevalence survey was implemented in local healthy inhabitants to obtain the overall positive rate for the specific immunoglobulin (Ig) G antibody against dengue virus (DENV). Results The overall annual incidence rate was 1.87/100000. A significant difference was found in age-specific incidence (Pearson's Chi-Square value 498.008, P<0.001). Children under 5 years of age had the lowest incidence of 0.28/100000. The vast majority of cases presented with a mild manifestation typical to dengue fever. The overall seroprevalence of dengue IgG antibody in local populations was 2.43% (range 0.28%–5.42%). DENV-1 was the predominant serotype in circulation through the years, while all 4 serotypes were identified in indigenous patients from different outbreak localities since 2009. Conclusions A gradual change in the epidemic pattern of dengue infection has been observed in recent years in Guangdong. With the endemic nature of dengue infections, the transition from a monotypic to a multitypic circulation of dengue virus in the last several years will have an important bearing on the prevention and control of dengue in the province and in the neighboring districts. PMID:24465613

Guo, Ru-ning; Lin, Jin-yan; Li, Lin-hui; Ke, Chang-wen; He, Jian-feng; Zhong, Hao-jie; Zhou, Hui-qiong; Peng, Zhi-qiang; Yang, Fen; Liang, Wen-jia

2014-01-01

74

Dengue fever in the Indian Subcontinent: an overview.  

PubMed

The Indian Subcontinent has emerged as a scene of many mosquito-borne infectious diseases, including malaria and dengue fever. After the 1990s, the rate of malaria declined owing largely to preventive measures, but at the same time dengue fever (DF) and dengue hemorrhagic fever (DHF) were increasing in the region. Outbreaks were recorded in all countries of the Indian Subcontinent with India, Pakistan, Bangladesh and Sri Lanka on the forefront and suffering from the largest number of cases and deaths. We discuss annual cases of DF/DHF in these four countries and possible factors involved in DF outbreaks. We also discuss prevalent serotypes in this region where data suggest the emergence of DEN2 and DEN3 as the most dominant and lethal serotypes. Climate is an important factor influencing DF outbreaks, and rainfall, temperature and humidity play a pivotal role in DF outbreaks. Finally the economic impact of DF/DHF cases is discussed showing that direct and indirect economic loss due to DF/DHF reaches millions of USD each year. PMID:21537064

Raheel, Ummar; Faheem, Muhammad; Riaz, Mohammad Nasir; Kanwal, Naghmana; Javed, Farakh; Zaidi, Najam us Sahar Sadaf; Qadri, Ishtiaq

2011-04-01

75

Post-dengue parkinsonism  

PubMed Central

Background Dengue is a common illness in the tropics. Equally common are neurological complications that stem from dengue infection. However, to date, parkinsonism following dengue has not been reported in medical literature. Case presentation A previously well 18-year old man developed parkinsonism, in addition to other neurological symptoms following serologically confirmed dengue fever. Alternative etiologies were excluded by way of imaging and blood investigations. Conclusions The authors detail the first reported case of parkinsonism complicating dengue fever. Keeping rare presentations of common illnesses in mind, it behoves clinicians to consider parkinsonism as a complication following dengue infection. This would prevent injudicious treatment with L-dopa and dopamine agonists. Immunosuppression with steroids has been shown to be helpful in certain cases. PMID:23594500

2013-01-01

76

A portable approach for the surveillance of dengue virus-infected mosquitoes.  

PubMed

Dengue virus is the most significant human viral pathogen spread by the bite of an infected mosquito. With no vaccine or antiviral therapy currently available, disease prevention relies largely on surveillance and mosquito control. Preventing the onset of dengue outbreaks and effective vector management would be considerably enhanced through surveillance of dengue virus prevalence in natural mosquito populations. However, current approaches to the identification of virus in field-caught mosquitoes require relatively slow and labor intensive techniques such as virus isolation or RT-PCR involving specialized facilities and personnel. A rapid and portable method for detecting dengue virus-infected mosquitoes is described. Using a hand held battery operated homogenizer and a dengue diagnostic rapid strip the viral protein NS1 was detected as a marker of dengue virus infection. This method could be performed in less than 30 min in the field, requiring no downstream processing, and is able to detect a single infected mosquito in a pool of at least 50 uninfected mosquitoes. The method described in this study allows rapid, real-time monitoring of dengue virus presence in mosquito populations and could be a useful addition to effective monitoring and vector control responses. PMID:22575689

Muller, David A; Frentiu, Francesca D; Rojas, Alejandra; Moreira, Luciano A; O'Neill, Scott L; Young, Paul R

2012-07-01

77

Aedes albopictus and the reemergence of Dengue.  

PubMed

Dengue is a vector-borne disease that is estimated to affect millions of individuals each year in tropical and subtropical areas, and it is reemerging in areas that have been disease-free for relatively long periods of time. In this issue of the journal, Peng et al. report on a Dengue outbreak in a city in southern China that had been disease-free for more than two decades. The infection, which was due to serotype 1, was introduced by a traveler from South-east Asia and transmitted by Aedes albopictus, the Asian tiger mosquito. Compared to Aedes aegypti, which is the most important vector of Dengue, Ae albopictus is a less competent vector of arboviruses, and the epidemics it causes are milder. However, Ae albopictus is becoming an increasingly important vector because of its rapidly changing global distribution. In particular, the worldwide trade in second hand tires, which often contain water and are an ideal place for eggs and larvae, has been a key factor in the large-scale conquest of Ae albopictus, which easily adapts to new environments, even in a temperate climate. This expansion is creating new opportunities for viruses to circulate in new areas, becoming a common cause of epidemics in Ae aegypti-free countries, from Hawaii to Mauritius. The outbreak in China, like similar events, was mild and short-lived. Because epidemics due to Ae albopictus are milder, the replacement of Ae aegypti with the tiger mosquito could even result in public-health benefits. However, there is no solid evidence of this, and the milder course of the outbreak could be in part explained by the relatively short duration of the hot season in some affected areas. Since it is almost impossible to prevent Ae albopictus from being introduced in a country, mosquito-control measures at local level remain the most effective means of controlling arbovirus outbreaks. PMID:22272602

Rezza, Giovanni

2012-01-01

78

A spatiotemporal dengue fever early warning model accounting for nonlinear associations with meteorological factors: a Bayesian maximum entropy approach  

NASA Astrophysics Data System (ADS)

Dengue fever has been identified as one of the most widespread vector-borne diseases in tropical and sub-tropical. In the last decade, dengue is an emerging infectious disease epidemic in Taiwan especially in the southern area where have annually high incidences. For the purpose of disease prevention and control, an early warning system is urgently needed. Previous studies have showed significant relationships between climate variables, in particular, rainfall and temperature, and the temporal epidemic patterns of dengue cases. However, the transmission of the dengue fever is a complex interactive process that mostly understated the composite space-time effects of dengue fever. This study proposes developing a one-week ahead warning system of dengue fever epidemics in the southern Taiwan that considered nonlinear associations between weekly dengue cases and meteorological factors across space and time. The early warning system based on an integration of distributed lag nonlinear model (DLNM) and stochastic Bayesian Maximum Entropy (BME) analysis. The study identified the most significant meteorological measures including weekly minimum temperature and maximum 24-hour rainfall with continuous 15-week lagged time to dengue cases variation under condition of uncertainty. Subsequently, the combination of nonlinear lagged effects of climate variables and space-time dependence function is implemented via a Bayesian framework to predict dengue fever occurrences in the southern Taiwan during 2012. The result shows the early warning system is useful for providing potential outbreak spatio-temporal prediction of dengue fever distribution. In conclusion, the proposed approach can provide a practical disease control tool for environmental regulators seeking more effective strategies for dengue fever prevention.

Lee, Chieh-Han; Yu, Hwa-Lung; Chien, Lung-Chang

2014-05-01

79

Quantifying the Spatial Dimension of Dengue Virus Epidemic Spread within a Tropical Urban Environment  

PubMed Central

Background Dengue infection spread in naive populations occurs in an explosive and widespread fashion primarily due to the absence of population herd immunity, the population dynamics and dispersal of Ae. aegypti, and the movement of individuals within the urban space. Knowledge on the relative contribution of such factors to the spatial dimension of dengue virus spread has been limited. In the present study we analyzed the spatio-temporal pattern of a large dengue virus-2 (DENV-2) outbreak that affected the Australian city of Cairns (north Queensland) in 2003, quantified the relationship between dengue transmission and distance to the epidemic's index case (IC), evaluated the effects of indoor residual spraying (IRS) on the odds of dengue infection, and generated recommendations for city-wide dengue surveillance and control. Methods and Findings We retrospectively analyzed data from 383 DENV-2 confirmed cases and 1,163 IRS applications performed during the 25-week epidemic period. Spatial (local k-function, angular wavelets) and space-time (Knox test) analyses quantified the intensity and directionality of clustering of dengue cases, whereas a semi-parametric Bayesian space-time regression assessed the impact of IRS and spatial autocorrelation in the odds of weekly dengue infection. About 63% of the cases clustered up to 800 m around the IC's house. Most cases were distributed in the NW-SE axis as a consequence of the spatial arrangement of blocks within the city and, possibly, the prevailing winds. Space-time analysis showed that DENV-2 infection spread rapidly, generating 18 clusters (comprising 65% of all cases), and that these clusters varied in extent as a function of their distance to the IC's residence. IRS applications had a significant protective effect in the further occurrence of dengue cases, but only when they reached coverage of 60% or more of the neighboring premises of a house. Conclusion By applying sound statistical analysis to a very detailed dataset from one of the largest outbreaks that affected the city of Cairns in recent times, we not only described the spread of dengue virus with high detail but also quantified the spatio-temporal dimension of dengue virus transmission within this complex urban environment. In areas susceptible to non-periodic dengue epidemics, effective disease prevention and control would depend on the prompt response to introduced cases. We foresee that some of the results and recommendations derived from our study may also be applicable to other areas currently affected or potentially subject to dengue epidemics. PMID:21200419

Vazquez-Prokopec, Gonzalo M.; Kitron, Uriel; Montgomery, Brian; Horne, Peter; Ritchie, Scott A.

2010-01-01

80

Reseña de una experiencia de Promoción de la Salud y Lucha contra el Dengue utilizando el control biológico, en escuelas de Chacarita, Puntarenas, Costa Rica  

Microsoft Academic Search

Both dengue fever and malaria are endemic diseases in Chacarita, Puntarenas, Costa Rica. Vector mosquitoes thrive due to poor living conditions in highly populated areas where garbage, including empty containers, accumulate and, due to high humidity and precipitation, favor larval development. Spraying of insecticides and garbage collection during outbreaks have not been successful in preventing new ones. A different approach

Ana Cecilia; Cordero Conejo; Fernando Sandí Nogueral; Geoconda Mejías Fonseca; Ronal Antonio Silva Silva; María Victoria Campos Rodríquez; Lisbeth Soto; Leonel Angulo; Jorge Danilo García; Francisco Hernández Chavarría

81

Characteristic of Dengue Disease in Taiwan: 2002-2007  

PubMed Central

Taiwan's dengue outbreaks have a unique type of transmission: starting by import from abroad in early summer, spreading out locally, and ending in the winter. This pattern repeats every year. Most of the dengue patients are adults, with dengue fever peaking in the 50–54 year age range, and dengue hemorrhagic fever in the 60–64 year age range. Two patterns of dengue infection were found: DENV-2 in 2002 with 74% of secondary infection in contrast to non-DENV-2 (DENV-1 or DENV-3) in 2004–2007 with ~70% of primary infection. Secondary dengue virus infection increases disease morbidity, but not mortality in adults. The active serological surveillance shows two-thirds of the dengue-infected adults are symptomatic post infection. The Taiwanese experience of adult dengue should be valuable for countries or areas where, although dengue is not endemic, the Aedes aegypti vector exists and dengue virus can be introduced by travelers. PMID:20348527

Lin, Chien-Chou; Huang, Yh-Hsiung; Shu, Pei-Yun; Wu, Ho-Sheng; Lin, Yee-Shin; Yeh, Trai-Ming; Liu, Hsiao-Sheng; Liu, Ching-Chuan; Lei, Huan-Yao

2010-01-01

82

DENGUE VIRAL INFECTIONS  

PubMed Central

Dengue viral infections are one of the most important mosquito-borne diseases in the world. Presently dengue is endemic in 112 countries in the world. It has been estimated that almost 100 million cases of dengue fever and half a million cases of dengue hemorrhagic fever (DHF) occur worldwide. An increasing proportion of DHF is in children less than 15 years of age, especially in South East and South Asia. The unique structure of the dengue virus and the pathophysiologic responses of the host, different serotypes, and favorable conditions for vector breeding have led to the virulence and spread of the infections. The manifestations of dengue infections are protean from being asymptomatic to undifferentiated fever, severe dengue infections, and unusual complications. Early recognition and prompt initiation of appropriate supportive treatment are often delayed resulting in unnecessarily high morbidity and mortality. Attempts are underway for the development of a vaccine for preventing the burden of this neglected disease. This review outlines the epidemiology, clinical features, pathophysiologic mechanisms, management, and control of dengue infections. PMID:20418983

Gurugama, Padmalal; Garg, Pankaj; Perera, Jennifer; Wijewickrama, Ananda; Seneviratne, Suranjith L

2010-01-01

83

Transfusion support in patients with dengue fever.  

PubMed

Dengue fever has emerged as a global public health problem in the recent decades. The clinical spectrum of the disease ranges from dengue fever to dengue hemorrhagic fever and dengue shock syndrome. The disease is characterized by increased capillary permeability, thrombocytopenia and coagulopathy. Thrombocytopenia with hemorrhagic manifestations warrants platelet transfusions. There is lack of evidence-based guidelines for transfusion support in patients with dengue fever. This contributes to inappropriate use of blood components and blood centers constantly face the challenge of inventory management during dengue outbreaks. The current review is aimed to highlight the role of platelets and other blood components in the management of dengue. The review was performed after searching relevant published literature in PubMed, Science Direct, Google scholar and various text books and journal articles. PMID:25298950

Kaur, Paramjit; Kaur, Gagandeep

2014-09-01

84

Transfusion support in patients with dengue fever  

PubMed Central

Dengue fever has emerged as a global public health problem in the recent decades. The clinical spectrum of the disease ranges from dengue fever to dengue hemorrhagic fever and dengue shock syndrome. The disease is characterized by increased capillary permeability, thrombocytopenia and coagulopathy. Thrombocytopenia with hemorrhagic manifestations warrants platelet transfusions. There is lack of evidence-based guidelines for transfusion support in patients with dengue fever. This contributes to inappropriate use of blood components and blood centers constantly face the challenge of inventory management during dengue outbreaks. The current review is aimed to highlight the role of platelets and other blood components in the management of dengue. The review was performed after searching relevant published literature in PubMed, Science Direct, Google scholar and various text books and journal articles. PMID:25298950

Kaur, Paramjit; Kaur, Gagandeep

2014-01-01

85

Studies on dengue and dengue haemorrhagic fever (DHF) in West Bengal State, India.  

PubMed

A large outbreak of dengue and dengue haemorrhagic fever (DHF) occurred from August to November 2005 involving all districts of West Bengal. Altogether 6293 persons were serologically diagnosed to be suffering from dengue through detection of IgM antibodies, with 27 (0.42%) seropositive deaths. In Kolkata alone 3967 persons were affected with 14 deaths. A total of 874 sera samples from febrile patients were quantitatively analysed for IgG and IgM antibodies using the IVD microwell ELISA dengue fever test kit. In 21.6%, no antibody was detected and 52.6% had only IgG antibodies. In 8.9% only IgM antibodies and in 16.8% both IgG, IgM antibodies were present, suggesting primary and secondary dengue respectively. About 10% of secondary dengue would develop DHF. As in this outbreak secondary dengue was 65.3% of total dengue cases, so of the 6293 dengue victims presumably, 3998 had secondary dengue, thus having risk of DHF in about 400 persons. Case fatality rate amongst DHF patients was 8.5%. This study also indicated that DHF would be a nagging problem in coming days. Age-group analysis of primary and secondary dengue cases revealed that although secondary cases occurred in all ages, more of primary cases belonged to younger ages (1-10) years and more of secondary cases in middle to older ages. Prevailing type during this outbreak was DEN3. This epidemiological study of an outbreak categorized prevalence of primary and secondary dengue, calculated risk factors for precipitation of DHF, model of which could be utilized to compare and evaluate future epidemiological pattern, where-ever and whenever applicable. PMID:17370674

Hati, A K

2006-03-01

86

Dengue Occurrence in the Population (Epidemiology)  

MedlinePLUS

... and, since 1969, CDC’s Dengue Branch, located at San Juan, has operated the island-wide passive dengue surveillance ... Control and Prevention Dengue Branch 1324 Calle Cañada San Juan, Puerto Rico 00920-3860 800-CDC-INFO (800- ...

87

Lessons raised by the major 2010 dengue epidemics in the French West Indies.  

PubMed

Dengue fever has been endemo-epidemic in the whole Region of America. In 2010, Guadeloupe and Martinique experienced historical epidemics, with an estimated attack rate of 10% in two islands. When considering the temporal evolution of epidemiological indicators, an unusual increase in the number of dengue cases could be detected very early. Two main factors might have facilitated the settlement of a viral transmission despite the dry season: a low immunity of the population against the circulating serotype and particular climatic conditions, notably very high temperatures which could have improved both virus and vector efficiency. This unusual situation was considered as a warning sign, and indeed led to major outbreaks in both islands a few weeks later. This event underlines that follow-up of epidemiological indicators is necessary to detect the unusual situations as soon as possible. Furthermore, development of biological and modelling tools should be promoted, as well as integrated management strategies for dengue prevention and control. PMID:24315801

Larrieu, S; Cassadou, S; Rosine, J; Chappert, J L; Blateau, A; Ledrans, M; Quénel, P

2014-03-01

88

Poliomyelitis outbreaks in Angola genetically linked to India: risk factors and implications for prevention of outbreaks due to wild poliovirus importations.  

PubMed

We conducted an investigation of two outbreaks of poliomyelitis in Angola during 2007-2008 due to wild poliovirus (WPV) genetically linked to India. A case-control study including 27 case-patients and 76 age- and neighborhood-matched control-subjects was conducted to assess risk factors associated with paralytic poliomyelitis, and epidemiologic links to India were explored through in-depth case-patient interviews. In multivariable analysis, case-patients were more likely than control-subjects to be undervaccinated with fewer than four routine doses of oral poliovirus vaccine (adjusted matched odds ratio [aMOR], 4.1; 95% confidence interval [CI], 1.2-13.6) and have an adult household member who traveled outside the province of residence in the 2 months preceding onset of paralysis (aMOR, 3.2; 95% CI, 1.2-8.6). No epidemiologic link with India was identified. These findings underscore the importance of routine immunization to prevent outbreaks following WPV importations and suggest a possible role of adults in sustaining WPV transmission. PMID:21440639

Kidd, Sarah; Goodson, James L; Aramburu, Javier; Morais, Alda; Gaye, Abou; Wannemuehler, Kathleen; Buffington, Joanna; Gerber, Sue; Wassilak, Steven; Uzicanin, Amra

2011-05-12

89

Gravitraps for Management of Dengue Clusters in Singapore  

PubMed Central

Although Singapore has an intensive dengue control program, dengue remains endemic with regular outbreaks. We report development and use of a novel adult oviposition trap, the Gravitrap, in managing dengue cluster areas. The Gravitrap is a simple, hay infusion-filled cylindrical trap with a sticky inner surface to serve as an oviposition site for gravid female Aedes mosquitoes. Wire gauze fitted above the water level minimizes the risk of it being an unwanted breeding habitat. The Gravitrap was deployed in 11 dengue cluster areas throughout Singapore. Aedes aegypti was the predominant mosquito caught in the trap and some (5.73%) were found to be positive for dengue virus. PMID:23478581

Lee, Caleb; Vythilingam, Indra; Chong, Chee-Seng; Razak, Muhammad Aliff Abdul; Tan, Cheong-Huat; Liew, Christina; Pok, Kwoon-Yong; Ng, Lee-Ching

2013-01-01

90

Auditing the Management of Vaccine-Preventable Disease Outbreaks: The Need for a Tool  

PubMed Central

Public health activities, especially infectious disease control, depend on effective teamwork. We present the results of a pilot audit questionnaire aimed at assessing the quality of public health services in the management of VPD outbreaks. Audit questionnaire with three main areas indicators (structure, process and results) was developed. Guidelines were set and each indicator was assessed by three auditors. Differences in indicator scores according to median size of outbreaks were determined by ANOVA (significance at p?0.05). Of 154 outbreaks; eighteen indicators had a satisfactory mean score, indicator “updated guidelines” and “timely reporting” had a poor mean score (2.84±106 and 2.44±1.67, respectively). Statistically significant differences were found according to outbreak size, in the indicators “availability of guidelines/protocol updated less than 3 years ago” (p?=?0.03) and “days needed for outbreak control” (p?=?0.04). Improving availability of updated guidelines, enhancing timely reporting and adequate recording of control procedures taken is needed to allow for management assessment and improvement. PMID:21249188

Torner, Nuria; Carnicer-Pont, Dolors; Castilla, Jesus; Cayla, Joan; Godoy, Pere; Dominguez, Angela

2011-01-01

91

Oyster-associated hepatitis. Failure of shellfish certification programs to prevent outbreaks.  

PubMed

During October and November 1973, outbreaks of hepatitis A associated with consumption of raw oysters occurred in Houston and in Calhoun, Ga. The oysters implicated in both outbreaks had been harvested in two Louisiana bays. Although the bays had been contaminated with polluted Mississippi River water two months before the oysters were harvested, at the time of harvesting the bays met national sanitation standards for shellfish growing and were certified for oyster fishing. These epidemics raise serious questions about the adequacy of shellfish sanitation monitoring systems currently in use. PMID:1174151

Portnoy, B L; Mackowiak, P A; Caraway, C T; Walker, J A; McKinley, T W; Klein, C A

1975-09-01

92

Dengue Fever in Mainland China  

PubMed Central

Dengue is an acute emerging infectious disease transmitted by Aedes mosquitoes and has become a serious global public health problem. In mainland China, a number of large dengue outbreaks with serious consequences have been reported as early as 1978. In the three decades from 1978 to 2008, a total of 655,324 cases were reported, resulting in 610 deaths. Since the 1990s, dengue epidemics have spread gradually from Guangdong, Hainan, and Guangxi provinces in the southern coastal regions to the relatively northern and western regions including Fujian, Zhejiang, and Yunnan provinces. As the major transmission vectors of dengue viruses, the biological behavior and vectorial capacity of Aedes mosquitoes have undergone significant changes in the last two decades in mainland China, most likely the result of urbanization and global climate changes. In this review, we summarize the geographic and temporal distributions, the serotype and genotype distributions of dengue viruses in mainland China, and analyze the current status of surveillance and control of vectors for dengue transmission. PMID:20810836

Wu, Jin-Ya; Lun, Zhao-Rong; James, Anthony A.; Chen, Xiao-Guang

2010-01-01

93

Prevention and management of avian influenza outbreaks: experiences from the United States of America  

Microsoft Academic Search

Summary The epidemiology and control of avian influenza (AI) are complex. The virus is transported in nature by the activities of wild birds and in commercial poultry by the activities of people. In general, all the outbreaks of AI in the United States of America (USA) have involved AI virus spread by the movement of poultry and manure and objects

D. A. Halvorson

94

Dengue virus type 3, South Pacific Islands, 2013.  

PubMed

After an 18-year absence, dengue virus serotype 3 reemerged in the South Pacific Islands in 2013. Outbreaks in western (Solomon Islands) and eastern (French Polynesia) regions were caused by different genotypes. This finding suggested that immunity against dengue virus serotype, rather than virus genotype, was the principal determinant of reemergence. PMID:24856252

Cao-Lormeau, Van-Mai; Roche, Claudine; Musso, Didier; Mallet, Henri-Pierre; Dalipanda, Tenneth; Dofai, Alfred; Nogareda, Francisco; Nilles, Eric J; Aaskov, John

2014-06-01

95

Dengue Virus Type 3, South Pacific Islands, 2013  

PubMed Central

After an 18-year absence, dengue virus serotype 3 reemerged in the South Pacific Islands in 2013. Outbreaks in western (Solomon Islands) and eastern (French Polynesia) regions were caused by different genotypes. This finding suggested that immunity against dengue virus serotype, rather than virus genotype, was the principal determinant of reemergence. PMID:24856252

Roche, Claudine; Musso, Didier; Mallet, Henri-Pierre; Dalipanda, Tenneth; Dofai, Alfred; Nogareda, Francisco; Nilles, Eric J.; Aaskov, John

2014-01-01

96

Dengue retinochoroiditis.  

PubMed

Dengue is a mosquito-borne infection caused by a flavivirus. I describe the ocular findings observed in two patients infected with dengue virus who presented with acute onset of loss of vision preceded by febrile illness, malaise, generalized fatigue headache, and maculopapular rash. Ophthalmologic evaluation in each patient revealed a normal anterior segment. Vitreous cells were noted in one patient. Ophthalmoscopy revealed multiple foci of retinochoroiditis, vasculitis, cotton-wool spots, and retinal hemorrhages. The healing of the lesion showed discrete atrophic and pigmented retinochoroiditic scars. Fluorescein angiography displayed early hypofluorescence and late hyperfluorescence suggestive of leakage. The healed scars showed late staining. The serologic testing showed elevated IgG antibodies, and one had high IgM antibodies to dengue virus. Ocular findings of dengue fever consist of multifocal areas of retinochoroiditis and may lead to loss of vision. In Saudi Arabia, dengue fever should be considered in the differential diagnosis of multifocal chorioretinal lesions and retinal vasculitis. PMID:22871625

Tabbara, Khalid

2012-01-01

97

Dengue/dengue haemorrhagic fever  

NSDL National Science Digital Library

A World Health Organization page devoted to the control of dengue. Many excellent informative PDF files are available from this page dealing with vector control, as well as recognition of symptoms, and treatment of dengue haemorrhagic fever. Estimated numbers of at risk people are staggering. A powerful resource for teaching the importance of vector borne diseases.

0002-11-30

98

139 Dengue vector control: critical needs and opportunities for helping to control the dengue pandemic  

PubMed Central

Aedes aegypti mosquito control is currently the only option for controlling and preventing epidemic dengue and dengue hemorrhagic fever. However, current approaches for vector control are not stemming the rising tide of dengue disease throughout the tropical world. In the absence of a vaccine, new and effective approaches are needed to improve vector control. Novel approaches to prevent dengue virus transmission will be described and discussed, including (1) the Casa Segura approach to prevent dengue transmission in the home, (2) development of a new generation of molecular mosquitocides to address the rise of resistance to existing insecticides, and (3) engineering dengue virus resistant mosquitoes. There is a public health imperative to increase the armamentarium for vector control.

Beaty, Barry

2014-01-01

99

Ongoing dengue epidemic - Angola, June 2013.  

PubMed

On April 1, 2013, the Public Health Directorate of Angola announced that six cases of dengue had been reported to the Ministry of Health of Angola (MHA). As of May 31, a total of 517 suspected dengue cases had been reported and tested for dengue with a rapid diagnostic test (RDT). A total of 313 (60.5%) specimens tested positive for dengue, including one from a patient who died. All suspected cases were reported from Luanda Province, except for two from Malanje Province. Confirmatory diagnostic testing of 49 specimens (43 RDT-positive and six RDT-negative) at the CDC Dengue Branch confirmed dengue virus (DENV) infection in 100% of the RDT-positive specimens and 50% of the RDT-negative specimens. Only DENV-1 was detected by molecular diagnostic testing. Phylogenetic analysis indicated this virus has been circulating in the region since at least 1968, strongly suggesting that dengue is endemic in Angola. Health-care professionals throughout Angola should be aware of the ongoing epidemic, the recommended practices for clinical management of dengue patients, and the need to report cases to MHA. Persons in Angola should seek medical care for acute febrile illness to reduce the risk for developing complications. Laboratory-confirmed dengue also has been reported from seven countries on four continents among persons who had recently traveled to Luanda, including 79 persons from Portugal. Angola is the third of four African countries to report a dengue outbreak in 2013. Persons returning from Africa with acute febrile illness should seek medical care, including testing for DENV infection, and suspected cases should be reported to public health authorities. PMID:23784016

2013-06-21

100

Strategies for preventing invasive plant outbreaks after prescribed fire in ponderosa pine forest  

USGS Publications Warehouse

Land managers use prescribed fire to return a vital process to fire-adapted ecosystems, restore forest structure from a state altered by long-term fire suppression, and reduce wildfire intensity. However, fire often produces favorable conditions for invasive plant species, particularly if it is intense enough to reveal bare mineral soil and open previously closed canopies. Understanding the environmental or fire characteristics that explain post-fire invasive plant abundance would aid managers in efficiently finding and quickly responding to fire-caused infestations. To that end, we used an information-theoretic model-selection approach to assess the relative importance of abiotic environmental characteristics (topoedaphic position, distance from roads), pre-and post-fire biotic environmental characteristics (forest structure, understory vegetation, fuel load), and prescribed fire severity (measured in four different ways) in explaining invasive plant cover in ponderosa pine forest in South Dakota’s Black Hills. Environmental characteristics (distance from roads and post-fire forest structure) alone provided the most explanation of variation (26%) in post-fire cover of Verbascum thapsus (common mullein), but a combination of surface fire severity and environmental characteristics (pre-fire forest structure and distance from roads) explained 36–39% of the variation in post-fire cover of Cirsium arvense (Canada thistle) and all invasives together. For four species and all invasives together, their pre-fire cover explained more variation (26–82%) in post-fire cover than environmental and fire characteristics did, suggesting one strategy for reducing post-fire invasive outbreaks may be to find and control invasives before the fire. Finding them may be difficult, however, since pre-fire environmental characteristics explained only 20% of variation in pre-fire total invasive cover, and less for individual species. Thus, moderating fire intensity or targeting areas of high severity for post-fire invasive control may be the most efficient means for reducing the chances of post-fire invasive plant outbreaks when conducting prescribed fires in this region.

Symstad, Amy J.; Newton, Wesley E.; Swanson, Daniel J.

2014-01-01

101

Prevention of a Malaria Outbreak among Non-Immune Japanese Workers Engaged in the Construction of a Thermal Power Plant in Sonebhadra, India  

Microsoft Academic Search

Abstract: Prevention of a Malaria Outbreak among Non-Immune,Japanese ,Workers ,Engaged ,in the Construction of a Thermal Power Plant in Sonebhadra, India: Hironobu KATSUYAMA, et al. Department of Health, Mitsubishi Heavy Industries—Continuous consumption of anti-malarialdrugs,is not always recognized as the first choice for prevention of malaria among,workers,residing in malarious areas for long periods. In Japan, personal protective measures,have been,primarily recommended. However,

Hironobu KATSUYAMA; Shigeyuki KANO; Mamoru SUZUKI; Kiyofumi SAIJOH; Kimiaki SUMINO; Goro TSUCHIYA

1997-01-01

102

Travelers' Health: Dengue Fever  

MedlinePLUS

... with any 1 of 4 related positive-strand RNA viruses of the genus Flavivirus , dengue viruses (DENV) ... Box 3-01 for information regarding the new World Health Organization (WHO) guidelines for classifying dengue. Dengue ...

103

Outbreak of Escherichia coli O157 in a nursery: lessons for prevention  

Microsoft Academic Search

OBJECTIVESTo identify risk factors for transmission of verocytotoxin producingEscherichia coli O157 (VTECO157) and means of prevention.STUDY DESIGNOutbreak investigation: retrospective cohort study.SETTINGA nursery (child care centre) in North Wales.SUBJECTSChildren attending (n = 104).METHODSFaeces were examined using sorbitol MacConkey agar (SMAC), with cefixime, tellurite, and rhamnose; enrichment in modified tryptone soya broth; and immunomagnetic separation. Symptoms and exposure data were obtained from

L Al-Jader; R L Salmon; A M Walker; H M Williams; G A Willshaw; T Cheasty

1999-01-01

104

Dengue vectors, human activity, and dengue virus transmission potential in the lower Rio Grande Valley, Texas, United States.  

PubMed

Dengue virus is an emerging disease of concern in the Americas. Recent outbreaks in Florida highlight the potential for the virus to return to the United States. The Lower Rio Grande Valley region of Texas directly borders Mexico, and has experienced dengue transmission in the past concurrent with outbreaks in Mexico along the border region. We examined the potential for dengue virus transmission by examining the vectors in the region, as well as assessing human behavior. We further hypothesized that dengue vector abundance would influence human behavior. Two dengue vectors, Aedes aegypti (L.) and Aedes albopictus (Skuse), were found in the region in high abundance. More mosquitoes were collected in rural sites and sites with high vegetation. Of the two species, only Ae. albopictus showed any significant habitat preferences, being more common in rural site. While there was no correlation between human behavior and mosquito abundance, the results support a significant correlation between knowledge of mosquitoes and dengue virus and behavioral practices that might reduce risk of disease transmission. Dengue risk may be higher in certain regions of the Lower Rio Grande Valley based on socioeconomic conditions, specifically in economically poor regions such as the undeveloped colonias found in the region. Because of the proximity of this region to an area with endemic dengue, continued surveillance and risk assessment is suggested. PMID:25276932

Vitek, Christopher J; Gutierrez, Joann A; Dirrigl, Frank J

2014-09-01

105

Role of cognitive parameters in dengue hemorrhagic fever and dengue shock syndrome  

PubMed Central

Dengue is becoming recognized as one of the most important vector-borne human diseases. It is predominant in tropical and subtropical zones but its geographical distribution is progressively expanding, making it an escalating global health problem of today. Dengue presents with spectrum of clinical manifestations, ranging from asymptomatic, undifferentiated mild fever, dengue fever (DF), to dengue hemorrhagic fever (DHF) with or without shock (DSS), a life-threatening illness characterized by plasma leakage due to increased vascular permeability. Currently, there are no antiviral modalities or vaccines available to treat and prevent dengue. Supportive care with close monitoring is the standard clinical practice. The mechanisms leading to DHF/DSS remains poorly understood. Multiple factors have been attributed to the pathological mechanism, but only a couple of these hypotheses are popular in scientific circles. The current discussion focuses on underappreciated factors, temperature, natural IgM, and endotoxin, which may be critical components playing roles in dengue pathogenesis. PMID:24305068

2013-01-01

106

DengueTools: innovative tools and strategies for the surveillance and control of dengue  

PubMed Central

Dengue fever is a mosquito-borne viral disease estimated to cause about 230 million infections worldwide every year, of which 25,000 are fatal. Global incidence has risen rapidly in recent decades with some 3.6 billion people, over half of the world's population, now at risk, mainly in urban centres of the tropics and subtropics. Demographic and societal changes, in particular urbanization, globalization, and increased international travel, are major contributors to the rise in incidence and geographic expansion of dengue infections. Major research gaps continue to hamper the control of dengue. The European Commission launched a call under the 7th Framework Programme with the title of ‘Comprehensive control of Dengue fever under changing climatic conditions’. Fourteen partners from several countries in Europe, Asia, and South America formed a consortium named ‘DengueTools’ to respond to the call to achieve better diagnosis, surveillance, prevention, and predictive models and improve our understanding of the spread of dengue to previously uninfected regions (including Europe) in the context of globalization and climate change. The consortium comprises 12 work packages to address a set of research questions in three areas: Research area 1: Develop a comprehensive early warning and surveillance system that has predictive capability for epidemic dengue and benefits from novel tools for laboratory diagnosis and vector monitoring. Research area 2: Develop novel strategies to prevent dengue in children. Research area 3: Understand and predict the risk of global spread of dengue, in particular the risk of introduction and establishment in Europe, within the context of parameters of vectorial capacity, global mobility, and climate change. In this paper, we report on the rationale and specific study objectives of ‘DengueTools’. DengueTools is funded under the Health theme of the Seventh Framework Programme of the European Community, Grant Agreement Number: 282589 Dengue Tools. PMID:22451836

Wilder-Smith, Annelies; Renhorn, Karl-Erik; Tissera, Hasitha; Abu Bakar, Sazaly; Alphey, Luke; Kittayapong, Pattamaporn; Lindsay, Steve; Logan, James; Hatz, Christoph; Reiter, Paul; Rocklov, Joacim; Byass, Peter; Louis, Valerie R.; Tozan, Yesim; Massad, Eduardo; Tenorio, Antonio; Lagneau, Christophe; L'Ambert, Gregory; Brooks, David; Wegerdt, Johannah; Gubler, Duane

2012-01-01

107

Epidemiology of dengue: past, present and future prospects  

PubMed Central

Dengue is currently regarded globally as the most important mosquito-borne viral disease. A history of symptoms compatible with dengue can be traced back to the Chin Dynasty of 265–420 AD. The virus and its vectors have now become widely distributed throughout tropical and subtropical regions of the world, particularly over the last half-century. Significant geographic expansion has been coupled with rapid increases in incident cases, epidemics, and hyperendemicity, leading to the more severe forms of dengue. Transmission of dengue is now present in every World Health Organization (WHO) region of the world and more than 125 countries are known to be dengue endemic. The true impact of dengue globally is difficult to ascertain due to factors such as inadequate disease surveillance, misdiagnosis, and low levels of reporting. Currently available data likely grossly underestimates the social, economic, and disease burden. Estimates of the global incidence of dengue infections per year have ranged between 50 million and 200 million; however, recent estimates using cartographic approaches suggest this number is closer to almost 400 million. The expansion of dengue is expected to increase due to factors such as the modern dynamics of climate change, globalization, travel, trade, socioeconomics, settlement and also viral evolution. No vaccine or specific antiviral therapy currently exists to address the growing threat of dengue. Prompt case detection and appropriate clinical management can reduce the mortality from severe dengue. Effective vector control is the mainstay of dengue prevention and control. Surveillance and improved reporting of dengue cases is also essential to gauge the true global situation as indicated in the objectives of the WHO Global Strategy for Dengue Prevention and Control, 2012–2020. More accurate data will inform the prioritization of research, health policy, and financial resources toward reducing this poorly controlled disease. The objective of this paper is to review historical and current epidemiology of dengue worldwide and, additionally, reflect on some potential reasons for expansion of dengue into the future. PMID:23990732

Murray, Natasha Evelyn Anne; Quam, Mikkel B; Wilder-Smith, Annelies

2013-01-01

108

Comparative susceptibility of mosquito populations in North Queensland, Australia to oral infection with dengue virus.  

PubMed

Dengue is the most prevalent arthropod-borne virus, with at least 40% of the world's population at risk of infection each year. In Australia, dengue is not endemic, but viremic travelers trigger outbreaks involving hundreds of cases. We compared the susceptibility of Aedes aegypti mosquitoes from two geographically isolated populations to two strains of dengue virus serotype 2. We found, interestingly, that mosquitoes from a city with no history of dengue were more susceptible to virus than mosquitoes from an outbreak-prone region, particularly with respect to one dengue strain. These findings suggest recent evolution of population-based differences in vector competence or different historical origins. Future genomic comparisons of these populations could reveal the genetic basis of vector competence and the relative role of selection and stochastic processes in shaping their differences. Lastly, we show the novel finding of a correlation between midgut dengue titer and titer in tissues colonized after dissemination. PMID:24420782

Ye, Yixin H; Ng, Tat Siong; Frentiu, Francesca D; Walker, Thomas; van den Hurk, Andrew F; O'Neill, Scott L; Beebe, Nigel W; McGraw, Elizabeth A

2014-03-01

109

Re-Emergence of Dengue Virus Type 3 in Canton, China, 2009-2010, Associated with Multiple Introductions through Different Geographical Routes  

PubMed Central

Background Endemic dengue virus type 3 (DENV-3) infections have not been reported in Canton, China, since 1980. In March 2009, DENV-3 was isolated for the second time, occurring about 30 years after the previous circulation. In August, 3 other cases emerged. One much larger outbreak occurred again in 2010. To address the origin and particularly to determine whether the outbreaks were caused by the same viral genotype, we investigated the epidemiological and molecular characteristics of the introduction, spread and genetic microevolution of DENV-3 involved. Methodology/Principal Findings Three imported cases (index-1,2,3) separately traveled back from Vietnam, India and Tanzania, resulted in 1, 3 and 60 secondary autochthonous cases, respectively. In autochthonous cases, 64.6% positive in IgM anti-DENV and 18.6% in IgG from a total of 48 submitted serum samples, accompanied by 7 DENV-3 isolates. With 99.8%, 99.7%, and 100% envelope gene nucleotidic identity, 09/GZ/1081 from index-1 and endemic strain (09/GZ/1483) belonged to genotype V; 09/GZ/10616 from index-2 and endemic strains (09/GZ/11144 and 09/GZ/11194) belonged to genotype III Clade-A; and 10/GZ/4898 from index-3 and all four 2010 endemic DENV-3 strains belonged to genotype III Clade-B, respectively. Conclusions/Significance Both epidemiological and phylogenetic analyses showed that the 2010 outbreak of dengue was not a reemergence of the 2009 strain. Introductions of different genotypes following more than one route were important contributory factors for the 2009–2010 dengue epidemics/outbreaks in Canton. These findings underscore the importance of early detection and case management of imported case in preventing large-scale dengue epidemics among indigenous peoples of Canton. PMID:23405138

Di, Biao; Bai, Zhijun; He, Peng; Jing, Qinlong; Zheng, Xueli

2013-01-01

110

Dengue/Severe Dengue Frequently Asked Questions  

MedlinePLUS

... Français ??????? Español RSS Feed Youtube Twitter Facebook Google + iTunes Dengue control Menu Dengue Control strategies Monitoring ... 8 9 Next page » Share Email Twitter Facebook Google Delicious LinkedIn More... Print Last update: 22 April ...

111

Wolbachia versus dengue  

PubMed Central

A novel form of biological control is being applied to the dengue virus. The agent is the maternally transmitted bacterium Wolbachia, naturally absent from the main dengue vector, the mosquito Aedes aegypti. Three Wolbachia-based control strategies have been proposed. One is suppression of mosquito populations by large-scale releases of males incompatible with native females; this intervention requires ongoing releases. The other interventions transform wild mosquito populations with Wolbachia that spread via the frequency-dependent fitness advantage of Wolbachia-infected females; those interventions potentially require just a single, local release for area-wide disease control. One of these latter strategies uses Wolbachia that shortens mosquito life, indirectly preventing viral maturation/transmission. The other strategy uses Wolbachia that block viral transmission. All interventions can be undermined by viral, bacterial or mosquito evolution; viral virulence in humans may also evolve. We examine existing theory, experiments and comparative evidence to motivate predictions about evolutionary outcomes. (i) The life-shortening strategy seems the most likely to be thwarted by evolution. (ii) Mosquito suppression has a reasonable chance of working locally, at least in the short term, but long-term success over large areas is challenging. (iii) Dengue blocking faces strong selection for viral resistance but may well persist indefinitely at some level. Virulence evolution is not mathematically predictable, but comparative data provide no precedent for Wolbachia increasing dengue virulence. On balance, our analysis suggests that the considerable possible benefits of these technologies outweigh the known negatives, but the actual risk is largely unknown. PMID:24481199

Bull, James J.; Turelli, Michael

2013-01-01

112

Importance of Internet Surveillance in Public Health Emergency Control and Prevention: Evidence From a Digital Epidemiologic Study During Avian Influenza A H7N9 Outbreaks  

PubMed Central

Background Outbreaks of human infection with a new avian influenza A H7N9 virus occurred in China in the spring of 2013. Control and prevention of a new human infectious disease outbreak can be strongly affected by public reaction and social impact through the Internet and social media. Objective This study aimed to investigate the potential roles of Internet surveillance in control and prevention of the human H7N9 outbreaks. Methods Official data for the human H7N9 outbreaks were collected via the China National Health and Family Planning Committee website from March 31 to April 24, 2013. We obtained daily posted and forwarded number of blogs for the keyword “H7N9” from Sina microblog website and a daily Baidu Attention Index (BAI) from Baidu website, which reflected public attention to the outbreak. Rumors identified and confirmed by the authorities were collected from Baidu search engine. Results Both daily posted and forwarded number and BAI for keyword H7N9 increased quickly during the first 3 days of the outbreaks and remained at a high level for 5 days. The total daily posted and forwarded number for H7N9 on Sina microblog peaked at 850,000 on April 3, from zero blogs before March 31, increasing to 97,726 on April 1 and to 370,607 on April 2, and remaining above 500,000 from April 5-8 before declining to 208,524 on April 12. The total daily BAI showed a similar pattern of change to the total daily posted and forwarded number over time from March 31 to April 12. When the outbreak locations spread, especially into other areas of the same province/city and the capital, Beijing, daily posted and forwarded number and BAI increased again to a peak at 368,500 and 116,911, respectively. The median daily BAI during the studied 25 days was significantly higher among the 7 provinces/cities with reported human H7N9 cases than the 2 provinces without any cases (P<.001). So were the median daily posted and forwarded number and daily BAI in each province/city except Anhui province. We retrieved a total of 32 confirmed rumors spread across 19 provinces/cities in China. In all, 84% (27/32) of rumors were disseminated and transmitted by social media. Conclusions The first 3 days of an epidemic is a critical period for the authorities to take appropriate action through Internet surveillance to prevent and control the epidemic, including preparation of personnel, technology, and other resources; information release; collection of public opinion and reaction; and clarification, prevention, and control of rumors. Internet surveillance can be used as an efficient and economical tool to prevent and control public health emergencies, such as H7N9 outbreaks. PMID:24440770

Zhu, Honghong; Jiang, Tao; Wang, Xinyi; Chen, Lei; Jiang, Zhenggang; Zheng, Dawei

2014-01-01

113

Kinetics of non-structural protein 1, IgM and IgG antibodies in dengue type 1 primary infection  

Microsoft Academic Search

BACKGROUND: Early and accurate diagnosis of dengue infection is essential for control of disease outbreaks. Recently, the dengue virus non-structural antigen 1 (NS1), a conserved and secreted glycoprotein, has been used as a marker for early diagnosis of dengue with convenience and cost-effectiveness. Serological tests of dengue IgM and IgG antibodies are still the most widely used for diagnosis of

Dongmei Hu; Biao Di; Xixia Ding; Yadi Wang; Yue Chen; Yuxian Pan; Kun Wen; Ming Wang; Xiaoyan Che

2011-01-01

114

Spatio-temporal diffusion pattern and hotspot detection of dengue in Chachoengsao province, Thailand.  

PubMed

In recent years, dengue has become a major international public health concern. In Thailand it is also an important concern as several dengue outbreaks were reported in last decade. This paper presents a GIS approach to analyze the spatial and temporal dynamics of dengue epidemics. The major objective of this study was to examine spatial diffusion patterns and hotspot identification for reported dengue cases. Geospatial diffusion pattern of the 2007 dengue outbreak was investigated. Map of daily cases was generated for the 153 days of the outbreak. Epidemiological data from Chachoengsao province, Thailand (reported dengue cases for the years 1999-2007) was used for this study. To analyze the dynamic space-time pattern of dengue outbreaks, all cases were positioned in space at a village level. After a general statistical analysis (by gender and age group), data was subsequently analyzed for temporal patterns and correlation with climatic data (especially rainfall), spatial patterns and cluster analysis, and spatio-temporal patterns of hotspots during epidemics. The results revealed spatial diffusion patterns during the years 1999-2007 representing spatially clustered patterns with significant differences by village. Villages on the urban fringe reported higher incidences. The space and time of the cases showed outbreak movement and spread patterns that could be related to entomologic and epidemiologic factors. The hotspots showed the spatial trend of dengue diffusion. This study presents useful information related to the dengue outbreak patterns in space and time and may help public health departments to plan strategies to control the spread of disease. The methodology is general for space-time analysis and can be applied for other infectious diseases as well. PMID:21318014

Jeefoo, Phaisarn; Tripathi, Nitin Kumar; Souris, Marc

2011-01-01

115

Outbreak of cryptosporidiosis at a California waterpark: employee and patron roles and the long road towards prevention.  

PubMed

In August-September 2004, a cryptosporidiosis outbreak affected >250 persons who visited a California waterpark. Employees and patrons of the waterpark were affected, and three employees and 16 patrons admitted to going into recreational water while ill with diarrhoea. The median illness onset date for waterpark employees was 8 days earlier than that for patrons. A case-control study determined that getting water in one's mouth on the waterpark's waterslides was associated with illness (adjusted odds ratio 7.4, 95% confidence interval 1.7-32.2). Laboratory studies identified Cryptosporidium oocysts in sand and backwash from the waterslides' filter, and environmental investigations uncovered inadequate water-quality record keeping and a design flaw in one of the filtration systems. Occurring more than a decade after the first reported outbreaks of cryptosporidiosis in swimming pools, this outbreak demonstrates that messages about healthy swimming practices have not been adopted by pool operators and the public. PMID:17291365

Wheeler, C; Vugia, D J; Thomas, G; Beach, M J; Carnes, S; Maier, T; Gorman, J; Xiao, L; Arrowood, M J; Gilliss, D; Werner, S B

2007-02-01

116

Laboratory diagnosis of dengue virus infection: current and future perspectives in clinical diagnosis and public health  

Microsoft Academic Search

Since no protective vaccine or specific treatments are available for dengue fever\\/dengue hemorrhagic fever (DHF), accurate diagnosis is critical for the early initiation of specific preventive health measures to curtail epidemic spread and reduce economic losses. Commonly used diagnosis methods for confirming dengue infection involve virus isolation, detection of virus antigen or RNA in plasma or serum or tissues, and

Chuan-Liang Kao; Chwan-Chuen King; Day-Yu Chao; Hui-Lin Wu; Gwong-Jen J. Chang

117

Predicting the Dengue Incidence in Singapore using Univariate Time Series Models  

PubMed Central

Dengue is endemic in Singapore with year-around transmission. Prediction of dengue incidence is important for effective use of limited resources for vector-control and contingency measures. In the work, we develop a set of time series models based on the observed weekly dengue incidence since 2000. The dengue incidence data of Singapore from 2000 – 2011 is used to develop and fit the predictive models. For testing and validation, we use the 2012 data at two levels: A) real versus predicted incidence and B) real versus predicted outbreak severity. The statistical measures of validation show that the models predict both the dengue incidence and the outbreak severity level with acceptable level of accuracy. PMID:24551338

Dayama, Pankaj; Kameshwaran, S.

2013-01-01

118

A review of the vector management methods to prevent and control outbreaks of West Nile virus infection and the challenge for Europe  

PubMed Central

West Nile virus infection is a growing concern in Europe. Vector management is often the primary option to prevent and control outbreaks of the disease. Its implementation is, however, complex and needs to be supported by integrated multidisciplinary surveillance systems and to be organized within the framework of predefined response plans. The impact of the vector control measures depends on multiple factors and the identification of the best combination of vector control methods is therefore not always straightforward. Therefore, this contribution aims at critically reviewing the existing vector control methods to prevent and control outbreaks of West Nile virus infection and to present the challenges for Europe. Most West Nile virus vector control experiences have been recently developed in the US, where ecological conditions are different from the EU and vector control is organized under a different regulatory frame. The extrapolation of information produced in North America to Europe might be limited because of the seemingly different epidemiology in the European region. Therefore, there is an urgent need to analyse the European experiences of the prevention and control of outbreaks of West Nile virus infection and to perform robust cost-benefit analysis that can guide the implementation of the appropriate control measures. Furthermore, to be effective, vector control programs require a strong organisational backbone relying on a previously defined plan, skilled technicians and operators, appropriate equipment, and sufficient financial resources. A decision making guide scheme is proposed which may assist in the process of implementation of vector control measures tailored on specific areas and considering the available information and possible scenarios. PMID:25015004

2014-01-01

119

A review of the vector management methods to prevent and control outbreaks of West Nile virus infection and the challenge for Europe.  

PubMed

West Nile virus infection is a growing concern in Europe. Vector management is often the primary option to prevent and control outbreaks of the disease. Its implementation is, however, complex and needs to be supported by integrated multidisciplinary surveillance systems and to be organized within the framework of predefined response plans. The impact of the vector control measures depends on multiple factors and the identification of the best combination of vector control methods is therefore not always straightforward. Therefore, this contribution aims at critically reviewing the existing vector control methods to prevent and control outbreaks of West Nile virus infection and to present the challenges for Europe.Most West Nile virus vector control experiences have been recently developed in the US, where ecological conditions are different from the EU and vector control is organized under a different regulatory frame. The extrapolation of information produced in North America to Europe might be limited because of the seemingly different epidemiology in the European region. Therefore, there is an urgent need to analyse the European experiences of the prevention and control of outbreaks of West Nile virus infection and to perform robust cost-benefit analysis that can guide the implementation of the appropriate control measures. Furthermore, to be effective, vector control programs require a strong organisational backbone relying on a previously defined plan, skilled technicians and operators, appropriate equipment, and sufficient financial resources. A decision making guide scheme is proposed which may assist in the process of implementation of vector control measures tailored on specific areas and considering the available information and possible scenarios. PMID:25015004

Bellini, Romeo; Zeller, Herve; Van Bortel, Wim

2014-01-01

120

The use of typing methods and infection prevention measures to control a bullous impetigo outbreak on a neonatal ward  

PubMed Central

Background We describe an outbreak of Bullous Impetigo (BI), caused by a (methicillin susceptible, fusidic acid resistant) Staphylococcus aureus (SA) strain, spa-type t408, at the neonatal and gynaecology ward of the Jeroen Bosch hospital in the Netherlands, from March-November 2011. Methods We performed an outbreak investigation with revision of the hygienic protocols, MSSA colonization surveillance and environmental sampling for MSSA including detailed typing of SA isolates. Spa typing was performed to discriminate between the SA isolates. In addition, Raman-typing was performed on all t408 isolates. Results Nineteen cases of BI were confirmed by SA positive cultures. A cluster of nine neonates and three health care workers (HCW) with SA t408 was detected. These strains were MecA-, PVL-, Exfoliative Toxin (ET)A-, ETB+, ETAD-, fusidic acid-resistant and methicillin susceptible. Eight out of nine neonates and two out of three HCW t408 strains yielded a similar Raman type. Positive t408 HCW were treated and infection control procedures were reinforced. These measures stopped the outbreak. Conclusions We conclude that treatment of patients and HCW carrying a predominant SA t408, and re-implementing and emphasising hygienic measures were effective to control the outbreak of SA t408 among neonates. PMID:23168170

2012-01-01

121

One Dose of Varicella Vaccine Does Not Prevent School Outbreaks: Is it Time for a Second Dose?  

Microsoft Academic Search

OBJECTIVES.The implementation of a routine childhood varicella vaccination pro- gram in the United States in 1995 has resulted in a dramatic decline in varicella morbidity and mortality. Although disease incidence has decreased, outbreaks of varicella continue to be reported, increasingly in highly vaccinated populations. In 2000, a varicella vaccination requirement was introduced for kindergarten entry in Arkansas. In October 2003,

Adriana S. Lopez; Dalya Guris; Laura Zimmerman; Linda Gladden; Tamara Moore; Dirk T. Haselow; Vladimir N. Loparev; D. Scott Schmid; Aisha O. Jumaan; Sandra L. Snow

2010-01-01

122

Flu Outbreaks Force Schools to Adjust Plans: Classes Canceled in Some Places to Prevent Spread of Influenza  

ERIC Educational Resources Information Center

A flu outbreak at Madison Junior High School in Ohio prompted school officials to close the building for two days. At Webber Junior High School in Fort Collins, Colorado, where absenteeism recently hit 20 percent for two bad weeks, educators were forced to slow the pace of schoolwork so sick students did not fall behind. This article reports on…

Jacobson, Linda; Bowman, Darcia Harris

2004-01-01

123

Infection prevention and control interventions in the first outbreak of methicillin-resistant Staphylococcus aureus infections in an equine hospital in Sweden  

PubMed Central

Background The first outbreak of methicillin-resistant Staphylococcus aureus (MRSA) infection in horses in Sweden occurred in 2008 at the University Animal Hospital and highlighted the need for improved infection prevention and control. The present study describes interventions and infection prevention control in an equine hospital setting July 2008 - April 2010. Method This descriptive study of interventions is based on examination of policy documents, medical records, notes from meetings and cost estimates. MRSA cases were identified through clinical sampling and telephone enquiries about horses post-surgery. Prospective sampling in the hospital environment with culture for MRSA and genotyping of isolates by spa-typing and pulsed-field gel electrophoresis (PFGE) were performed. Results Interventions focused on interruption of indirect contact spread of MRSA between horses via staff and equipment and included: Temporary suspension of elective surgery; and identification and isolation of MRSA-infected horses; collaboration was initiated between authorities in animal and human public health, human medicine infection control and the veterinary hospital; extensive cleaning and disinfection was performed; basic hygiene and cleaning policies, staff training, equipment modification and interior renovation were implemented over seven months. Ten (11%) of 92 surfaces sampled between July 2008 and April 2010 tested positive for MRSA spa-type 011, seven of which were from the first of nine sampling occasions. PFGE typing showed the isolates to be the outbreak strain (9 of 10) or a closely related strain. Two new cases of MRSA infection occurred 14 and 19 months later, but had no proven connections to the outbreak cases. Conclusions Collaboration between relevant authorities and the veterinary hospital and formation of an infection control committee with an executive working group were required to move the intervention process forward. Support from hospital management and the dedication of staff were essential for the development and implementation of new, improved routines. Demonstration of the outbreak strain in the environment was useful for interventions such as improvement of cleaning routines and interior design, and increased compliance with basic hygienic precautions. The interventions led to a reduction in MRSA-positive samples and the outbreak was considered curbed as no new cases occurred for over a year. PMID:22401493

2012-01-01

124

Dengue fever (image)  

MedlinePLUS

Dengue fever, or West Nile fever, is a mild viral illness transmitted by mosquitoes which causes fever, ... second exposure to the virus can result in Dengue hemorrhagic fever, a life-threatening illness.

125

Dengue Fever Treatment  

MedlinePLUS

... JavaScript on. Read more information on enabling JavaScript. Dengue Fever Skip Content Marketing Share this: Main Content ... Treatment There is no specific treatment for classic dengue fever, and most people recover within 2 weeks. ...

126

Analysis of Effects of Meteorological Factors on Dengue Incidence in Sri Lanka Using Time Series Data  

PubMed Central

In tropical and subtropical regions of eastern and South-eastern Asia, dengue fever (DF) and dengue hemorrhagic fever (DHF) outbreaks occur frequently. Previous studies indicate an association between meteorological variables and dengue incidence using time series analyses. The impacts of meteorological changes can affect dengue outbreak. However, difficulties in collecting detailed time series data in developing countries have led to common use of monthly data in most previous studies. In addition, time series analyses are often limited to one area because of the difficulty in collecting meteorological and dengue incidence data in multiple areas. To gain better understanding, we examined the effects of meteorological factors on dengue incidence in three geographically distinct areas (Ratnapura, Colombo, and Anuradhapura) of Sri Lanka by time series analysis of weekly data. The weekly average maximum temperature and total rainfall and the total number of dengue cases from 2005 to 2011 (7 years) were used as time series data in this study. Subsequently, time series analyses were performed on the basis of ordinary least squares regression analysis followed by the vector autoregressive model (VAR). In conclusion, weekly average maximum temperatures and the weekly total rainfall did not significantly affect dengue incidence in three geographically different areas of Sri Lanka. However, the weekly total rainfall slightly influenced dengue incidence in the cities of Colombo and Anuradhapura. PMID:23671694

Goto, Kensuke; Kumarendran, Balachandran; Mettananda, Sachith; Gunasekara, Deepa; Fujii, Yoshito; Kaneko, Satoshi

2013-01-01

127

First isolation of dengue virus from the 2010 epidemic in Nepal.  

PubMed

Dengue is an emerging disease in Nepal and was first observed as an outbreak in nine lowland districts in 2006. In 2010, however, a large epidemic of dengue occurred with 4,529 suspected and 917 serologically-confirmed cases and five deaths reported in government hospitals in Nepal. The collection of demographic information was performed along with an entomological survey and clinical evaluation of the patients. A total of 280 serum samples were collected from suspected dengue patients. These samples were subjected to routine laboratory investigations and IgM-capture ELISA for dengue serological identification, and 160 acute serum samples were used for virus isolation, RT-PCR, sequencing and phylogenetic analysis. The results showed that affected patients were predominately adults, and that 10% of the cases were classified as dengue haemorrhagic fever/ dengue shock syndrome. The genetic characterization of dengue viruses isolated from patients in four major outbreak areas of Nepal suggests that the DENV-1 strain was responsible for the 2010 epidemic. Entomological studies identified Aedes aegypti in all epidemic areas. All viruses belonged to a monophyletic single clade which is phylogenetically close to Indian viruses. The dengue epidemic started in the lowlands and expanded to the highland areas. To our knowledge, this is the first dengue isolation and genetic characterization reported from Nepal. PMID:24155651

Pandey, Basu D; Nabeshima, Takeshi; Pandey, Kishor; Rajendra, Saroj P; Shah, Yogendra; Adhikari, Bal R; Gupta, Govinda; Gautam, Ishan; Tun, Mya M N; Uchida, Reo; Shrestha, Mahendra; Kurane, Ichiro; Morita, Kouichi

2013-09-01

128

First Isolation of Dengue Virus from the 2010 Epidemic in Nepal  

PubMed Central

Dengue is an emerging disease in Nepal and was first observed as an outbreak in nine lowland districts in 2006. In 2010, however, a large epidemic of dengue occurred with 4,529 suspected and 917 serologically-confirmed cases and five deaths reported in government hospitals in Nepal. The collection of demographic information was performed along with an entomological survey and clinical evaluation of the patients. A total of 280 serum samples were collected from suspected dengue patients. These samples were subjected to routine laboratory investigations and IgM-capture ELISA for dengue serological identification, and 160 acute serum samples were used for virus isolation, RT-PCR, sequencing and phylogenetic analysis. The results showed that affected patients were predominately adults, and that 10% of the cases were classified as dengue haemorrhagic fever/ dengue shock syndrome. The genetic characterization of dengue viruses isolated from patients in four major outbreak areas of Nepal suggests that the DENV-1 strain was responsible for the 2010 epidemic. Entomological studies identified Aedes aegypti in all epidemic areas. All viruses belonged to a monophyletic single clade which is phylogenetically close to Indian viruses. The dengue epidemic started in the lowlands and expanded to the highland areas. To our knowledge, this is the first dengue isolation and genetic characterization reported from Nepal. PMID:24155651

Pandey, Basu D.; Nabeshima, Takeshi; Pandey, Kishor; Rajendra, Saroj P.; Shah, Yogendra; Adhikari, Bal R.; Gupta, Govinda; Gautam, Ishan; Tun, Mya M. N.; Uchida, Reo; Shrestha, Mahendra; Kurane, Ichiro; Morita, Kouichi

2013-01-01

129

Time series analysis of dengue incidence in Guadeloupe, French West Indies: Forecasting models using climate variables as predictors  

Microsoft Academic Search

Background  During the last decades, dengue viruses have spread throughout the Americas region, with an increase in the number of severe\\u000a forms of dengue. The surveillance system in Guadeloupe (French West Indies) is currently operational for the detection of\\u000a early outbreaks of dengue. The goal of the study was to improve this surveillance system by assessing a modelling tool to\\u000a predict

Myriam Gharbi; Philippe Quenel; Joël Gustave; Sylvie Cassadou; Guy La Ruche; Laurent Girdary; Laurence Marrama

2011-01-01

130

Fire fighting truck-based emergency mosquito biolarviciding to prevent outbreaks of malaria and arboviral disease in Kabul, Afghanistan  

Microsoft Academic Search

Emergency control of disease vectors requires high efficacy, rapid reaction and safe use of biocides in order interrupt transmission\\u000a cycles without harming humans, non-target animals and the environment. In countries with complex emergencies, air-borne large-scale\\u000a vector control is often limited, or impossible, due to questionable security as well as military, safety, equipment, or logistical\\u000a constraints. While facing a potential outbreak

M. K. Faulde; J. J. Scharninghausen; M. Tisch

2008-01-01

131

Emergence of the Severe Syndrome and Mortality Associated with Dengue and Dengue-Like Illness: Historical Records (1890 to 1950) and Their Compatibility with Current Hypotheses on the Shift of Disease Manifestation  

PubMed Central

Summary: Outbreaks of the severe dengue syndrome, dengue hemorrhagic fever (DHF), emerged beginning in the 1950s, marking a dramatic change in the dengue syndrome. While intense investigations in multiple directions have been conducted for many years to elucidate the intrinsic mechanisms conducive to the development of DHF, no consensus has yet emerged. Meanwhile, relatively little attention has been paid to the occurrence of severe dengue and death prior to the 1950s. This comprehensive review was designed to evaluate outbreak records in the early dengue history to better understand the epidemiologic background and other factors that existed before the emergence of DHF outbreaks. By applying a set of stringent criteria to remove unreliable data as much as possible and by interpreting the results conservatively, a short list of etiologically more reliable outbreaks with high mortality was obtained. The results show that severe dengue syndrome, clinically very much compatible with DHF, occurred far more frequently in multiple locations than it had been assumed before; that the magnitudes of mortality in several outbreaks were not negligible; and that the epidemiologic background features shared among these outbreaks in the early period were, with the exceptions of more limited demographic changes, generally similar to the post-1950 conditions. PMID:19366911

Kuno, Goro

2009-01-01

132

Prediction of High Incidence of Dengue in the Philippines  

PubMed Central

Background Accurate prediction of dengue incidence levels weeks in advance of an outbreak may reduce the morbidity and mortality associated with this neglected disease. Therefore, models were developed to predict high and low dengue incidence in order to provide timely forewarnings in the Philippines. Methods Model inputs were chosen based on studies indicating variables that may impact dengue incidence. The method first uses Fuzzy Association Rule Mining techniques to extract association rules from these historical epidemiological, environmental, and socio-economic data, as well as climate data indicating future weather patterns. Selection criteria were used to choose a subset of these rules for a classifier, thereby generating a Prediction Model. The models predicted high or low incidence of dengue in a Philippines province four weeks in advance. The threshold between high and low was determined relative to historical incidence data. Principal Findings Model accuracy is described by Positive Predictive Value (PPV), Negative Predictive Value (NPV), Sensitivity, and Specificity computed on test data not previously used to develop the model. Selecting a model using the F0.5 measure, which gives PPV more importance than Sensitivity, gave these results: PPV?=?0.780, NPV?=?0.938, Sensitivity?=?0.547, Specificity?=?0.978. Using the F3 measure, which gives Sensitivity more importance than PPV, the selected model had PPV?=?0.778, NPV?=?0.948, Sensitivity?=?0.627, Specificity?=?0.974. The decision as to which model has greater utility depends on how the predictions will be used in a particular situation. Conclusions This method builds prediction models for future dengue incidence in the Philippines and is capable of being modified for use in different situations; for diseases other than dengue; and for regions beyond the Philippines. The Philippines dengue prediction models predicted high or low incidence of dengue four weeks in advance of an outbreak with high accuracy, as measured by PPV, NPV, Sensitivity, and Specificity. PMID:24722434

Buczak, Anna L.; Baugher, Benjamin; Babin, Steven M.; Ramac-Thomas, Liane C.; Guven, Erhan; Elbert, Yevgeniy; Koshute, Phillip T.; Velasco, John Mark S.; Roque, Vito G.; Tayag, Enrique A.; Yoon, In-Kyu; Lewis, Sheri H.

2014-01-01

133

Secondary dengue virus type 4 infections in Vietnam.  

PubMed

This study was designated to describe clinical and biological features of patients with a suspected diagnosis of dengue fever/dengue hemorrhagic fever during an outbreak in Central Vietnam. One hundred and twenty-five consecutive patients hospitalized at Khanh Hoa and Binh Thuan Provincial hospitals between November 2001 and January 2002 with a diagnosis of suspected dengue infection were included in the present study. Viruses were isolated in C6/36 and VERO E6 cell cultures or detected by RT-PCR. A hemagglutination-inhibition test (HI) was done on each paired sera using dengue antigens type 1-4, Japanese encephalitis (JE) virus antigen, Chickungunya virus antigen and Sindbis virus antigen. Anti-dengue and anti-JE virus IgM were measured by a capture enzyme-linked immunosorbent assay (MAC-ELISA). Anti-dengue and anti-JE virus IgG were measured by an ELISA test. Dengue viruses were isolated in cell culture and/or detected by RT-PCR in 20.8% of blood samples. DEN-4 and DEN-2 serotypes were found in 18.4% and 2.4% of the patients, respectively. A total of 86.4% of individuals had a diagnosis of acute dengue fever by using the HI test and/or dengue virus-specific IgM capture-ELISA and/or virus isolation and/or RT-PCR. The prevalence of primary and secondary acute dengue infection was 4% and 78.4%, respectively. Anti-dengue IgG ELISA test was positive in 88.8% of the patients. In 5 cases (4%), Japanese encephalitis virus infection was positive by serology but the cell culture was negative. No Chickungunya virus or Sindbis virus infection was detected by the HI test. In patients with acute dengue virus infection, the most common presenting symptom was headache, followed by conjunctivitis, petechial rash, muscle and joint pain, nausea and abdominal pain. Four percent of hospitalized patients were classified as dengue hemorrhagic fever. The clinical presentation and blood cell counts were similar between patients hospitalized with acute dengue fever and patients with other febrile illnesses. PMID:15906664

Buchy, Philippe; Vo, Van Luong; Bui, Khanh Toan; Trinh, Thi Xuan Mai; Glaziou, Philippe; Le, Thi Thu Ha; Le, Viet Lo; Bui, Trong Chien

2005-01-01

134

Inclusion of dengue in TDR's disease portfolio.  

PubMed

This article reports the outcome of the informal consultation of the WHO in-house expert scientists on the proposed inclusion of dengue and tuberculosis in the Training in Tropical Diseases (TDR) portfolio to be reviewed during the 22nd session of the Joint Coordinating Board. The purpose of the meeting was to identify research gaps, pinpoint research needed, and proposed a potential agenda for TDR activities regarding dengue and dengue hemorrhagic fever (DHF). During the meeting, WHO staff presented an analysis of the global situation for dengue and an outline of WHO activities in dengue control and vaccine development. Three discussion groups proposed a list of priority subjects where TDR could initiate activities: 1) in social, economic and behavioral research; 2) in vector research; 3) in diagnosis; 4) in pathophysiology; and 5) in vaccine discovery and development. At present, the only method for controlling or preventing dengue and DHF rely on controlling the mosquito vector. Therefore, developing appropriate and efficient vector control methods, improving laboratory diagnosis and case management of patients, and developing an effective vaccine were the primary objectives of research and capability strengthening. PMID:12322389

1999-08-01

135

Latest developments and future directions in dengue vaccines  

PubMed Central

Dengue is a mosquito-borne disease which is currently an expanding global health problem. The disease is caused by four closely related viruses, the dengue virus. There are no specific dengue therapeutics and prevention is currently limited to vector control measures. Development of an effective tetravalent dengue vaccine would therefore represent a major advance in the control of the disease and is considered a high public health priority. While a licensed dengue vaccine is not yet available, the scope and intensity of dengue vaccine development has increased dramatically in the last decade. The uniqueness of the dengue viruses and the spectrum of disease resulting from infection have made dengue vaccine development difficult. Several vaccine candidates are currently being evaluated in clinical studies. The candidate currently at the most advanced clinical development stage, a live-attenuated tetravalent vaccine based on chimeric yellow fever dengue virus, has progressed to phase III efficacy studies. Several other live-attenuated vaccines, as well as subunit, DNA and purified inactivated vaccine candidates, are at earlier stages of clinical development. Additional technological approaches, such as virus-vectored and virus-like particle-based vaccines, are under evaluation in preclinical studies. PMID:24757522

Thisyakorn, Chule

2014-01-01

136

First Evidence of Simultaneous Circulation of Three Different Dengue Virus Serotypes in Africa  

PubMed Central

Gabon, in Central Africa, was affected for the first time in 2007 and then in 2010 by simultaneous outbreaks of chikungunya and Dengue serotype 2 (DENV-2) viruses. Through the national surveillance of dengue-like syndromes between 2007 and 2010, we observed continuous circulation of DENV-2 in a southward movement. This rapid spread of DENV-2 was associated with the emergence of DENV-1 in 2007 and DENV-3 in 2010. Interestingly, we detected six DENV-2 infected patients with hemorrhagic signs during the second outbreak in 2010. Although these cases do not meet all standard WHO criteria for severe Dengue with hemorrhage (formerly DHF), this is the first report of several dengue fever cases associated with hemorrhagic signs during a simultaneous circulation of different DENV serotypes in Africa. Together, these findings suggest that DENV is becoming more widely established on this continent and that DHF will likely become a serious public-health problem in the near future. PMID:24205075

Caron, Melanie; Grard, Gilda; Paupy, Christophe; Mombo, Illich Mamfred; Bikie Bi Nso, Branly; Kassa Kassa, Fabrice Roland; Nkoghe, Dieudonne; Leroy, Eric Maurice

2013-01-01

137

Hyperferritinaemia in Dengue Virus Infected Patients Is Associated with Immune Activation and Coagulation Disturbances  

PubMed Central

Background During a dengue outbreak on the Caribbean island Aruba, highly elevated levels of ferritin were detected in dengue virus infected patients. Ferritin is an acute-phase reactant and hyperferritinaemia is a hallmark of diseases caused by extensive immune activation, such as haemophagocytic lymphohistiocytosis. The aim of this study was to investigate whether hyperferritinaemia in dengue patients was associated with clinical markers of extensive immune activation and coagulation disturbances. Methodology/Principal Findings Levels of ferritin, standard laboratory markers, sIL-2R, IL-18 and coagulation and fibrinolytic markers were determined in samples from patients with uncomplicated dengue in Aruba. Levels of ferritin were significantly increased in dengue patients compared to patients with other febrile illnesses. Moreover, levels of ferritin associated significantly with the occurrence of viraemia. Hyperferritinaemia was also significantly associated with thrombocytopenia, elevated liver enzymes and coagulation disturbances. The results were validated in a cohort of dengue virus infected patients in Brazil. In this cohort levels of ferritin and cytokine profiles were determined. Increased levels of ferritin in dengue virus infected patients in Brazil were associated with disease severity and a pro-inflammatory cytokine profile. Conclusions/Significance Altogether, we provide evidence that ferritin can be used as a clinical marker to discriminate between dengue and other febrile illnesses. The occurrence of hyperferritinaemia in dengue virus infected patients is indicative for highly active disease resulting in immune activation and coagulation disturbances. Therefore, we recommend that patients with hyperferritinaemia are monitored carefully. PMID:25299654

Pannuti, Claudio S.; Brouns, Rosalba M.; van den Berg, Riemsdijk W. A.; van den Ham, Henk-Jan; Martina, Byron E. E.; Osterhaus, Albert D. M. E.; Netea, Mihai G.; Meijers, Joost C. M.; van Gorp, Eric C. M.; Kallas, Esper G.

2014-01-01

138

Assessing Weather Effects on Dengue Disease in Malaysia  

PubMed Central

The number of dengue cases has been increasing on a global level in recent years, and particularly so in Malaysia, yet little is known about the effects of weather for identifying the short-term risk of dengue for the population. The aim of this paper is to estimate the weather effects on dengue disease accounting for non-linear temporal effects in Selangor, Kuala Lumpur and Putrajaya, Malaysia, from 2008 to 2010. We selected the weather parameters with a Poisson generalized additive model, and then assessed the effects of minimum temperature, bi-weekly accumulated rainfall and wind speed on dengue cases using a distributed non-linear lag model while adjusting for trend, day-of-week and week of the year. We found that the relative risk of dengue cases is positively associated with increased minimum temperature at a cumulative percentage change of 11.92% (95% CI: 4.41–32.19), from 25.4 °C to 26.5 °C, with the highest effect delayed by 51 days. Increasing bi-weekly accumulated rainfall had a positively strong effect on dengue cases at a cumulative percentage change of 21.45% (95% CI: 8.96, 51.37), from 215 mm to 302 mm, with the highest effect delayed by 26–28 days. The wind speed is negatively associated with dengue cases. The estimated lagged effects can be adapted in the dengue early warning system to assist in vector control and prevention plan. PMID:24287855

Cheong, Yoon Ling; Burkart, Katrin; Leitao, Pedro J.; Lakes, Tobia

2013-01-01

139

Endothelial cells in dengue hemorrhagic fever.  

PubMed

Therapies to prevent or reverse endothelial dysfunction and vascular leak found in dengue hemorrhagic fever (DHF) have not been identified. In this review we summarize dengue viruses and the spectrum of human disease and highlight evidence of endothelial cell dysfunction in DHF based on studies in patients and mouse and tissue culture models. Evidence suggests that both virus antigen and host immune response, can cause endothelial cell dysfunction and weaken endothelial barrier integrity. We suggest possible therapeutic interventions and highlight how therapies targeting altered endothelial function might be evaluated in animal models and in patients with DHF. PMID:25025934

Srikiatkhachorn, Anon; Kelley, James F

2014-09-01

140

Distribution, seasonal variation & dengue transmission prediction in Sisaket, Thailand  

PubMed Central

Background & objectives: Environmental factors including weather variables may play a significant role in the transmission of dengue. This study investigated the effect of seasonal variation on the abundance of Aedes aegypti and Ae. albopictus larvae and explored the impact of weather variability on dengue transmission in Sisaket, Thailand. Methods: The monthly mosquito larval surveys were carried out in urban and rural areas in Sisaket, Thailand from January to December 2010. Data on monthly-reported cases of dengue fever over the period 2004-2010 were obtained from the Ministry of Public Health. Weather data over the same period were obtained from the Thai Meteorological Department. Chi-square test was used to find the differences relating to seasonal variability, areas of study, and mosquito species factors using entomological survey data. Time series Poisson regression analysis was performed using data on monthly weather variables and dengue cases. Results: There were more Ae. aegypti larvae per household than Ae. albopictus larvae in the winter and rainy seasons. More Aedes larvae per household were found in the rainy season than in the winter and summer seasons. Relative humidity at a lag of one month and rainy days in the current month were significant predictors of dengue incidence in Sisaket. Interpretation & conclusions: Increased rain during the current month and less humidity during the previous month might trigger a higher incidence of dengue epidemic in Sisaket. The present findings suggest that the dengue incidence corresponds with the number of Aedes larvae. The seasonal patterns of dengue outbreaks coincide with the rainy season. PMID:24135179

Wongkoon, S.; Jaroensutasinee, M.; Jaroensutasinee, K.

2013-01-01

141

Molecular characterization of dengue viruses circulating during 2009-2012 in Uttar Pradesh, India.  

PubMed

Dengue is the most rapidly spreading mosquito-borne viral disease in the world; in India it has taken endemic proportion implicating all the four known dengue virus serotypes. Dengue infection is caused by a small, single stranded RNA virus comprising of four antigenically distinct virus serotypes designated as dengue virus type 1-4 (DENV-1-4). On the basis of genomic variations, each serotype is classified further into its genotypes. Epidemiological studies have shown that the emergence of a newer dengue serotype/genotype after an interval always leads to a major outbreak; therefore a continuous epidemiological surveillance is needed to monitor the epidemiology of dengue viruses. The present study was planned to identify the serotype/genotype of dengue viruses circulating in Uttar Pradesh, India. Of 433 dengue suspected patients, tested by reverse transcriptase PCR (RT-PCR), 136 were positive for dengue virus RNA. Of these, DENV-1, 2, and 3 were detected in 26 (19.1%), 77 (56.6%), and 33 (24.3%) patients, respectively. Of 136 RT-PCR positive samples, 24 samples were sequenced to identify their genotypes. For sequencing C-prM gene junction of dengue virus genome was chosen. Phylogenetic analysis of sequenced dengue strains revealed that all the 12 DENV-1 strains were genotype III, all the eight DENV-2 strains were genotype IV (Cosmopolitan genotype) and among four DENV-3 strains, three were genotype III and one was genotype I. In conclusion, the co-circulation of multiple dengue virus serotypes and genotypes is alarming in U.P., India. J. Med. Virol. 87: 68-75, 2015. © 2014 Wiley Periodicals, Inc. PMID:24889214

Mishra, Gitika; Jain, Amita; Prakash, Om; Prakash, Shantanu; Kumar, Rashmi; Garg, Ravindra K; Pandey, Nidhi; Singh, Mastan

2015-01-01

142

Review of Dengue Hemorrhagic Fever Fatal Cases Seen Among Adults: A Retrospective Study  

PubMed Central

Background Dengue is a mosquito-borne viral disease endemic in many countries in the tropics and sub-tropics. The disease affects mainly children, but in recent years it is becoming more of an adult disease. Malaysia experienced a large dengue outbreak in 2006 to 2007, involving mostly adults, with a high number of deaths. Methodology/Principal Findings We undertook a retrospective study to examine dengue death cases in our hospital from June 2006 to October 2007 with a view to determine if there have been changes in the presentation of severe to fatal dengue. Nine of ten fatal cases involved adult females with a median age of 32 years. All had secondary dengue infection. The mean duration of illness prior to hospitalization was 4.7 days and deaths occurred at an average of 2.4 days post-admission. Gastrointestinal pain, vomiting, diarrhea, intravascular leakages and bleeding occurred in the majority of cases. DSS complicated with severe bleeding, multi-organ failure and coagulopathy were the primary causes of deaths. Seven patients presented with thrombocytopenia and hypoalbuminemia, five of which had hemoconcentration and increased ALT and AST indicative of liver damage. Co-morbidities particularly diabetes mellitus was common in our cohort. Prominent unusual presentations included acute renal failure, acute respiratory distress syndrome, myocarditis with pericarditis, and hemorrhages over the brain and heart. Conclusions In our cohort, dengue fatalities are seen primarily in adult females with secondary dengue infection. The majority of the patients presented with common clinical and laboratory warning signs of severe dengue. Underlying co-morbidities may contribute to the rapid clinical deterioration in severe dengue. The uncommon presentations of dengue are likely a reflection of the changing demographics where adults are now more likely to contract dengue in dengue endemic regions. PMID:23658849

Sam, Sing-Sin; Omar, Sharifah Faridah Syed; Teoh, Boon-Teong; Abd-Jamil, Juraina; AbuBakar, Sazaly

2013-01-01

143

The Role of Imported Cases and Favorable Meteorological Conditions in the Onset of Dengue Epidemics  

PubMed Central

Background Travelers who acquire dengue infection are often routes for virus transmission to other regions. Nevertheless, the interplay between infected travelers, climate, vectors, and indigenous dengue incidence remains unclear. The role of foreign-origin cases on local dengue epidemics thus has been largely neglected by research. This study investigated the effect of both imported dengue and local meteorological factors on the occurrence of indigenous dengue in Taiwan. Methods and Principal Findings Using logistic and Poisson regression models, we analyzed bi-weekly, laboratory-confirmed dengue cases at their onset dates of illness from 1998 to 2007 to identify correlations between indigenous dengue and imported dengue cases (in the context of local meteorological factors) across different time lags. Our results revealed that the occurrence of indigenous dengue was significantly correlated with temporally-lagged cases of imported dengue (2–14 weeks), higher temperatures (6–14 weeks), and lower relative humidity (6–20 weeks). In addition, imported and indigenous dengue cases had a significant quantitative relationship in the onset of local epidemics. However, this relationship became less significant once indigenous epidemics progressed past the initial stage. Conclusions These findings imply that imported dengue cases are able to initiate indigenous epidemics when appropriate weather conditions are present. Early detection and case management of imported cases through rapid diagnosis may avert large-scale epidemics of dengue/dengue hemorrhagic fever. The deployment of an early-warning surveillance system, with the capacity to integrate meteorological data, will be an invaluable tool for successful prevention and control of dengue, particularly in non-endemic countries. PMID:20689820

Shang, Chuin-Shee; Wen, Tzai-Hung; Tsai, Kun-Hsien

2010-01-01

144

Laboratory Surveillance of Dengue in Rio Grande do Sul, Brazil, from 2007 to 2013  

PubMed Central

Background According to official records, dengue was introduced in Brazil in the 80's; since then several epidemics have occurred. Meanwhile, in Rio Grande do Sul (RS, Southern Brazil) the first autochthonous case occurred only in 2007. Methodology and Principal Findings In this study we report laboratory surveillance of dengue cases and seasonality of positive cases, describe serotypes and characterize the epidemiological pattern of dengue in RS from 2007 to 2013. A total of 9,779 serum samples from patients with suspected dengue fever were collected and submitted to molecular and/or serological analyses for dengue virus identification and serotyping, based on viral isolation, NS1 antigen detection and qRT-PCR, or Dengue IgM capture ELISA and MAC-ELISA. The first autochthonous dengue case in RS was confirmed in 2007 (DENV-3). While in 2008 and 2009 only imported cases were registered, autochthonous infection waves have been occurring since 2010. The highest number of dengue infections occurred in 2010, with DENV-1 and DENV-2 outbreaks in Northwestern RS. In 2011, another DENV-1 and DENV-2 outbreak occurred in the Northwestern region; moreover, DENV-4 was detected in travelers. In 2012, DENV-1 and DENV-4 co-circulated. DENV-2 circulation was only detected again in 2013, in high frequency (56.7%), co-circulating with DENV-4 (35%). Most infections occur in adults during summer. Differences in prevalence between genders were observed in 2007 (60% females), 2008 (60.8% males) and 2009 (77.5% males). Conclusions According to results of dengue surveillance, there was an increase in the number of dengue cases in RS and of cities infested with Aedes aegypti, possibly as a consequence of introduction of new serotypes and the difficulty of health programs to control the vector. PMID:25116186

Tumioto, Gabriela Luchiari; Gregianini, Tatiana Schaffer; Dambros, Bibiana Paula; Cestari, Beatriz Carneiro; Alves Nunes, Zenaida Marion; Veiga, Ana Beatriz Gorini

2014-01-01

145

Phylogenetic reconstruction of dengue virus type 2 in Colombia  

PubMed Central

Background Dengue fever is perhaps the most important viral re-emergent disease especially in tropical and sub-tropical countries, affecting about 50 million people around the world yearly. In Colombia, dengue virus was first detected in 1971 and still remains as a major public health issue. Although four viral serotypes have been recurrently identified, dengue virus type 2 (DENV-2) has been involved in the most important outbreaks during the last 20 years, including 2010 when the fatality rate highly increased. As there are no major studies reviewing virus origin and genotype distribution in this country, the present study attempts to reconstruct the phylogenetic history of DENV-2 using a sequence analysis from a 224 bp PCR-amplified product corresponding to the carboxyl terminus of the envelope (E) gene from 48 Colombian isolates. Results As expected, the oldest isolates belonged to the American genotype (subtype V), but the strains collected since 1990 represent the American/Asian genotype (subtype IIIb) as previously reported in different American countries. Interestingly, the introduction of this genotype coincides with the first report of dengue hemorrhagic fever in Colombia at the end of 1989 and the increase of cases during the next years. Conclusion After replacement of the American genotype, several lineages of American/Asian subtype have rapidly spread all over the country evolving in new clades. Nevertheless, the direct association of these new variants in the raise of lethality rate observed during the last outbreak has to be demonstrated. PMID:22405440

2012-01-01

146

Fulminant hepatic failure due to dengue.  

PubMed

Dengue Fever (DF) is only rarely considered as a cause of acute liver failure even globally and only a few case reports of acute hepatic failure and encephalopathy occurring in DF in adults are available. We report a case of Acute Liver Failure due to Dengue during a major outbreak in 2010 in Chitwan. A 20 year old previously healthy female presented to the emergency department of Chitwan Medical College with fever, jaundice and altered sensorium. She was tested positive for Dengue IgM. Her biochemical and clinical parameters were suggestive of acute liver failure with total billirubin of 10.1 mg/dL, direct billirubin of 5.2 mg/dL, ALT 5760 IU, AST 14100 IU, alkaline phosphatase of 1250 IU, PT INR of 1.76 and platelet count of 30,000/mm3. Other causes for acute hepatic failure like acute viral hepatitis, leptospirosis, malaria, Reyes syndrome were ruled out. The patient was admitted and managed in the ICU with supportive care and platelet transfusion. With treatment she made a significant clinical and biochemical improvement with AST of 105 IU, ALT of 120 IU and platelet count of 150,000/mm3. She was discharged after 11 days of hospital stay. PMID:22610874

Sedhain, A; Adhikari, S; Regmi, S; Chaudhari, S K; Shah, M; Shrestha, B

2011-01-01

147

Emergence of traveling waves in the spreading of dengue fever  

NASA Astrophysics Data System (ADS)

Dengue fever is a multistrain mosquito-borne subtropical disease that exhibits complex oscillatory outbreaks. Epidemiological data from Thailand displays traveling waves of infection originating in Bangkok, the largest population center (Cummings et al., Nature 427: 344, 2004). We present a multistrain metapopulation model in which traveling wave like behavior results from migration coupling between heterogeneous regions. The region with the highest effective person-to-person contact rate leads the dynamics. A stochastic version of the model will also be presented.

Bianco, Simone; Faatz, Andrea; Cummings, Derek; Shaw, Leah

2010-03-01

148

Significant increase in travel-associated dengue fever in Germany  

Microsoft Academic Search

Increasing numbers of dengue fever (DF) cases reflect the increasing travel mobility together with the expanding geographical\\u000a distribution of the vector Aedes aegypti. Compared with earlier surveys in Germany, higher incidences occur and correlate\\u000a well with ongoing outbreaks. Therefore, we investigated 767 serum samples from 594 returning travellers with suspected DF\\u000a between 2005 and 2010, which where sent from different

Regina Allwinn

2011-01-01

149

Dengue fever triggering systemic lupus erythematosus and lupus nephritis: a case report  

PubMed Central

We report a rare case of dengue fever triggering systemic lupus erythematosus and lupus nephritis. The patient presented herself during a large outbreak of dengue fever in December 2012 in Maharashtra, India. The diagnosis of dengue fever was confirmed by the presence of NS-1 antigen during the first few days of febrile illness. Eight weeks later, kidney tissue biopsy studies revealed evidence of lupus nephritis on microscopic examination and immunofluorescence. The report interpreted it as focal proliferative glomerulonephritis and segmental sclerosis (Stage IIIC). The case was also found positive for perinuclear antineutrophil cytoplasmic antibodies by indirect immunofluorescence assay. An active and effective management of a case essentially calls for clear perception of differentiating dengue-induced lupus flare, antineutrophil cytoplasmic antibody-related nephropathy, and/or dengue-induced de-novo lupus disease. Dengue viremia may be the trigger for immune complex formation in patients who are predisposed to developing autoimmune diseases. The present case explains the importance of considering the diagnosis of dengue-related lupus nephritis as an atypical occurrence in appropriate situations, as in this case. It would not be improper to regard this escalating disease as an expanded feature of dengue. PMID:24204176

Talib, SH; Bhattu, SR; Bhattu, R; Deshpande, SG; Dahiphale, DB

2013-01-01

150

Food-borne Salmonella outbreak in a single hospital ward.  

PubMed

In June 2012, an outbreak of Salmonella group C gastroenteritis occurred on a single hospital ward among 54.2% (13/24) of volunteers undergoing an unrelated clinical trial and among 14.3% (1/7) hospital ward worker. Food-borne transmission was suspected, so a retrospective cohort study was conducted to identify the vehicle of the outbreak along with implementing outbreak control measures. None of the food items was significantly associated with the outbreak. An epidemic curve suggests a common source of the outbreak. No cases were reported after outbreak control. Food should be stored, cooked and handled using strict hygiene to prevent future outbreaks. PMID:24968679

Luvira, Viravarn; Iamsirithaworn, Sopon; Thantamnu, Narumon; Pitisuttiithum, Punnee

2014-03-01

151

Impact of Dengue  

MedlinePLUS

... South-East Asia, the Eastern Mediterranean and the Western Pacific and dengue fever is present mainly in ... WHO European Region WHO Eastern Mediterranean Region WHO Western Pacific Region RSS Feeds WHO YouTube channel Follow ...

152

Dengue Fever Testing  

MedlinePLUS

... Sample , provides a glimpse at the collection and processing of a blood sample and throat culture. Is ... Confirmed in Florida (2013), New CDC Test Can Speed Up Diagnosis of Dengue Fever (2012), FDA Approves ...

153

Dengue Virus Diagnostics  

Microsoft Academic Search

\\u000a Dengue fever (DF) is an emerging arborviral disease caused by infection with dengue virus (DENV) which has emerged as the\\u000a most important vector-borne viral disease in tropical areas and it continues to expand geographically. The four serotypes\\u000a of DENV that cause human disease are transmitted by Aedes mosquitoes. Expansion in geographic distribution of both viruses\\u000a and mosquito vectors, has led

Evgeni Eltzov; Danit Atias; Levi Gheber; Robert S. Marks

154

Using Geographically Weighted Regression (GWR) to Explore Spatial Varying Relationships of Immature Mosquitoes and Human Densities with the Incidence of Dengue  

PubMed Central

The only way for dengue to spread in the human population is through the human-mosquito-human cycle. Most research in this field discusses the dengue-mosquito or dengue-human relationships over a particular study area, but few have explored the local spatial variations of dengue-mosquito and dengue-human relationships within a study area. This study examined whether spatial heterogeneity exists in these relationships. We used Ordinary Least Squares (OLS) and Geographically Weighted Regression (GWR) models to analyze spatial relationships and identify the geographical heterogeneities by using the information of entomology and dengue cases in the cities of Kaohsiung and Fengshan in 2002. Our findings indicate that dengue-mosquito and dengue-human relationships were significantly spatially non-stationary. This means that in some areas higher dengue incidences were associated with higher vector/host densities, but in some areas higher incidences were related to lower vector/host densities. We demonstrated that a GWR model can be used to geographically differentiate the relationships of dengue incidence with immature mosquito and human densities. This study provides more insights into spatial targeting of intervention and control programs against dengue outbreaks within the study areas. PMID:21845159

Lin, Chia-Hsien; Wen, Tzai-Hung

2011-01-01

155

Dengue viruses - an overview  

PubMed Central

Dengue viruses (DENVs) cause the most common arthropod-borne viral disease in man with 50–100 million infections per year. Because of the lack of a vaccine and antiviral drugs, the sole measure of control is limiting the Aedes mosquito vectors. DENV infection can be asymptomatic or a self-limited, acute febrile disease ranging in severity. The classical form of dengue fever (DF) is characterized by high fever, headache, stomach ache, rash, myalgia, and arthralgia. Severe dengue, dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS) are accompanied by thrombocytopenia, vascular leakage, and hypotension. DSS, which can be fatal, is characterized by systemic shock. Despite intensive research, the underlying mechanisms causing severe dengue is still not well understood partly due to the lack of appropriate animal models of infection and disease. However, even though it is clear that both viral and host factors play important roles in the course of infection, a fundamental knowledge gap still remains to be filled regarding host cell tropism, crucial host immune response mechanisms, and viral markers for virulence. PMID:24003364

Back, Anne Tuiskunen; Lundkvist, Ake

2013-01-01

156

A climate-based spatiotemporal prediction for dengue fever epidemics: a case study in southern Taiwan  

NASA Astrophysics Data System (ADS)

Dengue Fever (DF) has been identified by the World Health organization (WHO) as one of the most serious vector-borne infectious diseases in tropical and sub-tropical areas. DF has been one of the most important epidemics in Taiwan which occur annually especially in southern Taiwan during summer and autumn. Most DF studies have focused mainly on temporal DF patterns and its close association with climatic covariates, whereas few studies have investigated the spatial DF patterns (spatial dependence and clustering) and composite space-time effects of the DF epidemics. The present study proposes a spatio-temporal DF prediction approach based on stochastic Bayesian Maximum Entropy (BME) analysis. Core and site-specific knowledge bases are considered, including climate and health datasets under conditions of uncertainty, space-time dependence functions, and a Poisson regression model of climatic variables contributing to DF occurrences in southern Taiwan during 2007, when the highest number of DF cases was recorded in the history of Taiwan epidemics (over 2000). The obtained results show that the DF outbreaks in the study area are highly influenced by climatic conditions. Furthermore, the analysis can provide the required "one-week-ahead" outbreak warnings based on spatio-temporal predictions of DF distributions. Therefore, the proposed analysis can provide the Taiwan Disease Control Agency with a valuable tool to timely identify, control, and even efficiently prevent DF spreading across space-time.

Yu, H.-L.; Yang, S.-J.; Lin, Y.-C.

2012-04-01

157

Health Economics of Dengue: A Systematic Literature Review and Expert Panel's Assessment  

PubMed Central

Dengue vaccines are currently in development and policymakers need appropriate economic studies to determine their potential financial and public health impact. We searched five databases (PubMed, EMBASE, LILAC, EconLit, and WHOLIS) to identify health economics studies of dengue. Forty-three manuscripts were identified that provided primary data: 32 report economic burden of dengue and nine are comparative economic analyses assessing various interventions. The remaining two were a willingness-to-pay study and a policymaker survey. An expert panel reviewed the existing dengue economic literature and recommended future research to fill information gaps. Although dengue is an important vector-borne disease, the economic literature is relatively sparse and results have often been conflicting because of use of inconsistent assumptions. Health economic research specific to dengue is urgently needed to ensure informed decision making on the various options for controlling and preventing this disease. PMID:21363989

Beatty, Mark E.; Beutels, Philippe; Meltzer, Martin I.; Shepard, Donald S.; Hombach, Joachim; Hutubessy, Raymond; Dessis, Damien; Coudeville, Laurent; Dervaux, Benoit; Wichmann, Ole; Margolis, Harold S.; Kuritsky, Joel N.

2011-01-01

158

VARIACION ESPACIO-TEMPORAL DEL RIESGO DE TRANSMISION DE DENGUE EN LA CIUDAD DE BUENOS AIRES  

Microsoft Academic Search

Spatio-temporal variability in the transmission of dengue in Buenos Aires City. Cases of den- gue detected in Buenos Aires City between 1999 and 2000 confirmed the possibility of epidemic outbreaks. The activity of its vector Aedes aegypi was monitored to study the spatial and temporal risk of den- gue transmission. Adult oviposition activity of Aedes aegypti showed an heterogeneous spatio-temporal

ANIBAL E. CARBAJO; SANDRA M. GOMEZ; SUSANA I. CURTO; NICOLAS J. SCHWEIGMANN; Academia Nacional de Medicina

2004-01-01

159

Aedes aegypti in Brazil: genetically differentiated populations with high susceptibility to dengue and yellow fever viruses  

Microsoft Academic Search

Aedes aegypti was eliminated from Brazil in 1955, but re-infested the country in the 1970s. Dengue outbreaks have occurred since 1981 and became endemic in several cities in Brazil after 1986. Urban yellow fever has not occurred since 1942, and only jungle yellow fever cases have been reported. A population genetic analysis using isoenzyme variation combined with an evaluation of

R Lourenço-de-Oliveira; M Vazeille; A. M. B de Filippis; A. B Failloux

2004-01-01

160

Advice to travelers on topical insect repellent use against dengue mosquitoes in Far North Queensland, Australia.  

PubMed

Dengue outbreaks occur annually in Far North Queensland, Australia. Advice on topical insect repellents provided by health authorities rarely addresses the wide range of formulations and active ingredients currently registered for use in Australia. Recommendations on the use of registered products require review. PMID:21722241

Webb, Cameron E; Russell, Richard C

2011-01-01

161

Fault tree analysis of the causes of waterborne outbreaks.  

PubMed

Prevention and containment of outbreaks requires examination of the contribution and interrelation of outbreak causative events. An outbreak fault tree was developed and applied to 61 enteric outbreaks related to public drinking water supplies in the EU. A mean of 3.25 causative events per outbreak were identified; each event was assigned a score based on percentage contribution per outbreak. Source and treatment system causative events often occurred concurrently (in 34 outbreaks). Distribution system causative events occurred less frequently (19 outbreaks) but were often solitary events contributing heavily towards the outbreak (a mean % score of 87.42). Livestock and rainfall in the catchment with no/inadequate filtration of water sources contributed concurrently to 11 of 31 Cryptosporidium outbreaks. Of the 23 protozoan outbreaks experiencing at least one treatment causative event, 90% of these events were filtration deficiencies; by contrast, for bacterial, viral, gastroenteritis and mixed pathogen outbreaks, 75% of treatment events were disinfection deficiencies. Roughly equal numbers of groundwater and surface water outbreaks experienced at least one treatment causative event (18 and 17 outbreaks, respectively). Retrospective analysis of multiple outbreaks of enteric disease can be used to inform outbreak investigations, facilitate corrective measures, and further develop multi-barrier approaches. PMID:17890833

Risebro, Helen L; Doria, Miguel F; Andersson, Yvonne; Medema, Gertjan; Osborn, Keith; Schlosser, Olivier; Hunter, Paul R

2007-01-01

162

Assessing the Relationship between Vector Indices and Dengue Transmission: A Systematic Review of the Evidence  

PubMed Central

Background Despite doubts about methods used and the association between vector density and dengue transmission, routine sampling of mosquito vector populations is common in dengue-endemic countries worldwide. This study examined the evidence from published studies for the existence of any quantitative relationship between vector indices and dengue cases. Methodology/Principal Findings From a total of 1205 papers identified in database searches following Cochrane and PRISMA Group guidelines, 18 were included for review. Eligibility criteria included 3-month study duration and dengue case confirmation by WHO case definition and/or serology. A range of designs were seen, particularly in spatial sampling and analyses, and all but 3 were classed as weak study designs. Eleven of eighteen studies generated Stegomyia indices from combined larval and pupal data. Adult vector data were reported in only three studies. Of thirteen studies that investigated associations between vector indices and dengue cases, 4 reported positive correlations, 4 found no correlation and 5 reported ambiguous or inconclusive associations. Six out of 7 studies that measured Breteau Indices reported dengue transmission at levels below the currently accepted threshold of 5. Conclusions/Significance There was little evidence of quantifiable associations between vector indices and dengue transmission that could reliably be used for outbreak prediction. This review highlighted the need for standardized sampling protocols that adequately consider dengue spatial heterogeneity. Recommendations for more appropriately designed studies include: standardized study design to elucidate the relationship between vector abundance and dengue transmission; adult mosquito sampling should be routine; single values of Breteau or other indices are not reliable universal dengue transmission thresholds; better knowledge of vector ecology is required. PMID:24810901

Bowman, Leigh R.; Runge-Ranzinger, Silvia; McCall, P. J.

2014-01-01

163

Outbreak Simulation  

NSDL National Science Digital Library

This page provides a problem-based activity on risk assessment of environmental health issues. The activity asks students to "study and research emerging and re-emerging infectious diseases, particularly through vector-borne, food-borne, and water-borne educational activities" and "understand that certain exposures in the environment cause various infectious diseases." The activity asks students to simulate a food borne salmonella outbreak, and carry out the resulting investigation. This resource is free to download. Users must first create a login with ATEEC's website to access the file.

2013-07-22

164

Novel, Meso-Substituted Cationic Porphyrin Molecule for Photo-Mediated Larval Control of the Dengue Vector Aedes aegypti  

PubMed Central

Background Control of the mosquito vector population is the most effective strategy currently available for the prevention of dengue fever and the containment of outbreaks. Photo-activated oxidants may represent promising tools for developing effective, safe and ecofriendly novel larvicides. The purpose of this study was to evaluate the potential of the synthetic meso-substituted porphyrin meso-tri(N-methylpyridyl), meso-mono(N-tetradecylpyridyl)porphine (C14) as a photoactivatable larvicide against the dengue vector Aedes (Stegomyia) aegypti. Methodology The photophysical and photochemical properties of the C14 molecule were assessed spectrophotometrically. Photomediated larvicidal efficacy, route of intake and site of action were determined on Ae. aegypti larvae by laboratory bioassays and fluorescence microscopy. Using powdered food pellet for laboratory rodents (a common larval food used in the laboratory) as a carrier for C14, loading-release dynamics, larvicidal efficacy and residual activity of the C14-carrier complex were investigated. Main Findings The C14 molecule was found to exert a potent photosensitizing activity on Ae. aegypti larvae. At irradiation intervals of 12 h and 1 h, at a light intensity of 4.0 mW/cm2, which is 50–100 times lower than that of natural sunlight, LC50 values of 0.1 µM (0.15 mg/l) and 0.5 µM (0.77 mg/l) were obtained, respectively. The molecule was active after ingestion by the larvae and caused irreversible, lethal damage to the midgut and caecal epithelia. The amphiphilic nature of C14 allowed a formulate to be produced that not only was as active against the larvae as C14 in solution, but also possessed a residual activity of at least two weeks, in laboratory conditions. Conclusions The meso-substituted synthetic porphyrin C14, thanks to its photo-sensitizing properties represents an attractive candidate for the development of novel photolarvicides for dengue vector control. PMID:22206031

Lucantoni, Leonardo; Magaraggia, Michela; Lupidi, Giulio; Ouedraogo, Robert Kossivi; Coppellotti, Olimpia; Esposito, Fulvio; Fabris, Clara; Jori, Giulio; Habluetzel, Annette

2011-01-01

165

Use of Multiple Data Sources to Estimate the Economic Cost of Dengue Illness in Malaysia  

PubMed Central

Dengue represents a substantial burden in many tropical and sub-tropical regions of the world. We estimated the economic burden of dengue illness in Malaysia. Information about economic burden is needed for setting health policy priorities, but accurate estimation is difficult because of incomplete data. We overcame this limitation by merging multiple data sources to refine our estimates, including an extensive literature review, discussion with experts, review of data from health and surveillance systems, and implementation of a Delphi process. Because Malaysia has a passive surveillance system, the number of dengue cases is under-reported. Using an adjusted estimate of total dengue cases, we estimated an economic burden of dengue illness of US$56 million (Malaysian Ringgit MYR196 million) per year, which is approximately US$2.03 (Malaysian Ringgit 7.14) per capita. The overall economic burden of dengue would be even higher if we included costs associated with dengue prevention and control, dengue surveillance, and long-term sequelae of dengue. PMID:23033404

Shepard, Donald S.; Undurraga, Eduardo A.; Lees, Rosemary Susan; Halasa, Yara; Lum, Lucy Chai See; Ng, Chiu Wan

2012-01-01

166

Generating temporal model using climate variables for the prediction of dengue cases in Subang Jaya, Malaysia  

PubMed Central

Objective To develop a forecasting model for the incidence of dengue cases in Subang Jaya using time series analysis. Methods The model was performed using the Autoregressive Integrated Moving Average (ARIMA) based on data collected from 2005 to 2010. The fitted model was then used to predict dengue incidence for the year 2010 by extrapolating dengue patterns using three different approaches (i.e. 52, 13 and 4 weeks ahead). Finally cross correlation between dengue incidence and climate variable was computed over a range of lags in order to identify significant variables to be included as external regressor. Results The result of this study revealed that the ARIMA (2,0,0) (0,0,1)52 model developed, closely described the trends of dengue incidence and confirmed the existence of dengue fever cases in Subang Jaya for the year 2005 to 2010. The prediction per period of 4 weeks ahead for ARIMA (2,0,0)(0,0,1)52 was found to be best fit and consistent with the observed dengue incidence based on the training data from 2005 to 2010 (Root Mean Square Error=0.61). The predictive power of ARIMA (2,0,0) (0,0,1)52 is enhanced by the inclusion of climate variables as external regressor to forecast the dengue cases for the year 2010. Conclusions The ARIMA model with weekly variation is a useful tool for disease control and prevention program as it is able to effectively predict the number of dengue cases in Malaysia.

Dom, Nazri Che; Hassan, A Abu; Latif, Z Abd; Ismail, Rodziah

2013-01-01

167

Anamnestic immune response to dengue and decreased severity of yellow Fever.  

PubMed

A protective immunity against yellow fever, from cross-reactive dengue antibodies, has been hypothesized as an explanation for the absence of yellow fever in Southern Asia where dengue immunity is almost universal. This study evaluates the association between protective immunity from cross-reactive dengue antibodies with yellow fever infection and severity of the disease. The study population consisted of military personnel of a jungle garrison and its detachments located in the Ecuadorian Amazonian rainforest. The cross-sectional study employed interviews as well as seroepidemiological methods. Humoral immune response to yellow fever, Mayaro, Venezuelan equine encephalitis, Oropouche, and dengue 2 infections was assessed by evaluating IgM and IgG specific antibodies. Log-linear regression analysis was used to evaluate age and presence of antibodies, against dengue type 2 virus, as predictors of yellow fever infection or severe disease. During the seroepidemiological survey, presence of dengue antibodies among yellow fever cases were observed in 77.3% cases from the coastal region, where dengue is endemic, 14.3% cases from the Amazon and 16.7 % cases from the Andean region. Dengue cross-reactive antibodies were not significantly associated with yellow fever infection but significantly associated with severity of the disease. The findings of this study suggest that previous exposure to dengue infection may have induced an anamnestic immune response that did not prevent yellow fever infection but greatly reduced the severity of the disease. PMID:20300401

Izurieta, Ricardo O; Macaluso, Maurizio; Watts, Douglas M; Tesh, Robert B; Guerra, Bolivar; Cruz, Ligia M; Galwankar, Sagar; Vermund, Sten H

2009-07-01

168

Scabies: Prevention and Control  

MedlinePLUS

... gov . Parasites - Scabies Parasites Home Share Compartir Prevention & Control When a person is infested with scabies mites ... avoid outbreaks. Institutional outbreaks can be difficult to control and require a rapid, aggressive, and sustained response. ...

169

Stochastic epidemic outbreaks: why epidemics are like lasers  

NASA Astrophysics Data System (ADS)

Many diseases, such as childhood diseases, dengue fever, and West Nile virus, appear to oscillate randomly as a function of seasonal environmental or social changes. Such oscillations appear to have a chaotic bursting character, although it is still uncertain how much is due to random fluctuations. Such bursting in the presence of noise is also observed in driven lasers. In this talk, I will show how noise can excite random outbreaks in simple models of seasonally driven outbreaks, as well as lasers. The models for both population dynamics will be shown to share the same class of underlying topology, which plays a major role in the cause of observed stochastic bursting.

Schwartz, Ira B.; Billings, Lora

2004-05-01

170

Dengue Serosurvey in Sint Eustatius  

PubMed Central

Four distinct serotypes of dengue viruses (DENV) are the cause of re-emerging dengue fever (DF) and dengue hemorrhagic fever (DHF). Dengue circulation in the Caribbean has gone from none or single serotype to multiple serotypes co-circulating with reports of continuing cycles of progressively more severe disease in the region. Few studies have investigated dengue on Sint Eustatius. Blood samples were collected to determine the prevalence of antibodies against dengue in the Sint Eustatius population. Greater than 90% of the serum samples (184 of 204) were positive for anti-flavivirus antibodies by enzyme linked immunosorbance assay (ELISA). Plaque reduction neutralization test (PRNT), specific for dengue viruses, showed that 171 of these 184 flavivirus antibody positive sera had a neutralization titer against one or more DENV serotypes. A majority of the sera (62%) had neutralizing antibody to all four dengue serotypes. Only 26 PRNT positive sera (15%) had monotypic dengue virus neutralizing antibody, most of which (20 of 26) were against DENV2. Evidence of infection with all four serotypes was observed across all age groups except in the youngest age group (10–19 years) which contained only DENV2 positive individuals. In a multiple logistic regression model, only the length of residence on the island was a predictor of a positive dengue PRNT50 result. To our knowledge this is the first dengue serosurveillance study conducted on Sint Eustatius since the 1970s. The lack of antibodies to the DEN1, 3, and 4 in the samples collected from participants under 20 years of age suggests that only DEN2 has circulated on island since the early 1990s. The high prevalence of antibodies against dengue (83.8%) and the observation that the length of time on the island was the strongest predictor of infection suggests dengue is endemic on Sint Eustatius and a public health concern that warrants further investigation. PMID:24914538

Leslie, Teresa; Martin, Nicholas J.; Jack-Roosberg, Carol; Odongo, George; Beausoleil, Edwin; Tuck, Jennifer; Raviprakash, Kanakatte; Kochel, Tadeusz J.

2014-01-01

171

Animal models in dengue.  

PubMed

Validation of a mouse model of dengue virus (DENV) infection relies on verification of viremia and productive replication in mouse tissues following infection. Here, we describe a quantitative assay for determining viral RNA levels in mouse serum and tissues. For the purpose of confirming DENV replication, we outline a fluorescence immunohistochemistry (FIHC) protocol for staining a nonstructural protein of DENV. PMID:24696349

Plummer, Emily; Shresta, Sujan

2014-01-01

172

Identification of Chimpanzee Fab Fragments by Repertoire Cloning and Production of a Full-Length Humanized Immunoglobulin G1 Antibody That Is Highly Efficient for Neutralization of Dengue Type 4 Virus  

Microsoft Academic Search

A safe and effective dengue vaccine is still not available. Passive immunization with monoclonal antibodies from humans or nonhuman primates represents an attractive alternative for the prevention of dengue virus infection. Fab monoclonal antibodies to dengue type 4 virus (DENV-4) were recovered by repertoire cloning of bone marrow mRNAs from an immune chimpanzee and analyzed for antigen binding specificity, VH

Ruhe Men; Tetsu Yamashiro; Ana P. Goncalvez; Claire Wernly; Darren J. Schofield; Suzanne U. Emerson; Robert H. Purcell; Ching-Juh Lai

2004-01-01

173

Surveillance for Norovirus Outbreaks  

MedlinePLUS

... norovirus outbreaks are investigated by state and local public health authorities, CDC coordinates outbreaks that involve multiple states. Such outbreaks may result from contaminated food that is widely distributed to ... and local public health agencies during norovirus outbreaks. CDC is also ...

174

Outlook for a dengue vaccine.  

PubMed

Dengue is an increasing medical problem in subtropical and tropical countries. The search for a safe and effective vaccine is complicated by the fact that there are four types of dengue virus and that, if a vaccine is live attenuated, it should be proven not to cause the life-threatening form of dengue, dengue haemorrhagic fever. So far one vaccine candidate, a four-valent chimeric vaccine constructed from a yellow fever vaccine strain, has reached large clinical trials and has been shown to offer protection against dengue types 1, 3 and 54 but not against dengue type 2. It is highly likely that an effective vaccine will be available in the next decade. PMID:24438016

Norrby, R

2014-05-01

175

Airport sentinel surveillance and entry quarantine for dengue infections following a fever screening program in Taiwan  

PubMed Central

Background Dengue has not reached an endemic status in Taiwan; nevertheless, we have implemented a fever screening program at airports for the early detection of febrile passengers with a dengue infection. This study is intended to assess the performance of the airport screening procedures for dengue infection. Methods We analyzed data from the national surveillance system of the Taiwan Centers for Disease Control. We included the imported dengue cases reported by sentinel airports and clinics as well as the domestic cases from 2007–2010. Results Approximately 44.9% (95%CI: 35.73-54.13%) of the confirmed imported dengue cases with an apparent symptom (febrile) in the viremic stage were detected via the airport fever screening program, with an estimated positive predictive value of 2.36% (95% CI: 0.96- 3.75%) and a negative predictive value?>?99.99%. Fluctuations in the number of the symptomatic imported dengue cases identified in the airports (X) were associated with the total number of imported dengue cases (Y) based on a regression analysis of a biweekly surveillance (i.e., n?=?104, R2X:Y?=?0.61, P?dengue cases (X) with a 1–2?month lead time (t) was in parallel with that of the domestic dengue cases (Y) based on a consecutive 4-year surveillance (i.e., n?=?48, R2X(t-1):Y?=?0.22, R2X(t-2):Y?=?0.31, P?dengue at the airports examined in this study indicated some limitations of the fever screening program for the prevention of importation. The screening program could assist in the rapid triage for self-quarantine of some symptomatic dengue cases that were in the viremic stage at the borders and contribute to active sentinel surveillance; however, the blocking of viral transmission to susceptible populations (neighbors or family) from all of the viremic travelers, including those with or without symptoms, is critical to prevent dengue epidemics. Therefore, the reinforcement of mosquito bite prevention and household vector control in dengue-endemic or dengue-competent hotspots during an epidemic season is essential and highly recommended. PMID:22867003

2012-01-01

176

Self-organized critical phenomenon as a q-exponential decay - Avalanche epidemiology of dengue  

NASA Astrophysics Data System (ADS)

We studied the evolution of dengue disease in the state of Bahia. The number of epidemiological dengue cases for each city follows a Self-Organized Criticality behavior (SOC). However, the analysis of the number of cases in Bahia exhibits a q-exponential distribution. To understand this different behavior, we analyzed the distribution of the power law of SOC (?) to all cities of Bahia. Our findings show that the distribution of ? exhibits a dependence between the exponents, which may be because of migration between cities, causing the emergence of outbreaks in different cities in a correlated and asynchronous time series.

Saba, H.; Miranda, J. G. V.; Moret, M. A.

2014-11-01

177

Lessons from malaria control to help meet the rising challenge of dengue  

PubMed Central

Summary Achievements in malaria control could inform efforts to control the increasing global burden of dengue. Better methods for quantifying dengue endemicity—equivalent to parasite prevalence surveys and endemicity mapping used for malaria—would help target resources, monitor progress, and advocate for investment in dengue prevention. Success in controlling malaria has been attributed to widespread implementation of interventions with proven efficacy. An improved evidence base is needed for large-scale delivery of existing and novel interventions for vector control, alongside continued investment in dengue drug and vaccine development. Control of dengue is unlikely to be achieved without coordinated international financial and technical support for national programmes, which has proven effective in reducing the global burden of malaria. PMID:23174383

Anders, Katherine L; Hay, Simon I

2012-01-01

178

Regional Differences in the Growing Incidence of Dengue Fever in Vietnam Explained by Weather Variability  

PubMed Central

Dengue fever is a major health problem in Vietnam, but its incidence differs from province to province. To understand this at the local level, we assessed the effect of four weather components (humidity, rainfall, temperature and sunshine) on the number of dengue cases in nine provinces of Vietnam. Monthly data from 1999 to 2009 were analysed by time-series regression using negative binomial models. A test for heterogeneity was applied to assess the weather-dengue association in the provinces. Those associations were significantly heterogeneous (for temperature, humidity, and sunshine: P < 0.001 heterogeneity test; for rainfall: P = 0.018 heterogeneity test). This confirms that weather components strongly affect dengue transmission at a lag time of 0 to 3 months, with considerable variation in their influence among different areas in Vietnam. This finding may promote the strategic prevention of dengue disease by suggesting specific plans at the local level, rather than a nationally unified approach. PMID:24808744

Vu, Ha Hai; Okumura, Junko; Hashizume, Masahiro; Tran, Duong Nhu; Yamamoto, Taro

2014-01-01

179

Epidemic dengue 2 in the city of Djibouti 1991-1992.  

PubMed

From October 1991 to February 1992, an outbreak of acute fever (in which thick blood films were negative for malaria) spread rapidly in the city of Djibouti, Djibouti Republic, affecting all age groups and both nationals and foreigners. The estimated number of cases was 12,000. The clinical features were consistent with a non-haemorrhagic dengue-like illness. Serum samples from 91 patients were analysed serologically for flavivirus infection (dengue 1-4, West Nile, yellow fever, Zika, Banzi, and Uganda-S), and virus isolation was attempted. Twelve strains of dengue 2 virus were isolated. Dengue infection was confirmed by a 4-fold or greater rise in immunoglobulin (Ig) G antibody in paired serum specimens, the presence of IgM antibody, or isolation of the virus. Overall, 46 of the suspected cases (51%) were confirmed virologically or had serological evidence of a recent flavivirus infection. Statistical analysis showed that the presence of a rash was the best predictor of flavivirus seropositivity. In November 1992, Aedes aegypti was widespread and abundant in several districts of Djibouti city. A serological study of serum samples collected from Djiboutian military personnel 5 months before the epidemic showed that only 15/177 (8.5%) had flavivirus antibodies. These findings, together with a negative serosurvey for dengue serotypes 1-4 and yellow fever virus performed in 1987, support the conclusion that dengue 2 virus has only recently been introduced to Djibouti. PMID:8758061

Rodier, G R; Gubler, D J; Cope, S E; Cropp, C B; Soliman, A K; Polycarpe, D; Abdourhaman, M A; Parra, J P; Maslin, J; Arthur, R R

1996-01-01

180

Planning against Biological Terrorism: Lessons from Outbreak Investigations  

PubMed Central

We examined outbreak investigations conducted around the world from 1988 to 1999 by the Centers for Disease Control and Prevention’s Epidemic Intelligence Service. In 44 (4.0%) of 1,099 investigations, identified causative agents had bioterrorism potential. In six investigations, intentional use of infectious agents was considered. Healthcare providers reported 270 (24.6%) outbreaks and infection control practitioners reported 129 (11.7%); together they reported 399 (36.3%) of the outbreaks. Health departments reported 335 (30.5%) outbreaks. For six outbreaks in which bioterrorism or intentional contamination was possible, reporting was delayed for up to 26 days. We confirmed that the most critical component for bioterrorism outbreak detection and reporting is the frontline healthcare profession and the local health departments. Bioterrorism preparedness should emphasize education and support of this frontline as well as methods to shorten the time between outbreak and reporting. PMID:12737732

Kaiser, Robyn M.; Bales, Michael E.; Shutt, Kathleen; Patrawalla, Amee; McShan, Andre; Tappero, Jordan W.; Perkins, Bradley A.; Dannenberg, Andrew L.

2003-01-01

181

Synchrony of Sylvatic Dengue Isolations: A Multi-Host, Multi-Vector SIR Model of Dengue Virus Transmission in Senegal  

PubMed Central

Isolations of sylvatic dengue-2 virus from mosquitoes, humans and non-human primates in Senegal show synchronized multi-annual dynamics over the past 50 years. Host demography has been shown to directly affect the period between epidemics in other pathogen systems, therefore, one might expect unsynchronized multi-annual cycles occurring in hosts with dramatically different birth rates and life spans. However, in Senegal, we observe a single synchronized eight-year cycle across all vector species, suggesting synchronized dynamics in all vertebrate hosts. In the current study, we aim to explore two specific hypotheses: 1) primates with different demographics will experience outbreaks of dengue at different periodicities when observed as isolated systems, and that coupling of these subsystems through mosquito biting will act to synchronize incidence; and 2) the eight-year periodicity of isolations observed across multiple primate species is the result of long-term cycling in population immunity in the host populations. To test these hypotheses, we develop a multi-host, multi-vector Susceptible, Infected, Removed (SIR) model to explore the effects of coupling multiple host-vector systems of dengue virus transmission through cross-species biting rates. We find that under small amounts of coupling, incidence in the host species synchronize. Long-period multi-annual dynamics are observed only when prevalence in troughs reaches vanishingly small levels (), suggesting that these dynamics are inconsistent with sustained transmission in this setting, but are consistent with local dengue virus extinctions followed by reintroductions. Inclusion of a constant introduction of infectious individuals into the system causes the multi-annual periods to shrink, while the effects of coupling remain the same. Inclusion of a stochastic rate of introduction allows for multi-annual periods at a cost of reduced synchrony. Thus, we conclude that the eight-year period separating amplifications of dengue may be explained by cycling in immunity with stochastic introductions. PMID:23209867

Althouse, Benjamin M.; Lessler, Justin; Sall, Amadou A.; Diallo, Mawlouth; Hanley, Kathryn A.; Watts, Douglas M.; Weaver, Scott C.; Cummings, Derek A. T.

2012-01-01

182

Hepatitis in Dengue Shock Syndrome  

Microsoft Academic Search

Dengue fever is the most frequent arbovirus disease in the world and the most important one in terms of morbidity and mortality. Atypical manifestations of dengue have become commonplace during the last few years, including hepatic damage, which manifests mainly by pain in the right hypochondrium and an increase in the levels of aminotransferases. We describe a case of acute

Luiz José de Souza; Helder Gonçalves Carneiro; João Tadeu Damian Souto Filho; Thiago Ferreira de Souza; Vitor Azevedo Côrtes; Carlos Gicovate Neto; Diogo Assed Bastos; Edno Wallace da Silva Siqueira

2002-01-01

183

Predicting outbreaks of dengue fever according to climate  

E-print Network

.IRDscientistsandtheirpartners1 compared these monthly, quarterly and annual meteorological and epidemiological data over 40 years years. In parallel, daily meteorological measurements have been made since the1950's the meteorological conditions that were decisive in the occurrence of epidemics. From explanation... In order

184

Stochastic Epidemic Outbreaks, or Why Epidemics Behave Like Lasers  

NASA Astrophysics Data System (ADS)

Many diseases, such childhood diseases, dengue fever, and West Nile virus, appear to oscillate randomly as a function of seasonal environmental or social changes. Such oscillations appear to have a chaotic bursting character, although it is still uncertain how much is due to random fluctuations. Such bursting in the presence of noise is also observed in driven lasers. In this talk, I will show how noise can excite random outbreaks in simple models of seasonally driven outbreaks, as well as lasers. The models for both population dynamics will be shown to share the same class of underlying topology, which plays a major role in the cause of observed stochastic bursting. New tools for predicting stcohastic outbreaks will be presented.

Schwartz, Ira; Billings, Lora; Bollt, Erik; Carr, Thomas

2004-03-01

185

Synthetic 1,4-Pyran Naphthoquinones Are Potent Inhibitors of Dengue Virus Replication  

PubMed Central

Dengue virus infection is a serious public health problem in endemic areas of the world where 2.5 billion people live. Clinical manifestations of the Dengue infection range from a mild fever to fatal cases of hemorrhagic fever. Although being the most rapidly spreading mosquito-borne viral infection in the world, until now no strategies are available for effective prevention or control of Dengue infection. In this scenario, the development of compounds that specifically inhibit viral replication with minimal effects to the human hosts will have a substantial effect in minimizing the symptoms of the disease and help to prevent viral transmission in the affected population. The aim of this study was to screen compounds with potential activity against dengue virus from a library of synthetic naphthoquinones. Several 1,2- and 1,4-pyran naphthoquinones were synthesized by a three-component reaction of lawsone, aldehyde (formaldehyde or arylaldehydes) and different dienophiles adequately substituted. These compounds were tested for the ability to inhibit the ATPase activity of the viral NS3 enzyme in in vitro assays and the replication of dengue virus in cultured cells. We have identified two 1,4-pyran naphthoquinones, which inhibited dengue virus replication in mammal cells by 99.0% and three others that reduced the dengue virus ATPase activity of NS3 by two-fold in in vitro assays. PMID:24376541

da Costa, Emmerson C. B.; Amorim, Raquel; da Silva, Fernando C.; Rocha, David R.; Papa, Michelle P.; de Arruda, Luciana B.; Mohana-Borges, Ronaldo; Ferreira, Vitor F.; Tanuri, Amilcar

2013-01-01

186

The AFHSC-Division of GEIS Operations Predictive Surveillance Program: a multidisciplinary approach for the early detection and response to disease outbreaks.  

PubMed

The Armed Forces Health Surveillance Center, Division of Global Emerging Infections Surveillance and Response System Operations (AFHSC-GEIS) initiated a coordinated, multidisciplinary program to link data sets and information derived from eco-climatic remote sensing activities, ecologic niche modeling, arthropod vector, animal disease-host/reservoir, and human disease surveillance for febrile illnesses, into a predictive surveillance program that generates advisories and alerts on emerging infectious disease outbreaks. The program's ultimate goal is pro-active public health practice through pre-event preparedness, prevention and control, and response decision-making and prioritization. This multidisciplinary program is rooted in over 10 years experience in predictive surveillance for Rift Valley fever outbreaks in Eastern Africa. The AFHSC-GEIS Rift Valley fever project is based on the identification and use of disease-emergence critical detection points as reliable signals for increased outbreak risk. The AFHSC-GEIS predictive surveillance program has formalized the Rift Valley fever project into a structured template for extending predictive surveillance capability to other Department of Defense (DoD)-priority vector- and water-borne, and zoonotic diseases and geographic areas. These include leishmaniasis, malaria, and Crimea-Congo and other viral hemorrhagic fevers in Central Asia and Africa, dengue fever in Asia and the Americas, Japanese encephalitis (JE) and chikungunya fever in Asia, and rickettsial and other tick-borne infections in the U.S., Africa and Asia. PMID:21388561

Witt, Clara J; Richards, Allen L; Masuoka, Penny M; Foley, Desmond H; Buczak, Anna L; Musila, Lillian A; Richardson, Jason H; Colacicco-Mayhugh, Michelle G; Rueda, Leopoldo M; Klein, Terry A; Anyamba, Assaf; Small, Jennifer; Pavlin, Julie A; Fukuda, Mark M; Gaydos, Joel; Russell, Kevin L; Wilkerson, Richard C; Gibbons, Robert V; Jarman, Richard G; Myint, Khin S; Pendergast, Brian; Lewis, Sheri; Pinzon, Jorge E; Collins, Kathrine; Smith, Matthew; Pak, Edwin; Tucker, Compton; Linthicum, Kenneth; Myers, Todd; Mansour, Moustafa; Earhart, Ken; Kim, Heung Chul; Jiang, Ju; Schnabel, Dave; Clark, Jeffrey W; Sang, Rosemary C; Kioko, Elizabeth; Abuom, David C; Grieco, John P; Richards, Erin E; Tobias, Steven; Kasper, Matthew R; Montgomery, Joel M; Florin, Dave; Chretien, Jean-Paul; Philip, Trudy L

2011-01-01

187

Mumps Cases and Outbreaks  

MedlinePLUS

... for these years were at usual levels (several hundred cases per year). In 2009- 2010, two large outbreaks occurred. One ... of reported cases returned to usual levels (several hundred cases per year), and outbreaks involved fewer than 20 cases. In ...

188

Tweeting Fever: Are Tweet Extracts a Valid Surrogate Data Source for Dengue Fever?  

PubMed Central

Objective To determine whether Twitter data contains information on dengue-like illness and whether the temporal trend of such data correlates with the incidence dengue or dengue-like illness as identified by city and national health authorities. Introduction Dengue fever is a major cause of morbidity and mortality in the Republic of the Philippines (RP) and across the world. Early identification of geographic outbreaks can help target intervention campaigns and mitigate the severity of outbreaks. Electronic disease surveillance can improve early identification but, in most dengue endemic areas data pre-existing digital data are not available for such systems. Data must be collected and digitized specifically for electronic disease surveillance. Twitter, however, is heavily used in these areas; for example, the RP is among the top 20 producers of tweets in the world. If social media could be used as a surrogate data source for electronic disease surveillance, it would provide an inexpensive pre-digitized data source for resource-limited countries. This study investigates whether Twitter extracts can be used effectively as a surrogate data source to monitor changes in the temporal trend of dengue fever in Cebu City and the National Capitol Region surrounding Manila (NCR) in the RP. Methods We obtained two sources of ground truth incidence for dengue. The first was daily dengue fever incidence for Cebu City and the NCR taken from the Philippines Integrated Disease Surveillance and Response System (PIDSR). The second ground truth source was fever incidence from Cebu City for 2011. The Cebu City Health Office (CCHO) has monitored fever incidence as a surrogate for dengue fever since the 1980s. Tweets from Cebu City, and the NCR were collected prospectively thru Twitter’s public application program interface. The Cebu City fever ground truth data set was smoothed with a seven day moving average to facilitate comparison to the PIDSR and Twitter data. A vocabulary of words and phrases describing fever and dengue fever in the tweets collected were identified and used to mark relevant tweets. A subset of these ‘fever’ tweets that mentioned fever related to a medical situation were identified. The incidence and the temporal pattern of these medically-relevant tweets were compared with the incidence and pattern of fever and dengue fever in the two ground truth data sets. Pearson correlation coefficient was used to compare the correlation among the different data sets. Noted lag periods were adjusted by moving the data in time and re-computing the correlation coefficient. Results 26,023,103 tweets were collected from the two geographic regions: 10,303,366 from Cebu City and 15,719,767 tweets from the NCR. 8,814 (0.02%) Tweets contained the word fever and 4099 (0.01% of total) mentioned fever in a medically-relevant context, for example. “…I have a fever…” vs. “…football fever….” The medically-relevant tweets were compared with both ground truth data sets. The correlation between the Tweets and each of the incidence data sets is shown below. Conclusions Tweets containing medically-relevant fever references were correlated (p<0.0001) with both fever and dengue fever incidence in the ground truth data sets. The signal indicating fever in the medically-related tweets led the incidence data significantly: by 6 days for the Cebu City fever incidence; and by 12 days for the PIDSR dengue fever incidence. Temporal adjustment to account for observed lag periods increased the correlation coefficient by about one-third in both cases. This was a limited pilot study, but it suggests that Twitter extracts may provide a valid and timely surrogate data source to monitor dengue fever in this population. Further study of the correlation of Twitter and dengue in other areas, and of Twitter with other illnesses is warranted.

Coberly, Jacqueline S.; Fink, Clayton R.; Elbert, Eugene; Yoon, In-Kyu; Velasco, John M.; Tomayo, Agnes; Roque, V.; Ygano, S.; Macasoco, Durinda; Lewis, Sheri

2013-01-01

189

Modeling cholera outbreaks  

PubMed Central

Mathematical modeling can be a valuable tool for studying infectious disease outbreak dynamics and simulating the effects of possible interventions. Here, we describe approaches to modeling cholera outbreaks and how models have been applied to explore intervention strategies, particularly in Haiti. Mathematical models can play an important role in formulating and evaluating complex cholera outbreak response options. Major challenges to cholera modeling are insufficient data for calibrating models and the need to tailor models for different outbreak scenarios. PMID:23412687

Longini, Ira M.; Morris, J. Glenn

2014-01-01

190

Seroprevalence of Dengue Fever in US Army Special Operations Forces: Initial Results and the Way Ahead.  

PubMed

The endemicity of dengue fever (DF) and, consequently, sequelae of DF are increasing worldwide. The increases are largely a result of widespread international travel and the increased range of the mosquito vectors. US Army Special Operations Command (USASOC) personnel are at an increased risk of exposure to dengue based on their frequent deployments to and presence in dengue endemic areas worldwide. Repeated deployments to different endemic areas can increase the risk for developing the more serious sequelae of dengue: dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Information about the seroprevalence rate of dengue in USASOC personnel, in particular, is lacking and is critical to assessing the risk, tailoring preventive medicine countermeasures, leveraging field diagnostics, and maintaining mission capability. In the first part of a two-part project to assess baseline seroprevalence in USASOC units, a random, unit-stratified sample of 500 anonymous serum specimens from personnel assigned to the highest-risk units in USASOC were screened for dengue using a microneutralization assay. Of the 500 specimens screened, 56 (11.2%) of 500 had neutralizing titers (NT) (MN?? ? 10) against at least one DENV serotype. Subsequent sample titration resulted in 48 (85.7%) of 56 of the samples with NT (MN?? ? 10) against at least one dengue serotype for an overall dengue exposure rate of 9.6% (48 of 500). The second part of the ongoing project, started in 2012, was a multicenter, serosurveillance project using predeployment and postdeployment sera collected from USASOC personnel deployed to South and Central America, Africa, and Southeast Asia. Preliminary results show a 13.2% (55 of 414) seropositivity rate. The significance of these findings as they relate to personal risk and operational impact is discussed. PMID:25344719

Caci, Jennifer B; Blaylock, Jason M; De La Barrera, Rafael; Griggs, April N; Lin, Leyi; Jarman, Richard G; Thomas, Stephen J; Lyons, Arthur G

2014-01-01

191

Viral Genetics as a Basis of Dengue Pathogenesis  

Microsoft Academic Search

Dengue is the most widespread mosquito-borne human viral disease. The disease is now endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, South-East Asia and the Western Pacific regions. Dengue viruses cause dengue infection, which ranges from mild febrile illness (dengue fever, DF) to fatal haemorrhagic manifestation (dengue haemorrhagic fever, DHF) leading to shock syndrome (dengue

Suchita Chaudhry; Sathyamangalam Swaminathan; Navin Khanna

2006-01-01

192

An online spatiotemporal prediction model for dengue fever epidemic in Kaohsiung (Taiwan).  

PubMed

The emergence and re-emergence of disease epidemics is a complex question that may be influenced by diverse factors, including the space-time dynamics of human populations, environmental conditions, and associated uncertainties. This study proposes a stochastic framework to integrate space-time dynamics in the form of a Susceptible-Infected-Recovered (SIR) model, together with uncertain disease observations, into a Bayesian maximum entropy (BME) framework. The resulting model (BME-SIR) can be used to predict space-time disease spread. Specifically, it was applied to obtain a space-time prediction of the dengue fever (DF) epidemic that took place in Kaohsiung City (Taiwan) during 2002. In implementing the model, the SIR parameters were continually updated and information on new cases of infection was incorporated. The results obtained show that the proposed model is rigorous to user-specified initial values of unknown model parameters, that is, transmission and recovery rates. In general, this model provides a good characterization of the spatial diffusion of the DF epidemic, especially in the city districts proximal to the location of the outbreak. Prediction performance may be affected by various factors, such as virus serotypes and human intervention, which can change the space-time dynamics of disease diffusion. The proposed BME-SIR disease prediction model can provide government agencies with a valuable reference for the timely identification, control, and prevention of DF spread in space and time. PMID:24615833

Yu, Hwa-Lung; Angulo, José M; Cheng, Ming-Hung; Wu, Jiaping; Christakos, George

2014-05-01

193

c-Src protein kinase inhibitors block assembly and maturation of dengue virus  

PubMed Central

Dengue virus is a mosquito-borne flavivirus that represents an important emerging infectious disease and is an international health concern. Currently, there is no vaccine or effective antiviral therapy to prevent or to treat dengue virus infection. The slow progress in developing antiviral agents might be alleviated by the availability of efficient high-throughput anti-dengue virus screening assays. In this study, we report an immunofluorescence image-based assay suitable for identification of small molecule inhibitors of dengue virus infection and replication. Using this assay, we have discovered that inhibitors of the c-Src protein kinase exhibit a potent inhibitory effect on dengue virus (serotypes 1–4) and murine flavivirus Modoc. Mechanism of action studies demonstrated that the c-Src protein kinase inhibitor dasatinib prevents the assembly of dengue virions within the virus-induced membranous replication complex. These results demonstrate that this cell-based screen may provide a powerful means to identify new potential targets for anti-dengue drug development while simultaneously providing pharmacological probes to investigate dengue virus–host cell interactions at the biochemical level. Given the simplicity and excellent reproducibility of the assay, it should be useful in high-throughput screens of both small molecule and RNAi libraries when implemented on a robotic image-based high-throughput screen (HTS) platform. Given the reasonable clinical safety of inhibitors such as dasatinib and AZD0530, inhibitors of c-Src protein kinase may have the potential to become a new class of anti-dengue viral therapeutic agents. PMID:17360676

Chu, J. J. H.; Yang, Priscilla L.

2007-01-01

194

PH 412 Syllabus 2013 Control and Prevention of  

E-print Network

microbiology, pathophysiology, or medical treatment. Special attention will be focused on outbreak, unique risk factors, outbreak investigations, surveillance, strategies for control and prevention, malaria, foodborne illness, etc) and a public health tool (vector control, immunization, outbreak

Chisholm, Rex L.

195

Planning against biological terrorism: lessons from outbreak investigations.  

PubMed

We examined outbreak investigations conducted around the world from 1988 to 1999 by the Centers for Disease Control and Prevention's Epidemic Intelligence Service. In 44 (4.0%) of 1,099 investigations, identified causative agents had bioterrorism potential. In six investigations, intentional use of infectious agents was considered. Healthcare providers reported 270 (24.6%) outbreaks and infection control practitioners reported 129 (11.7%); together they reported 399 (36.3%) of the outbreaks. Health departments reported 335 (30.5%) outbreaks. For six outbreaks in which bioterrorism or intentional contamination was possible, reporting was delayed for up to 26 days. We confirmed that the most critical component for bioterrorism outbreak detection and reporting is the frontline healthcare profession and the local health departments. Bioterrorism preparedness should emphasize education and support of this frontline as well as methods to shorten the time between outbreak and reporting. PMID:12737732

Ashford, David A; Kaiser, Robyn M; Bales, Michael E; Shutt, Kathleen; Patrawalla, Amee; McShan, Andre; Tappero, Jordan W; Perkins, Bradley A; Dannenberg, Andrew L

2003-05-01

196

Dengue encephalopathy - still an enigma?  

PubMed

Dengue encephalopathy or dengue hemorrhagic fever (DHF) with neurological involvement was once considered to be one of the rarer presentations of this infectious agent. In recent years, many such clinical cases have been reported, though they still remain isolated. We hereby report a case of confirmed dengue fever with features of encephalopathy with previously unreported cranial magnetic resonance imaging findings suggestive of extensive involvement of the bilateral cerebellar region, brainstem, and thalami along with peculiar rim enhancement but normal cerebrospinal fluid analysis. PMID:25116679

Malik, Rupali; Gogna, Arun; Meher, Jhasketan; Singh, Kumud Kumar; Sharma, Susheel Kumar

2014-08-01

197

Recent Epidemiological Trends of Dengue in the French Territories of the Americas (2000-2012): A Systematic Literature Review  

PubMed Central

Dengue is a public health concern across the globe, and an escalating problem in the Americas. As part of a wider programme (covering Latin America and South East Asia) to characterize the epidemiology of dengue in dengue endemic areas, we undertook a systematic literature review to assess epidemiological trends (incidence, timing and duration of outbreaks/epidemics, age and sex distribution, serotype distribution, seroprevalence and disease severity) for dengue across the French Territories of the Americas (FTA), in French Guiana, Guadeloupe, Martinique, Saint Martin and Saint Barthélemy between 2000 and 2012 (CRD42012002341: http://www.crd.york.ac.uk/prospero/display_record.asp?ID=CRD42012002341). Of 413 relevant data sources identified, 45 were eligible for inclusion. A large proportion of the available data were from national surveillance reports, and 12 publications were from peer-reviewed journals. During the review period, 3–5 epidemics were identified in each of the island territories and French Guiana, and epidemics were often associated with a shift in the predominant circulating dengue virus serotype. Substantial gaps in epidemiological knowledge were identified. In particular, information regarding dengue virus genotype distribution, seroprevalence and age distribution of dengue were lacking. Additionally, much of the available data were from epidemic years; data from inter-epidemic periods were sparse. Nevertheless, the available epidemiological data showed that dengue is endemic across the FTA and suggest an evolution towards hyperendemicity, highlighting the need to continue the efforts with the existing surveillance programmes to assist in planning an effective vaccination programme once a dengue vaccine is deployed. Protocol registration PROSPERO CRD42012002341 PMID:25375627

L'Azou, Maina; Taurel, Anne-Frieda; Flamand, Claude; Quenel, Philippe

2014-01-01

198

Public Acceptance and Willingness-to-Pay for a Future Dengue Vaccine: A Community-Based Survey in Bandung, Indonesia  

PubMed Central

Background All four serotypes of dengue virus are endemic in Indonesia, where the population at risk for infection exceeds 200 million people. Despite continuous control efforts that were initiated more than four decades ago, Indonesia still suffers from multi-annual cycles of dengue outbreak and dengue remains as a major public health problem. Dengue vaccines have been viewed as a promising solution for controlling dengue in Indonesia, but thus far its potential acceptability has not been assessed. Methodology/Principal Findings We conducted a household survey in the city of Bandung, Indonesia by administering a questionnaire to examine (i) acceptance of a hypothetical pediatric dengue vaccine; (ii) participant's willingness-to-pay (WTP) for the vaccine, had it not been provided for free; and (iii) whether people think vector control would be unnecessary if the vaccine was available. A proportional odds model and an interval regression model were employed to identify determinants of acceptance and WTP, respectively. We demonstrated that out of 500 heads of household being interviewed, 94.2% would agree to vaccinate their children with the vaccine. Of all participants, 94.6% were willing to pay for the vaccine with a median WTP of US$1.94. In addition, 7.2% stated that vector control would not be necessary had there been a dengue vaccination program. Conclusions/Significance Our results suggest that future dengue vaccines can have a very high uptake even when delivered through the private market. This, however, can be influenced by vaccine characteristics and price. In addition, reduction in community vector control efforts may be observed following vaccine introduction but its potential impact in the transmission of dengue and other vector-borne diseases requires further study. PMID:24069482

Hadisoemarto, Panji Fortuna; Castro, Marcia C.

2013-01-01

199

Close contact precautions could prevent an outbreak of crimean-congo hemorrhagic Fever: a case series report from southern part of tehran.  

PubMed

Between the end of June and the middle of July 2011, an outbreak of Crimean-Congo Hemorrhagic Fever occurred in southern part of Tehran, Iran. This study reports clinical, laboratory findings and outcome of six cases, who were all consanguine. Index case who was livestock-worker died with hemorrhagic manifestations; thereafter his pregnant wife, three brothers, mother-in-law and his pregnant sister-in-law were admitted and except for the latter, ribavirin was administered. The brother with close contact with body fluids and blood of index case, died with hemorrhage. Low platelet, high aminotransferases and elevated PT, PTT were detected in this case. Skin manifestations were present in five cases. Only in one case RT-PCR and IgM serology were reported as positive for CCHF virus by reference laboratory. In endemic areas, high index of suspicion should be kept in mind in successfully finding and treating cases in early phase of the disease. PMID:23930191

Mardani, Masoud; Namazee, Najmeh

2013-06-01

200

Close Contact Precautions Could Prevent an Outbreak of Crimean-Congo Hemorrhagic Fever: A Case Series Report from Southern Part of Tehran  

PubMed Central

Between the end of June and the middle of July 2011, an outbreak of Crimean-Congo Hemorrhagic Fever occurred in southern part of Tehran, Iran. This study reports clinical, laboratory findings and outcome of six cases, who were all consanguine. Index case who was livestock-worker died with hemorrhagic manifestations; thereafter his pregnant wife, three brothers, mother-in-law and his pregnant sister-in-law were admitted and except for the latter, ribavirin was administered. The brother with close contact with body fluids and blood of index case, died with hemorrhage. Low platelet, high aminotransferases and elevated PT, PTT were detected in this case. Skin manifestations were present in five cases. Only in one case RT-PCR and IgM serology were reported as positive for CCHF virus by reference laboratory. In endemic areas, high index of suspicion should be kept in mind in successfully finding and treating cases in early phase of the disease. PMID:23930191

Mardani, Masoud; Namazee, Najmeh

2013-01-01

201

First dengue haemorrhagic fever epidemic in the Americas, 1981: insights into the causative agent.  

PubMed

Historical records describe a disease in North America that clinically resembled dengue haemorrhagic fever during the latter part of the slave-trading period. However, the dengue epidemic that occurred in Cuba in 1981 was the first laboratory-confirmed and clinically diagnosed outbreak of dengue haemorrhagic fever in the Americas. At that time, the presumed source of the dengue type 2 strain isolated during this epidemic was considered controversial, partly because of the limited sequence data and partly because the origin of the virus appeared to be southern Asia. Here, we present a molecular characterisation at the whole-genome level of the original strains isolated at different time points during the epidemic. Phylogenetic trees constructed using Bayesian methods indicated that 1981 Cuban strains group within the Asian 2 genotype. In addition, the study revealed that viral evolution occurred during the epidemic - a fact that could be related to the increasing severity from month to month. Moreover, the Cuban strains exhibited particular amino acid substitutions that differentiate them from the New Guinea C prototype strain as well as from dengue type 2 strains isolated globally. PMID:25091743

Rodriguez-Roche, Rosmari; Hinojosa, Yoandri; Guzman, Maria G

2014-12-01

202

Small Molecule Pan-dengue and West Nile Virus NS3 Protease Inhibitors  

PubMed Central

Background Dengue fever, dengue hemorrhagic fever, and dengue shock syndrome are caused by infections with any of the four serotypes of the dengue virus (DENV) and are an increasing global health risk. The related West Nile Virus (WNV) causes significant morbidity and mortality as well and continues to be a threat in endemic areas. Currently no FDA approved vaccines or therapeutics are available to prevent or treat any of these infections. Like the other members of the Flaviviridae family, DENV and WNV encode a protease (NS3) which is essential for viral replication and therefore is a promising target for developing therapies to treat dengue and West Nile infections. Methods Flaviviral protease inhibitors were identified and biologically characterized for mechanism of inhibition and DENV anti-viral activity. Results A guanidinylated 2, 5-dideoxystreptamine class of compounds was identified that competitively inhibited the NS3 protease from DENV(1-4) and WNV with IC50 values in the 1-70 ?M range. Cytotoxicity was low; however, antiviral activity versus DENV-2 on VERO cells was not detectable. Conclusions This class of compounds is the first to demonstrate competitive pan-dengue and WNV NS3 protease inhibition and, given the sequence conservation among flavivirus NS3 proteins, suggests that developing a pan-dengue or possibly pan-flavivirus therapeutic is feasible. PMID:21566267

Cregar-Hernandez, Lynne; Jiao, Guan-Sheng; Johnson, Alan T.; Lehrer, Axel T.; Wong, Teri Ann S.; Margosiak, Stephen A.

2011-01-01

203

[Principles of an outbreak investigation in public health practice].  

PubMed

An outbreak (or epidemic) is a higher number of cases of a given disease in a given population and time interval. A timely investigation has for aim to identify the source and vehicle of the outbreak and provides unique opportunities to better understand its occurrence and the role of contributing risk factors to implement the most appropriate measures to control it and prevent further recurrences. The investigation of an outbreak is based on a multidisciplinary approach (clinical, epidemiological, environmental, and microbiological) with a descriptive and analytical (hypothesis testing) phase. In this article, we describe the methodological approach of a field outbreak investigation illustrated by examples taken from our experience. The investigation includes the following steps: establishing the existence of the outbreak; defining the disease; finding cases; describing cases by time, place, and person characteristics; establishing a hypothesis related to the mode of occurrence; testing the hypotheses; conducting an environmental investigation; conducting a microbiological investigation; controlling the outbreak, preventing further occurrences, and writing an investigation report to share experience with the public health and scientific community. The investigation of an outbreak is an evolving process: information gathered or conclusions made at a given stage must be fully used for following steps. The social, institutional, and political background associated with outbreaks usually makes their investigation complex and should be taken into account. The earlier the outbreak is detected and investigated in close relation with public health authorities, the greater will be the potential preventive impact of control measures. PMID:17196781

Desenclos, J-C; Vaillant, V; Delarocque Astagneau, E; Campèse, C; Che, D; Coignard, B; Bonmarin, I; Lévy Bruhl, D; de Valk, H

2007-02-01

204

Dengue Virus 1 in Buenos Aires from 1999 to 2010: Towards Local Spread  

PubMed Central

Dengue virus (DENV) is a public health problem representing the most important arthropod-borne viral disease in humans. In Argentina, Northern provinces have reported autochthonous cases since 1997, though these outbreaks have originated in bordering countries, where co-circulation of more than one serotype has been reported. In the last decade, imported dengue cases have been reported in Buenos Aires, the urban area of Argentina with the highest population density. In 2009, a dengue outbreak affected Buenos Aires and, for the first time, local transmission was detected. All cases of this outbreak were caused by DENV-1. In this report, we present the full-length sequences of 27 DENV-1 isolates, corresponding to imported cases of 1999–2000, as well as local and imported cases of the 2009 and 2010 outbreaks. We analyzed their phylogenetic and phylodynamic relationships and their global and local spread. Additionally, we characterized their genomic and phenotypic features. All cases belonged to DENV-1 genotype V. The most recent ancestor for this genotype was dated ?1934, whereas that for the 2009 outbreak was dated ?2007. The mean rates of nucleotide substitution were 4.98E-4 and 8.53E-4 subs./site/yr, respectively. We inferred an introduction from Paraguay in 1999–2000 and mainly from Venezuela during 2009–2010. Overall, the number of synonymous substitutions per synonymous site significantly exceeded the number of non-synonymous substitutions per site and 12 positively selected sites were detected. These analyses could contribute to a better understanding regarding spread and evolution of this pathogen in the Southern Cone of South America. PMID:25343372

Tittarelli, Estefania; Mistchenko, Alicia S.

2014-01-01

205

Fusion of protegrin-1 and plectasin to MAP30 shows significant inhibition activity against dengue virus replication.  

PubMed

Dengue virus (DENV) broadly disseminates in tropical and sub-tropical countries and there are no vaccine or anti-dengue drugs available. DENV outbreaks cause serious economic burden due to infection complications that requires special medical care and hospitalization. This study presents a new strategy for inexpensive production of anti-DENV peptide-fusion protein to prevent and/or treat DENV infection. Antiviral cationic peptides protegrin-1 (PG1) and plectasin (PLSN) were fused with MAP30 protein to produce recombinant antiviral peptide-fusion protein (PG1-MAP30-PLSN) as inclusion bodies in E. coli. High yield production of PG1-MAP30-PLSN protein was achieved by solubilization of inclusion bodies in alkaline buffer followed by the application of appropriate refolding techniques. Antiviral PG1-MAP30-PLSN protein considerably inhibited DENV protease (NS2B-NS3pro) with half-maximal inhibitory concentration (IC50) 0.5±0.1 ?M. The real-time proliferation assay (RTCA) and the end-point proliferation assay (MTT assay) showed that the maximal-nontoxic dose of the peptide-fusion protein against Vero cells is approximately 0.67±0.2 ?M. The cell-based assays showed considerable inhibition of the peptide-fusion protein against binding and proliferating stages of DENV2 into the target cells. The peptide-fusion protein protected DENV2-challeged mice with 100% of survival at the dose of 50 mg/kg. In conclusion, producing recombinant antiviral peptide-fusion protein by combining short antiviral peptide with a central protein owning similar activity could be useful to minimize the overall cost of short peptide production and take advantage of its synergistic antiviral activities. PMID:24722532

Rothan, Hussin A; Bahrani, Hirbod; Mohamed, Zulqarnain; Abd Rahman, Noorsaadah; Yusof, Rohana

2014-01-01

206

[Aedes aegypti in French Guiana. Some aspects of history, general ecology and vertical transmission of the dengue virus].  

PubMed

Aedes aegypti is suspected to be present in the country since the late 18th century, and was responsible of urban yellow fever epidemics in the last century. This mosquito was identified for the first time in French Guiana in 1902. More recently, in 1940, an eradication campaign started and Aedes aegypti was eradicated between 1950 and 1963, date of the reinfestation. During the past 30 years, some dengue outbreaks occurred every 2 to 6 years, and the first dengue haemorrhagic fever epidemic spread over the country in 1992. Actually, Ae. aegypti is distributed almost all inhabited areas of French Guiana: in the towns, villages, smaller human settlements, and was also found in a wild area. The most frequent Ae. aegypti breeding-sources are the outside discarded small containers, other less frequent breeding-sites are the outside flower pots and the outside big containers. The type of breeding-source significantly influences the duration of larval and pupal development. In French Guiana, Ae. aegypti is the only vector of dengue. The vertical transmission of dengue viruses under field conditions was demonstrated. Dengue is thus endemic in the country and has almost the same distribution as Ae. aegypti, with most probably the same possibilities of extension. Ae. aegypti can be considered not only as vector and an amplificator of dengue in French Guiana, but also as a reservoir, even if occasional. PMID:8924768

Fouque, F; Carinci, R

1996-01-01

207

Risk factors and clinical features associated with severe dengue infection in adults and children during the 2001 epidemic in Chonburi, Thailand  

Microsoft Academic Search

Summary objectives Dengue haemorrhagic fever (DHF) is an important cause of morbidity in South-east Asia and used to occur almost exclusively in young children. In recent years, there has been a progressive shift in age-distribution towards older children and adults. We investigated an outbreak in 2001 in both children and adults, in an endemic area of Thailand. methods Retrospective study

Ole Wichmann; Suchat Hongsiriwon; Chureeratana Bowonwatanuwong; Kesinee Chotivanich; Yoawalark Sukthana; Sasithon Pukrittayakamee

2004-01-01

208

Poliomyelitis in Oman. I. The last outbreak?  

PubMed

Since 1988, the Sultanate of Oman has experienced three outbreaks of paralytic poliomyelitis. The last outbreak occurred in December 1993 and involved two children aged 10 months and 4 1/2 years. The children had received five and four doses, respectively, of trivalent oral polio vaccine (OPV) and lived in the same village. Serum neutralizing antibody tests suggested that paralytic polio in these children was due to poor antibody response to OPV. Wild poliovirus type 1 was isolated from both patients, as well as from seven of ten close contacts of the older child, and one of eight contacts of the younger child. All contacts had received three to six doses of OPV. Genomic sequence studies indicated that the virus isolates belonged to a genotypic group prevalent in southern and western Asia, but differed markedly from virus isolated during the 1988/89 outbreak, suggesting another importation of poliovirus. In response to the outbreak, supplementary immunization with OPV was given to children <6 years of age, initially in the affected district, and subsequently to children in the whole country. This study demonstrates that immunization with three to six doses of OPV did not prevent infection with wild poliovirus. In those children with sub-optimal response to OPV, infection resulted in paralytic poliomyelitis. The outbreak remained localized in one village, indicating that the outbreak control measures were effective. PMID:11600090

Al-Dhahry, S H; Koul, R L; Al-Busaidy, S M; Al-Awaidy, S T; Al-Khusaiby, S M; Suleman, A J

2001-10-22

209

Outbreaks of Enteric Disease Associated with Animal Contact: Not Just a Foodborne Problem Anymore  

Microsoft Academic Search

In the past 10 years, an increasing number of outbreaks of enteric disease associated with animals in public settings, such as fairs and petting zoos, have been reported. Fifty-five of these outbreaks that occurred in the United States during 1991- 2005 are reviewed in this article. Lessons learned from these outbreaks and recommendations for prevention are also discussed. Physicians should

Frederick J. Angulo; Nicole Steinmuller; Linda Demma; Jeff B. Bender; Millicent Eidson

2006-01-01

210

Recombinant Multiepitope Protein for Early Detection of Dengue Infections  

Microsoft Academic Search

Dengue fever is a mosquito-borne viral disease prevalent mainly in tropical countries. As the clinical manifestations of dengue are not very unique, laboratory diagnosis is crucial in identifying cases of dengue infection. Detection of dengue infection based on the identification of antidengue antibodies has emerged as a practical and reliable means of diagnosing dengue fever. We recently developed a customized

Ravulapalli AnandaRao; Sathyamangalam Swaminathan; Sirimali Fernando; Asha M. Jana; Navin Khanna

2006-01-01

211

Factors Predicting Severe Dengue in Patients with Dengue Fever  

PubMed Central

Introduction Dengue virus (DENV) affects over half the world’s population in 112 countries, and dengue fever (DF) is the second largest arthropod borne infectious global hazard after malaria with complications like Dengue Hemorrhagic Fever (DHF) and Dengue Shock Syndrome (DSS), accounting for significant morbidity and mortality world-over. Pakistan is significantly affected with DENV infection and to-date no study identifying risk factors associated with development of severe complications of DF has been done. Methods 997 confirmed cases of DF were collected from a tertiary care hospital in Lahore, Pakistan and their clinical and biochemical data were collected. Univariate, multivariate and logistics regression analysis was performed to identify risk factors associated with development of DHF and DSS. Results Bleeding OR 70.7 (CI 38.4–129.9), deranged liver function test OR 1.9 (CI 0.97–0.99), presence of urinary red blood cells OR 1.4 (95%CI 0.179–0.900) and presence of urinary protein OR 1.1 (95%CI 0.191–0.974) were related to development of DHF and DSS. Discussion Severe Dengue, like DHF and DSS can be predicted by the presence of clinical and biochemical factors like signs of bleeding, deranged liver function test, presence of urinary red blood cells and urinary protein; so that the patients at high risk for complication be identified early and started on treatment timely. Conclusion Predictors of severe dengue are identified in this study but further large scale multi-centered studies are needed for better interpretation. PMID:23505602

Khan, Muhammad Imran Hasan; Anwar, Eram; Agha, Adnan; Hassanien, Noha Saleh Mohamed; Ullah, Ehsan; Syed, Imran Ali; Raja, Arsalan

2013-01-01

212

Dengue in peri-urban Pak-Ngum district, Vientiane capital of Laos: a community survey on knowledge, attitudes and practices  

PubMed Central

Background Dengue remains an important cause of morbidity in Laos. Good knowledge, attitudes and practices (KAP) among the public regarding dengue prevention are required for the success of disease control. Very little is known about dengue KAP among the Lao general population. Methods This was a KAP household survey on dengue conducted in a peri-urban Pak-Ngum district of Vientiane capital, Laos. A two-stage cluster sampling method was used to select a sample of participants to represent the general community. Participants from 231 households were surveyed using an interviewer-administered questionnaire. Results Although 97% of the participants heard of dengue, there was a lack of depth of knowledge on dengue: 33% of them did not know that malaria and dengue were different diseases, 32% incorrectly believed that Aedes mosquito transmits malaria, 36% could not correctly report that Aedes mosquitoes bite most frequently at sunrise and sunset; and?dengue was a severe yet preventable disease. Self reported prevention methods were quite high yet observation of the participants’ yards showed use of prevention methods to be only moderate. The majority (93%) of the interviewees did not believe that they had enough information on dengue. There was an association between good knowledge and better practices, but good knowledge was associated with worse attitudes. Conclusions There is a lack of depth of knowledge regarding dengue in Pak-Ngum community and observation methods revealed that more needs to be done by community members themselves to prevent the spread of Aedes mosquitoes. PMID:23641953

2013-01-01

213

A Guide to the Investigation of Waterborne Outbreaks  

ERIC Educational Resources Information Center

Explained is the process of investigating an alleged waterborne disease outbreak. The information is designed to help water personnel work more effectively with health authorities in tracing, controlling, and preventing waterborne disease. (Author/MA)

Rosenberg, Mark L.

1977-01-01

214

Determinants of lemming outbreaks.  

PubMed

Population outbreaks in tundra rodents have intrigued scientists for a century as a result of their spectacular appearances and their general lessons in ecology. One outstanding question that has led to competing hypotheses is why sympatric lemmings and voles differ in regularity and shape of their outbreaks. Lemming outbreaks may be lost for decades while vole populations maintain regular population cycles. Moreover, when lemming populations eventually irrupt, they do so more steeply than the vole populations. Norwegian lemmings exhibited a large-scale outbreak synchronously with gray-sided voles in Finnmark, northern Fennoscandia, during 2006 to 2007 for the first time in two decades. Analyses of spatial variability of this outbreak across altitudinal gradients allowed us to identify determinants of the contrasting lemming and vole dynamics. The steeper lemming outbreak trajectories were caused by breeding and population growth during winter, when nonbreeding vole populations consistently declined. The differently shaped lemming and vole outbreaks appear to result from a particular demographic tactic of lemmings that evolved as an adaptation to the long and cold Arctic-Alpine winters. The lemming outbreak amplitude increased with altitude and vole density, indicating that lemming outbreaks are jointly facilitated by low temperatures and apparent mutualism with voles mediated by shared predators. High sensitivity to variation in climate and predation is likely to be the reasons why lemmings have more erratic population dynamics than sympatric voles. The combination of continued climatic warming and dampened vole cycles is expected to further decrease the frequency, amplitude, and geographic range of lemming outbreaks in tundra ecosystems. PMID:21245340

Ims, Rolf A; Yoccoz, Nigel G; Killengreen, Siw T

2011-02-01

215

Dengue: a new challenge for neurology  

PubMed Central

Dengue infection is a leading cause of illness and death in tropical and subtropical regions of the world. Forty percent of the world's population currently lives in these areas. The clinical picture resulting from dengue infection can range from relatively minor to catastrophic hemorrhagic fever. Recently, reports have increased of neurological manifestations. Neuropathogenesis seems to be related to direct nervous system viral invasion, autoimmune reaction, metabolic and hemorrhagic disturbance. Neurological manifestations include encephalitis, encephalopathy, meningitis, Guillain-Barré syndrome, myelitis, acute disseminated encephalomyelitis, polyneuropathy, mononeuropathy, and cerebromeningeal hemorrhage. The development of neurological symptoms in patients with positive Immunoglobulin M (IgM) dengue serology suggests a means of diagnosing the neurological complications associated with dengue. Viral antigens, specific IgM antibodies, and the intrathecal synthesis of dengue antibodies have been successfully detected in cerebrospinal fluid. However, despite diagnostic advancements, the treatment of neurological dengue is problematic. The launch of a dengue vaccine is expected to be beneficial. PMID:23355928

Puccioni-Sohler, Marzia; Orsini, Marco; Soares, Cristiane N.

2012-01-01

216

Temperature related storage evaluation of an RT-PCR test kit for the detection of dengue infection in mosquitoes.  

PubMed

The rapid detection of dengue infection in mosquito vectors is important for early warning to forestall an outbreak. Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) provides a rapid method for dengue detection in man and mosquitoes. An RT-PCR kit developed by the Medical Entomology Unit, Institute for Medical Research to detect dengue infection in mosquitoes, was tested for its shelf life at 3 storage temperatures: room temperature, refrigerator and freezer. Test kits were tested once every 3 days for kits stored at room temperature, and once every week for those stored at refrigerator and freezer temperatures. The results showed that the test kit could only be stored above its recommended storage temperature of -20 degrees C for not more than 3 days. DNA 100 bp markers in the kits appeared to be stable at the tested temperatures and were usable up to the 20th day when stored at 2 degrees C and below. PMID:16880757

Ooi, Cher Pheng; Rohani, Ahmad; Zamree, Ismail; Lee, H L

2005-06-01

217

Long-Term and Seasonal Dynamics of Dengue in Iquitos, Peru  

PubMed Central

Introduction Long-term disease surveillance data provide a basis for studying drivers of pathogen transmission dynamics. Dengue is a mosquito-borne disease caused by four distinct, but related, viruses (DENV-1-4) that potentially affect over half the world's population. Dengue incidence varies seasonally and on longer time scales, presumably driven by the interaction of climate and host susceptibility. Precise understanding of dengue dynamics is constrained, however, by the relative paucity of laboratory-confirmed longitudinal data. Methods We studied 10 years (2000–2010) of laboratory-confirmed, clinic-based surveillance data collected in Iquitos, Peru. We characterized inter and intra-annual patterns of dengue dynamics on a weekly time scale using wavelet analysis. We explored the relationships of case counts to climatic variables with cross-correlation maps on annual and trimester bases. Findings Transmission was dominated by single serotypes, first DENV-3 (2001–2007) then DENV-4 (2008–2010). After 2003, incidence fluctuated inter-annually with outbreaks usually occurring between October and April. We detected a strong positive autocorrelation in case counts at a lag of ?70 weeks, indicating a shift in the timing of peak incidence year-to-year. All climatic variables showed modest seasonality and correlated weakly with the number of reported dengue cases across a range of time lags. Cases were reduced after citywide insecticide fumigation if conducted early in the transmission season. Conclusions Dengue case counts peaked seasonally despite limited intra-annual variation in climate conditions. Contrary to expectations for this mosquito-borne disease, no climatic variable considered exhibited a strong relationship with transmission. Vector control operations did, however, appear to have a significant impact on transmission some years. Our results indicate that a complicated interplay of factors underlie DENV transmission in contexts such as Iquitos. PMID:25033412

Stoddard, Steven T.; Wearing, Helen J.; Reiner, Robert C.; Morrison, Amy C.; Astete, Helvio; Vilcarromero, Stalin; Alvarez, Carlos; Ramal-Asayag, Cesar; Sihuincha, Moises; Rocha, Claudio; Halsey, Eric S.; Scott, Thomas W.; Kochel, Tadeusz J.; Forshey, Brett M.

2014-01-01

218

Epidemiological and molecular features of dengue virus type-1 in New Caledonia, South Pacific, 2001-2013  

PubMed Central

Background The epidemiology of dengue in the South Pacific has been characterized by transmission of a single dominant serotype for 3–5 years, with subsequent replacement by another serotype. From 2001 to 2008 only DENV-1 was reported in the Pacific. In 2008, DENV-4 emerged and quickly displaced DENV-1 in the Pacific, except in New Caledonia (NC) where DENV-1 and DENV-4 co-circulated in 2008–2009. During 2012–2013, another DENV-1 outbreak occurred in NC, the third DENV-1 outbreak in a decade. Given that dengue is a serotype-specific immunizing infection, the recurrent outbreaks of a single serotype within a 10-year period was unexpected. Findings This study aimed to inform this phenomenon by examining the phylogenetic characteristics of the DENV-1 viruses in NC and other Pacific islands between 2001 and 2013. As a result, we have demonstrated that NC experienced introductions of viruses from both the Pacific (genotype IV) and South-east Asia (genotype I). Moreover, whereas genotype IV and I were co-circulating at the beginning of 2012, we observed that from the second half of 2012, i.e. during the major DENV-1 outbreak, all analyzed viruses were genotype I suggesting that a genotype switch occurred. Conclusions Repeated outbreaks of the same dengue serotype, as observed in NC, is uncommon in the Pacific islands. Why the earlier DENV-1 outbreaks did not induce sufficient herd immunity is unclear, and likely multifactorial, but the robust vector control program may have played a role by limiting transmission and thus maintaining a large susceptible pool in the population. PMID:24684835

2014-01-01

219

Building and analyzing an innovative community-centered dengue-ecosystem management intervention in Yogyakarta, Indonesia  

PubMed Central

Background and Objectives Dengue is an important public health problem in Yogyakarta city, Indonesia. The aim of this study was to build an innovative community-centered dengue-ecosystem management intervention in the city and to assess the process and results. Methods For describing the baseline situation, entomological surveys and household surveys were carried out in six randomly selected neighborhoods in Yogyakarta city, documents were analyzed and different stakeholders involved in dengue control and environmental management were interviewed. Then a community-centered dengue-ecosystem management intervention was built up in two of the neighborhoods (Demangan and Giwangan) whereas two neighborhoods served as controls with no intervention (Tahunan and Bener). Six months after the intervention follow up surveys (household interviews and entomological) were conducted as well as focus group discussions and key informant interviews. FIindings The intervention results included: better community knowledge, attitude and practices in dengue prevention; increased household and community participation; improved partnership including a variety of stakeholders with prospects for sustainability; vector control efforts refocused on environmental and health issues; increased community ownership of dengue vector management including broader community development activities such as solid waste management and recycling. Conclusion The community-centred approach needs a lot of effort at the beginning but has better prospects for sustainability than the vertical “top-down” approach. PMID:23318239

Tana, Susilowati; Umniyati, SittiRahmah; Petzold, Max; Kroeger, Axel; Sommerfeld, Johannes

2012-01-01

220

Spatio-temporal distribution of dengue fever under scenarios of climate change in the southern Taiwan  

NASA Astrophysics Data System (ADS)

Dengue fever has been recognized as the most important widespread vector-borne infectious disease in recent decades. Over 40% of the world's population is risk from dengue and about 50-100 million people are infected world wide annually. Previous studies have found that dengue fever is highly correlated with climate covariates. Thus, the potential effects of global climate change on dengue fever are crucial to epidemic concern, in particular, the transmission of the disease. This present study investigated the nonlinearity of time-delayed impact of climate on spatio-temporal variations of dengue fever in the southern Taiwan during 1998 to 2011. A distributed lag nonlinear model (DLNM) is used to assess the nonlinear lagged effects of meteorology. The statistically significant meteorological factors are considered, including weekly minimum temperature and maximum 24-hour rainfall. The relative risk and the distribution of dengue fever then predict under various climate change scenarios. The result shows that the relative risk is similar for different scenarios. In addition, the impact of rainfall on the incidence risk is higher than temperature. Moreover, the incidence risk is associated to spatially population distribution. The results can be served as practical reference for environmental regulators for the epidemic prevention under climate change scenarios.

Lee, Chieh-Han; Yu, Hwa-Lung

2014-05-01

221

Castanospermine, a Potent Inhibitor of Dengue Virus Infection In Vitro and In Vivo  

PubMed Central

Previous studies have suggested that ?-glucosidase inhibitors such as castanospermine and deoxynojirimycin inhibit dengue virus type 1 infection by disrupting the folding of the structural proteins prM and E, a step crucial to viral secretion. We extend these studies by evaluating the inhibitory activity of castanospermine against a panel of clinically important flaviviruses including all four serotypes of dengue virus, yellow fever virus, and West Nile virus. Using in vitro assays we demonstrated that infections by all serotypes of dengue virus were inhibited by castanospermine. In contrast, yellow fever virus and West Nile virus were partially and almost completely resistant to the effects of the drug, respectively. Castanospermine inhibited dengue virus infection at the level of secretion and infectivity of viral particles. Importantly, castanospermine prevented mortality in a mouse model of dengue virus infection, with doses of 10, 50, and 250 mg/kg of body weight per day being highly effective at promoting survival (P ? 0.0001). Correspondingly, castanospermine had no adverse or protective effect on West Nile virus mortality in an analogous mouse model. Overall, our data suggest that castanospermine has a strong antiviral effect on dengue virus infection and warrants further development as a possible treatment in humans. PMID:15994763

Whitby, Kevin; Pierson, Theodore C.; Geiss, Brian; Lane, Kelly; Engle, Michael; Zhou, Yi; Doms, Robert W.; Diamond, Michael S.

2005-01-01

222

Castanospermine, a potent inhibitor of dengue virus infection in vitro and in vivo.  

PubMed

Previous studies have suggested that alpha-glucosidase inhibitors such as castanospermine and deoxynojirimycin inhibit dengue virus type 1 infection by disrupting the folding of the structural proteins prM and E, a step crucial to viral secretion. We extend these studies by evaluating the inhibitory activity of castanospermine against a panel of clinically important flaviviruses including all four serotypes of dengue virus, yellow fever virus, and West Nile virus. Using in vitro assays we demonstrated that infections by all serotypes of dengue virus were inhibited by castanospermine. In contrast, yellow fever virus and West Nile virus were partially and almost completely resistant to the effects of the drug, respectively. Castanospermine inhibited dengue virus infection at the level of secretion and infectivity of viral particles. Importantly, castanospermine prevented mortality in a mouse model of dengue virus infection, with doses of 10, 50, and 250 mg/kg of body weight per day being highly effective at promoting survival (P < or = 0.0001). Correspondingly, castanospermine had no adverse or protective effect on West Nile virus mortality in an analogous mouse model. Overall, our data suggest that castanospermine has a strong antiviral effect on dengue virus infection and warrants further development as a possible treatment in humans. PMID:15994763

Whitby, Kevin; Pierson, Theodore C; Geiss, Brian; Lane, Kelly; Engle, Michael; Zhou, Yi; Doms, Robert W; Diamond, Michael S

2005-07-01

223

Impact of meteorological factors on the spatiotemporal patterns of dengue fever incidence.  

PubMed

Dengue fever is one of the most widespread vector-borne diseases and has caused more than 50million infections annually over the world. For the purposes of disease prevention and climate change health impact assessment, it is crucial to understand the weather-disease associations for dengue fever. This study investigated the nonlinear delayed impact of meteorological conditions on the spatiotemporal variations of dengue fever in southern Taiwan during 1998-2011. We present a novel integration of a distributed lag nonlinear model and Markov random fields to assess the nonlinear lagged effects of weather variables on temporal dynamics of dengue fever and to account for the geographical heterogeneity. This study identified the most significant meteorological measures to dengue fever variations, i.e., weekly minimum temperature, and the weekly maximum 24-hour rainfall, by obtaining the relative risk (RR) with respect to disease counts and a continuous 20-week lagged time. Results show that RR increased as minimum temperature increased, especially for the lagged period 5-18weeks, and also suggest that the time to high disease risks can be decreased. Once the occurrence of maximum 24-hour rainfall is >50mm, an associated increased RR lasted for up to 15weeks. A temporary one-month decrease in the RR of dengue fever is noted following the extreme rain. In addition, the elevated incidence risk is identified in highly populated areas. Our results highlight the high nonlinearity of temporal lagged effects and magnitudes of temperature and rainfall on dengue fever epidemics. The results can be a practical reference for the early warning of dengue fever. PMID:25084561

Chien, Lung-Chang; Yu, Hwa-Lung

2014-12-01

224

Biosurveillance in outbreak investigations.  

PubMed

Following the terrorist attacks of September 11 and the anthrax attacks in 2001, public health entities implemented automated surveillance systems based on disease syndromes for early detection of bioterror events and to increase timeliness of responses. Despite widespread adoption, syndromic surveillance systems' ability to provide early notification of outbreaks is unproven, and there is little documentation on their role in outbreak response. We hypothesized that biosurveillance is used in practice to augment classical outbreak investigations, and we used case studies conducted in 2007-08 to determine (1) which steps in outbreak investigations were best served by biosurveillance, and (2) which steps presented the greatest opportunities for improvement. The systems used in the case studies varied in how they functioned, and there were examples in which syndromic systems had identified outbreaks before other methods. Biosurveillance was used successfully for all steps of outbreak investigations. Key advantages of syndromic systems were sensitivity, timeliness, and flexibility and as a source of data for situational awareness. Limitations of biosurveillance were a lack of specificity, reliance on chief complaint data, and a lack of formal training for users. Linking syndromic data to triage notes and medical chart data would substantially increase the value of biosurveillance in the conduct of outbreak investigations and reduce the burden on health department staff. PMID:23448272

Kaydos-Daniels, S Cornelia; Rojas Smith, Lucia; Farris, Tonya R

2013-03-01

225

Natural, persistent oscillations in a spatial multi-strain disease system with application to dengue.  

PubMed

Many infectious diseases are not maintained in a state of equilibrium but exhibit significant fluctuations in prevalence over time. For pathogens that consist of multiple antigenic types or strains, such as influenza, malaria or dengue, these fluctuations often take on the form of regular or irregular epidemic outbreaks in addition to oscillatory prevalence levels of the constituent strains. To explain the observed temporal dynamics and structuring in pathogen populations, epidemiological multi-strain models have commonly evoked strong immune interactions between strains as the predominant driver. Here, with specific reference to dengue, we show how spatially explicit, multi-strain systems can exhibit all of the described epidemiological dynamics even in the absence of immune competition. Instead, amplification of natural stochastic differences in disease transmission, can give rise to persistent oscillations comprising semi-regular epidemic outbreaks and sequential dominance of dengue's four serotypes. Not only can this mechanism explain observed differences in serotype and disease distributions between neighbouring geographical areas, it also has important implications for inferring the nature and epidemiological consequences of immune mediated competition in multi-strain pathogen systems. PMID:24204241

Lourenço, José; Recker, Mario

2013-10-01

226

Natural, Persistent Oscillations in a Spatial Multi-Strain Disease System with Application to Dengue  

PubMed Central

Many infectious diseases are not maintained in a state of equilibrium but exhibit significant fluctuations in prevalence over time. For pathogens that consist of multiple antigenic types or strains, such as influenza, malaria or dengue, these fluctuations often take on the form of regular or irregular epidemic outbreaks in addition to oscillatory prevalence levels of the constituent strains. To explain the observed temporal dynamics and structuring in pathogen populations, epidemiological multi-strain models have commonly evoked strong immune interactions between strains as the predominant driver. Here, with specific reference to dengue, we show how spatially explicit, multi-strain systems can exhibit all of the described epidemiological dynamics even in the absence of immune competition. Instead, amplification of natural stochastic differences in disease transmission, can give rise to persistent oscillations comprising semi-regular epidemic outbreaks and sequential dominance of dengue's four serotypes. Not only can this mechanism explain observed differences in serotype and disease distributions between neighbouring geographical areas, it also has important implications for inferring the nature and epidemiological consequences of immune mediated competition in multi-strain pathogen systems. PMID:24204241

Lourenco, Jose; Recker, Mario

2013-01-01

227

Worldwide Outbreak Database: the largest collection of nosocomial outbreaks  

Microsoft Academic Search

Epidemiological findings of a single outbreak event may not be generalized; however, the characteristics of a typical outbreak\\u000a can be determined on the basis of a large number of similar events. The Outbreak Database (http:\\/\\/www.outbreak-database.com) is the largest collection of nosocomial outbreaks currently available—and is still expanding. Articles are filed systematically,\\u000a enabling those on a specific parameter of interest to

R.-P. Vonberg; D. Weitzel-Kage; M. Behnke; P. Gastmeier

2011-01-01

228

USING DISABILITY-ADJUSTED LIFE YEARS TO ASSESS THE ECONOMIC IMPACT OF DENGUE IN PUERTO RICO: 1984-1994  

Microsoft Academic Search

This study presents the disability-adjusted life years (DALYs), a non-monetary economic measure of impact, lost to dengue in Puerto Rico for the period 1984-1994. Data on the number of reported cases, cases with hemorrhagic manifestations, hospitalizations, and deaths were obtained from a surveillance system maintained at the Dengue Branch, Division of Vector-Borne Infectious Diseases, Centers for Disease Control and Prevention

MARTIN I. MELTZER; GARY G. CLARK; PAUL REITER; DUANE J. GUBLER

1998-01-01

229

Aedes aegypti from temperate regions of South America are highly competent to transmit dengue virus  

PubMed Central

Background Aedes aegypti is extensively spread throughout South America where it has been responsible for large dengue epidemics during the last decades. Intriguingly, dengue transmission has not been reported in Uruguay and is essentially prevalent in subtropical northern Argentina which borders Uruguay. Methods We assessed vector competence for dengue virus (DENV) of Ae. aegypti populations collected in subtropical Argentina (Corrientes) as well as temperate Uruguay (Salto) and Argentina (Buenos Aires) in 2012 using experimental oral infections with DENV-2. Mosquitoes were incubated at 28°C and examined at 14 and 21 days p.i. to access viral dissemination and transmission. Batches of the Buenos Aires mosquitoes were also incubated at 15°C and 20°C. Results Although mosquitoes from temperate Uruguay and Argentina were competent to transmit DENV, those from subtropical Argentina were more susceptible, displaying the highest virus titters in the head and presenting the highest dissemination of infection and transmission efficiency rates when incubated at 28°C. Interestingly, infectious viral particles could be detected in saliva of mosquitoes from Buenos Aires exposed to 15°C and 20°C. Conclusions There is a potential risk of establishing DENV transmission in Uruguay and for the spread of dengue outbreaks to other parts of subtropical and temperate Argentina, notably during spring and summer periods. PMID:24373423

2013-01-01

230

A Heterocyclic Molecule with Significant Activity Against Dengue Virus  

PubMed Central

There are no specific approved drugs or vaccines for the treatment or prevention of infectious dengue virus and there are very few compounds known that inhibit the replication of this virus. This communication describes the concise synthesis of two uracil-based multifunctional compounds. One of these compounds (1) has strong activity against dengue virus. It also exhibits low activity against a few other RNA viruses, but is highly active against yellow fever virus, a related flavivirus. It is likely that the mechanism of action of the antiviral activity of this compound is through its inhibition of the enzyme, inosine monophosphate dehydrogenase (IMPDH). Molecular modeling studies reveal that the compound can have specific hydrogen bonding interactions with a number of amino acids in the active site of IMPDH, a stacking interaction with the bound natural substrate, IMP, and the ability to interfere with the binding of NAD+ with IMPDH, prior to the hydration step. PMID:19185487

Nair, Vasu; Chi, Guochen; Shu, Qingning; Julander, Justin; Smee, Donald F.

2009-01-01

231

Food- and waterborne disease outbreaks in Australian long-term care facilities, 2001-2008.  

PubMed

Abstract Food- or waterborne diseases in long-term care facilities (LTCF) can result in serious outcomes, including deaths, and they are potentially preventable. We analyzed data collected by OzFoodNet on food- and waterborne disease outbreaks occurring in LTCF in Australia from 2001 to 2008. We compared outbreaks by the number of persons affected, etiology, and implicated vehicle. During 8 years of surveillance, 5.9% (55/936) of all food- and waterborne outbreaks in Australia occurred in LTCF. These LTCF outbreaks affected a total of 909 people, with 66 hospitalized and 23 deaths. The annual incidence of food- or waterborne outbreaks was 1.9 (95% confidence intervals 1.0-3.7) per 1000 facilities. Salmonella caused 17 outbreaks, Clostridium perfringens 14 outbreaks, Campylobacter 8 outbreaks, and norovirus 1 outbreak. Residents were at higher risk of death during outbreaks of salmonellosis than for all other outbreaks combined (relative risk 7.8, 95% confidence intervals 1.8-33.8). Of 15 outbreaks of unknown etiology, 11 were suspected to be due to C. perfringens intoxication. Food vehicles were only identified in 27% (14/52) of outbreaks, with six outbreak investigations implicating pureed foods. Dishes containing raw eggs were implicated as the cause of four outbreaks. Three outbreaks of suspected waterborne disease were attributed to rainwater collected from facility roofs. To prevent disease outbreaks, facilities need to improve handling of pureed foods, avoid feeding residents raw or undercooked eggs, and ensure that rainwater tanks have a scheduled maintenance and disinfection program. PMID:21034268

Kirk, Martyn D; Lalor, Karin; Raupach, Jane; Combs, Barry; Stafford, Russell; Hall, Gillian V; Becker, Niels

2011-01-01

232

Alfalfa Seed Decontamination in Salmonella Outbreak  

PubMed Central

Based on in vitro data, the U.S. Food and Drug Administration recommends chemical disinfection of raw sprout seeds to reduce enteric pathogens contaminating the seed coats. However, little is known about the effectiveness of decontamination at preventing human disease. In 1999, an outbreak of Salmonella enterica serotype Mbandaka occurred in Oregon, Washington, Idaho, and California. Based on epidemiologic and pulsed-field gel electrophoresis evidence from 87 confirmed cases, the outbreak was linked to contaminated alfalfa seeds grown in California’s Imperial Valley. Trace-back and trace-forward investigations identified a single lot of seeds used by five sprout growers during the outbreak period. Cases of salmonellosis were linked with two sprout growers who had not employed chemical disinfection; no cases were linked to three sprout growers who used disinfection. This natural experiment provides empiric evidence that chemical disinfection can reduce the human risk for disease posed by contaminated seed sprouts. PMID:12702229

Gill, Christopher J.; Mohle-Boetani, Janet C.; Farrar, Jeff A.; Waller, Patti L.; Hahn, Christine G.; Cieslak, Paul R.

2003-01-01

233

Lessons from nosocomial viral haemorrhagic fever outbreaks.  

PubMed

The outbreak of Marburg haemorrhagic fever in Angola in 2004-2005 shows once again the devastating and rapid spread of viral haemorrhagic fevers in medical settings where hygiene practices are poorly applied or ignored. The legacy of years of war and poverty in Angola has resulted in very poor medical education and services. The initial high rate of infection among infants in Angola may have been related to poor hospital practices, possibly administration of vaccines. Though the outbreak in Angola was in a part of Africa not previously known to have filovirus infection, prior ecological modelling had predicted this location and many others. Prevention of future outbreaks will not be easy. The urgent need is dissemination of knowledge and the training, discipline and resources for good clinical practice. Educating the public to demand higher standards could be a powerful tool. Good practices are difficult to establish and maintain on the scale needed. PMID:16373655

Fisher-Hoch, Susan P

2005-01-01

234

Pertussis Outbreak Trends  

MedlinePLUS

... IAC) Parents of Kids with Infectious Diseases (PKIDs) Pertussis Outbreak Trends Language: English Español (Spanish) Share Compartir ... ol: Tendencias de los brotes de tosferina California Whooping Cough Epidemic, 2014 See California's latest numbers of reported ...

235

Fungal Diseases Outbreaks  

MedlinePLUS

... Sheet [PDF - 2 pages] Fungal meningitis after contaminated steroid injections Multistate outbreak of fungal meningitis and other fungal infections associated with contaminated steroid injections, October 2012 This investigation is ongoing. For ...

236

Disease Outbreak News  

MedlinePLUS

... for communicating with the public during an outbreak Communication for behavioural impact (COMBI) COMBI toolkit for behavioural ... WHO Western Pacific Region RSS Feeds WHO YouTube channel Follow WHO on Twitter WHO Facebook page WHO ...

237

Forecasting fluctuating outbreaks in seasonally driven epidemics  

NASA Astrophysics Data System (ADS)

Seasonality is a driving force that has major impact on the spatio-temporal dynamics of natural systems and their populations. This is especially true for the transmission of common infectious diseases such as influenza, measles, chickenpox, and pertussis. Here we gain new insights into the nonlinear dynamics of recurrent diseases through the analysis of the classical seasonally forced SIR epidemic model. Despite many efforts over the last decades, it has been difficult to gain general analytical insights because of the complex synchronization effects that can evolve between the external forcing and the model's natural oscillations. The analysis advanced here attempts to make progress in this direction by focusing on the dynamics of ``skips'' where we identify and predict years in which the epidemic is absent rather than outbreak years. Skipping events are intrinsic to the forced SIR model when parameterised in the chaotic regime. In fact, it is difficult if not impossible to locate realistic chaotic parameter regimes in which outbreaks occur regularly each year. This contrasts with the well known Rossler oscillator whose outbreaks recur regularly but whose amplitude vary chaotically in time (Uniform Phase Chaotic Amplitude oscillations). The goal of the present study is to develop a ``language of skips'' that makes it possible to predict under what conditions the next outbreak is likely to occur, and how many ``skips'' might be expected after any given outbreak. We identify a new threshold effect and give clear analytical conditions that allow accurate predictions. Moreover, the time of occurrence (i.e., phase) of an outbreak proves to be a useful new parameter that carries important epidemiological information. In forced systems, seasonal changes can prevent late-initiating outbreaks (i.e., having high phase) from running to completion. These principles yield forecasting tools that should have relevance for the study of newly emerging and reemerging diseases.

Stone, Lewi

2009-03-01

238

Markers of dengue disease severity.  

PubMed

Infection with one of the four serotypes of dengue virus (DENV) causes a wide spectrum of clinical disease ranging from asymptomatic infection, undifferentiated fever, dengue fever (DF) to dengue hemorrhagic fever (DHF). DHF occurs in a minority of patients and is characterized by bleeding and plasma leakage which may lead to shock. There are currently no reliable clinical or laboratory indicators that accurately predict the development of DHF. Human studies have shown that high viral load and intense activation of the immune system are associated with DHF. Recently, endothelial cells and factors regulating vascular permeability have been demonstrated to play a role. In the absence of animal models that closely mimic DHF, human studies are essential in identifying predictors of severe illness. Well planned prospective studies with samples collected at different time points of the illness in well characterized patients are crucial for this effort. Ideally, clinical and laboratory predictive tools should be suitable for resource poor countries where dengue is endemic. PMID:19802579

Srikiatkhachorn, Anon; Green, Sharone

2010-01-01

239

HAITI: ABSENCE OF DENGUE HEMORRHAGIC FEVER DESPITE HYPERENDEMIC DENGUE VIRUS TRANSMISSION  

Microsoft Academic Search

In 1994-1996, 185 strains of dengue (DEN) virus types 1, 2, and 4 were recovered from febrile United States and other United Nations military personnel in Haiti. We wondered whether risk factors for dengue hemorrhagic fever (DHF) existed and, if so, were DHF cases occurring among Haitian children. Dengue transmission rates were studied in 210 school children (6-13 years old)

SCOTT B. HALSTEAD; THOMAS G. STREIT; JACK GUY LAFONTANT; RAVITHAT PUTVATANA; KEVIN RUSSELL; WELLINGTON SUN; NIRANJAN KANESA-THASAN; CURTIS G. HAYES; DOUGLAS M. WATTS

2001-01-01

240

Dengue Human Infection Models Supporting Drug Development  

PubMed Central

Dengue is a arboviral infection that represents a major global health burden. There is an unmet need for effective dengue therapeutics to reduce symptoms, duration of illness and incidence of severe complications. Here, we consider the merits of a dengue human infection model (DHIM) for drug development. A DHIM could allow experimentally controlled studies of candidate therapeutics in preselected susceptible volunteers, potentially using smaller sample sizes than trials that recruited patients with dengue in an endemic country. In addition, the DHIM would assist the conduct of intensive pharmacokinetic and basic research investigations and aid in determining optimal drug dosage. Furthermore, a DHIM could help establish proof of concept that chemoprophylaxis against dengue is feasible. The key challenge in developing the DHIM for drug development is to ensure the model reliably replicates the typical clinical and laboratory features of naturally acquired, symptomatic dengue. PMID:24872399

Whitehorn, James; Van, Vinh Chau Nguyen; Simmons, Cameron P.

2014-01-01

241

Dengue human infection models supporting drug development.  

PubMed

Dengue is a arboviral infection that represents a major global health burden. There is an unmet need for effective dengue therapeutics to reduce symptoms, duration of illness and incidence of severe complications. Here, we consider the merits of a dengue human infection model (DHIM) for drug development. A DHIM could allow experimentally controlled studies of candidate therapeutics in preselected susceptible volunteers, potentially using smaller sample sizes than trials that recruited patients with dengue in an endemic country. In addition, the DHIM would assist the conduct of intensive pharmacokinetic and basic research investigations and aid in determining optimal drug dosage. Furthermore, a DHIM could help establish proof of concept that chemoprophylaxis against dengue is feasible. The key challenge in developing the DHIM for drug development is to ensure the model reliably replicates the typical clinical and laboratory features of naturally acquired, symptomatic dengue. PMID:24872399

Whitehorn, James; Van, Vinh Chau Nguyen; Simmons, Cameron P

2014-06-15

242

Update: The diagnosis and management of dengue virus infection in North America.  

PubMed

Dengue is a mosquito-transmitted infection that poses significant global health risks for travelers and individuals living in the tropics and subtropics. The reported global incidence has increased dramatically in the past century, with dengue now ranking as the most common cause of febrile illness in travelers. While sporadic cases have been reported within the southern United States since 1980, autochthonous outbreaks have now been described in Hawaii, St. Croix (US Virgin Islands), along the Texas-Mexico border, and, most recently, in Key West, Florida. Although many infections are mild or asymptomatic, 5-10% of patients may experience hemorrhagic disease, with shock and even death. Laboratory identification commonly involves serologic and nucleic acid amplification methods. Due to rising incidence worldwide, physicians should be familiar with the clinical manifestations, laboratory diagnosis, and management of this illness. PMID:22541792

Wright, William F; Pritt, Bobbi S

2012-07-01

243

Management of dengue fever in ICU  

Microsoft Academic Search

Dengue virus infection can cause a wide spectrum of illness. Thrombocytopenia with concurrent haemoconcentration differentiates\\u000a dengue haemorrhagic fever from classical dengue fever. Only cases with shock or unstable vitals signs need admission in the\\u000a pediatric intensive care. The management is essentially supportive and symptomatic. The key to success is frequent monitoring\\u000a and changing strategies. A rise in hematocrit of 20%

Arun Soni; Krishan Chugh; Anil Sachdev; Dhiren Gupta

2001-01-01

244

An online spatio-temporal prediction model for dengue fever epidemic in Kaohsiung,Taiwan  

NASA Astrophysics Data System (ADS)

Dengue Fever (DF) is one of the most serious vector-borne infectious diseases in tropical and subtropical areas. DF epidemics occur in Taiwan annually especially during summer and fall seasons. Kaohsiung city has been one of the major DF hotspots in decades. The emergence and re-emergence of the DF epidemic is complex and can be influenced by various factors including space-time dynamics of human and vector populations and virus serotypes as well as the associated uncertainties. This study integrates a stochastic space-time "Susceptible-Infected-Recovered" model under Bayesian maximum entropy framework (BME-SIR) to perform real-time prediction of disease diffusion across space-time. The proposed model is applied for spatiotemporal prediction of the DF epidemic at Kaohsiung city during 2002 when the historical series of high DF cases was recorded. The online prediction by BME-SIR model updates the parameters of SIR model and infected cases across districts over time. Results show that the proposed model is rigorous to initial guess of unknown model parameters, i.e. transmission and recovery rates, which can depend upon the virus serotypes and various human interventions. This study shows that spatial diffusion can be well characterized by BME-SIR model, especially at the district surrounding the disease outbreak locations. The prediction performance at DF hotspots, i.e. Cianjhen and Sanmin, can be degraded due to the implementation of various disease control strategies during the epidemics. The proposed online disease prediction BME-SIR model can provide the governmental agency with a valuable reference to timely identify, control, and efficiently prevent DF spread across space-time.

Cheng, Ming-Hung; Yu, Hwa-Lung; Angulo, Jose; Christakos, George

2013-04-01

245

An unusual ocular emergency in severe dengue.  

PubMed

Dengue, one of the most common mosquito-borne flavivirus diseases affecting humans, is spread by the Aedes aegypti mosquito. Most people infected with dengue virus are asymptomatic or only have mild symptoms such as an uncomplicated fever; few have more severe features, while in a small proportion it is life-threatening. Severe dengue is defined as that associated with severe bleeding, severe organ dysfunction, or severe plasma leakage. Ophthalmic manifestations can involve both the anterior and posterior segment. We report an ocular emergency of proptosis and globe rupture in a patient with severe dengue. PMID:25371643

Nagaraj, Kalpana Badami; Jayadev, Chaitra; Yajmaan, Soumya; Prakash, Savitha

2014-10-01

246

Exploratory space-time analysis of dengue incidence in Trinidad: a retrospective study using travel hubs as dispersal points, 1998–2004  

PubMed Central

Background Dengue is an acute arboviral disease responsible for most of the illness and death in tropical and subtropical regions. Over the last 25 years there has been increase epidemic activity of the disease in the Caribbean, with the co-circulation of multiple serotypes. An understanding of the space and time dynamics of dengue could provide health agencies with important clues for reducing its impact. Methods Dengue Haemorrhagic Fever (DHF) cases observed for the period 1998–2004 were georeferenced using Geographic Information System software. Spatial clustering was calculated for individual years and for the entire study period using the Nearest Neighbor Index. Space and time interaction between DHF cases was determined using the Knox Test while the Nearest Neighbor Hierarchical method was used to extract DHF hot spots. All space and time distances calculated were validated using the Pearson r significance test. Results Results shows that (1) a decrease in mean distance between DHF cases correlates with activity leading up to an outbreak, (2) a decrease in temporal distance between DHF cases leads to increased geographic spread of the disease, with an outbreak occurrence about every 2 years, and (3) a general pattern in the movement of dengue incidents from more rural to urban settings leading up to an outbreak with hotspot areas associated with transportation hubs in Trinidad. Conclusion Considering only the spatial dimension of the disease, results suggest that DHF cases become more concentrated leading up to an outbreak. However, with the additional consideration of time, results suggest that when an outbreak occurs incidents occur more rapidly in time leading to a parallel increase in the rate of distribution of the disease across space. The results of this study can be used by public health officers to help visualize and understand the spatial and temporal patterns of dengue, and to prepare warnings for the public. Dengue space-time patterns and hotspot detection will provide useful information to support public health officers in their efforts to control and predict dengue spread over critical hotspots allowing better allocation of resources. PMID:25052242

2014-01-01

247

Characterization of retrovirus-based reporter viruses pseudotyped with the precursor membrane and envelope glycoproteins of four serotypes of dengue viruses  

SciTech Connect

In this study, we successfully established retrovirus-based reporter viruses pseudotyped with the precursor membrane and envelope (PrM/E) proteins of each of the four serotypes of dengue viruses, which caused the most important arboviral diseases in this century. Co-sedimentation of the dengue E protein and HIV-1 core proteins by sucrose gradient analysis of the pseudotype reporter virus of dengue virus type 2, D2(HIVluc), and detection of HIV-1 core proteins by immunoprecipitation with anti-E monoclonal antibody suggested that dengue viral proteins were incorporated into the pseudotype viral particles. The infectivity in target cells, as assessed by the luciferase activity, can be inhibited by the lysosomotropic agents, suggesting a pH-dependent mechanism of entry. Amino acid substitutions of the leucine at position 107, a critical residue at the fusion loop of E protein, with lysine resulted in severe impairment in infectivity, suggesting that entry of the pseudotype reporter virus is mediated through the fusogenic properties of E protein. With more and more dengue viral sequences available from different outbreaks worldwide, this sensitive and convenient tool has the potential to facilitate molecular characterization of the PrM/E proteins of dengue field isolates.

Hu, H.-P.; Hsieh, S.-C. [Institute of Microbiology, College of Medicine, National Taiwan University, No 1 Sec1 Jen-Ai Rd, Taipei 100, Taiwan (China); King, C.-C. [Institute of Epidemiology, College of Public Health, National Taiwan University, No 1 Sec1 Jen-Ai Rd, Taipei 100, Taiwan (China); Wang, W.-K. [Institute of Microbiology, College of Medicine, National Taiwan University, No 1 Sec1 Jen-Ai Rd, Taipei 100, Taiwan (China); Department of Internal Medicine, National Taiwan University Hospital, No 7 Chung-Shan S Rd, Taipei 100, Taiwan (China)], E-mail: wwang60@yahoo.com

2007-11-25

248

The Utility of a Board Game for Dengue Haemorrhagic Fever Health Education  

ERIC Educational Resources Information Center

Purpose: The purpose of this study is to test the effectiveness of an educational board game for increasing knowledge, positive attitudes-beliefs, and self-efficacy for dengue prevention in a sample of Philippine school children and adolescents. Effective board games are more advantageous than lectures because they are adaptable, inexpensive and…

Lennon, Jeffrey L.; Coombs, David W.

2007-01-01

249

Diagnostic methods for detection & isolation of dengue viruses from vector mosquitoes  

Microsoft Academic Search

Dengue is a deadly mosquito-borne infection warranting urgent attention for its containment particularly in the tropical and subtropical countries. In the absence of a vaccine or any specific drug for its treatment, an early diagnosis is considered indispensable to prevent any casualty. Detection of viruses in human sera particularly in endemic areas is cumbersome, difficult and also not desirable. Therefore,

P. Philip Samuel; B. K. Tyagi

2006-01-01

250

Origin of the Dengue Fever Mosquito, Aedes aegypti, in California  

PubMed Central

Dengue fever is among the most widespread vector-borne infectious diseases. The primary vector of dengue is the Aedes aegypti mosquito. Ae. aegypti is prevalent in the tropics and sub-tropics and is closely associated with human habitats outside its native range of Africa. While long established in the southeastern United States of America where dengue is re-emerging, breeding populations have never been reported from California until the summer of 2013. Using 12 highly variable microsatellite loci and a database of reference populations, we have determined that the likely source of the California introduction is the southeastern United States, ruling out introductions from abroad, from the geographically closer Arizona or northern Mexico populations, or an accidental release from a research laboratory. The power to identify the origin of new introductions of invasive vectors of human disease relies heavily on the availability of a panel of reference populations. Our work demonstrates the importance of generating extensive reference databases of genetically fingerprinted human-disease vector populations to aid public health efforts to prevent the introduction and spread of vector-borne diseases. PMID:25077804

Gloria-Soria, Andrea; Brown, Julia E.; Kramer, Vicki; Hardstone Yoshimizu, Melissa; Powell, Jeffrey R.

2014-01-01

251

Update: cholera outbreak --- Haiti, 2010.  

PubMed

On October 19, 2010, the Haitian Ministry of Public Health and Population (MSPP) was notified of unusually high numbers of patients from Artibonite and Centre departments who had acute watery diarrhea and dehydration, in some cases leading to death. Within 4 days, the National Public Health Laboratory (LNSP) in Haiti isolated Vibrio cholerae serogroup O1, serotype Ogawa, from stool specimens obtained from patients in the affected areas by an investigation team from MSPP and CDC Haiti. This report describes the investigation of the initial cases, the ongoing outbreak of cholera in Haiti, and initial control measures. Since the initial identification of cholera, the outbreak has expanded to include cases in seven of Haiti's 10 departments and the capital city of Port-au-Prince. As of November 13, MSPP had reported 16,111 persons hospitalized with acute watery diarrhea and 992 cholera deaths, 620 of which occurred among hospitalized patients. Prevention and control measures implemented by MSPP with assistance from governmental and nongovernmental partners include 1) providing better access to treated drinking water; 2) providing education on improvement of sanitation, hygiene, and food preparation practices; 3) advising ill persons to begin using oral rehydration solution immediately and seek health care at the onset of watery diarrhea; 4) enhancing cholera treatment capacity at existing health-care institutions; and 5) establishing cholera treatment centers. PMID:21085088

2010-11-19

252

Description of outbreaks of healthcare associated infections related to compounding pharmacies, 2000-2012  

PubMed Central

Purpose The 2012 multistate fungal meningitis outbreak caused by contaminated methylprednisolone suggests that contaminated compounded drugs can pose a public health threat. The problem has not been well described. Our objective was to systematically review the literature to describe: a) features of infectious outbreaks associated with exposure to contaminated drugs produced by compounding pharmacies, b) sterile compounding procedures that caused microbial contamination, and c) outbreak features relevant for detection and investigation. Methods We searched PubMed (reviewing 850 citations) and the CDC and FDA Web sites to identify infectious outbreaks associated with compounding pharmacies outside the hospital setting between January 2000 and November 2012. We extracted information from peer-reviewed literature, FDA and CDC documents, meeting abstracts, and congressional testimony. Results Between 2000 and prior to the 2012 fungal meningitis outbreak, 11 infectious outbreaks from contaminated compounded drugs were reported involving 207 case-patients with 17 deaths (8.2% case fatality rate). The 2012 meningitis outbreak increased totals almost 5-fold. Half the outbreaks involved case-patients in more than 1 state. Three outbreaks involved ophthalmic drugs: trypan blue and Brilliant Blue-G ophthalmic solutions used during surgery, and triamcinolone and bevacizumab for intravitreal injection. Remaining outbreaks involved corticosteroids (n=2), heparin flush solutions (n=2), cardioplegia, intravenous magnesium sulfate, total parenteral nutrition, and fentanyl. The outbreaks were caused by pathogens commonly associated with healthcare associated infections (n=6), common skin commensals (n=1), and organisms that rarely cause infection (n=5). Morbidity was substantial, including vision loss; mortality rates during earlier outbreaks were similar to the 2012 meningitis outbreak. A variety of problems with sterile procedures were found. No single source reported all outbreaks. Conclusion Sporadic but serious infectious outbreaks associated with contaminated drugs from compounding pharmacies occurred before the 2012 fungal meningitis outbreak. These outbreaks illustrate root causes that could be addressed with preventive policies and practices. PMID:23867487

Staes, Catherine; Jacobs, Jason; Mayer, Jeanmarie; Allen, Jill

2013-01-01

253

Dengue Virus Structural Differences That Correlate with Pathogenesis  

Microsoft Academic Search

The understanding of dengue virus pathogenesis has been hampered by the lack of in vitro and in vivo models of disease. The study of viral factors involved in the production of severe dengue, dengue hemorrhagic fever (DHF), versus the more common dengue fever (DF), have been limited to indirect clinical and epidemi- ologic associations. In an effort to identify viral

KATRIN C. LEITMEYER; DAVID W. VAUGHN; DOUGLAS M. WATTS; ROSALBA SALAS; De Chacon I. V; C Ramos; R Rico-hesse

1999-01-01

254

Dengue: The Risk to Developed and Developing Countries  

Microsoft Academic Search

Dengue viruses are members of the Flaviviridae, transmitted principally in a cycle involving humans and mosquito vectors. In the last 20 years the incidence of dengue fever epidemics has increased and hyperendemic transmission has been established over a geographically expanding area. A severe form, dengue hemorrhagic fever (DHF), is an immunopathologic disease occurring in persons who experience sequential dengue infections.

Thomas P. Monath

1994-01-01

255

Policy Platform Assessing the Potential of a Candidate Dengue Vaccine  

E-print Network

syndrome (DSS). The most distinctive feature of dengue's clinical/epidemiological profile is the increasedPolicy Platform Assessing the Potential of a Candidate Dengue Vaccine with Mathematical Modeling WHO-VMI Dengue Vaccine Modeling Group*" Background Dengue viruses are single-stranded pos- itive

Rohani, Pej

256

RESEARCH Open Access Detection of dengue group viruses by  

E-print Network

syndrome. The causative agent of DF is dengue virus (genus Flavivirus) that comprises four distinctRESEARCH Open Access Detection of dengue group viruses by fluorescence in situ hybridization and Patrick Mavingui1* Abstract Background: Dengue fever (DF) and dengue hemorrhagic fever (DHF) represent

Boyer, Edmond

257

Planning for smallpox outbreaks  

NASA Astrophysics Data System (ADS)

Mathematical models of viral transmission and control are important tools for assessing the threat posed by deliberate release of the smallpox virus and the best means of containing an outbreak. Models must balance biological realism against limitations of knowledge, and uncertainties need to be accurately communicated to policy-makers. Smallpox poses the particular challenge that key biological, social and spatial factors affecting disease spread in contemporary populations must be elucidated largely from historical studies undertaken before disease eradication in 1979. We review the use of models in smallpox planning within the broader epidemiological context set by recent outbreaks of both novel and re-emerging pathogens.

Ferguson, Neil M.; Keeling, Matt J.; John Edmunds, W.; Gani, Raymond; Grenfell, Bryan T.; Anderson, Roy M.; Leach, Steve

2003-10-01

258

Dengue - The Underestimated Risk in Travellers  

Microsoft Academic Search

In recent decades, the incidence, distribution and clinical severity of dengue have increased dramatically in most tropical and subtropical areas worldwide. As a consequence, and due to the expanding international tourism, health care providers in European travel clinics are more and more confronted with dengue, reflecting its global impact. Based on data of the European Network on Imported Infectious Disease

O Wichmann; N Mühlberger; T Jelinek

2003-01-01

259

Dengue and Malaria in Cayenne Hospital,  

E-print Network

-patients resid- ing >1 year in an area of malaria transmission). Virus iso- lation or reverse transcription. falciparum and P. vivax malaria cases ranges from 3,500 to 4,500. In addition, all 4 dengue virus serotypes. In our study, dengue investigations were conducted retro- spectively at the Pasteur Institute of French

Paris-Sud XI, Université de

260

An adenosine nucleoside inhibitor of dengue virus  

PubMed Central

Dengue virus (DENV), a mosquito-borne flavivirus, is a major public health threat. The virus poses risk to 2.5 billion people worldwide and causes 50 to 100 million human infections each year. Neither a vaccine nor an antiviral therapy is currently available for prevention and treatment of DENV infection. Here, we report a previously undescribed adenosine analog, NITD008, that potently inhibits DENV both in vitro and in vivo. In addition to the 4 serotypes of DENV, NITD008 inhibits other flaviviruses, including West Nile virus, yellow fever virus, and Powassan virus. The compound also suppresses hepatitis C virus, but it does not inhibit nonflaviviruses, such as Western equine encephalitis virus and vesicular stomatitis virus. A triphosphate form of NITD008 directly inhibits the RNA-dependent RNA polymerase activity of DENV, indicating that the compound functions as a chain terminator during viral RNA synthesis. NITD008 has good in vivo pharmacokinetic properties and is biologically available through oral administration. Treatment of DENV-infected mice with NITD008 suppressed peak viremia, reduced cytokine elevation, and completely prevented the infected mice from death. No observed adverse effect level (NOAEL) was achieved when rats were orally dosed with NITD008 at 50 mg/kg daily for 1 week. However, NOAEL could not be accomplished when rats and dogs were dosed daily for 2 weeks. Nevertheless, our results have proved the concept that a nucleoside inhibitor could be developed for potential treatment of flavivirus infections. PMID:19918064

Yin, Zheng; Chen, Yen-Liang; Schul, Wouter; Wang, Qing-Yin; Gu, Feng; Duraiswamy, Jeyaraj; Kondreddi, Ravinder Reddy; Niyomrattanakit, Pornwaratt; Lakshminarayana, Suresh B.; Goh, Anne; Xu, Hao Ying; Liu, Wei; Liu, Boping; Lim, Joanne Y. H.; Ng, Chuan Young; Qing, Min; Lim, Chin Chin; Yip, Andy; Wang, Gang; Chan, Wai Ling; Tan, Hui Pen; Lin, Kai; Zhang, Bo; Zou, Gang; Bernard, Kristen A.; Garrett, Christine; Beltz, Karen; Dong, Min; Weaver, Margaret; He, Handan; Pichota, Arkadius; Dartois, Veronique; Keller, Thomas H.; Shi, Pei-Yong

2009-01-01

261

Thailand Momentum on Policy and Practice in Local Legislation on Dengue Vector Control  

PubMed Central

Over a past decade, an administrative decentralization model, adopted for local administration development in Thailand, is replacing the prior centralized (top-down) command system. The change offers challenges to local governmental agencies and other public health agencies at all the ministerial, regional, and provincial levels. A public health regulatory and legislative framework for dengue vector control by local governmental agencies is a national topic of interest because dengue control program has been integrated into healthcare services at the provincial level and also has been given priority in health plans of local governmental agencies. The enabling environments of local administrations are unique, so this critical review focuses on the authority of local governmental agencies responsible for disease prevention and control and on the functioning of local legislation with respect to dengue vector control and practices. PMID:24799896

Bhumiratana, Adisak; Intarapuk, Apiradee; Chujun, Suriyo; Kaewwaen, Wuthichai; Sorosjinda-Nunthawarasilp, Prapa; Koyadun, Surachart

2014-01-01

262

Dengue, Urbanization and Globalization: The Unholy Trinity of the 21st Century  

PubMed Central

Dengue is the most important arboviral disease of humans with over half of the world’s population living in areas of risk. The frequency and magnitude of epidemic dengue have increased dramatically in the past 40 years as the viruses and the mosquito vectors have both expanded geographically in the tropical regions of the world. There are many factors that have contributed to this emergence of epidemic dengue, but only three have been the principal drivers: 1) urbanization, 2) globalization and 3) lack of effective mosquito control. The dengue viruses have fully adapted to a human-Aedes aegypti-human transmission cycle, in the large urban centers of the tropics, where crowded human populations live in intimate association with equally large mosquito populations. This setting provides the ideal home for maintenance of the viruses and the periodic generation of epidemic strains. These cities all have modern airports through which 10s of millions of passengers pass each year, providing the ideal mechanism for transportation of viruses to new cities, regions and continents where there is little or no effective mosquito control. The result is epidemic dengue. This paper discusses this unholy trinity of drivers, along with disease burden, prevention and control and prospects for the future. PMID:22500131

Gubler, Duane J.

2011-01-01

263

[Is the fight against dengue complicated with the emergence of a new viral serotype?].  

PubMed

Dengue is a viral acute febrile illness, currently considered one of the most important arbovirosis worldwide in terms of morbidity, mortality and economic impact. Various theories have been proposed to explain the pathogenesis of severe forms of dengue, involving among other factors, features related to the virus, such as the presence of more virulent strains and/or strains with increased replicative capacity. A crucial point at this time is the discovery of a new viral type, dengue 5, from nonhuman primates in Malaysia-Borneo, which could result in greater difficulties for control and vaccine production (currently in efficacy tests). Once the circulation of this viral type has been demonstrated in the human population, the high risk of infection will have extreme or controversial public health implications. Therefore, a worldwide program to combat dengue should include an urgent need to implement continuous vector elimination, community education and prevention and control of the disease. Only then, we will be aiming to reduce the morbidity and transmission risk of dengue, while new technological and effective alternatives come about. PMID:25272519

Valero, Nereida; Quiroz, Yasmir

2014-09-01

264

Molecular and Epidemiologic Analysis of Dengue Virus Isolates from Somalia  

Microsoft Academic Search

Nucleotide sequence analysis was performed on 14 dengue virus isolates (13 dengue-2 viruses and 1 dengue-3 virus) recovered from febrile soldiers in Somalia in 1993. The dengue-2 viruses were most closely related to dengue-2 virus recovered in Somalia in 1984. However, differences in nucleotide sequence (0.35% to 1.35%) were evident among the 1993 isolates. These differences were closely associated with

Niranjan Kanesa-thasan; Gwong-Jen J. Chang; Bonnie L. Smoak; Alan Magill; M. Jeanne Burrous; Charles H. Hoke

1998-01-01

265

[Inequities in health: the casus of dengue].  

PubMed

Impoverished populations carry a disproportionately high share of the burden of neglected tropical diseases, including dengue. The burden of dengue is high among poor people because they often live in communities where mosquito vectors are abundant, because they use less vector-human barrier methods, and because interventions tend to be less effective in disadvantaged populations. We believe that a better understanding and management of the "causes behind the causes" of dengue would lead to more equitable and more effective control strategies. Two main ideas are worked out. First, we propose targeted interventions in well-defined geographical areas with high risk of dengue transmission. The definition of these high-risk areas should be based on socio-economical, entomological, environmental as well as epidemiological information. Second, there is a need to adapt dengue control tools to local, context-specific factors, in active collaboration with the sectors involved in risk management as well as with the affected communities. PMID:24448949

Vanlerberghe, Veerle; Verdonck, Kristien

2013-01-01

266

Rift Valley fever outbreak--Kenya, November 2006-January 2007.  

PubMed

In mid-December 2006, several unexplained fatalities associated with fever and generalized bleeding were reported to the Kenya Ministry of Health (KMOH) from Garissa District in North Eastern Province (NEP). By December 20, a total of 11 deaths had been reported. Of serum samples collected from the first 19 patients, Rift Valley fever (RVF) virus RNA or immunoglobulin M (IgM) antibodies against RVF virus were found in samples from 10 patients; all serum specimens were negative for yellow fever, Ebola, Crimean-Congo hemorrhagic fever, and dengue viruses. The outbreak was confirmed by isolation of RVF virus from six of the specimens. Humans can be infected with RVF virus from bites of mosquitoes or other arthropod vectors that have fed on animals infected with RVF virus, or through contact with viremic animals, particularly livestock. Reports of livestock deaths and unexplained animal abortions in NEP provided further evidence of an RVF outbreak. On December 20, an investigation was launched by KMOH, the Kenya Field Epidemiology and Laboratory Training Program (FELTP), the Kenya Medical Research Institute (KEMRI), the Walter Reed Project of the U.S. Army Medical Research Unit, CDC-Kenya's Global Disease Detection Center, and other partners, including the World Health Organization (WHO) and Médecins Sans Frontières (MSF). This report describes the findings from that initial investigation and the control measures taken in response to the RVF outbreak, which spread to multiple additional provinces and districts, resulting in 404 cases with 118 deaths as of January 25, 2007. PMID:17268404

2007-02-01

267

Planning for smallpox outbreaks  

Microsoft Academic Search

Mathematical models of viral transmission and control are important tools for assessing the threat posed by deliberate release of the smallpox virus and the best means of containing an outbreak. Models must balance biological realism against limitations of knowledge, and uncertainties need to be accurately communicated to policy-makers. Smallpox poses the particular challenge that key biological, social and spatial factors

Matt J. Keeling; W. John Edmunds; Raymond Gani; Bryan T. Grenfell; Roy M. Anderson; Steve Leach; Neil M. Ferguson

2003-01-01

268

Swimming Associated Disease Outbreaks.  

ERIC Educational Resources Information Center

Presents a literature review of recreational waterborne outbreaks and cases of disease, covering publications of 1976-77. This review includes: (1) retrospective and prospective epidemiological studies; (2) predictive models of the risk of recreational waterborn disease. A list of 35 references is also presented. (HM)

Cabelli, V. J.

1978-01-01

269

A waterborne tularemia outbreak  

Microsoft Academic Search

A waterborne tularemia outbreak is described. Forty nine cases were identified in Sansepolcro, a small Medioeval town in the province of Arezzo, Tuscany, Italy. All cases had laterocervical or sub-mandibular adenitis, and occurred within a period of three weeks during March and April 1982.

D. Greco; G. Allegrini; T. Tizzi; E. Ninu; A. Lamanna; S. Luzi

1987-01-01

270

Symptoms and What To Do If You Think You Have Dengue  

MedlinePLUS

... 4 RT-PCR Assay Case Definition Dengue Panel Project Education/Training Patient Education & Training Media Resources Dengue Clinical Case Management (DCCM) Publications and Related Links Dengue Branch Dengue ...

271

Outbreak of norovirus gastroenteritis infection, Thailand.  

PubMed

Norovirus is a leading cause of gastrointestinal illness worldwide. We investigated an outbreak of gastrointestinal illness in Pattaya, Thailand, among participants of a course. We asked participants and family members to complete a questionnaire asking about symptoms, meals eaten, and foods consumed during the course. We collected stool samples from persons reporting illness and analyzed specimens for several viruses and enteropathogenic bacteria. We defined a case as a person having one or more episodes of diarrhea, with onset between 30 August and 1 September 2010, in a participant or family member who attended the course. Of 56 people who attended, 95% completed the questionnaire: nine met the case definition (attack rate, 17%). Common symptoms included abdominal cramps, nausea, fatigue, headache, and vomiting. Food items with elevated risk ratios included: crispy fish maw, dried squid, and cashew nut salad [risk ratio (RR) 5.1; 95% confidence interval (CI) 0.7-37]; assorted salad bar with dressing (RR 3.0; 95% CI 0.9-11); and seafood kebab (RR 5.8; 95% CI 0.8-43). Among ill persons, four (44%) provided stool samples and two (50%) were positive for norovirus. Our data suggest a foodborne outbreak of norovirus. Increased use of norovirus diagnostics as well as measures to prevent transmission may help identify additional outbreaks and improve control measures to limit the spread of outbreaks. PMID:24050072

McCarthy, Katie S; Guntapong, Ratigorn; Thattiyaphong, Aree; Wangroongsarb, Piyada; Hall, Aron J; Olsen, Sonja J; Holtz, Timothy H

2013-05-01

272

Effect of Hippophae rhamnoides leaf extract against Dengue virus infection in human blood-derived macrophages  

Microsoft Academic Search

Dengue virus occurs as four distinct serotypes, called Dengue 1, 2, 3, and 4. Symptomatic dengue virus infection ranges from a self limited febrile illness, dengue fever (DF), to a more severe disease, dengue hemorrhagic fever\\/dengue shock syndrome (DHF\\/DSS). The anti-Dengue treatment is severely hampered as no specific therapeutic agents are available. Even present treatment strategies for Dengue are more

Monika Jain; L. Ganju; A. Katiyal; Y. Padwad; K. P. Mishra; S. Chanda; D. Karan; K. M. S. Yogendra; R. C. Sawhney

2008-01-01

273

Virological surveillance of dengue in Saint Martin and Saint Barthelemy, French West Indies, using blood samples on filter paper.  

PubMed

To strengthen active dengue surveillance in Saint Martin and Saint Barthélemy, two French Caribbean islands, we evaluated the epidemiological usefulness of collecting blood samples from NS1-positive dengue patients on filter paper to identify the dengue serotypes circulating in these regions during a 27-month period. This approach allowed dengue serotypes to be identified by reverse transcriptase-polymerase chain reaction in 90.1% of the total set of 666 samples analyzed and, in 95.5% of the samples collected during the acute phase of the disease. This prospective virological surveillance using blood samples absorbed onto filter paper, which were stored at 4°C and shipped at ambient temperature to a specialized laboratory for analysis, allowed us to avoid the logistic and financial costs associated with shipping frozen venous blood samples. This surveillance system offers a low-cost alternative for reinforcing dengue prevention in areas where specialized laboratories do not exist, notably by facilitating the early detection of potentially new dengue serotypes. PMID:22232467

Matheus, Séverine; Chappert, Jean-Loup; Cassadou, Sylvie; Berger, Franck; Labeau, Bhetty; Bremand, Laetitia; Winicki, Alain; Huc-Anais, Patricia; Quenel, Philippe; Dussart, Philippe

2012-01-01

274

The importance of waterborne disease outbreak surveillance in the United States.  

PubMed

Analyses of the causes of disease outbreaks associated with contaminated drinking water in the United States have helped inform prevention efforts at the national, state, and local levels. This article describes the changing nature of disease outbreaks in public water systems during 1971-2008 and discusses the importance of a collaborative waterborne outbreak surveillance system established in 1971. Increasing reports of outbreaks throughout the early 1980s emphasized that microbial contaminants remained a health-risk challenge for suppliers of drinking water. Outbreak investigations identified the responsible etiologic agents and deficiencies in the treatment and distribution of drinking water, especially the high risk associated with unfiltered surface water systems. Surveillance information was important in establishing an effective research program that guided government regulations and industry actions to improve drinking water quality. Recent surveillance statistics suggest that prevention efforts based on these research findings have been effective in reducing outbreak risks especially for surface water systems. PMID:23247140

Craun, Gunther Franz

2012-01-01

275

Spray application of Bacillus thuringiensis israelensis (Bti strain AM65-52) against Aedes aegypti (L.) and Ae. albopictus Skuse populations and impact on dengue transmission in a dengue endemic residential site in Malaysia.  

PubMed

A one year study was conducted to evaluate the impact of spray application of Bacillus thuringiensis israelensis (Bti), strain AM65-52 on vector populations and dengue transmission in a dengue endemic state in Malaysia. Residential sites with similar populations of Aedes aegypti (L.) and Aedes albopictus Skuse were studied. One site was treated with spray application of Bti into all outdoor target vector habitats, which consisted of natural and artificial containers. The other site was not treated. The impact of spray application was measured with an indoor and outdoor ovitrap index (OI) and epidemiologic data. Significant reductions in both Ae. aegypti and Ae. albopictus, OI were observed both indoors and outdoors, in treated sites compared to untreated sites (p < 0.05). OI reduction was achieved over time in the treated area. The OI was suppressed to below 10%. This was maintained for 4 weeks into the post-treatment phase. The outdoor OI at the untreated site remained at more than 40% for 38 weeks during the evaluation period. One dengue case occurred at the Bti treatment site at the beginning of the treatment phase, but no further cases were detected during the remainder of the treatment phase. However, there was an ongoing dengue outbreak in the untreated area with 15 serologically confirmed cases during weeks 37-54. Intensive fogging operations with pyrethroids at the untreated (Bti) site had a positive impact on Ae. albopictus, but not on Ae. aegypti. PMID:23082582

Tan, A W A; Loke, S R; Benjamin, S; Lee, H L; Chooi, K H; Sofian-Azirun, M

2012-03-01

276

Influenza Outbreak in a Vaccinated Population - USS Ardent, February 2014.  

PubMed

On February 10, 2014, the USS Ardent, a U.S. Navy minesweeper, was moored in San Diego, California, while conducting training. Over the course of 3 days, 25 of 102 crew members sought medical care because of influenza-like illness (ILI). Nasal swab specimens were collected from each patient, and initial rapid influenza testing indicated 16 cases of influenza A. Ultimately, polymerase chain reaction (PCR) testing conducted by the Naval Health Research Center determined that 20 specimens were influenza A, of which 18 were subtype H3N2. Two specimens could not be subtyped. The HA gene sequence of an outbreak isolate was 99% identical to strains circulating during the 2013-14 influenza season and antigenically similar to the H3N2 component of the 2013-14 influenza vaccine. At the time of the outbreak, 99% of the crew had received influenza vaccine. Through the duration of the outbreak, the minesweeper squadron medical officer collaborated with Navy Environmental and Preventive Medicine Unit Five, higher-level Navy authorities, and County of San Diego Public Health Services to implement the outbreak response, which included disseminating outbreak information to surrounding Navy units, disinfecting the ship, sending home infected crew members, identifying family members at high risk, and providing antiviral medications and guidance. No crew member had onset of symptoms >6 days after the first crew member became ill. This outbreak highlights the risk for an H3N2 influenza outbreak among vaccinated and otherwise healthy young persons. PMID:25340911

Aquino, Theodore L; Brice, Gary T; Hayes, Sherry; Myers, Christopher A; McDowell, Jaqueline; White, Brenda; Garten, Rebecca; Johnston, Daniel

2014-10-24

277

Sphingosine 1-Phosphate in Acute Dengue Infection  

PubMed Central

Background Vascular leak is the hallmark of severe dengue infections and leads to complications such as shock and multi-organ failure. Although many mediators have been implicated in the vascular leak in dengue, the role of sphingosine 1-phosphate (S1P) has not been investigated. Metholodology/Principal findings As S1P has been shown to be important in barrier integrity, we assessed the S1P levels in 28 patients with acute dengue and 12 healthy individuals. The S1P levels were significantly lower in patients with acute dengue (p?=?0.002) and the levels in patients with grade IV dengue haemorrhagic fever (DHF) were significantly lower than those with dengue fever (p?=?0.005). We then investigated the kinetics of S1P levels throughout the course of the illness in another 32 patients in serum samples obtained twice a day. We found that S1P levels were low throughout the course of illness and S1P levels were <0.5 µM in 12/23 patients with DHF when compared to 1/9 with DF. Conclusions/Significance As S1P has shown to be important in the endothelial barrier integrity and increases transendothelial resistance, low levels of S1P in acute dengue infection are likely to contribute to increased vascular permeability. PMID:25409037

Gomes, Laksiri; Fernando, Samitha; Fernando, Randika Heshan; Wickramasinghe, Nilanka; Shyamali, Narangoda Liyanage Ajantha

2014-01-01

278

Acute gastroenteritis outbreaks associated with ground-waterborne norovirus in South Korea during 2008-2012.  

PubMed

SUMMARY Epidemiological and virological studies indicate that noroviruses-contaminated groundwater was the primary source of four acute gastroenteritis outbreaks in South Korea between 2008 and 2012. Furthermore, cabbage kimchi was first identified as the vehicle of transmission between groundwater and infected patients in an outbreak in 2011. The proper treatment of groundwater sources prior to use for drinking or in food preparation is necessary to prevent further outbreaks. PMID:24534556

Cho, H G; Lee, S G; Kim, W H; Lee, J S; Park, P H; Cheon, D S; Jheong, W H; Jho, E H; Lee, J B; Paik, S Y

2014-12-01

279

Estimating the basic reproduction number for single-strain dengue fever epidemics  

PubMed Central

Background Dengue, an infectious tropical disease, has recently emerged as one of the most important mosquito-borne viral diseases in the world. We perform a retrospective analysis of the 2011 dengue fever epidemic in Pakistan in order to assess the transmissibility of the disease. We obtain estimates of the basic reproduction number R0 from epidemic data using different methodologies applied to different epidemic models in order to evaluate the robustness of our estimate. Results We first estimate model parameters by fitting a deterministic ODE vector-host model for the transmission dynamics of single-strain dengue to the epidemic data, using both a basic ordinary least squares (OLS) as well as a generalized least squares (GLS) scheme. Moreover, we perform the same analysis for a direct-transmission ODE model, thereby allowing us to compare our results across different models. In addition, we formulate a direct-transmission stochastic model for the transmission dynamics of dengue and obtain parameter estimates for the stochastic model using Markov chain Monte Carlo (MCMC) methods. In each of the cases we have considered, the estimate for the basic reproduction number R0 is initially greater than unity leading to an epidemic outbreak. However, control measures implemented several weeks after the initial outbreak successfully reduce R0 to less than unity, thus resulting in disease elimination. Furthermore, it is observed that there is strong agreement in our estimates for the pre-control value of R0, both across different methodologies as well across different models. However, there are also significant differences between our estimates for the post-control value of the basic reproduction number across the two different models. Conclusion In conclusion, we have obtained robust estimates for the value of the basic reproduction number R0 associated with the 2011 dengue fever epidemic before the implementation of public health control measures. Furthermore, we have shown that there is close agreement between our estimates for the post-control value of R0 across the different methodologies. Nevertheless, there are also significant differences between the estimates for the post-control value of R0 across the two different models. PMID:24708869

2014-01-01

280

Listeriosis Outbreaks and Associated Food Vehicles, United States, 1998–2008  

PubMed Central

Listeria monocytogenes, a bacterial foodborne pathogen, can cause meningitis, bacteremia, and complications during pregnancy. This report summarizes listeriosis outbreaks reported to the Foodborne Disease Outbreak Surveillance System of the Centers for Disease Control and Prevention during 1998–2008. The study period includes the advent of PulseNet (a national molecular subtyping network for outbreak detection) in 1998 and the Listeria Initiative (enhanced surveillance for outbreak investigation) in 2004. Twenty-four confirmed listeriosis outbreaks were reported during 1998–2008, resulting in 359 illnesses, 215 hospitalizations, and 38 deaths. Outbreaks earlier in the study period were generally larger and longer. Serotype 4b caused the largest number of outbreaks and outbreak-associated cases. Ready-to-eat meats caused more early outbreaks, and novel vehicles (i.e., sprouts, taco/nacho salad) were associated with outbreaks later in the study period. These changes may reflect the effect of PulseNet and the Listeria Initiative and regulatory initiatives designed to prevent contamination in ready-to-eat meat and poultry products. PMID:23260661

Cartwright, Emily J.; Jackson, Kelly A.; Johnson, Shacara D.; Graves, Lewis M.; Mahon, Barbara E.

2013-01-01

281

Issues Related to Recent Dengue Vaccine Development  

PubMed Central

Dengue fever (DF) and dengue hemorrhagic fever (DHF) are mosquito-transmitted diseases of global importance. Despite significant research efforts, no approved vaccines or antiviral drugs against these diseases are currently available. This brief article reviews the status of dengue vaccine development, with particular emphasis on the vaccine strategies in more advanced stages of evaluation; these include traditional attenuation, chimerization and engineered attenuation. Several aspects of these vaccine design strategies, including concerns about vaccine candidates inducing infection-enhancing antibodies, are also presented. PMID:22500138

Konishi, Eiji

2011-01-01

282

Challenges and future perspective for dengue vector control in the Western Pacific Region  

PubMed Central

Dengue remains a significant public health issue in the Western Pacific Region. In the absence of a vaccine, vector control is the mainstay for dengue prevention and control. In this paper we describe vector surveillance and vector control in the Western Pacific countries and areas. Vector surveillance and control strategies used by countries and areas of the Western Pacific Region vary. Vector control strategies include chemical, biological and environmental management that mainly target larval breeding sites. The use of insecticides targeting larvae and adult mosquitoes remains the mainstay of vector control programmes. Existing vector control tools have several limitations in terms of cost, delivery and long-term sustainability. However, there are several new innovative tools in the pipeline. These include Release of Insects Carrying a Dominant Lethal system and Wolbachia, an endosymbiotic bacterium, to inhibit dengue virus in the vector. In addition, the use of biological control such as larvivorous fish in combination with community participation has potential to be scaled up. Any vector control strategy should be selected based on evidence and appropriateness for the entomological and epidemiological setting and carried out in both inter-epidemic and epidemic periods. Community participation and interagency collaboration are required for effective and sustainable dengue prevention and control. Countries and areas are now moving towards integrated vector management. PMID:23908883

Christophel, Eva Maria; Gopinath, Deyer; Abdur, Rashid Md.; Vectorborne, Other; Diseases, Parasitic

2011-01-01

283

A review of outbreaks of foodborne disease associated with passenger ships: evidence for risk management.  

PubMed Central

OBJECTIVE: Foodborne disease outbreaks on ships are of concern because of their potentially serious health consequences for passengers and crew and high costs to the industry. The authors conducted a review of outbreaks of foodborne diseases associated with passenger ships in the framework of a World Health Organization project on setting guidelines for ship sanitation. METHODS: The authors reviewed data on 50 outbreaks of foodborne disease associated with passenger ships. For each outbreak, data on pathogens/toxins, type of ship, factors contributing to outbreaks, mortality and morbidity, and food vehicles were collected. RESULTS: The findings of this review show that the majority of reported outbreaks were associated with cruise ships and that almost 10,000 people were affected. Salmonella spp were most frequently associated with outbreaks. Foodborne outbreaks due to enterotoxigenic E. coli spp, Shigella spp, noroviruses (formally called Norwalk-like viruses), Vibrio spp, Staphylococcus aureus, Clostridium perfringens, Cyclospora sp, and Trichinella sp also occurred on ships. Factors associated with the outbreaks reviewed include inadequate temperature control, infected food handlers, contaminated raw ingredients, cross-contamination, inadequate heat treatment, and onshore excursions. Seafood was the most common food vehicle implicated in outbreaks. CONCLUSIONS: Many ship-associated outbreaks could have been prevented if measures had been taken to ensure adequate temperature control, avoidance of cross-contamination, reliable food sources, adequate heat treatment, and exclusion of infected food handlers from work. PMID:15219800

Rooney, Roisin M.; Cramer, Elaine H.; Mantha, Stacey; Nichols, Gordon; Bartram, Jamie K.; Farber, Jeffrey M.; Benembarek, Peter K.

2004-01-01

284

Consequences of the Expanding Global Distribution of Aedes albopictus for Dengue Virus Transmission  

PubMed Central

The dramatic global expansion of Aedes albopictus in the last three decades has increased public health concern because it is a potential vector of numerous arthropod-borne viruses (arboviruses), including the most prevalent arboviral pathogen of humans, dengue virus (DENV). Ae. aegypti is considered the primary DENV vector and has repeatedly been incriminated as a driving force in dengue's worldwide emergence. What remains unresolved is the extent to which Ae. albopictus contributes to DENV transmission and whether an improved understanding of its vector status would enhance dengue surveillance and prevention. To assess the relative public health importance of Ae. albopictus for dengue, we carried out two complementary analyses. We reviewed its role in past dengue epidemics and compared its DENV vector competence with that of Ae. aegypti. Observations from “natural experiments” indicate that, despite seemingly favorable conditions, places where Ae. albopictus predominates over Ae. aegypti have never experienced a typical explosive dengue epidemic with severe cases of the disease. Results from a meta-analysis of experimental laboratory studies reveal that although Ae. albopictus is overall more susceptible to DENV midgut infection, rates of virus dissemination from the midgut to other tissues are significantly lower in Ae. albopictus than in Ae. aegypti. For both indices of vector competence, a few generations of mosquito colonization appear to result in a relative increase of Ae. albopictus susceptibility, which may have been a confounding factor in the literature. Our results lead to the conclusion that Ae. albopictus plays a relatively minor role compared to Ae. aegypti in DENV transmission, at least in part due to differences in host preferences and reduced vector competence. Recent examples of rapid arboviral adaptation to alternative mosquito vectors, however, call for cautious extrapolation of our conclusion. Vector status is a dynamic process that in the future could change in epidemiologically important ways. PMID:20520794

Lambrechts, Louis; Scott, Thomas W.; Gubler, Duane J.

2010-01-01

285

Dengue transmission model by means of viremic adult immuno-competent mouse  

PubMed Central

Background Dengue virus infection manifests in three distinct forms in humans: dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. Infection with the virus is a fatal disease; no vaccine is available and prevention depends on interruption of the chain of transmission. The study of dengue viral transmission by mosquitoes is hindered due to the lack of an affordable animal model. In general, immuno-competent mice are used as a simple and inexpensive animal model, but mice are not susceptible to dengue virus infection and therefore viremia will not occur following the inoculation of the virus in such mice. Here, we report a method for creating artificial viremia in immuno-competent mice, and further demonstrate the use of viremic mice to simultaneously infect a large number of Aedes aegypti. Methods We infected K562 cells with DENV-2 in the presence of an antibody against DENV-4. We then incubated the cells for 2 d before injecting the infected cells into C3H mice. After 5 h incubation, we allowed 100–150 female Aedes aegypti to feed on blood from the mice directly. We collected blood samples from the mice and from randomly selected Ae. aegypti at 2, 6, 12, and 24 h post-blood meal and screened the samples for DENV-2 genome as well as for virus concentration. Results Our procedure provided high virus concentrations in the mice for at least 7 h after viral inoculation. We found that 13 out of 14 randomly picked mosquitoes were infected with DENV-2. High concentrations of virus were detected in the mosquitoes until at least 12 h post-infection. Conclusions Using the viremic immuno-competent mouse, we show that mass infection of Ae. aegypti is achievable. Compared to other infection techniques using direct inoculation, membrane-feeding, or immuno-deficient/humanized mice, we are confident that this method will provide a simpler and more efficient infection technique. PMID:24685121

2014-01-01

286

Acceptability of impregnated school uniforms for dengue control in Thailand: a mixed methods approach  

PubMed Central

Background As current dengue control strategies have been shown to be largely ineffective in reducing dengue in school-aged children, novel approaches towards dengue control need to be studied. Insecticide-impregnated school uniforms represent an innovative approach with the theoretical potential to reduce dengue infections in school children. Objectives This study took place in the context of a randomised control trial (RCT) to test the effectiveness of permethrin-impregnated school uniforms (ISUs) for dengue prevention in Chachoengsao Province, Thailand. The objective was to assess the acceptability of ISUs among parents, teachers, and principals of school children involved in the trial. Methodology Quantitative and qualitative tools were used in a mixed methods approach. Class-clustered randomised samples of school children enrolled in the RCT were selected and their parents completed 321 self-administered questionnaires. Descriptive statistics and logistic regression were used to analyse the quantitative data. Focus group discussions and individual semi-structured interviews were conducted with parents, teachers, and principals. Qualitative data analysis involved content analysis with coding and thematic development. Results The knowledge and experience of dengue was substantial. The acceptability of ISUs was high. Parents (87.3%; 95% CI 82.9–90.8) would allow their child to wear an ISU and 59.9% (95% CI 53.7–65.9) of parents would incur additional costs for an ISU over a normal uniform. This was significantly associated with the total monthly income of a household and the educational level of the respondent. Parents (62.5%; 95% CI 56.6–68.1) indicated they would be willing to recommend ISUs to other parents. Conclusions Acceptability of the novel tool of ISUs was high as defined by the lack of concern along with the willingness to pay and recommend. Considering issues of effectiveness and scalability, assessing acceptability of ISUs over time is recommended. PMID:25183313

Murray, Natasha; Jansarikij, Suphachai; Olanratmanee, Phanthip; Maskhao, Pongsri; Souares, Aurelia; Wilder-Smith, Annelies; Kittayapong, Pattamaporn; Louis, Valerie R.

2014-01-01

287

Dengue Expansion in Africa--Not Recognized or Not Happening?  

PubMed Central

An expert conference on Dengue in Africa was held in Accra, Ghana, in February 2013 to consider key questions regarding the possible expansion of dengue in Africa. Four key action points were highlighted to advance our understanding of the epidemiology of dengue in Africa. First, dengue diagnostic tools must be made more widely available in the healthcare setting in Africa. Second, representative data need to be collected across Africa to uncover the true burden of dengue. Third, established networks should collaborate to produce these types of data. Fourth, policy needs to be informed so the necessary steps can be taken to provide dengue vector control and health services. PMID:25271370

Junghanss, Thomas; Wills, Bridget; Brady, Oliver J.; Eckerle, Isabella; Farlow, Andrew; Hay, Simon I.; McCall, Philip J.; Messina, Jane P.; Ofula, Victor; Sall, Amadou A.; Sakuntabhai, Anavaj; Velayudhan, Raman; Wint, G.R. William; Zeller, Herve; Margolis, Harold S.; Sankoh, Osman

2014-01-01

288

Contributing factors to disease outbreaks associated with untreated groundwater.  

PubMed

Disease outbreaks associated with drinking water drawn from untreated groundwater sources represent a substantial proportion (30.3%) of the 818 drinking water outbreaks reported to CDC's Waterborne Disease and Outbreak Surveillance System (WBDOSS) during 1971 to 2008. The objectives of this study were to identify underlying contributing factors, suggest improvements for data collection during outbreaks, and inform outbreak prevention efforts. Two researchers independently reviewed all qualifying outbreak reports (1971 to 2008), assigned contributing factors and abstracted additional information (e.g., cases, etiology, and water system attributes). The 248 outbreaks resulted in at least 23,478 cases of illness, 390 hospitalizations, and 13 deaths. The majority of outbreaks had an unidentified etiology (n?=?135, 54.4%). When identified, the primary etiologies were hepatitis A virus (n?=?21, 8.5%), Shigella spp. (n?=?20, 8.1%), and Giardia intestinalis (n?=?14, 5.7%). Among the 172 (69.4%) outbreaks with contributing factor data available, the leading contamination sources included human sewage (n?=?57, 33.1%), animal contamination (n?=?16, 9.3%), and contamination entering via the distribution system (n?=?12, 7.0%). Groundwater contamination was most often facilitated by improper design, maintenance or location of the water source or nearby waste water disposal system (i.e., septic tank; n?=?116, 67.4%). Other contributing factors included rapid pathogen transport through hydrogeologic formations (e.g., karst limestone; n?=?45, 26.2%) and preceding heavy rainfall or flooding (n?=?36, 20.9%). This analysis underscores the importance of identifying untreated groundwater system vulnerabilities through frequent inspection and routine maintenance, as recommended by protective regulations such as Environmental Protection Agency's (EPA's) Groundwater Rule, and the need for special consideration of the local hydrogeology. PMID:24116713

Wallender, Erika K; Ailes, Elizabeth C; Yoder, Jonathan S; Roberts, Virginia A; Brunkard, Joan M

2014-11-01

289

Fitting outbreak models to data from many small norovirus outbreaks.  

PubMed

Infectious disease often occurs in small, independent outbreaks in populations with varying characteristics. Each outbreak by itself may provide too little information for accurate estimation of epidemic model parameters. Here we show that using standard stochastic epidemic models for each outbreak and allowing parameters to vary between outbreaks according to a linear predictor leads to a generalized linear model that accurately estimates parameters from many small and diverse outbreaks. By estimating initial growth rates in addition to transmission rates, we are able to characterize variation in numbers of initially susceptible individuals or contact patterns between outbreaks. With simulation, we find that the estimates are fairly robust to the data being collected at discrete intervals and imputation of about half of all infectious periods. We apply the method by fitting data from 75 norovirus outbreaks in health-care settings. Our baseline regression estimates are 0.0037 transmissions per infective-susceptible day, an initial growth rate of 0.27 transmissions per infective day, and a symptomatic period of 3.35 days. Outbreaks in long-term-care facilities had significantly higher transmission and initial growth rates than outbreaks in hospitals. PMID:24593918

O'Dea, Eamon B; Pepin, Kim M; Lopman, Ben A; Wilke, Claus O

2014-03-01

290

The epidemiology of published norovirus outbreaks: a review of risk factors associated with attack rate and genogroup.  

PubMed

The purpose of this study was to examine global epidemiological trends in human norovirus (NoV) outbreaks by transmission route and setting, and describe relationships between these characteristics, viral attack rates, and the occurrence of genogroup I (GI) or genogroup II (GII) strains in outbreaks. We analysed data from 902 reverse transcriptase-polymerase chain reaction-confirmed, human NoV outbreaks abstracted from a systematic review of articles published from 1993 to 2011 and indexed under the terms 'norovirus' and 'outbreak'. Multivariate regression analyses demonstrated that foodservice and winter outbreaks were significantly associated with higher attack rates. Foodborne and waterborne outbreaks were associated with multiple strains (GI+GII). Waterborne outbreaks were significantly associated with GI strains, while healthcare-related and winter outbreaks were associated with GII strains. These results identify important trends for epidemic NoV detection, prevention, and control. PMID:22444943

Matthews, J E; Dickey, B W; Miller, R D; Felzer, J R; Dawson, B P; Lee, A S; Rocks, J J; Kiel, J; Montes, J S; Moe, C L; Eisenberg, J N S; Leon, J S

2012-07-01

291

Dengue virus in Mexican bats  

PubMed Central

SUMMARY Individuals belonging to five families, 12 genera, and 19 different species of bats from dengue endemic areas in the Gulf and Pacific coasts of Mexico were examined by ELISA, RT–PCR, and for the presence of dengue virus (DV) NS1 protein. Nine individuals from four species were seropositive by ELISA: three insectivorous, Myotis nigricans (four positives/12 examined), Pteronotus parnellii (3/19), and Natalus stramineus (1/4), and one frugivorous Artibeus jamaicensis (1/35) (12·86% seroprevalence in positive species). DV serotype 2 was detected by RT–PCR in four samples from three species (all from the Gulf coast – rainy season): two frugivorous, A. jamaicensis (2/9), and Carollia brevicauda (1/2), and one insectivorous, M. nigricans (1/11). The latter was simultaneously positive for NS1 protein. DV RT–PCR positive animals were all antibody seronegative. M. nigricans showed positive individuals for all three tests. This is the first evidence suggesting the presence of DV in bats from Mexico. PMID:18325131

AGUILAR-SETIEN, A.; ROMERO-ALMARAZ, M. L.; SANCHEZ-HERNANDEZ, C.; FIGUEROA, R.; JUAREZ-PALMA, L. P.; GARCIA-FLORES, M. M.; VAZQUEZ-SALINAS, C.; SALAS-ROJAS, M.; HIDALGO-MARTINEZ, A. C.; PIERLE, S. AGUILAR; GARCIA-ESTRADA, C.; RAMOS, C.

2008-01-01

292

CORRELATION OF SERUM LEVELS OF MACROPHAGE MIGRATION INHIBITORY FACTOR WITH DISEASE SEVERITY AND CLINICAL OUTCOME IN DENGUE PATIENTS  

Microsoft Academic Search

Dengue virus infection can cause mild dengue fever (DF) or severe dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Cytokines are believed to be involved in the pathogenesis of dengue infection. However, the role of the pro-inflammatory cytokine macrophage migration inhibitory factor (MIF) in dengue infection is unclear. In this study, serum levels of MIF in adult dengue patients

LIEN-CHENG CHEN; HUAN-YAO LEI; CHING-CHUAN LIU; SHU-CHU SHIESH; SHUN-HUA CHEN; HSIAO-SHENG LIU; YEE-SHIN LIN; SHAN-TAIR WANG; HUEY-WEN SHYU; TRAI-MING YEH

2006-01-01

293

WATERBORN OUTBREAK OF VIBRIO CHOLERAE O1 OGAWA; IN WADH AREA OF BALOCHISTAN  

Microsoft Academic Search

gspirkani@yahoo.com Objective: To isolate the etiological agent of severe diarrheal outbreak, identification, ant ibiogram of isolated agent and preventive m easures to c ontrol the spread of infection. Design: Samples of stool and drinking water supply of affected area collected in Cary- Blair transport medium, inoculated on various media. The isolated strains were identified as responsible for diarrheal outbreak tested

GHULAM SARWAR PIRKANI; GHULAM RASOOL; Essa Khan Jogezai

294

Community Strain of Methicillin-Resistant Staphylococcus aureus Involved in a Hospital Outbreak  

Microsoft Academic Search

Western Australia (WA) has been able to prevent methicillin-resistant Staphylococcus aureus (MRSA) strains from outside of the state from becoming established in its hospitals. Recently, a single-strain outbreak of MRSA occurred in a WA metropolitan teaching hospital following admission of an infected patient from a remote community. The strain responsible for the outbreak was unrelated to any imported strains and

F. G. O'BRIEN; J. W. PEARMAN; M. GRACEY; T. V. RILEY; W. B. GRUBB

1999-01-01

295

Role of fomite contamination during an outbreak of norovirus on houseboats  

Microsoft Academic Search

An outbreak of suspected norovirus gastroenteritis among three consecutive groups of houseboaters on a large recreational lake in Arizona was investigated to assess the role of fomite contamination, and to provide recommendations for prevention of future outbreaks. Interior boat surfaces were sampled for norovirus using transport swabs. Onboard toilet reservoirs were swabbed as a surrogate for stool samples from ill

Ellen L. Jones; Adam Kramer; Marlene Gaither; Charles P. Gerba

2007-01-01

296

Lung in Dengue: Computed Tomography Findings  

PubMed Central

Background Dengue is the most important mosquito-borne viral disease in the world. Dengue virus infection may be asymptomatic or lead to undifferentiated fever, dengue fever with or without warning signs, or severe dengue. Lower respiratory symptoms are unusual and lung-imaging data in patients with dengue are scarce. Methodology/Principal Findings To evaluate lung changes associated with dengue infection, we retrospectively analyzed 2,020 confirmed cases of dengue. Twenty-nine of these patients (11 females and 18 males aged 16–90 years) underwent chest computed tomography (CT), which yielded abnormal findings in 17 patients: 16 patients had pleural effusion (the sole finding in six patients) and 11 patients had pulmonary abnormalities. Lung parenchyma involvement ranged from subtle to moderate unilateral and bilateral abnormalities. The most common finding was ground-glass opacity in eight patients, followed by consolidation in six patients. Less common findings were airspace nodules (two patients), interlobular septal thickening (two patients), and peribronchovascular interstitial thickening (one patient). Lung histopathological findings in four fatal cases showed thickening of the alveolar septa, hemorrhage, and interstitial edema. Conclusions/Significance In this largest series involving the use of chest CT to evaluate lung involvement in patients with dengue, CT findings of lower respiratory tract involvement were uncommon. When abnormalities were present, pleural effusion was the most frequent finding and lung involvement was often mild or moderate and bilateral. Extensive lung abnormalities are infrequent even in severe disease and when present should lead physicians to consider other diagnostic possibilities. PMID:24836605

Rodrigues, Rosana Souza; Brum, Ana Livia Garcia; Paes, Marciano Viana; Povoa, Tiago Fajardo; Basilio-de-Oliveira, Carlos Alberto; Marchiori, Edson; Borghi, Danielle Provencano; Ramos, Grazielle Viana; Bozza, Fernando Augusto

2014-01-01

297

Dengue fever and bone marrow myelofibrosis.  

PubMed

Myelofibrosis is characterized by reticulin and/or collagen fibrosis in the bone marrow stroma resulting in secondary cytopenia. In addition to clonal hematologic neoplasms, myelofibrosis may also develop in association with other clinical conditions, including hematological disorders, solid malignancies, Down syndrome, autoimmune diseases and others. We report the first case to our knowledge of myelofibrosis associated with dengue fever. We briefly describe dengue infections and hypothesize the causes of myelofibrosis in this condition. PMID:25016180

Qing, Xin; Sun, Nora; Yeh, James; Yue, Changjun; Cai, Junchao

2014-10-01

298

Incentives for Reporting Disease Outbreaks  

PubMed Central

Background Countries face conflicting incentives to report infectious disease outbreaks. Reports of outbreaks can prompt other countries to impose trade and travel restrictions, which has the potential to discourage reporting. However, reports can also bring medical assistance to contain the outbreak, including access to vaccines. Methods We compiled data on reports of meningococcal meningitis to the World Health Organization (WHO) from 54 African countries between 1966 and 2002, a period is marked by two events: first, a large outbreak reported from many countries in 1987 associated with the Hajj that resulted in more stringent requirements for meningitis vaccination among pilgrims; and second, another large outbreak in Sub-Saharan Africa in 1996 that led to a new international mechanism to supply vaccines to countries reporting a meningitis outbreak. We used fixed-effects regression modeling to statistically estimate the effect of external forcing events on the number of countries reporting cases of meningitis to WHO. Findings We find that the Hajj vaccination requirements started in 1988 were associated with reduced reporting, especially among countries with relatively fewer cases reported between 1966 and 1979. After the vaccine provision mechanism was in place in 1996, reporting among countries that had previously not reported meningitis outbreaks increased. Interpretation These results indicate that countries may respond to changing incentives to report outbreaks when they can do so. In the long term, these incentives are likely to be more important than surveillance assistance in prompt reporting of outbreaks. PMID:24603414

Laxminarayan, Ramanan; Reif, Julian; Malani, Anup

2014-01-01

299

Epidemiological dynamics of Ebola outbreaks.  

PubMed

Ebola is a deadly virus that causes frequent disease outbreaks in the human population. In this study, we analyse its rate of new introductions, case fatality ratio, and potential to spread from person to person. The analysis is performed for all completed outbreaks and for a scenario where these are augmented by a more severe outbreak of several thousand cases. The results show a fast rate of new outbreaks, a high case fatality ratio, and an effective reproductive ratio of just less than 1. PMID:25217532

House, Thomas

2014-01-01

300

Country- and age-specific optimal allocation of dengue vaccines.  

PubMed

Several dengue vaccines are under development, and some are expected to become available imminently. Concomitant with the anticipated release of these vaccines, vaccine allocation strategies for dengue-endemic countries in Southeast Asia and Latin America are currently under development. We developed a model of dengue transmission that incorporates the age-specific distributions of dengue burden corresponding to those in Thailand and Brazil, respectively, to determine vaccine allocations that minimize the incidence of dengue hemorrhagic fever, taking into account limited availability of vaccine doses in the initial phase of production. We showed that optimal vaccine allocation strategies vary significantly with the demographic burden of dengue hemorrhagic fever. Consequently, the strategy that is optimal for one country may be sub-optimal for another country. More specifically, we showed that, during the first years following introduction of a dengue vaccine, it is optimal to target children for dengue mass vaccination in Thailand, whereas young adults should be targeted in Brazil. PMID:24161462

Ndeffo Mbah, Martial L; Durham, David P; Medlock, Jan; Galvani, Alison P

2014-02-01

301

Dengue Virus Serotype 2 from a Sylvatic Lineage Isolated from a Patient with Dengue Hemorrhagic Fever  

PubMed Central

Dengue viruses circulate in both human and sylvatic cycles. Although dengue viruses (DENV) infecting humans can cause major epidemics and severe disease, relatively little is known about the epidemiology and etiology of sylvatic dengue viruses. A 20-year-old male developed dengue hemorrhagic fever (DHF) with thrombocytopenia (12,000/ul) and a raised hematocrit (29.5% above baseline) in January 2008 in Malaysia. Dengue virus serotype 2 was isolated from his blood on day 4 of fever. A phylogenetic analysis of the complete genome sequence revealed that this virus was a member of a sylvatic lineage of DENV-2 and most closely related to a virus isolated from a sentinel monkey in Malaysia in 1970. This is the first identification of a sylvatic DENV circulating in Asia since 1975. PMID:19399166

Cardosa, Jane; Ooi, Mong How; Tio, Phaik Hooi; Perera, David; Holmes, Edward C.; Bibi, Khatijar; Abdul Manap, Zahara

2009-01-01

302

Unusual Dengue Virus 3 Epidemic in Nicaragua, 2009  

Microsoft Academic Search

The four dengue virus serotypes (DENV1–4) cause the most prevalent mosquito-borne viral disease affecting humans worldwide. In 2009, Nicaragua experienced the largest dengue epidemic in over a decade, marked by unusual clinical presentation, as observed in two prospective studies of pediatric dengue in Managua. From August 2009–January 2010, 212 dengue cases were confirmed among 396 study participants at the National

Gamaliel Gutierrez; Katherine Standish; Federico Narvaez; Maria Angeles Perez; Saira Saborio; Douglas Elizondo; Oscar Ortega; Andrea Nuñez; Guillermina Kuan; Angel Balmaseda; Eva Harris

2011-01-01

303

Successful use of N-acetyl cysteine and activated recombinant factor VII in fulminant hepatic failure and massive bleeding secondary to dengue hemorrhagic fever.  

PubMed

Consensus on management of complicated cases of dengue infection is evolving. Dengue hemorrhagic fever (DHF) occasionally progress to fulminant liver failure with high fatality rate. Inadvertent use of blood products to control massive bleeding in dengue shock syndrome may worsen fluid overload and subsequently the multi-organ dysfunction. We report a case of 37-years-old Sri Lankan man who developed fulminant liver failure and massive bleeding associated with DHF, subsequently recovered completely with supportive measures including administration of N-acetyl cysteine and activated recombinant factor VII. In conclusion, prevention of ischemic injury to liver and adoption of early aggressive supportive measures in complicated cases of dengue hemorrhagic fever is crucial for a favorable outcome. Indications for rFVIIa to arrest uncontrolled internal bleeding and use of NAC in non-acetaminophen-induced acute liver failure in complicated DHF are a platform for discussion. PMID:25400395

Manoj, Edirisooriya Maddumage; Ranasinghe, Gayan; Ragunathan, M K

2014-10-01

304

Wild Animal Mortality Monitoring and Human Ebola Outbreaks, Gabon and Republic of Congo, 2001-2003  

PubMed Central

All human Ebola virus outbreaks during 2001–2003 in the forest zone between Gabon and Republic of Congo resulted from handling infected wild animal carcasses. After the first outbreak, we created an Animal Mortality Monitoring Network in collaboration with the Gabonese and Congolese Ministries of Forestry and Environment and wildlife organizations (Wildlife Conservation Society and Programme de Conservation et Utilisation Rationnelle des Ecosystèmes Forestiers en Afrique Centrale) to predict and possibly prevent human Ebola outbreaks. Since August 2001, 98 wild animal carcasses have been recovered by the network, including 65 great apes. Analysis of 21 carcasses found that 10 gorillas, 3 chimpanzees, and 1 duiker tested positive for Ebola virus. Wild animal outbreaks began before each of the 5 human Ebola outbreaks. Twice we alerted the health authorities to an imminent risk for human outbreaks, weeks before they occurred. PMID:15752448

Froment, Jean-Marc; Bermejo, Magdalena; Kilbourn, Annelisa; Karesh, William; Reed, Patricia; Kumulungui, Brice; Yaba, Philippe; Delicat, Andre; Rollin, Pierre E.; Leroy, Eric M.

2005-01-01

305

School Meal Programs: Few Outbreaks of Foodborne Illness Reported. Report to the Ranking Minority Member, Committee on Agriculture, Nutrition, and Forestry, U.S. Senate.  

ERIC Educational Resources Information Center

Twenty outbreaks of foodborne illness in schools were reported to the Centers for Disease Control and Prevention (CDC) during 1997; however, only 8 cases were associated with food served in the school meal programs. Preliminary findings identified nine outbreaks in 1998, affecting an estimated 1,609 individuals. CDC notes that such outbreaks are…

Robertson, Robert E.

306

Stochastic dynamics of dengue epidemics  

NASA Astrophysics Data System (ADS)

We use a stochastic Markovian dynamics approach to describe the spreading of vector-transmitted diseases, such as dengue, and the threshold of the disease. The coexistence space is composed of two structures representing the human and mosquito populations. The human population follows a susceptible-infected-recovered (SIR) type dynamics and the mosquito population follows a susceptible-infected-susceptible (SIS) type dynamics. The human infection is caused by infected mosquitoes and vice versa, so that the SIS and SIR dynamics are interconnected. We develop a truncation scheme to solve the evolution equations from which we get the threshold of the disease and the reproductive ratio. The threshold of the disease is also obtained by performing numerical simulations. We found that for certain values of the infection rates the spreading of the disease is impossible, for any death rate of infected mosquitoes.

de Souza, David R.; Tomé, Tânia; Pinho, Suani T. R.; Barreto, Florisneide R.; de Oliveira, Mário J.

2013-01-01

307

Human and entomological surveillance of West Nile fever, dengue and chikungunya in Veneto Region, Italy, 2010-2012  

PubMed Central

Background Since 2010 Veneto region (North-Eastern Italy) planned a special integrated surveillance of summer fevers to promptly identify cases of West Nile Fever (WNF), dengue (DENV) and chikungunya (CHIKV). The objectives of this study were (i) To increase the detection rate of imported CHIKV and DENV cases in travellers from endemic areas and promptly identify potential autochthonous cases.(ii) To detect autochthonous cases of WNF, besides those of West Nile Neuroinvasive Disease (WNND) that were already included in a national surveillance. Methods Human surveillance: a traveler who had returned within the previous 15 days from endemic countries, with fever >38°C, absence of leucocytosis (leukocyte count <10,000 ?L), and absence of other obvious causes of fever, after ruling out malaria, was considered a possible case of CHIKV or DENV. A possible autochthonous case of WNF was defined as a patient with fever >38°C for <7 days, no recent travel history and absence of other obvious causes of fever. Entomologic surveillance: for West Nile (WNV) it was carried out from May through November placing CDC-CO2 traps in five provinces of Veneto Region, while for DENV and CHIKV it was also performed around residences of viremic cases. Results Human surveillance: between 2010 and 2012, 234 patients with fever after travelling were screened, of which 27 (11,5%) were found infected (24 with DENV and 3 with CHIKV). No autochthonous case of DENV or CHIKV was detected. Autochthonous patients screened for WNF were 408, and 24 (5,9%) were confirmed cases. Entomologic surveillance: the WNV was found in 10, 2 and 11 pools of Culex pipiens from 2010 to 2012 respectively, in sites of Rovigo, Verona, Venezia and Treviso provinces). No infected Aedes albopictus with DENV or CHIKV was found. Conclusions Veneto is the only Italian region reporting WNV human cases every year since 2008. WNV is likely to cause sporadic cases and unforeseeable outbreaks for decades. Including WNF in surveillance provides additional information and possibly an early alert system. Timely detection of DENV and CHIKV should prompt vector control measures to prevent local outbreaks. PMID:24499011

2014-01-01

308

Describing dengue epidemics: Insights from simple mechanistic models  

NASA Astrophysics Data System (ADS)

We present a set of nested models to be applied to dengue fever epidemiology. We perform a qualitative study in order to show how much complexity we really need to add into epidemiological models to be able to describe the fluctuations observed in empirical dengue hemorrhagic fever incidence data offering a promising perspective on inference of parameter values from dengue case notifications.

Aguiar, Maíra; Stollenwerk, Nico; Kooi, Bob W.

2012-09-01

309

Dengue as a cause of acute undifferentiated fever in Vietnam  

Microsoft Academic Search

BACKGROUND: Dengue is a common cause of fever in the tropics but its contribution to the total burden of febrile illnesses that is presented to primary health facilities in endemic regions such as Vietnam, is largely unknown. We aimed to report the frequency of dengue as a cause of fever in Binh Thuan Province, to describe the characteristics of dengue

Hoang Lan Phuong; Peter J de Vries; Tran TT Nga; Phan T Giao; Le Q Hung; Tran Q Binh; Nguyen V Nam; Nico Nagelkerke; Piet A Kager

2006-01-01

310

Disease Outbreaks Caused by Water.  

ERIC Educational Resources Information Center

Presents a literature review of the disease outbreaks caused by drinking polluted water, covering publications of 1976-77. Some of the waterborn outbreaks included are: (1) cholera; (2) gastroenteritis; (3) giardiasis; and (4) typhoid fever and salmonellosis. A list of 66 references is also presented. (HM)

Craun, Gunther F.

1978-01-01

311

INVESTIGATIONS OF WATERBORNE DISEASE OUTBREAKS  

EPA Science Inventory

From 1971-2000, there were about 751 waterborne disease outbreaks recognized and reported, with over 500,000 associated cases of illness. From 1989-1994, of 90 total outbreaks, 2% were associated with untreated surface water, 30% with untreated ground water, 42% with treatment de...

312

Connecting Environmental Observations with Cholera Outbreaks in Bangladesh  

NASA Astrophysics Data System (ADS)

Research has demonstrated that cholera epidemics in Bangladesh occur seasonally. This bimodal outbreak pattern closely follows times when large monsoon events are most frequent (spring and fall). While these patterns are presented in regional data, this knowledge alone cannot forecast the severity and location of cholera outbreaks until a monsoon event occurs, or an outbreak is reported. Therefore, there can only be reactive responses to cholera outbreaks. A heightened understanding of the link between environmental factors and outbreak occurrence will greatly enhance disease management capabilities. A predictive tool capable of giving an advanced warning of the environmental hazards that lead to location specific outbreaks allows for proactive and preventative responses, minimizing negative effects. A specific goal of this research was to relate latitude-longitude data with existing points associated with V. cholerae human case data collected from four cities in Bangladesh. Remotely sensed products were used to better understand the correlation between human outbreak occurrences, chlorophyll-a estimates, sea surface temperature (SST), and rainfall. Using MODIS, SeaWiFS, and TRMM satellite data, a gridded regional image was developed. Correlation analyses of the data were studied within the context of geographically diverse locations for the four cities of interest. Seasonal relationships were found between the cholera case data and all three of the chosen remotely sensed parameters. The strongest correlation found was between chlorophyll-a concentrations and reported human cases. The primary deliverable of this project was the production of an interactive Google Earth base map for use in a pilot design study that will lead to the development of applications to connect earth science products with water and health studies. The base map, with its inherent value of merging remotely sensed data with in situ observation points, can be used as a basis for constructing better models of disease outbreaks. This effort will build upon current research at University of Maryland, College Park, which focuses on the impacts of climate on both water and health.

Stack, D.; Sandborn, A.; Widmeyer, P. A.; Escobar, V. M.

2011-12-01

313

Outbreak of West Nile Virus Infection in Greece, 2010  

PubMed Central

During 2010, an outbreak of West Nile virus infection occurred in Greece. A total of 197 patients with neuroinvasive disease were reported, of whom 33 (17%) died. Advanced age and a history of heart disease were independently associated with death, emphasizing the need for prevention of this infection in persons with these risk factors. PMID:22000357

Papa, Anna; Theocharopoulos, George; Dougas, Georgios; Athanasiou, Maria; Detsis, Marios; Baka, Agoritsa; Lytras, Theodoros; Mellou, Kassiani; Bonovas, Stefanos; Panagiotopoulos, Takis

2011-01-01

314

Surveillance for Waterborne Disease Outbreaks Associated with Drinking Water United States, 2007-2008  

EPA Science Inventory

Problem/Condition: Since 1971, the Centers for Disease Control and Prevention (CDC), the U.S. Environmental Protection Agency (EPA), and the Council of State and Territorial Epidemiologists have maintained a collaborative Waterborne Disease and Outbreak Surveillance System (WBDOS...

315

Deterministic SIR (Susceptible-Infected-Removed) models applied to varicella outbreaks  

PubMed Central

SUMMARY Deterministic SIR models were applied to simulate Susceptible–Infected–Removed and to estimate the threshold condition for varicella outbreaks in children, reported in Medellín, Colombia. The expected numbers of susceptible, infected and removed individuals were compared with observed cases from notification of varicella outbreaks to the local Board of Health and from survey data. The threshold condition was estimated by the basic reproductive ratio and by the relative removal rate, through which measures for preventing and curtailing the outbreaks were identified. The model demonstrated a reasonable fit to the observations, except in two of the six outbreaks which probably reflected under-registration of cases. In order to have prevented these outbreaks, between 4·4% and 52·9% of the susceptible population should have been vaccinated assuming an 85% vaccine effectiveness. Similarly, isolation of affected children should have been increased to between 4·3% and 44·8% per week. PMID:17655783

GIRALDO, J. OSPINA; PALACIO, D. HINCAPIE

2008-01-01

316

Membranotropic regions of the dengue virus prM protein.  

PubMed

The Dengue virus (DENV) prM protein consists of two moieties, the pr and M domains. Apart from preventing the premature fusion activity of the DENV E protein, prM has several other unknown biological roles, displaying both protein-protein and membrane-protein interactions. Although the prM protein is an essential component of the DENV viral cycle, little is known about its biological functions and what regions of this protein are responsible for said functions. By performing an exhaustive study of membrane rupture induced by a prM peptide library on simple and complex model membranes as well as their ability to modulate the phospholipid phase transitions of 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine and 1,2-dimyristoyl-sn-glycero-3-[phospho-rac-glycerol], we identified six membranotropic regions on the prM protein. Apart from the previously identified two transmembrane segments of the protein, one of these regions probably interacts with the fusion E protein and another one, the stem segment, would interact with the membrane modulating its structure. These data will help us understand the molecular mechanism of viral entry and morphogenesis, allow the identification of new targets for the treatment of Dengue virus infection, and make possible the future development of DENV entry inhibitors. PMID:25076193

Nemésio, Henrique; Villalaín, José

2014-08-19

317

Simulation study of the mechanisms underlying outbreaks of clinical disease caused by Actinobacillus pleuropneumoniae in finishing pigs.  

PubMed

Actinobacillus pleuropneumoniae is a major cause of respiratory disease in pigs. Many farms are endemically infected without apparent disease, but occasionally severe outbreaks of pleuropneumonia occur. To prevent and control these outbreaks without antibiotics, the underlying mechanisms of these outbreaks need to be understood. Outbreaks are probably initiated by a trigger (common risk factor) changing the host-pathogen interaction, but it is unclear whether this trigger causes all cases directly (trigger mechanism), or whether the first case starts a transmission chain inducing disease in the infected contacts (transmission mechanism). The aim of this study was to identify conditions under which these mechanisms could cause A.?pleuropneumoniae outbreaks, and to assess means for prevention and control. Outbreaks were first characterised by data from a literature review, defining an average outbreak at 12?weeks of age, affecting 50% of animals within 4?days. Simple mathematical models describing the two mechanisms can reproduce average outbreaks, with two observations supporting the trigger mechanism: (1) disease should be transmitted 50 times faster than supported by literature if there is a transmission chain; and (2) the trigger mechanism is consistent with the absence of reported outbreaks in young pigs as they have not yet been colonised by the bacterium. In conclusion, outbreaks of A.?pleuropneumoniae on endemic farms are most likely caused by a trigger inducing pneumonia in already infected pigs, but more evidence is needed to identify optimum preventive interventions. PMID:25155305

Klinkenberg, D; Tobias, T J; Bouma, A; van Leengoed, L A M G; Stegeman, J A

2014-10-01

318

Pediatric Measles Vaccine Expressing a Dengue Antigen Induces Durable Serotype-specific Neutralizing Antibodies to Dengue Virus  

Microsoft Academic Search

Dengue disease is an increasing global health problem that threatens one-third of the world's population. Despite decades of efforts, no licensed vaccine against dengue is available. With the aim to develop an affordable vaccine that could be used in young populations living in tropical areas, we evaluated a new strategy based on the expression of a minimal dengue antigen by

Samantha Brandler; Marianne Lucas-Hourani; Arnaud Moris; Marie-Pascale Frenkiel; Chantal Combredet; Michèle Février; Hugues Bedouelle; Olivier Schwartz; Philippe Desprès; Frédéric Tangy

2007-01-01

319

An information value based analysis of physical and climatic factors affecting dengue fever and dengue haemorrhagic fever incidence  

Microsoft Academic Search

BACKGROUND: Vector-borne diseases are the most dreaded worldwide health problems. Although many campaigns against it have been conducted, Dengue Fever (DF) and Dengue Haemorrhagic Fever (DHF) are still the major health problems of Thailand. The reported number of dengue incidences in 1998 for the Thailand was 129,954, of which Sukhothai province alone reported alarming number of 682. It was the

Kanchana Nakhapakorn; Nitin Kumar Tripathi

2005-01-01

320

Results from the First 12 Months of the National Surveillance of Healthcare Associated Outbreaks in Germany, 2011/2012  

PubMed Central

Background In August 2011, the German Protection against Infection Act was amended, mandating the reporting of healthcare associated infection (HAI) outbreak notifications by all healthcare workers in Germany via local public health authorities and federal states to the Robert Koch Institute (RKI). Objective To describe the reported HAI-outbreaks and the surveillance system’s structure and capabilities. Methods Information on each outbreak was collected using standard paper forms and notified to RKI. Notifications were screened daily and regularly analysed. Results Between November 2011 and November 2012, 1,326 paper forms notified 578 HAI-outbreaks, between 7 and 116 outbreaks per month. The main causative agent was norovirus (n?=?414/578; 72%). Among the 108 outbreaks caused by bacteria, the most frequent pathogens were Clostridium difficile (25%) Klebsiella spp. (19%) and Staphylococcus spp. (19%). Multidrug-resistant bacteria were responsible for 54/108 (50%) bacterial outbreaks. Hospitals were affected most frequently (485/578; 84%). Hospital outbreaks due to bacteria were mostly reported from intensive care units (ICUs) (45%), followed by internal medicine wards (16%). Conclusion The mandatory HAI-outbreak surveillance system describes common outbreaks. Pathogens with a particular high potential to cause large or severe outbreaks may be identified, enabling us to further focus research and preventive measures. Increasing the sensitivity and reliability of the data collection further will facilitate identification of outbreaks able to increase in size and severity, and guide specific control measures to interrupt their propagation. PMID:24875674

Haller, Sebastian; Eckmanns, Tim; Benzler, Justus; Tolksdorf, Kristin; Claus, Hermann; Gilsdorf, Andreas; Sin, Muna Abu

2014-01-01

321

Transmission thresholds for dengue in terms of Aedes aegypti pupae per person with discussion of their utility in source reduction efforts.  

PubMed

The expense and ineffectiveness of drift-based insecticide aerosols to control dengue epidemics has led to suppression strategies based on eliminating larval breeding sites. With the notable but short-lived exceptions of Cuba and Singapore, these source reduction efforts have met with little documented success; failure has chiefly been attributed to inadequate participation of the communities involved. The present work attempts to estimate transmission thresholds for dengue based on an easily-derived statistic, the standing crop of Aedes aegypti pupae per person in the environment. We have developed these thresholds for use in the assessment of risk of transmission and to provide targets for the actual degree of suppression required to prevent or eliminate transmission in source reduction programs. The notion of thresholds is based on 2 concepts: the mass action principal-the course of an epidemic is dependent on the rate of contact between susceptible hosts and infectious vectors, and threshold theory-the introduction of a few infectious individuals into a community of susceptible individuals will not give rise to an outbreak unless the density of vectors exceeds a certain critical level. We use validated transmission models to estimate thresholds as a function of levels of pre-existing antibody levels in human populations, ambient air temperatures, and size and frequency of viral introduction. Threshold levels were estimated to range between about 0.5 and 1.5 Ae. aegypti pupae per person for ambient air temperatures of 28 degrees C and initial seroprevalences ranging between 0% to 67%. Surprisingly, the size of the viral introduction used in these studies, ranging between 1 and 12 infectious individuals per year, was not seen to significantly influence the magnitude of the threshold. From a control perspective, these results are not particularly encouraging. The ratio of Ae. aegypti pupae to human density has been observed in limited field studies to range between 0.3 and >60 in 25 sites in dengue-endemic or dengue-susceptible areas in the Caribbean, Central America, and Southeast Asia. If, for purposes of illustration, we assume an initial seroprevalence of 33%, the degree of suppression required to essentially eliminate the possibility of summertime transmission in Puerto Rico, Honduras, and Bangkok, Thailand was estimated to range between 10% and 83%; however in Mexico and Trinidad, reductions of >90% would be required. A clearer picture of the actual magnitude of the reductions required to eliminate the threat of transmission is provided by the ratio of the observed standing crop of Ae. aegypti pupae per person and the threshold. For example, in a site in Mayaguez, Puerto Rico, the ratio of observed and threshold was 1.7, meaning roughly that about 7 of every 17 breeding containers would have to be eliminated. For Reynosa, Mexico, with a ratio of approximately 10, 9 of every 10 containers would have to be eliminated. For sites in Trinidad with ratios averaging approximately 25, the elimination of 24 of every 25 would be required. With the exceptions of Cuba and Singapore, no published reports of sustained source reduction efforts have achieved anything near these levels of reductions in breeding containers. Practical advice on the use of thresholds is provided for operational control projects. PMID:10761719

Focks, D A; Brenner, R J; Hayes, J; Daniels, E

2000-01-01

322

High Household Economic Burden Caused by Hospitalization of Patients with Severe Dengue Fever Cases in Can Tho Province, Vietnam  

PubMed Central

During 2006–2007, a cohort of 144 confirmed dengue cases in Can Tho Province, Vietnam were compared with a matching set of 144 households that had no dengue cases. Approximately 6–9 months after sickness, there were no significant differences in terms of knowledge of the etiology of dengue, mosquito breeding habitats, and prevention measures in respondents from both sets of households. There was also no difference in the abundance of Aedes aegypti (Linn.) adults but the average numbers of late instar and pupal Ae. aegypti per household were greater in the negative control houses. Thus, the risk seemed to be no higher in case households, although it is conceivable that changes may have occurred in either group over the intervening period. The average cost for a dengue patient was 2,798,000 Vietnamese Dong (VND) (US$167.77), 2,154,000 VND for direct costs, and 644,000 VND for indirect costs. There was a 22% difference in cost for those with and without health insurance. In terms of impact on family economies, 47.2% had to borrow money for treatment, and after 6 months, 71.7% had not begun or had only managed part repayments. Approximately 72.9% indicated that the cost of supporting a dengue patient had impacted on the family economy, with the loss averaging 36% of the annual income in the lowest economic quartile. PMID:22826478

Tam, Pham Thi; Dat, Nguyen Tan; Huu, Le Minh; Thi, Xuan Cuc Pham; Duc, Hoang Minh; Tu, Tran Cong; Kutcher, Simon; Ryan, Peter A.; Kay, Brian H.

2012-01-01

323

Heterotypic Dengue Infection with Live Attenuated Monotypic Dengue Virus Vaccines: Implications for Vaccination of Populations in Areas Where Dengue Is Endemic  

PubMed Central

Background. Because infection with any of the 4 Dengue virus serotypes may elicit both protective neutralizing antibodies and nonneutralizing antibodies capable of enhancing subsequent heterotypic Dengue virus infections, the greatest risk for severe dengue occurs during a second, heterotypic Dengue virus infection. It remains unclear whether the replication of live attenuated vaccine viruses will be similarly enhanced when administered to Dengue-immune individuals. Methods. We recruited 36 healthy adults who had previously received a monovalent live Dengue virus vaccine 0.6–7.4 years earlier. Participants were assigned to 1 of 4 cohorts and were randomly chosen to receive placebo or a heterotypic vaccine. The level of replication, safety, and immunogenicity of the heterotypic vaccine virus was compared with that of Dengue virus immunologically naive vaccinees. Results. Vaccine virus replication and reactogenicity after monovalent Dengue virus vaccination in naive and heterotypically immune vaccinees was similar. In contrast to naive vaccinees, the antibody response in heterotypically immune vaccinees was broadly neutralizing and mimicked the response observed by natural secondary Dengue virus infection. Conclusions. Enhanced replication of these live attenuated Dengue virus vaccines was minimal in heterotypically immune vaccinees and suggests that the further evaluation of these candidate vaccines in populations with preexisting DENV immunity can proceed safely. Clinical trials registration: NCT00458120 (http://www.clinicaltrials.gov/ct2/show/NCT00458120). PMID:21208923

Schmidt, Alexander; Elwood, Dan; Wanionek, Kimberli A.; Lovchik, Janece; Thumar, Bhavin; Murphy, Brian R.; Whitehead, Stephen S.

2011-01-01

324

Dengue Fever with rectus sheath hematoma: a case report.  

PubMed

Dengue fever, also known as breakbone fever, is an infectious tropical disease caused by the Dengue virus. It is associated with a number of complications, which are well documented. However, Dengue fever associated with rectus sheath hematoma (RSH) is a very rare complication. Only one case report has been published prior supporting the association of Dengue fever with RSH. We report a case of Dengue fever who presented with RSH and was successfully treated conservatively. RSH is also an uncommon cause of acute abdominal pain. It is accumulation of blood in the sheath of the rectus abdominis, secondary to rupture of an epigastric vessel or muscle tear. PMID:25161976

Sharma, Anurag; Bhatia, Sonia; Singh, Rajendra Pratap; Malik, Gaurav

2014-04-01

325

Dengue Vectors and their Spatial Distribution  

PubMed Central

The distribution of dengue vectors, Ae. aegypti and Ae. albopictus, is affected by climatic factors. In addition, since their life cycles are well adapted to the human environment, environmental changes resulting from human activity such as urbanization exert a great impact on vector distribution. The different responses of Ae. aegypti and Ae albopictus to various environments result in a difference in spatial distribution along north-south and urban-rural gradients, and between the indoors and outdoors. In the north-south gradient, climate associated with survival is an important factor in spatial distribution. In the urban-rural gradient, different distribution reflects a difference in adult niches and is modified by geographic and human factors. The direct response of the two species to the environment around houses is related to different spatial distribution indoors and outdoors. Dengue viruses circulate mainly between human and vector mosquitoes, and the vector presence is a limiting factor of transmission. Therefore, spatial distribution of dengue vectors is a significant concern in the epidemiology of the disease. Current technologies such as GIS, satellite imagery and statistical models allow researchers to predict the spatial distribution of vectors in the changing environment. Although it is difficult to confirm the actual effect of environmental and climate changes on vector abundance and vector-borne diseases, environmental changes caused by humans and human behavioral changes due to climate change can be expected to exert an impact on dengue vectors. Longitudinal monitoring of dengue vectors and viruses is therefore necessary. PMID:22500133

Higa, Yukiko

2011-01-01

326

Surveillance for outbreaks of gastroenteritis in elderly long-term care facilities in France, November 2010 to May 2012.  

PubMed

This article describes outbreaks of gastroenteritis in elderly long-term care facilities (LTCF) in France from November 2010 to May 2012 reported through the surveillance system for gastroenteritis outbreaks in LTCF. A total of 1,072 outbreaks were reported, causing 26,551 episodes of illness and 60 deaths. The median attack rate (AR) among residents was 32%. Norovirus and person-to-person transmission were the most frequently reported aetiology and mode of transmission. Control measures were implemented in 1,054 (98%) outbreaks and for 928 outbreaks, the timing of such measures could be inferred. Of these, 799 (86%) had put control measures into effect within three days of the occurrence of the first case. Outbreaks of gastroenteritis in LTCF cause substantial morbidity and mortality among elderly people in France. LTCF are encouraged to develop infection prevention and control plans and to notify any gastroenteritis outbreak to health authorities to ensure rapid control. PMID:25080141

Barret, A S; Jourdan-da Silva, N; Ambert-Balay, K; Delmas, G; Bone, A; Thiolet, J M; Vaillant, V

2014-01-01

327

Dendritic Cell Apoptosis and the Pathogenesis of Dengue  

PubMed Central

Dengue viruses and other members of the Flaviviridae family are emerging human pathogens. Dengue is transmitted to humans by Aedes aegypti female mosquitoes. Following infection through the bite, cells of the hematopoietic lineage, like dendritic cells, are the first targets of dengue virus infection. Dendritic cells (DCs) are key antigen presenting cells, sensing pathogens, processing and presenting the antigens to T lymphocytes, and triggering an adaptive immune response. Infection of DCs by dengue virus may induce apoptosis, impairing their ability to present antigens to T cells, and thereby contributing to dengue pathogenesis. This review focuses on general mechanisms by which dengue virus triggers apoptosis, and possible influence of DC-apoptosis on dengue disease severity. PMID:23202502

Martins, Sharon de T.; Silveira, Guilherme F.; Alves, Lysangela R.; dos Santos, Claudia Nunes Duarte; Bordignon, Juliano

2012-01-01

328

w RAPID RISK ASSESSMENT Outbreak of Ebola haemorrhagic  

E-print Network

Main conclusions and recommendations An outbreak of Ebola haemorrhagic fever is currently ongoing in Uganda with 38 cases reported, including 16 deaths. Two similar outbreaks have been seen in the past in Uganda. Through these, Uganda has developed a solid experience in dealing with such outbreaks, with the support currently of the World Health Organization, the US Centers for Disease Control and Prevention, and specialised non-governmental organisations. As the incubation period can be up to three weeks, it is likely that additional cases will be identified in the coming weeks. However, control measures currently implemented in Uganda with the support of international partners, such as isolation of cases and active monitoring of contacts, should prevent further spread of the disease. It is unlikely, but not impossible, that travellers infected in Uganda could arrive in the EU while incubating the disease and develop symptoms while in the EU. However, such cases should seek medical attention and be isolated, therefore preventing further transmission. EU citizens in Uganda are not at risk of becoming infected unless they are in direct contact with bodily fluids of dead or living infected persons or animals. Avoiding such contact would effectively mitigate this risk. Public health issue To assess the risk at EU level associated with the current Ebola haemorrhagic fever outbreak in Uganda. Source and date of request ECDC internal decision on 1 August 2012. Consulted experts ECDC experts.

unknown authors

2012-01-01

329

Metagenomic detection methods in biopreparedness outbreak scenarios.  

PubMed

In the field of diagnostic microbiology, rapid molecular methods are critically important for detecting pathogens. With rapid and accurate detection, preventive measures can be put in place early, thereby preventing loss of life and further spread of a disease. From a preparedness perspective, early detection and response are important in order to minimize the consequences. During the past 2 decades, advances in next-generation sequencing (NGS) technology have changed the playing field of molecular methods. Today, it is within reach to completely sequence the total microbiological content of a clinical sample, creating a metagenome, in a single week of laboratory work. As new technologies emerge, their dissemination and capacity building must be facilitated, and criteria for use, as well as guidelines on how to report results, must be established. This article focuses on the use of metagenomics, from sample collection to data analysis and to some extent NGS, for the detection of pathogens, the integration of the technique in outbreak response systems, and the risk-based evaluation of sample processing in routine diagnostics labs. The article covers recent advances in the field, current debate, gaps in research, and future directions. Examples of metagenomic detection, as well as possible applications of the methods, are described in various biopreparedness outbreak scenarios. PMID:23971800

Karlsson, Oskar Erik; Hansen, Trine; Knutsson, Rickard; Löfström, Charlotta; Granberg, Fredrik; Berg, Mikael

2013-09-01

330

Dynamics of Dengue epidemics using optimal control  

E-print Network

We present an application of optimal control theory to Dengue epidemics. This epidemiologic disease is an important theme in tropical countries due to the growing number of infected individuals. The dynamic model is described by a set of nonlinear ordinary differential equations, that depend on the dynamic of the Dengue mosquito, the number of infected individuals, and the people's motivation to combat the mosquito. The cost functional depends not only on the costs of medical treatment of the infected people but also on the costs related to educational and sanitary campaigns. Two approaches to solve the problem are considered: one using optimal control theory, another one by discretizing first the problem and then solving it with nonlinear programming. The results obtained with OC-ODE and IPOPT solvers are given and discussed. We observe that with current computational tools it is easy to obtain, in an efficient way, better solutions to Dengue problems, leading to a decrease of infected mosquitoes and individ...

Rodrigues, Helena Sofia; Torres, Delfim F M

2010-01-01

331

Preliminary evaluation on the efficiency of the kit Platelia Dengue NS1 Ag-ELISA to detect dengue virus in dried Aedes aegypti: a potential tool to improve dengue surveillance  

PubMed Central

Background Surveillance is a critical component of any dengue prevention and control programme. Herein, we investigate the efficiency of the commercial kit Platelia Dengue NS1 Ag-ELISA to detect dengue virus (DENV) antigens in Aedes aegypti mosquitoes infected under laboratory conditions. Methods Under insectary conditions, four to five day-old mosquitoes were orally challenged with DENV-2 titer of 3.6 x 105 PFU equivalent/ml, incubated for 14 days and then killed. At ten time-points following mosquito death (0, 6, 12, 24, 72, 96, 120, 144 and 168 h), i.e., during a one-week period, dried mosquitoes were comparatively tested for the detection of the NS1 antigen with other methods of detection, such as qRT-PCR and virus isolation in C6/36 cells. Results We first observed that the NS1 antigen was more effective in detecting DENV-2 in Ae. aegypti between 12 and 72 h after mosquito death when compared with qRT-PCR. A second round involved comparing the sensitivity of detection of the NS1 antigen and virus isolation in C6/36 cells. The NS1 antigen was also more effective than virus isolation, detecting DENV-2 at all time-points, i.e., up to 168 h after mosquito death. Meanwhile, virus isolation was successful up to 96 h after Ae. aegypti death, but the number of positive samples per time period presented a tendency to decline progressively over time. From the 43 samples positive by the virus isolation technique, 38 (88.4%) were also positive by the NS1 test. Conclusion Taken together, these results are the first to indicate that the NS1 antigen might be an interesting complementary tool to improve dengue surveillance through DENV detection in dried Ae. aegypti females. PMID:24690324

2014-01-01

332

[Epidemiological dynamics of Dengue on Easter Island].  

PubMed

Dengue is considered an emerging disease with an increasing prevalence especially in South America. In 2002, an epidemic of classic Dengue (DENV-1) occurred unexpectedly on Easter Island, where it had never been detected before. It reappeared in 2006-2007 and 2008, 2009 and 2011. The aim of this study was to estimate the most relevant parameters of the epidemiological dynamics of transmission of Dengue on Easter Island and to model the dynamics since 2002, comparing the predictions with the actual situation observed. Of the total cases, 52.27% were females and 47.73% men. The average age of infection was 31.38 ± 18.37 years, similar in men and women. We estimated the reproductive number R0 = 3.005 with an IC0,95 = [1.92, 4.61]. The inter-epidemic period reached an estimated T = 5.20 to 6.8 years. The case simulation showed recurrent epidemics with decreasing magnitude (damped oscillations), which is a known phenomenon in models of dengue and malaria. There was good qualitative fit to the epidemiological dynamics from 2002 onwards. It accurately predicted the rise in cases between 2006 and 2011. The predicted number of cases during the 2002 epidemic is greater than the confirmed cases and the predicted epidemic was faster than notified cases. Interepidemic period in the simulation was 6.72 years between 2002 and 2008 and 4.68 years between 2008 and 2013. From the theoretical perspective, the first epidemic had affected 94% of the population (approximately 3500 cases), but 639 were reported suggesting underreporting and a lot of sub-clinical cases occurred. Future epidemic of decreasing size are expected, although the main danger are epidemics of hemorrhagic dengue fever resulting from the introduction of different dengue virus serotypes. PMID:23096537

Canals, Mauricio; González, Christian; Canals, Andrea; Figueroa, Daniela

2012-08-01

333

Role of ultrasound in dengue fever.  

PubMed

This study was performed to find out whether ultrasound is an important adjunct to clinical and laboratory profile in diagnosing dengue fever or dengue haemorrhagic fever and to further determine whether ultrasound is useful in predicting the severity of the disease. Ultrasound was performed on 128 patients (2-9 years) with clinical suspicion of dengue fever. Serological tests were performed to confirm the diagnosis. 40 patients were serologically negative for dengue fever and later excluded from the study. Of the remaining 88 serologically positive cases, 32 patients underwent ultrasound on second to third day, repeated on fifth to seventh day of fever and in 56 patients ultrasound was done only on fifth to seventh day of fever. Of the 32 patients who underwent the study on second to third day of fever, all showed gall bladder wall thickening and pericholecystic fluid, 21% had hepatomegaly, 6.25% had splenomegaly and right minimal pleural effusion. Follow-up ultrasound on fifth to seventh day revealed ascites in 53% left pleural effusion in 22% and pericardial effusion in 28%. Of the 56 patients who underwent the study on fifth to seventh day of fever for the first time all had gall bladder wall thickening, 21% had hepatomegaly, 7% had splenomegaly, 96% had ascites, 87.5% had right pleural effusion, 66% had left pleural effusion and 28.5% had pericardial fluid. To conclude, in an epidemic of dengue, ultrasound features of thickened gall bladder wall, pleural effusion and ascites should strongly favour the diagnosis of dengue fever. PMID:15845934

Venkata Sai, P M; Dev, B; Krishnan, R

2005-05-01

334

Causes of Outbreaks Associated with Drinking Water in the United States from 1971 to 2006  

PubMed Central

Summary: Since 1971, the CDC, EPA, and Council of State and Territorial Epidemiologists (CSTE) have maintained the collaborative national Waterborne Disease and Outbreak Surveillance System (WBDOSS) to document waterborne disease outbreaks (WBDOs) reported by local, state, and territorial health departments. WBDOs were recently reclassified to better characterize water system deficiencies and risk factors; data were analyzed for trends in outbreak occurrence, etiologies, and deficiencies during 1971 to 2006. A total of 833 WBDOs, 577,991 cases of illness, and 106 deaths were reported during 1971 to 2006. Trends of public health significance include (i) a decrease in the number of reported outbreaks over time and in the annual proportion of outbreaks reported in public water systems, (ii) an increase in the annual proportion of outbreaks reported in individual water systems and in the proportion of outbreaks associated with premise plumbing deficiencies in public water systems, (iii) no change in the annual proportion of outbreaks associated with distribution system deficiencies or the use of untreated and improperly treated groundwater in public water systems, and (iv) the increasing importance of Legionella since its inclusion in WBDOSS in 2001. Data from WBDOSS have helped inform public health and regulatory responses. Additional resources for waterborne disease surveillance and outbreak detection are essential to improve our ability to monitor, detect, and prevent waterborne disease in the United States. PMID:20610821

Craun, Gunther F.; Brunkard, Joan M.; Yoder, Jonathan S.; Roberts, Virginia A.; Carpenter, Joe; Wade, Tim; Calderon, Rebecca L.; Roberts, Jacquelin M.; Beach, Michael J.; Roy, Sharon L.

2010-01-01

335

Measles (Rubeola) Cases and Outbreaks  

MedlinePLUS

... an increase in cases some years: 2014: The Philippines is experiencing a large, ongoing measles outbreak. Many ... been associated with cases brought in from the Philippines. For more information see the Measles in the ...

336

Dengue Virus Entry as Target for Antiviral Therapy  

PubMed Central

Dengue virus (DENV) infections are expanding worldwide and, because of the lack of a vaccine, the search for antiviral products is imperative. Four serotypes of DENV are described and they all cause a similar disease outcome. It would be interesting to develop an antiviral product that can interact with all four serotypes, prevent host cell infection and subsequent immune activation. DENV entry is thus an interesting target for antiviral therapy. DENV enters the host cell through receptor-mediated endocytosis. Several cellular receptors have been proposed, and DC-SIGN, present on dendritic cells, is considered as the most important DENV receptor until now. Because DENV entry is a target for antiviral therapy, various classes of compounds have been investigated to inhibit this process. In this paper, an overview is given of all the putative DENV receptors, and the most promising DENV entry inhibitors are discussed. PMID:22529868

Alen, Marijke M. F.; Schols, Dominique

2012-01-01

337

Estimating Costs Associated with a Community Outbreak of Meningococcal Disease in a Colombian Caribbean City  

PubMed Central

ABSTRACT Meningococcal disease is a serious and potentially life-threatening infection that is caused by the bacterium Neisseria meningitidis (N. meningitidis), and it can cause meningitis, meningococcaemia outbreaks and epidemics. The disease is fatal in 9-12% of cases and with a death rate of up to 40% among patients with meningococcaemia. The objective of this study was to estimate the costs of a meningococcal outbreak that occurred in a Caribbean city of Colombia. We contacted experts involved in the outbreak and asked them specific questions about the diagnosis and treatment for meningococcal cases during the outbreak. Estimates of costs of the outbreak were also based on extensive review of medical records available during the outbreak. The costs associated with the outbreak were divided into the cost of the disease response phase and the cost of the disease surveillance phase. The costs associated with the outbreak control and surveillance were expressed in US$ (2011) as cost per 1,000 inhabitants. The average age of patients was 4.6 years (SD 3.5); 50% of the cases died; 50% of the cases were reported to have meningitis (3/6); 33% were diagnosed with meningococcaemia and myocarditis (2/6); 50% of the cases had bacteraemia (3/6); 66% of the cases had a culture specimen positive for Neisseria meningitidis; 5 of the 6 cases had RT-PCR positive for N. meningitidis. All N. meningitidis were serogroup B; 50 doses of ceftriaxone were administered as prophylaxis. Vaccine was not available at the time. The costs associated with control of the outbreak were estimated at US$ 0.8 per 1,000 inhabitants, disease surveillance at US$ 4.1 per 1,000 inhabitants, and healthcare costs at US$ 5.1 per 1,000 inhabitants. The costs associated with meningococcal outbreaks are substantial, and the outbreaks should be prevented. The mass chemoprophylaxis implemented helped control the outbreak.

Pinzon-Redondo, Hernando; Coronell-Rodriguez, Wilfrido; Diaz-Martinez, Ines; Guzman-Corena, Angel; Constenla, Dagna

2014-01-01

338

Exploring new thermal fog and ultra-low volume technologies to improve indoor control of the dengue vector, Aedes aegypti (Diptera: Culicidae).  

PubMed

Control of the mosquito vector, Aedes aegypti (L.), inside human habitations must be performed quickly and efficiently to reduce the risk of transmission during dengue outbreaks. As part of abroad study to assess the efficacy of dengue vector control tools for the U.S. Military, two pesticide delivery systems (ultra-low volume [ULV] and thermal fog) were evaluated for their ability to provide immediate control of Ae. aegypti mosquitoes with a contact insecticide inside simulated urban structures. An insect growth regulator was also applied to determine how well each sprayer delivered lethal doses of active ingredient to indoor water containers for pupal control. Mortality of caged Ae. aegypti, pesticide droplet size, and droplet deposition were recorded after applications. In addition, larval and pupal mortality was measured from treated water samples for 4 wk after the applications. The ULV and the thermal fogger performed equally well in delivering lethal doses of adulticide throughout the structures. The ULV resulted in greater larval mortality and adult emergence inhibition in the water containers for a longer period than the thermal fogger. Therefore, the ULV technology is expected to be a better tool for sustained vector suppression when combined with an effective insect growth regulator. However, during a dengue outbreak, either delivery system should provide an immediate knockdown of vector populations that may lower the risk of infection and allow other suppression strategies to be implemented. PMID:25118418

Harwood, James F; Farooq, Muhammad; Richardson, Alec G; Doud, Carl W; Putnam, John L; Szumlas, Daniel E; Richardson, Jason H

2014-07-01

339

Complete genome sequence of a Dengue virus serotype 4 strain isolated in Roraima, Brazil.  

PubMed

Dengue is the most important arboviral disease worldwide. We report the complete genome sequence of a dengue virus serotype 4, genotype II strain isolated in 2010 from a patient with classical dengue fever in Boa Vista, Roraima, Brazil. PMID:22247521

Naveca, Felipe G; Souza, Victor C; Silva, George A V; Maito, Rodrigo M; Granja, Fabiana; Siqueira, Thalita; Acosta, Pablo O A

2012-02-01

340

75 FR 6211 - Prospective Grant of Exclusive License: Purified Inactivated Dengue Tetravalent Vaccine...  

Federal Register 2010, 2011, 2012, 2013

...Development of Mutations Useful for Attenuating Dengue Viruses and Chimeric Dengue Viruses''-- European Patent Application Number 02739358...2,3, and 4, or Antigenic Chimeric Dengue Viruses 1,2,3, and 4''--United States...

2010-02-08

341

Dengue virus–induced hemorrhage in a nonhuman primate model  

PubMed Central

Lack of a dengue hemorrhagic animal model recapitulating human dengue virus infection has been a significant impediment in advancing our understanding of the early events involved in the pathogenesis of dengue disease. In efforts to address this issue, a group of rhesus macaques were intravenously infected with dengue virus serotype 2 (strain 16?681) at 1 × 107 PFU/animal. A classic dengue hemorrhage developed 3 to 5 days after infection in 6 of 6 animals. Blood chemistry appeared to be normal with exception of creatine phosphokinase, which peaked at 7 days after infection. A modest thrombocytopenia and noticeable neutropenia concomitant with slight decrease of hemoglobin and hematocrit were registered. In addition, the concentration of D-dimer was elevated significantly. Viremia peaked at 3 to 5 days after infection followed by an inverse relationship between T and B lymphocytes and a bimodal pattern for platelet-monocytes and platelet-neutrophil aggregates. Dengue virus containing platelets engulfed by monocytes was noted at 8 or 9 days after infection. Thus, rhesus macaques inoculated intravenously with a high dose of dengue virus produced dengue hemorrhage, which may provide a unique platform to define the early events in dengue virus infection and help identify which blood components contribute to the pathogenesis of dengue disease. PMID:20042723

Onlamoon, Nattawat; Noisakran, Sansanee; Hsiao, Hui-Mien; Duncan, Alexander; Villinger, Francois; Ansari, Aftab A.

2010-01-01

342

El Niño Southern Oscillation and vegetation dynamics as predictors of dengue fever cases in Costa Rica  

NASA Astrophysics Data System (ADS)

Dengue fever (DF) and dengue hemorrhagic fever (DHF) are growing health concerns throughout Latin America and the Caribbean. This study focuses on Costa Rica, which experienced over 100 000 cases of DF/DHF from 2003 to 2007. We utilized data on sea-surface temperature anomalies related to the El Niño Southern Oscillation (ENSO) and two vegetation indices derived from the Moderate Resolution Imaging Spectrometer (MODIS) from the Terra satellite to model the influence of climate and vegetation dynamics on DF/DHF cases in Costa Rica. Cross-correlations were calculated to evaluate both positive and negative lag effects on the relationships between independent variables and DF/DHF cases. The model, which utilizes a sinusoid and non-linear least squares to fit case data, was able to explain 83% of the variance in weekly DF/DHF cases when independent variables were shifted backwards in time. When the independent variables were shifted forward in time, consistently with a forecasting approach, the model explained 64% of the variance. Importantly, when five ENSO and two vegetation indices were included, the model reproduced a major DF/DHF epidemic of 2005. The unexplained variance in the model may be due to herd immunity and vector control measures, although information regarding these aspects of the disease system are generally lacking. Our analysis suggests that the model may be used to predict DF/DHF outbreaks as early as 40 weeks in advance and may also provide valuable information on the magnitude of future epidemics. In its current form it may be used to inform national vector control programs and policies regarding control measures; it is the first climate-based dengue model developed for this country and is potentially scalable to the broader region of Latin America and the Caribbean where dramatic increases in DF/DHF incidence and spread have been observed.

Fuller, D. O.; Troyo, A.; Beier, J. C.

2009-01-01

343

Endemic Venezuelan equine encephalitis in the Americas: hidden under the dengue umbrella  

PubMed Central

Venezuelan equine encephalitis (VEE) is an emerging infectious disease in Latin America. Outbreaks have been recorded for decades in countries with enzootic circulation, and the recent implementation of surveillance systems has allowed the detection of additional human cases in countries and areas with previously unknown VEE activity. Clinically, VEE is indistinguishable from dengue and other arboviral diseases and confirmatory diagnosis requires the use of specialized laboratory tests that are difficult to afford in resource-limited regions. Thus, the disease burden of endemic VEE in developing countries remains largely unknown, but recent surveillance suggests that it may represent up to 10% of the dengue burden in neotropical cities, or tens-of-thousands of cases per year throughout Latin America. The potential emergence of epizootic viruses from enzootic progenitors further highlights the need to strengthen surveillance activities, identify mosquito vectors and reservoirs and develop effective strategies to control the disease. In this article, we provide an overview of the current status of endemic VEE that results from spillover of the enzootic cycles, and we discuss public health measures for disease control as well as future avenues for VEE research. PMID:21765860

Aguilar, Patricia V; Estrada-Franco, Jose G; Navarro-Lopez, Roberto; Ferro, Cristina; Haddow, Andrew D; Weaver, Scott C

2011-01-01

344

Dengue platelets meet Sir Arthur Conan Doyle.  

PubMed

In this issue of Blood, Hottz et al provide compelling evidence that dengue virus (DV) induces (1) platelet synthesis of interleukin-1b (IL-1b); (2) platelet-derived IL-1b–containing microvesicles (MVs) that increase vascular permeability; and (3) DV-triggered inflammasome activation in platelets. PMID:24235131

Bray, Paul F

2013-11-14

345

Pathogenesis of Dengue Vaccine Viruses in Mosquitoes.  

National Technical Information Service (NTIS)

The dengue-l candidate vaccine (TP 56, nonmutagenized) and it parent virus were compared for their ability to infect orally Aedes aegypti and Aedes albopictus mosquitoes. The vaccine virus was as infective orally as the parent virus for both mosquito spec...

B. J. Beaty

1983-01-01

346

Dengue Virus Type 4, Manaus, Brazil  

PubMed Central

We report dengue virus type 4 (DENV-4) in Amazonas, Brazil. This virus was isolated from serum samples of 3 patients treated at a tropical medicine reference center in Manaus. All 3 cases were confirmed by serologic and molecular tests; 1 patient was co-infected with DENV-3 and DENV-4. PMID:18394292

Naveca, Felipe Gomes; de Souza Bastos, Michele; do Nascimento Melo, Miriam; de Souza Viana, Suziane; Mourao, Maria Paula Gomes; Costa, Cristovao Alves; Farias, Izeni Pires

2008-01-01

347

Strategies for development of dengue virus inhibitors  

Microsoft Academic Search

Antiviral drug discovery is becoming increasingly important due to the global threat of viral disease pandemics. Many members of the genus Flavivirus are significant human pathogens, among which dengue virus (DENV) alone poses a public health threat to 2.5 billion worldwide, leading to 50–100 million human infections each year. Neither vaccine nor effective therapeutics is currently available for DENV. Development

Christian G. Noble; Yen-Liang Chen; Hongping Dong; Feng Gu; Siew Pheng Lim; Wouter Schul; Qing-Yin Wang; Pei-Yong Shi

2010-01-01

348

A Call to Action to Enhance Filovirus Disease Outbreak Preparedness and Response  

PubMed Central

The frequency and magnitude of recognized and declared filovirus-disease outbreaks have increased in recent years, while pathogenic filoviruses are potentially ubiquitous throughout sub-Saharan Africa. Meanwhile, the efficiency and effectiveness of filovirus-disease outbreak preparedness and response efforts are currently limited by inherent challenges and persistent shortcomings. This paper delineates some of these challenges and shortcomings and provides a proposal for enhancing future filovirus-disease outbreak preparedness and response. The proposal serves as a call for prompt action by the organizations that comprise filovirus-disease outbreak response teams, namely, Ministries of Health of outbreak-prone countries, the World Health Organization, Médecins Sans Frontières, the Centers for Disease Control and Prevention—Atlanta, and others. PMID:25271875

Roddy, Paul

2014-01-01

349

Epidemiology of Escherichia coli O157:H7 Outbreaks, United States, 1982-2002  

PubMed Central

Escherichia coli O157:H7 causes 73,000 illnesses in the United States annually. We reviewed E. coli O157 outbreaks reported to Centers for Disease Control and Prevention (CDC) to better understand the epidemiology of E. coli O157. E. coli O157 outbreaks (?2 cases of E. coli O157 infection with a common epidemiologic exposure) reported to CDC from 1982 to 2002 were reviewed. In that period, 49 states reported 350 outbreaks, representing 8,598 cases, 1,493 (17%) hospitalizations, 354 (4%) hemolytic uremic syndrome cases, and 40 (0.5%) deaths. Transmission route for 183 (52%) was foodborne, 74 (21%) unknown, 50 (14%) person-to-person, 31 (9%) waterborne, 11 (3%) animal contact, and 1 (0.3%) laboratory-related. The food vehicle for 75 (41%) foodborne outbreaks was ground beef, and for 38 (21%) outbreaks, produce. PMID:15829201

Sparling, Phyllis H.; Crowe, Collen; Griffin, Patricia M.; Swerdlow, David L.

2005-01-01

350

Large outbreak of Legionnaires' disease and Pontiac fever at a military base.  

PubMed

We investigated a mixed outbreak of Legionnaires' disease (LD) and Pontiac fever (PF) at a military base to identify the outbreak's environmental source as well as known legionellosis risk factors. Base workers with possible legionellosis were interviewed and, if consenting, underwent testing for legionellosis. A retrospective cohort study collected information on occupants of the buildings closest to the outbreak source. We identified 29 confirmed and probable LD and 38 PF cases. All cases were exposed to airborne pathogens from a cooling tower. Occupants of the building closest to the cooling tower were 6·9 [95% confidence interval (CI) 2·2-22·0] and 5·5 (95% CI 2·1-14·5) times more likely to develop LD and PF, respectively, than occupants of the next closest building. Thorough preventive measures and aggressive responses to outbreaks, including searching for PF cases in mixed legionellosis outbreaks, are essential for legionellosis control. PMID:25267405

Ambrose, J; Hampton, L M; Fleming-Dutra, K E; Marten, C; McClusky, C; Perry, C; Clemmons, N A; McCormic, Z; Peik, S; Mancuso, J; Brown, E; Kozak, N; Travis, T; Lucas, C; Fields, B; Hicks, L; Cersovsky, S B

2014-11-01

351

Emergence of salsa and guacamole as frequent vehicles of foodborne disease outbreaks in the United States, 1973-2008.  

PubMed

Fresh salsa and guacamole often contain diced raw produce, are often made in large batches, and are often poorly refrigerated, which may make them prone to contamination that can cause foodborne illness. The safety of salsa and guacamole is increasingly important as these foods gain popularity. Since 1973, local, state, and territorial health departments have voluntarily reported foodborne disease outbreaks to the Centers for Disease Control and Prevention's Foodborne Disease Outbreak Surveillance System (FDOSS) using a standard reporting form. FDOSS used paper-based reporting for 1973-1997 and switched to electronic reporting for 1998-2008. We reviewed all reports of outbreaks during 1973-2008 in which salsa or guacamole was reported as a vehicle. We found 136 outbreaks in which salsa or guacamole was reported as a possible vehicle, which resulted in 5,658 illnesses. Of these 136 salsa- or guacamole-associated (SGA) outbreaks additional possible food vehicles were reported for 33 (24%) outbreaks. There were no SGA outbreaks reported before 1984. Among reported outbreaks, most were caused by norovirus (24%), nontyphoidal Salmonella (19%), and Shigella (7%). Eighty-four percent of outbreaks were caused by foods prepared in restaurants or delis; of these, 19% reported ill foodworkers, and 29% reported improper storage as possible contributing factors. Among all foodborne disease outbreaks with a reported food vehicle during 1984-1997, 26 (0.9%) of 2,966 outbreaks were SGA, and during 1998-2008, 110 (1.4%) of 7,738 outbreaks were SGA. The number of reported foodborne disease outbreaks attributable to salsa or guacamole increased in the United States from 1984 to 2008, especially in later years, and especially in restaurants. Fresh salsa and guacamole require careful preparation and storage. Focused prevention strategies should reduce the risk of illness and ensure that these foods are enjoyed safely. PMID:23461608

Kendall, Magdalena E; Mody, Rajal K; Mahon, Barbara E; Doyle, Michael P; Herman, Karen M; Tauxe, Robert V

2013-04-01

352

The Effects of Weather and Climate Change on Dengue  

PubMed Central

Background There is much uncertainty about the future impact of climate change on vector-borne diseases. Such uncertainty reflects the difficulties in modelling the complex interactions between disease, climatic and socioeconomic determinants. We used a comprehensive panel dataset from Mexico covering 23 years of province-specific dengue reports across nine climatic regions to estimate the impact of weather on dengue, accounting for the effects of non-climatic factors. Methods and Findings Using a Generalized Additive Model, we estimated statistically significant effects of weather and access to piped water on dengue. The effects of weather were highly nonlinear. Minimum temperature (Tmin) had almost no effect on dengue incidence below 5°C, but Tmin values above 18°C showed a rapidly increasing effect. Maximum temperature above 20°C also showed an increasing effect on dengue incidence with a peak around 32°C, after which the effect declined. There is also an increasing effect of precipitation as it rose to about 550 mm, beyond which such effect declines. Rising access to piped water was related to increasing dengue incidence. We used our model estimations to project the potential impact of climate change on dengue incidence under three emission scenarios by 2030, 2050, and 2080. An increase of up to 40% in dengue incidence by 2080 was estimated under climate change while holding the other driving factors constant. Conclusions Our results indicate that weather significantly influences dengue incidence in Mexico and that such relationships are highly nonlinear. These findings highlight the importance of using flexible model specifications when analysing weather–health interactions. Climate change may contribute to an increase in dengue incidence. Rising access to piped water may aggravate dengue incidence if it leads to increased domestic water storage. Climate change may therefore influence the success or failure of future efforts against dengue. PMID:24244765

Colon-Gonzalez, Felipe J.; Fezzi, Carlo; Lake, Iain R.; Hunter, Paul R.

2013-01-01

353

Life history traits of Sirex noctilio F. (Hymenoptera: Siricidae) can explain outbreaks independently of environmental factors.  

PubMed

The woodwasp Sirex noctilio is a major pest of pine plantations worldwide. Economically significant damage is however limited to outbreak populations. To understand what determines outbreaks dynamics in this species, we developed an individual based model for a wasp population developing within a pine plantation. We show that outbreaks may be the result of the insect's life history. Specifically we show that limited dispersal may not only increase population persistence but also create the conditions for eruptive dynamics. When the probability of long distance dispersal is greater than zero, but relatively small (P(LDD) = 0.1) large outbreaks are the norm, with all of the suitable trees dead at the end of the simulation. For P(LDD) = 0 (only local dispersal allowed) outbreaks are smaller in size, and in some cases not well defined and spread over longer periods. For P(LDD) = 1 (only long distance dispersal allowed), the frequency of local population extinction (without outbreaks) increases significantly. Aggregated attacks may induce physiological changes in the trees which could allow other wasps to detect them. These changes may in turn trigger an outbreak. In contrast, healthy, vigorous trees are not suitable for wasp oviposition. In our model the density of suitable trees (healthy trees but yet suitable for oviposition) are a key factor determining population persistence before outbreaks. From an applied perspective, our results emphasize the importance of adequate plantation management in preventing woodwasp infestation. PMID:24245616

Aparicio, Juan Pablo; Corleya, Juan Carlos; Rabinovich, Jorge Eduardo

2013-01-01

354

Seir Model for Transmission of Dengue Fever in Selangor Malaysia  

NASA Astrophysics Data System (ADS)

In this paper, we study a system of differential equations that models the population dynamics of SEIR vector transmission of dengue fever. The model studied breeding value based on the number of reported cases of dengue fever in Selangor because the state had the highest case in Malaysia. The model explains that maximum level of human infection rate of dengue fever achieved in a very short period. It is also revealed that there existed suitability result between theoretical and empirical calculation using the model. The result of SEIR model will hopefully provide an insight into the spread of dengue fever in Selangor Malaysia and basic form for modeling this area.

Syafruddin, S.; Noorani, M. S. M.

355

RAPID RISK ASSESSMENT Outbreak of Ebola haemorrhagic fever in the Democratic Republic of Congo  

E-print Network

An outbreak of Ebola haemorrhagic fever is ongoing in the Democratic Republic of Congo (DRC) with 15 cases reported, including nine deaths in Orientale province. It is the first time that the Ebola species Bundibugyo has been laboratory confirmed as the cause of an Ebola outbreak in DRC. This finding indicates that the current outbreak in DRC is not related to the recently ended outbreak in Uganda, which was caused by the Ebola species Sudan. The epidemiological features of this outbreak are consistent with previous outbreaks of Ebola haemorrhagic fever, although the currently observed case fatality rate is significantly higher than the one observed in the first outbreak of Bundingbuyo virus in 2007 in Uganda. However, it is premature to draw final conclusions about the pathogenicity of this Bundingbuyo viral strain. As the incubation period can last up to three weeks, it is likely that additional cases will be identified in the coming weeks. However, control measures currently implemented in DRC with the support of international partners, e.g. isolation of cases and active monitoring of contacts, should prevent further spread of the disease. It is unlikely, but not impossible, that travellers infected in DRC could arrive in the EU while incubating the disease and develop symptoms while in the EU. These cases would seek medical attention and be isolated, preventing further transmission.

Main Conclusions

2012-01-01

356

Household water treatment uptake during a public health response to a large typhoid fever outbreak in Harare, Zimbabwe.  

PubMed

Locally manufactured sodium hypochlorite (chlorine) solution has been sold in Zimbabwe since 2010. During October 1, 2011-April 30, 2012, 4,181 suspected and 52 confirmed cases of typhoid fever were identified in Harare. In response to this outbreak, chlorine tablets were distributed. To evaluate household water treatment uptake, we conducted a survey and water quality testing in 458 randomly selected households in two suburbs most affected by the outbreak. Although 75% of households were aware of chlorine solution and 85% received chlorine tablets, only 18% had reportedly treated stored water and had the recommended protective level of free chlorine residuals. Water treatment was more common among households that reported water treatment before the outbreak, and those that received free tablets during the outbreak (P < 0.01), but was not associated with chlorine solution awareness or use before the outbreak (P > 0.05). Outbreak response did not build on pre-existing prevention programs. PMID:24664784

Imanishi, Maho; Kweza, Patience F; Slayton, Rachel B; Urayai, Tanaka; Ziro, Odrie; Mushayi, Wellington; Francis-Chizororo, Monica; Kuonza, Lazarus R; Ayers, Tracy; Freeman, Molly M; Govore, Emmaculate; Duri, Clemence; Chonzi, Prosper; Mtapuri-Zinyowera, Sekesai; Manangazira, Portia; Kilmarx, Peter H; Mintz, Eric; Lantagne, Daniele

2014-05-01

357

A point-source norovirus outbreak caused by exposure to fomites.  

PubMed

We investigated a norovirus outbreak (genotype GII.2) affecting 9 members of a soccer team. Illness was associated with touching a reusable grocery bag or consuming its packaged food contents (risk difference, 0.636; P < .01). By polymerase chain reaction, GII norovirus was recovered from the bag, which had been stored in a bathroom used before the outbreak by a person with norovirus-like illness. Airborne contamination of fomites can lead to subsequent point-source outbreaks. When feasible, we recommend dedicated bathrooms for sick persons and informing cleaning staff (professional or otherwise) about the need for adequate environmental sanitation of surfaces and fomites to prevent spread. PMID:22573873

Repp, Kimberly K; Keene, William E

2012-06-01

358

A Point-Source Norovirus Outbreak Caused by Exposure to Fomites  

PubMed Central

We investigated a norovirus outbreak (genotype GII.2) affecting 9 members of a soccer team. Illness was associated with touching a reusable grocery bag or consuming its packaged food contents (risk difference, 0.636; P < .01). By polymerase chain reaction, GII norovirus was recovered from the bag, which had been stored in a bathroom used before the outbreak by a person with norovirus-like illness. Airborne contamination of fomites can lead to subsequent point-source outbreaks. When feasible, we recommend dedicated bathrooms for sick persons and informing cleaning staff (professional or otherwise) about the need for adequate environmental sanitation of surfaces and fomites to prevent spread. PMID:22573873

Repp, Kimberly K.; Keene, William E.

2012-01-01

359

Using active microbiologic surveillance and enhanced infection control measures to control an outbreak of health care-associated extended-spectrum beta-lactamase-producing Klebsiella pneumoniae infections--New Jersey, 2007.  

PubMed

Between April and June 2007, an outbreak of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae infections occurred in an intensive care unit in New Jersey. The outbreak was contained through active microbiologic surveillance, contact precautions, cohorting, and frequent room cleaning. This outbreak demonstrates the importance of rapid response in identifying and isolating patients to prevent further transmission. PMID:18834744

Langer, Adam J; Lafaro, Pat; Genese, Carol A; McDonough, Pauline; Nahass, Ron; Robertson, Corwin

2009-02-01

360

The search and destroy strategy prevents spread and long-term carriage of methicillin-resistant Staphylococcus aureus: results from the follow-up screening of a large ST22 (E-MRSA 15) outbreak in Denmark.  

PubMed

In the aftermath of a methicillin-resistant Staphylococcus aureus (MRSA) ST22 hospital outbreak, we investigated the prevalence of long-term carriage, the efficacy of MRSA decolonization treatment (DT) and the spread of MRSA to households of patients and healthcare workers (HCWs). Furthermore, we evaluated the efficacy of repeated DT in long-term MRSA carriers. Of 250 index persons (58 HCWs and 192 patients), 102 persons (19 HCWs and 83 patients) and 67 household members agreed to participate. Samples from all 169 persons were taken from the nose, throat, wounds and devices/catheters, and urine samples were additionally taken from index persons. Samples from companion animals (n = 35) were taken from the nostrils and anus. Environmental sites (n = 490) screened were telephone, television remote control, toilet flush handle, favourite chair and skirting board beside the bed. Sixteen (19%) patients and two household members, but no HCWs, were ST22-positive. The throat was the most frequent site of colonization. In a multivariate analysis, chronic disease (p <0.001) and pharyngeal carriage (p <0.001) were associated with long-term MRSA carriage. MRSA was found in the environments of four long-term carriers. All animals tested were negative. MRSA-positive households were decolonized using nasal mupirocin TID and daily chlorhexidine body and hair wash for 5 days. Pharyngeal MRSA carriers also received fucidic acid (500 mg TID) combined with rifampicin (600 mg BID) or clindamycin (600 mg BID) for 7 days. The home environment was cleaned on days 2 and 5. At the end of follow-up, ten of 16 long-term carriers and the two household contacts were MRSA-negative. In conclusion, decolonization of MRSA carriers is possible, but should include treatment of household members and the environment. PMID:20041904

Böcher, S; Skov, R L; Knudsen, M A; Guardabassi, L; Mølbak, K; Schouenborg, P; Sørum, M; Westh, H

2010-09-01

361

Are bark beetle outbreaks less synchronous than forest Lepidoptera outbreaks?  

Microsoft Academic Search

Comparisons of intraspecific spatial synchrony across multiple epidemic insect species can be useful for generating hypotheses about major determinants of population patterns at larger scales. The present study compares patterns of spatial synchrony in outbreaks of six epidemic bark beetle species in North America and Europe. Spatial synchrony among populations of the Eurasian spruce bark beetle Ips typographus was significantly

Bjørn Økland; Andrew M. Liebhold; Ottar N. Bjørnstad; Nadir Erbilgin; Paal Krokene

2005-01-01

362

Screening of Dengue Virus Antiviral Activity of Marine Seaweeds by an In Situ Enzyme-Linked Immunosorbent Assay  

PubMed Central

Dengue is a significant public health problem worldwide. Despite the important social and clinical impact, there is no vaccine or specific antiviral therapy for prevention and treatment of dengue virus (DENV) infection. Considering the above, drug discovery research for dengue is of utmost importance; in addition natural marine products provide diverse and novel chemical structures with potent biological activities that must be evaluated. In this study we propose a target-free approach for dengue drug discovery based on a novel, rapid, and economic in situ enzyme-linked immunosorbent assay and the screening of a panel of marine seaweed extracts. The in situ ELISA was standardized and validated for Huh7.5 cell line infected with all four serotypes of DENV, among them clinical isolates and a laboratory strain. Statistical analysis showed an average S/B of 7.2 and Z-factor of 0.62, demonstrating assay consistency and reliability. A panel of fifteen seaweed extracts was then screened at the maximum non-toxic dose previously determined by the MTT and Neutral Red cytotoxic assays. Eight seaweed extracts were able to reduce DENV infection of at least one serotype tested. Four extracts (Phaeophyta: Canistrocarpus cervicornis, Padina gymnospora; Rhodophyta: Palisada perforate; Chlorophyta: Caulerpa racemosa) were chosen for further evaluation, and time of addition studies point that they might act at an early stage of the viral infection cycle, such as binding or internalization. PMID:23227238

Koishi, Andrea Cristine; Zanello, Paula Rodrigues; Bianco, Everson Miguel; Bordignon, Juliano; Nunes Duarte dos Santos, Claudia

2012-01-01

363

Synoptic Composites of Tornadic and Nontornadic Outbreaks ANDREW E. MERCER  

E-print Network

differences that result in the formation of a tornado outbreak (TO) and a primarily nontornadic outbreak (NTO different characteristics within each outbreak type, particularly in the wind fields. The tornado outbreak in the tornado outbreak environment, whereas instability fields are similar between the two outbreak types

Doswell III, Charles A.

364

DISEASE OUTBREAKS CAUSED BY DRINKING WATER  

EPA Science Inventory

Thirty-two waterborne disease outbreaks were reported to the Centers for Disease Control (CDC) and the Environmental Protection Agency in 1981. The outbreaks occurred in 17 states and involved 4430 cases. This was only 64% of the number of outbreaks that were reported in 1980 and...

365

Invariant NKT Cell Response to Dengue Virus Infection in Human  

PubMed Central

Background Dengue viral infection is a global health threat without vaccine or specific treatment. The clinical outcome varies from asymptomatic, mild dengue fever (DF) to severe dengue hemorrhagic fever (DHF). While adaptive immune responses were found to be detrimental in the dengue pathogenesis, the roles of earlier innate events remain largely uninvestigated. Invariant natural killer T (iNKT) cells represent innate-like T cells that could dictate subsequent adaptive response but their role in human dengue virus infection is not known. We hypothesized that iNKT cells play a role in human dengue infection. Methods Blood samples from a well-characterized cohort of children with DF, DHF, in comparison to non-dengue febrile illness (OFI) and healthy controls at various time points were studied. iNKT cells activation were analyzed by the expression of CD69 by flow cytometry. Their cytokine production was then analyzed after ?-GalCer stimulation. Further, the CD1d expression on monocytes, and CD69 expression on conventional T cells were measured. Results iNKT cells were activated during acute dengue infection. The level of iNKT cell activation associates with the disease severity. Furthermore, these iNKT cells had altered functional response to subsequent ex vivo stimulation with ?-GalCer. Moreover, during acute dengue infection, monocytic CD1d expression was also upregulated and conventional T cells also became activated. Conclusion iNKT cells might play an early and critical role in the pathogenesis of severe dengue viral infection in human. Targeting iNKT cells and CD1d serve as a potential therapeutic strategy for severe dengue infection in the future. PMID:24945350

Matangkasombut, Ponpan; Chan-in, Wilawan; Opasawaschai, Anunya; Pongchaikul, Pisut; Tangthawornchaikul, Nattaya; Vasanawathana, Sirijitt; Limpitikul, Wannee; Malasit, Prida; Duangchinda, Thaneeya; Screaton, Gavin; Mongkolsapaya, Juthathip

2014-01-01

366

Serum Metabolome and Lipidome Changes in Adult Patients with Primary Dengue Infection  

PubMed Central

Background Dengue virus (DENV) is the most widespread arbovirus with an estimated 100 million infections occurring every year. Endemic in the tropical and subtropical areas of the world, dengue fever/dengue hemorrhagic fever (DF/DHF) is emerging as a major public health concern. The complex array of concurrent host physiologic changes has hampered a complete understanding of underlying molecular mechanisms of dengue pathogenesis. Methodology/Principle Findings Systems level characterization of serum metabolome and lipidome of adult DF patients at early febrile, defervescence, and convalescent stages of DENV infection was performed using liquid chromatography- and gas chromatography-mass spectrometry. The tractability of following metabolite and lipid changes in a relatively large sample size (n?=?44) across three prominent infection stages allowed the identification of critical physiologic changes that coincided with the different stages. Sixty differential metabolites were identified in our metabolomics analysis and the main metabolite classes were free fatty acids, acylcarnitines, phospholipids, and amino acids. Major perturbed metabolic pathways included fatty acid biosynthesis and ?-oxidation, phospholipid catabolism, steroid hormone pathway, etc., suggesting the multifactorial nature of human host responses. Analysis of phospholipids and sphingolipids verified the temporal trends and revealed association with lymphocytes and platelets numbers. These metabolites were significantly perturbed during the early stages, and normalized to control levels at convalescent stage, suggesting their potential utility as prognostic markers. Conclusions/Significance DENV infection causes temporally distinct serum metabolome and lipidome changes, and many of the differential metabolites are involved in acute inflammatory responses. Our global analyses revealed early anti-inflammatory responses working in concert to modulate early pro-inflammatory processes, thus preventing the host from development of pathologies by excessive or prolonged inflammation. This study is the first example of how an omic- approach can divulge the extensive, concurrent, and dynamic host responses elicited by DENV and offers plausible physiological insights to why DF is self limiting. PMID:23967362

Kumar, Yadunanda; Xu, Fengguo; Lu, Kun; Ooi, Eng Eong; Tannenbaum, Steven R.; Ong, Choon Nam

2013-01-01

367

Temephos Resistance in Aedes aegypti in Colombia Compromises Dengue Vector Control  

PubMed Central

Background Control and prevention of dengue relies heavily on the application of insecticides to control dengue vector mosquitoes. In Colombia, application of the larvicide temephos to the aquatic breeding sites of Aedes aegypti is a key part of the dengue control strategy. Resistance to temephos was recently detected in the dengue-endemic city of Cucuta, leading to questions about its efficacy as a control tool. Here, we characterize the underlying mechanisms and estimate the operational impact of this resistance. Methodology/Principal Findings Larval bioassays of Ae. aegypti larvae from Cucuta determined the temephos LC50 to be 0.066 ppm (95% CI 0.06–0.074), approximately 15× higher than the value obtained from a susceptible laboratory colony. The efficacy of the field dose of temephos at killing this resistant Cucuta population was greatly reduced, with mortality rates <80% two weeks after application and <50% after 4 weeks. Neither biochemical assays nor partial sequencing of the ace-1 gene implicated target site resistance as the primary resistance mechanism. Synergism assays and microarray analysis suggested that metabolic mechanisms were most likely responsible for the temephos resistance. Interestingly, although the greatest synergism was observed with the carboxylesterase inhibitor, DEF, the primary candidate genes from the microarray analysis, and confirmed by quantitative PCR, were cytochrome P450 oxidases, notably CYP6N12, CYP6F3 and CYP6M11. Conclusions/Significance In Colombia, resistance to temephos in Ae. aegypti compromises the duration of its effect as a vector control tool. Several candidate genes potentially responsible for metabolic resistance to temephos were identified. Given the limited number of insecticides that are approved for vector control, future chemical-based control strategies should take into account the mechanisms underlying the resistance to discern which insecticides would likely lead to the greatest control efficacy while minimizing further selection of resistant phenotypes. PMID:24069492

Grisales, Nelson; Poupardin, Rodolphe; Gomez, Santiago; Fonseca-Gonzalez, Idalyd; Ranson, Hilary; Lenhart, Audrey

2013-01-01

368

Cost of Dengue Cases in Eight Countries in the Americas and Asia: A Prospective Study  

Microsoft Academic Search

Despite the growing worldwide burden of dengue fever, the global economic impact of dengue illness is poorly documented. Using a common protocol, we present the first multicountry estimates of the direct and indirect costs of dengue cases in eight American and Asian countries. We conducted prospective studies of the cost of dengue in five countries in the Americas (Brazil, El

Jose A. Suaya; Donald S. Shepard; João B. Siqueira; Celina T. Martelli; Lucy C. S. Lum; Lian Huat Tan; Sukhontha Kongsin; Sukhum Jiamton; Fàtima Garrido; Romeo Montoya; Blas Armien; Rekol Huy; Leticia Castillo; Mariana Caram; Binod K. Sah; Rana Sughayyar; Karen R. Tyo; Scott B. Halstead

2009-01-01

369

Dramatic caspase-dependent apoptosis in antibody-enhanced dengue virus infection of human mast cells  

Microsoft Academic Search

Severe forms of dengue virus disease, known as dengue hemorrhagic fever and dengue shock syndrome, result from an aberrant immune response involving antibody-dependent enhance- ment of infection, thrombocytopenia, and a loss of vascular integrity, culminating in hemorrhage, shock, and in some cases, death. Several studies have indicated that dengue virus infection results in the induction of apoptosis of certain cells

Michael G. Brown; Yan Y. Huang; Jean S. Marshall; Christine A. King; David W. Hoskin; Robert Anderson

2008-01-01

370

The Role of Imported Cases and Favorable Meteorological Conditions in the Onset of Dengue Epidemics  

Microsoft Academic Search

BackgroundTravelers who acquire dengue infection are often routes for virus transmission to other regions. Nevertheless, the interplay between infected travelers, climate, vectors, and indigenous dengue incidence remains unclear. The role of foreign-origin cases on local dengue epidemics thus has been largely neglected by research. This study investigated the effect of both imported dengue and local meteorological factors on the occurrence

Chuin-Shee Shang; Chi-Tai Fang; Chung-Ming Liu; Tzai-Hung Wen; Kun-Hsien Tsai; Chwan-Chuen King

2010-01-01

371

Germany tracks down source for dangerous E. coli outbreak  

NSDL National Science Digital Library

Number of Rare E. Coli Cases in U.S. Rose Last Yearhttp://www.nytimes.com/2011/06/08/us/08food.htmlEconomic costs of E. Coli outbreakhttp://video.ca.msn.com/watch/video/economic-costs-of-e-coli-outbreak/16ifpbqesEU boosts E. Coli compensation offer for farmershttp://www.dw-world.de/dw/article/0,,15141284,00.htmlQ&A: E. Coli outbreakhttp://www.bbc.co.uk/news/health-13600144FightBac!http://www.fightbac.org/Today, Germany's head of their Center for Disease Control, Reinhard Burger said, "It's the bean sprouts." After 29 deaths, thousands taken ill, and produce bans that included Spanish cucumbers, tomatoes, and lettuce, it is believed that they have found the source of one of history's most dangerous outbreaks of E. Coli. Nine countries were affected by the outbreak, including Great Britain, Germany, Spain, Poland, and the United States. Russia recently placed a ban on all EU produce, thus adding an economic crisis to the medical crisis. In Germany, so many people were infected that hospitals struggled to cope, and because it was a new strain and extremely aggressive many health institutions were often offering conflicting advice. Thankfully, German officials seem to have located the source and the hope is that now the spread of this particular strain can be contained. Burger warns that the outbreak is "not yet over" as there "will be new cases coming up." However, with the source of this outbreak found, perhaps the EU, and the rest of the world, can focus on how to prevent these outbreaks in the future.The first link will take visitors to a news article on the recent announcement about bean sprouts from the New York Times. The second link will take visitors to another article from the New York Times which discusses the increasing number of rare E. Coli cases in the U.S. The third link will take visitors to a MSN video that examines the financial toll an E. Coli outbreak can take on produce farmers. The fourth link leads to an article from Deutsche Welle that discusses compensation the EU is offering farmers affected by the outbreak and subsequent produce bans. The fifth link is an informative Q&A from the BBC about E. Coli. The last link will lead visitors to the FightBac! website, a food safety initiative that educates consumers about reducing the risk of food borne illnesses.

Grinnell, Max

372

Ebola Outbreak Killed 5000 Gorillas  

Microsoft Academic Search

Over the past decade, the Zaire strain of Ebola virus (ZEBOV) has repeatedly emerged in Gabon and Congo. Each human outbreak has been accompanied by reports of gorilla and chimpanzee carcasses in neighboring forests, but both the extent of ape mortality and the causal role of ZEBOV have been hotly debated. Here, we present data suggesting that in 2002 and

Magdalena Bermejo; José Domingo Rodríguez-Teijeiro; Germán Illera; Alex Barroso; Carles Vilà; Peter D. Walsh

2006-01-01

373

Outbreak Ethnography The Anthropologist's Toolkit  

E-print Network

epidemiologist at Ebola seminar at Pasteur Institute, Paris 2004 The epidemiologist was asking the question during Ebola outbreaks are challenging and relatively unusual for most anthropologists; they challenged abilities to do the Ebola work, but we went into the field with a limited background on the history

374

Chikungunya fever outbreak, Bhutan, 2012.  

PubMed

In 2012, chikungunya virus (CHIKV) was reported for the first time in Bhutan. IgM ELISA results were positive for 36/210 patient samples; PCR was positive for 32/81. Phylogenetic analyses confirmed that Bhutan CHIKV belongs to the East/Central/South African genotype. Appropriate responses to future outbreaks require a system of surveillance and improved laboratory capacity. PMID:24047543

Wangchuk, Sonam; Chinnawirotpisan, Piyawan; Dorji, Tshering; Tobgay, Tashi; Dorji, Tandin; Yoon, In-Kyu; Fernandez, Stefan

2013-10-01

375

First Experimental In Vivo Model of Enhanced Dengue Disease Severity through Maternally Acquired Heterotypic Dengue Antibodies  

PubMed Central

Dengue (DEN) represents the most serious arthropod-borne viral disease. DEN clinical manifestations range from mild febrile illness to life-threatening hemorrhage and vascular leakage. Early epidemiological observations reported that infants born to DEN-immune mothers were at greater risk to develop the severe forms of the disease upon infection with any serotype of dengue virus (DENV). From these observations emerged the hypothesis of antibody-dependent enhancement (ADE) of disease severity, whereby maternally acquired anti-DENV antibodies cross-react but fail to neutralize DENV particles, resulting in higher viremia that correlates with increased disease severity. Although in vitro and in vivo experimental set ups have indirectly supported the ADE hypothesis, direct experimental evidence has been missing. Furthermore, a recent epidemiological study has challenged the influence of maternal antibodies in disease outcome. Here we have developed a mouse model of ADE where DENV2 infection of young mice born to DENV1-immune mothers led to earlier death which correlated with higher viremia and increased vascular leakage compared to DENV2-infected mice born to dengue naïve mothers. In this ADE model we demonstrated the role of TNF-? in DEN-induced vascular leakage. Furthermore, upon infection with an attenuated DENV2 mutant strain, mice born to DENV1-immune mothers developed lethal disease accompanied by vascular leakage whereas infected mice born to dengue naïve mothers did no display any clinical manifestation. In vitro ELISA and ADE assays confirmed the cross-reactive and enhancing properties towards DENV2 of the serum from mice born to DENV1-immune mothers. Lastly, age-dependent susceptibility to disease enhancement was observed in mice born to DENV1-immune mothers, thus reproducing epidemiological observations. Overall, this work provides direct in vivo demonstration of the role of maternally acquired heterotypic dengue antibodies in the enhancement of dengue disease severity and offers a unique opportunity to further decipher the mechanisms involved. PMID:24699622

Ng, Jowin Kai Wei; Zhang, Summer Lixin; Tan, Hwee Cheng; Yan, Benedict; Maria Martinez Gomez, Julia; Tan, Wei Yu; Lam, Jian Hang; Tan, Grace Kai Xin; Ooi, Eng Eong; Alonso, Sylvie

2014-01-01

376

Seroepidemiology and active surveillance of dengue fever/dengue haemorrhagic fever in Delhi.  

PubMed

The aims of the present study were to carry out surveillance for dengue virus infection in adults with short-duration fever, and serological study of dengue virus infection in persons without fever. Patients were divided into two groups. Group 1 included patients above 12 years of age with fever of 2-12 days duration without any apparent cause. Of these, patients who presented with fever for 2-5 days were included for virus isolation (group 1a) while those who presented within 6-12 days of the onset of fever were included for the dengue-specific IgM serology (group 1b). Group 2 included a sample of population belonging to all age groups but without pyrexia and blood was collected for dengue-specific IgG serology. Twenty-six patients were enrolled in group 1a over a period of 4 months (September to December, 1997). Of these, DEN1 was isolated in 5 cases. Group 1b included 182 patients, out of which 34 (18.68%) were positive for dengue-specific IgM antibodies. Significantly, all the positive cases were detected during the months of September to November. Retro-orbital pain was present in a significantly more number of IgM-positive cases as compared to IgM-negative cases. Group 2 included 125 cases without fever. The overall positivity for dengue-specific IgG antibodies was 77.6%, with the highest positivity of 100% in the age group of 31-40 years. It was concluded that dengue virus infection is endemic in and around Delhi with peak incidence between September and Novemver. The prevalent serotype during September and December 1997 was DEN1. Since previous epidemic of DHF was due to DEN2 type, isolation of DEN1 serotype indicates changes of another epidemic of DHF due to DEN1 serotype. The stresses the urgent need for implementation of measures to control the transmission of dengue infection. PMID:11482168

Kurukumbi, M; Wali, J P; Broor, S; Aggarwal, P; Seth, P; Handa, R; Dhar, L; Vajapayee, M

2001-03-01

377

Outbreaks of salmonellosis in Minnesota (1998 through 2006) associated with frozen, microwaveable, breaded, stuffed chicken products.  

PubMed

From 1998 through 2006, four outbreaks of salmonellosis associated with raw, frozen, microwaveable, breaded, prebrowned, stuffed chicken products were identified in Minnesota. In 1998, 33 Salmonella Typhimurium cases were associated with a single brand of Chicken Kiev. In 2005, four Salmonella Heidelberg cases were associated with a different brand and variety (Chicken Broccoli and Cheese). From 2005 to 2006, 27 Salmonella Enteritidis cases were associated with multiple varieties of product, predominately of the same brand involved in the 1998 outbreak. In 2006, three Salmonella Typhimurium cases were associated with the same brand of product involved in the 2005 Salmonella Heidelberg outbreak. The outbreak serotype and pulsed-field gel electrophoresis subtype of Salmonella were isolated from product in each outbreak. In these outbreaks, most individuals affected thought that the product was precooked due to its breaded and prebrowned nature, most used a microwave oven, most did not follow package cooking instructions, and none took the internal temperature of the cooked product. Similar to previous salmonellosis outbreaks associated with raw, breaded chicken nuggets or strips in Canada and Australia, inadequate labeling, consumer responses to labeling, and microwave cooking were the key factors in the occurrence of these outbreaks. Modification of labels, verification of cooking instructions by the manufacturer, and notifications to alert the public that these products contain raw poultry, implemented because of the first two outbreaks, did not prevent the other outbreaks. Microwave cooking is not recommended as a preparation method for these types of products, unless they are precooked or irradiated prior to sale. PMID:18939771

Smith, Kirk E; Medus, Carlota; Meyer, Stephanie D; Boxrud, David J; Leano, Fe; Hedberg, Craig W; Elfering, Kevin; Braymen, Craig; Bender, Jeffrey B; Danila, Richard N

2008-10-01

378

Genetic elimination of dengue vector mosquitoes  

PubMed Central

An approach based on mosquitoes carrying a conditional dominant lethal gene (release of insects carrying a dominant lethal, RIDL) is being developed to control the transmission of dengue viruses by vector population suppression. A transgenic strain, designated OX3604C, of the major dengue vector, Aedes aegypti, was engineered to have a repressible female-specific flightless phenotype. This strain circumvents the need for radiation-induced sterilization, allows genetic sexing resulting in male-only releases, and permits the release of eggs instead of adult mosquitoes. OX3604C males introduced weekly into large laboratory cages containing stable target mosquito populations at initial ratios of 8.5–10?1 OX3604C?target eliminated the populations within 10–20 weeks. These data support the further testing of this strain in contained or confined field trials to evaluate mating competitiveness and environmental and other effects. Successful completion of the field trials should facilitate incorporation of this approach into area-wide dengue control or elimination efforts as a component of an integrated vector management strategy. PMID:21383140

Wise de Valdez, Megan R.; Nimmo, Derric; Betz, John; Gong, Hong-Fei; James, Anthony A.; Alphey, Luke; Black, William C.

2011-01-01

379

Dengue Virus Virulence and Transmission Determinants  

PubMed Central

The mechanisms of dengue virus (DENV) pathogenesis are little understood because we have no models of disease; only humans develop symptoms (dengue fever, DF, or dengue hemorrhagic fever, DHF) and research has been limited to studies involving patients. DENV is very diverse: there are four antigenic groups (serotypes) and three to five genetic groups (genotypes) within each sero-type. Thus, it has been difficult to evaluate the relative virulence or transmissibility of each DENV genotype; both of these factors are important determinants of epidemiology and their measurement is complex because the natural cycle of this disease involves human-mosquito-human transmission. Although epidemiological and evolutionary studies have pointed to viral factors in determining disease outcome, only recently developed models could prove the importance of specific viral genotypes in causing severe epidemics and their potential to spread to other continents. These new models involve infection of primary human cell cultures, “humanized” mice and field-collected mosquitoes; also, new mathematical models can estimate the impact of viral replication, human immunity and mosquito transmission on epidemic behavior. DENV evolution does not seem to be rapid and the transmission and dispersal of stable, replication-fit genotypes has been more important in the causation of more severe epidemics. Controversy regarding viral determinants of DENV pathogenesis and epidemiology will continue until virulence and transmissibility can be measured under various conditions. PMID:19802577

Rico-Hesse, R.

2011-01-01

380

Animal Models of Dengue Virus Infection  

PubMed Central

The development of animal models of dengue virus (DENV) infection and disease has been challenging, as epidemic DENV does not naturally infect non-human species. Non-human primates (NHPs) can sustain viral replication in relevant cell types and develop a robust immune response, but they do not develop overt disease. In contrast, certain immunodeficient mouse models infected with mouse-adapted DENV strains show signs of severe disease similar to the ‘vascular-leak’ syndrome seen in severe dengue in humans. Humanized mouse models can sustain DENV replication and show some signs of disease, but further development is needed to validate the immune response. Classically, immunocompetent mice infected with DENV do not manifest disease or else develop paralysis when inoculated intracranially; however, a new model using high doses of DENV has recently been shown to develop hemorrhagic signs after infection. Overall, each model has its advantages and disadvantages and is differentially suited for studies of dengue pathogenesis and immunopathogenesis and/or pre-clinical testing of antiviral drugs and vaccines. PMID:22355452

Zompi, Simona; Harris, Eva

2012-01-01

381

Linking Oviposition Site Choice to Offspring Fitness in Aedes aegypti: Consequences for Targeted Larval Control of Dengue Vectors  

Microsoft Academic Search

BackgroundCurrent Aedes aegypti larval control methods are often insufficient for preventing dengue epidemics. To improve control efficiency and cost-effectiveness, some advocate eliminating or treating only highly productive containers. The population-level outcome of this strategy, however, will depend on details of Ae. aegypti oviposition behavior.Methodology\\/Principal FindingsWe simultaneously monitored female oviposition and juvenile development in 80 experimental containers located across 20 houses

Jacklyn Wong; Amy C. Morrison; Steven T. Stoddard; Helvio Astete; Yui Yin Chu; Imaan Baseer; Thomas W. Scott

2012-01-01

382

Structure of the dengue virus envelope protein after membrane fusion  

E-print Network

, and filoviruses such as Ebola virus (reviewed in ref. 1). All of these `class I' viral fusion proteins are twoStructure of the dengue virus envelope protein after membrane fusion Yorgo Modis1 , Steven Ogata2 ........................................................................................................................................................................................................................... Dengue virus enters a host cell when the viral envelope glycoprotein, E, binds to a receptor and responds

Harrison, Stephen C.

383

The GOOD-BYE TO DENGUE GAME: Debriefing Study  

ERIC Educational Resources Information Center

This study examined the use of postgame debriefing of a health educational board game activity on dengue fever in a Filipino student population. The debriefing used a series of specific open-ended questions, exploring students' feelings about the game and game-related questionnaires, students' perceptions of important information about dengue from…

Lennon, Jeffrey L.; Coombs, David W.

2005-01-01

384

Climate-Based Models for Understanding and Forecasting Dengue Epidemics  

E-print Network

Climate-Based Models for Understanding and Forecasting Dengue Epidemics Elodie Descloux1 indices were available from March 2000 to December 2009. During epidemic years, the distribution of dengue cases was highly seasonal. The epidemic peak (March­April) lagged the warmest temperature by 1­2 months

Paris-Sud XI, Université de

385

Clinical Relevance and Discriminatory Value of Elevated Liver Aminotransferase Levels for Dengue Severity  

Microsoft Academic Search

BackgroundElevation of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) is prominent in acute dengue illness. The World Health Organization (WHO) 2009 dengue guidelines defined AST or ALT?1000 units\\/liter (U\\/L) as a criterion for severe dengue. We aimed to assess the clinical relevance and discriminatory value of AST or ALT for dengue hemorrhagic fever (DHF) and severe dengue.Methodology\\/Principal FindingsWe retrospectively studied

Linda K. Lee; Victor C. Gan; Vernon J. Lee; Adriana S. Tan; Yee Sin Leo; David C. Lye

2012-01-01

386

Dengue virus-specific suppressor T cells: current perspectives.  

PubMed

Dengue virus was the first microorganism that was shown to induce generation of antigen-specific suppressor T (TS) cells in mice. The cascade of the three generations of TS cells (TS1, TS2, TS3) and their secretary products, the suppressor factors (SF1, SF2), was delineated. The TS pathway was proposed to be protective through inhibition of the production of enhancing antibody, which may enhance the severity of dengue disease. The currently second most favoured mechanism of severe dengue disease is the 'cytokine tsunami'. During the last decade, suppressor/regulatory T cells have been studied in greater detail using modern techniques in various diseases, including viral infections. This brief review discusses the role of dengue-specific suppressor T cells in protection and/or induction of severe dengue disease in view of our current understanding of suppressor/regulatory T cells. PMID:17573929

Chaturvedi, Umesh C; Shrivastava, Richa; Tripathi, Raj K; Nagar, Rachna

2007-08-01

387

Dengue Hemorrhagic Fever in Infants: Research Opportunities Ignored  

PubMed Central

The age distribution of cases of dengue hemorrhagic fever and dengue shock syndrome (DHF/DSS) in infants under the age of 1 year are reported