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

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

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

2009-01-01

3

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

4

A local outbreak of dengue caused by an imported case in Dongguan China  

PubMed Central

Background Dengue, a mosquito-borne febrile viral disease, is found in tropical and sub-tropical regions around the world. Since the first occurrence of dengue was confirmed in Guangdong, China in 1978, dengue outbreaks have been reported sequentially in different provinces in South China transmitted by.peridomestic Ae. albopictus mosquitoes, diplaying Ae. aegypti, a fully domestic vector that transmits dengue worldwide. Rapid and uncontrolled urbanization is a characteristic change in developing countries, which impacts greatly on vector habitat, human lifestyle and transmission dynamics on dengue epidemics. In September 2010, an outbreak of dengue was detected in Dongguan, a city in Guangdong province characterized by its fast urbanization. An investigation was initiated to identify the cause, to describe the epidemical characteristics of the outbreak, and to implement control measures to stop the outbreak. This is the first report of dengue outbreak in Dongguan, even though dengue cases were documented before in this city. Methods Epidemiological data were obtained from local Center of Disease Control and prevention (CDC). Laboratory tests such as real-time Reverse Transcription Polymerase Chain Reaction (RT-PCR), the virus cDNA sequencing, and Enzyme-Linked immunosorbent assay (ELISA) were employed to identify the virus infection and molecular phylogenetic analysis was performed with MEGA5. The febrile cases were reported every day by the fever surveillance system. Vector control measures including insecticidal fogging and elimination of habitats of Ae. albopictus were used to control the dengue outbreak. Results The epidemiological studies results showed that this dengue outbreak was initiated by an imported case from Southeast Asia. The outbreak was characterized by 31 cases reported with an attack rate of 50.63 out of a population of 100,000. Ae. albopictus was the only vector species responsible for the outbreak. The virus cDNA sequencing analysis showed that the virus responsible for the outbreak was Dengue Virus serotype-1 (DENV-1). Conclusions Several characterized points of urbanization contributed to this outbreak of dengue in Dongguan: the residents are highly concentrated; the residents' life habits helped to form the habitats of Ae. albopictus and contributed to the high Breteau Index; the self-constructed houses lacks of mosquito prevention facilities. This report has reaffirmed the importance of a surveillance system for infectious diseases control and aroused the awareness of an imported case causing the epidemic of an infectious disease in urbanized region. PMID:22276682

2012-01-01

5

Study of potential risk of dengue disease outbreak in Sri Lanka using GIS and statistical modelling  

Microsoft Academic Search

The increasing incidence of dengue fever has become a priority health issue for Sri Lanka. Recent dengue outbreaks in Sri Lanka show two trends: yearly increase of total number of dengue incidence and increasing dengue outbreaks outside the endemic urbanised areas in the south and the west. Identification of factors responsible for dengue outbreaks and the mapping of potential risk

Sumith Pathirana; Masato Kawabata; Rohitha Goonatilake

2009-01-01

6

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 Martín, José L.; Montoya, Romeo H.; del Diego, Jorge; Zambrano, Betzana; Dayan, Gustavo H.

2012-01-01

7

Predicting outbreaks of dengue fever according to climate  

E-print Network

N° 410 July 2012 Predicting outbreaks of dengue fever according to climate Scientific news Actualidad cientifica Actualité scientifique Mainly vectored by the mosquito Aedes aegypti, dengue fever and even haemorrhaging, causing 25 000 deaths per year throughout the world. No vaccine or specific

8

Impact of vector control on a dengue fever outbreak in Trinidad, West Indies, in 1998.  

PubMed

In 1998, Trinidad experienced its first major outbreak of dengue haemorrhagic fever. Data from the Trinidad Public Health Laboratory, the National Surveillance Unit and Insect Vector Control Division, Ministry of Health, Trinidad and Tobago were analysed to determine the impact of vector control measures on the dengue outbreak. Geographical Information Systems (GIS)/Global Positioning Systems (GPS) were used to map cases and to distinguish epidemiological clusters. The Aedes aegypti population densities were higher than the 5% transmission threshold in all counties. The spatial distribution of dengue fever cases was significantly correlated with the heavily populated east-west corridor in the north and several distinctly separate clusters in the western part of the island. The temporal distribution patterns showed significantly more dengue fever cases occurring during the rainy season than during the dry season. This study documents the importance of vector control in the prevention of dengue transmission since no vaccine is currently available, and emphasizes the urgent need to understand better the environmental factors which contribute to the proliferation of this disease vector Ae. aegypti. PMID:16045461

Chadee, Dave D; Williams, Fiona L R; Kitron, Uriel D

2005-08-01

9

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 ...

10

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

11

An outbreak of dengue fever in St. Croix (U. S. Virgin Islands), 2005.  

Technology Transfer Automated Retrieval System (TEKTRAN)

In the summer of 2005, an outbreak of dengue virus serotype-2 with cases of dengue hemorrhagic fever (DHF) occurred in St. Croix, US Virgin Islands. The medical records of all dengue laboratory-positive patients either seen in the Emergency Department of or admitted to the Governor Juan F. Luis Hosp...

12

Spatiotemporal clustering, climate periodicity, and social-ecological risk factors for dengue during an outbreak in Machala, Ecuador, in 2010.  

PubMed

BackgroundDengue fever, a mosquito-borne viral disease, is a rapidly emerging public health problem in Ecuador and throughout the tropics. However, we have a limited understanding of the disease transmission dynamics in these regions. Previous studies in southern coastal Ecuador have demonstrated the potential to develop a dengue early warning system (EWS) that incorporates climate and non-climate information. The objective of this study was to characterize the spatiotemporal dynamics and climatic and social-ecological risk factors associated with the largest dengue epidemic to date in Machala, Ecuador, to inform the development of a dengue EWS.MethodsThe following data from Machala were included in analyses: neighborhood-level georeferenced dengue cases, national census data, and entomological surveillance data from 2010; and time series of weekly dengue cases (aggregated to the city-level) and meteorological data from 2003 to 2012. We applied LISA and Moran¿s I to analyze the spatial distribution of the 2010 dengue cases, and developed multivariate logistic regression models through a multi-model selection process to identify census variables and entomological covariates associated with the presence of dengue at the neighborhood level. Using data aggregated at the city-level, we conducted a time-series (wavelet) analysis of weekly climate and dengue incidence (2003-2012) to identify significant time periods (e.g., annual, biannual) when climate co-varied with dengue, and to describe the climate conditions associated with the 2010 outbreak.ResultsWe found significant hotspots of dengue transmission near the center of Machala. The best-fit model to predict the presence of dengue included older age and female gender of the head of the household, greater access to piped water in the home, poor housing condition, and less distance to the central hospital. Wavelet analyses revealed that dengue transmission co-varied with rainfall and minimum temperature at annual and biannual cycles, and we found that anomalously high rainfall and temperatures were associated with the 2010 outbreak.ConclusionsOur findings highlight the importance of geospatial information in dengue surveillance and the potential to develop a climate-driven spatiotemporal prediction model to inform disease prevention and control interventions. This study provides an operational methodological framework that can be applied to understand the drivers of local dengue risk. PMID:25420543

Stewart-Ibarra, Anna M; Muñoz, Angel G; Ryan, Sadie J; Ayala, Efraín; Borbor-Cordova, Mercy J; Finkelstein, Julia L; Mejía, Raúl; Ordoñez, Tania; Recalde-Coronel, G; Rivero, Keytia

2014-11-25

13

Dengue.  

PubMed

Dengue viruses have spread rapidly within countries and across regions in the past few decades, resulting in an increased frequency of epidemics and severe dengue disease, hyperendemicity of multiple dengue virus serotypes in many tropical countries, and autochthonous transmission in Europe and the USA. Today, dengue is regarded as the most prevalent and rapidly spreading mosquito-borne viral disease of human beings. Importantly, the past decade has also seen an upsurge in research on dengue virology, pathogenesis, and immunology and in development of antivirals, vaccines, and new vector-control strategies that can positively impact dengue control and prevention. PMID:25230594

Guzman, Maria G; Harris, Eva

2014-09-12

14

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

15

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

16

Risk factors associated with an outbreak of dengue fever/dengue haemorrhagic fever in Hanoi, Vietnam.  

PubMed

SUMMARY Dengue fever/dengue haemorrhagic fever (DF/DHF) appears to be emerging in Hanoi in recent years. A case-control study was performed to investigate risk factors for the development of DF/DHF in Hanoi. A total of 73 patients with DF/DHF and 73 control patients were included in the study. The risk factor analysis indicated that living in rented housing, living near uncovered sewers, and living in a house discharging sewage directly into to ponds were all significantly associated with DF/DHF. People living in rented houses were 2·2 times more at risk of DF/DHF than those living in their own homes [adjusted odds ratio (aOR) 2·2, 95% confidence interval (CI) 1·1-4·6]. People living in an unhygienic house, or in a house discharging sewage directly to the ponds were 3·4 times and 4·3 times, respectively, more likely to be associated with DF/DHF (aOR 3·4, 95% CI 1-11·7; aOR 4·3, 95% CI 1·1-16·9). These results contribute to the understanding of the dynamics of dengue transmission in Hanoi, which is needed to implement dengue prevention and control programmes effectively and efficiently. PMID:25308711

Toan, D T T; Hoat, L N; Hu, W; Wright, P; Martens, P

2014-10-13

17

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

18

Maiden outbreaks of dengue virus 1 genotype III in rural central India.  

PubMed

SUMMARY Dengue is regarded as the most important arboviral disease. Although sporadic cases have been reported, serotypes responsible for outbreaks have not been identified from central India over the last 20 years. We investigated two outbreaks of febrile illness, in August and November 2012, from Korea district (Chhattisgarh) and Narsinghpur district (Madhya Pradesh), respectively. Fever and entomological surveys were conducted in the affected regions. Molecular and serological tests were conducted on collected serum samples. Dengue-specific amplicons were sequenced and phylogenetic analyses were performed. In Korea and Narsinghpur districts 37·3% and 59% of cases were positive, respectively, for dengue infection, with adults being the worst affected. RT-PCR confirmed dengue virus serotype 1 genotype III as the aetiology. Ninety-six percent of infections were primary. This is the first time that dengue virus 1 outbreaks have been documented from central India. Introduction of the virus into the population and a conducive mosquitogenic environment favouring increased vector density caused the outbreak. Timely diagnosis and strengthening vector control measures are essential to avoid future outbreaks. PMID:24667083

Barde, P V; Kori, B K; Shukla, M K; Bharti, P K; Chand, G; Kumar, G; Ukey, M J; Ali, N A; Singh, N

2015-01-01

19

Unusual Emergence of Guate98-like Molecular Subtype of DEN3 during 2003 Dengue Outbreak in Delhi  

Microsoft Academic Search

With a view to identifying the molecular subtype of the circulating dengue virus responsible for a major outbreak of dengue fever (DF) \\/ dengue haemorrhagic fever (DHF) in and around Delhi during the post- monsoon period in 2003, 32 serum samples were collected from clinically suspected cases. These were subjected to reverse transcription\\/polymerase chain reaction (RT\\/PCR) for amplification of 511

Manoj Kumar; S. T. Pasha; Veena Mittal; D. S. Rawat; Subhash Chandra Arya; Nirmala Agarwal; Depesh Bhattacharya; Shiv Lal; Arvind Rai

20

Isolation and characterization of dengue virus serotype 2 from the large dengue outbreak in Guangdong, China in 2014.  

PubMed

Dengue has been well recognized as a global public health threat, but only sporadic epidemics and imported cases were reported in recent decades in China. Since July 2014, an unexpected large dengue outbreak has occurred in Guangdong province, China, resulting in more than 40000 patients including six deaths. To clarify and characterize the causative agent of this outbreak, the acute phase serum from a patient diagnosed with severe dengue was subjected to virus isolation and high-throughput sequencing (HTS). Traditional real-time RT-PCR and HTS with Ion Torrent PGM detected the presence of dengue virus serotype 2 (DENV-2). A clinical DENV-2 isolate GZ05/2014 was obtained by culturing the patient serum in mosquito C6/36 cells. The complete genome of GZ05/2014 was determined and deposited in GenBank under the access number KP012546. Phylogenetic analysis based on the complete envelope gene showed that the newly DENV-2 isolate belonged to Cosmopolitan genotype and clustered closely with other Guangdong strains isolated in the past decade. No amino acid mutations that are obviously known to increase virulence or replication were identified throughout the genome of GZ05/2014. The high homology of Guangdong DENV-2 strains indicated the possibility of establishment of local DENV-2 circulation in Guangdong, China. These results help clarify the origin of this epidemic and predict the future status of dengue in China. PMID:25502398

Zhao, Hui; Zhao, LingZhai; Jiang, Tao; Li, XiaoFeng; Fan, Hang; Hong, WenXin; Zhang, Yu; Zhu, Qin; Ye, Qing; Tong, YiGang; Cao, WuChun; Zhang, FuChun; Qin, ChengFeng

2014-12-01

21

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

22

Dengue and chikungunya: long-distance spread and outbreaks in naïve areas.  

PubMed

Mosquito-borne virus infections, such as dengue and chikungunya, are continuously expanding their geographical range. The dengue virus, which is known to be a common cause of febrile illness in tropical areas of the Old World, is now widespread in the Americas. In most affected areas, all the four dengue virus serotypes have circulated. Recently, small clusters of dengue have been identified also in Southern Europe during the hot season. The chikungunya virus, initially restricted to Central Africa, where is a common cause of sporadic cases or small outbreaks, and Asia, where it is used to cause large epidemics, has recently invaded new territories. After ravaging Indian Ocean Islands and the Indian subcontinent, CHIKV caused an outbreak in north-eastern Italy. Recently, chikungunya has reached the Caribbean, causing for the first time a large epidemic on the American continent. Although Aedes aegypti is the main vector of both viruses, Aedes albopictus, the Asian 'Tiger' mosquito, is now playing an increasingly important role, contributing to their spread in temperate climate areas. Hereby, we focus the attention on outbreaks of dengue and chikungunya occurring in previously disease-free areas and discuss factors associated with the long-distance spread of the vector-borne infections, such as mutations increasing viral fitness, climate change, urbanization, and globalization of humans and vectors. PMID:25491436

Rezza, Giovanni

2014-12-01

23

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

Lourenço, José; Recker, Mario

2014-01-01

24

E. Coli: Preventing Outbreaks at Camp.  

ERIC Educational Resources Information Center

One strain of E. coli is not usually found in foods, but has been related to consumption of undercooked ground beef. Symptoms are stomach cramps and diarrhea, and 2-7% of infections lead to hemolytic uremic syndrome, which is life threatening. Camps can prevent outbreaks by avoiding uncooked meat on overnight campouts and requiring appropriate…

McKinney, Mary D.

1996-01-01

25

Dengue fever outbreak in Karachi 2006 - A study of profile and outcome of children under 15 years of age  

Microsoft Academic Search

Objective: To evaluate children with serologically confirmed Dengue fever in order to identify common clinical features, progress of disease, grades of severity and outcome of cases during the outbreak in 2006. Methods: A cross-sectional, descriptive study was conducted on serologically positive children with Dengue fever (DF) admitted in Civil Hospital Karachi and Liaquat National Hospital between October and November 2006.

Saba Ahmed; Fehmina Arif; Yousuf Yahya; Arshaloos Rehman; Kashif Abbas; Sohail Ashraf; Dure Samin Akram

26

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

27

Clinical and Virological Descriptive Study in the 2011 Outbreak of Dengue in the Amazonas, Brazil  

PubMed Central

Background Dengue is a vector-borne disease in the tropical and subtropical region of the world and is transmitted by the mosquito Aedes aegypti. In the state of Amazonas, Brazil during the 2011 outbreak of dengue all the four Dengue virus (DENV) serotypes circulating simultaneously were observed. The aim of the study was to describe the clinical epidemiology of dengue in Manaus, the capital city of the state of the Amazonas, where all the four DENV serotypes were co-circulating simultaneously. Methodology Patients with acute febrile illness during the 2011 outbreak of dengue, enrolled at the Fundação de Medicina Tropical Dr. Heitor Viera Dourado (FMT-HVD), a referral centre for tropical and infectious diseases in Manaus, were invited to participate in a clinical and virological descriptive study. Sera from 677 patients were analyzed by RT-nested-PCRs for flaviviruses (DENV 1–4, Saint Louis encephalitis virus-SLEV, Bussuquara virus-BSQV and Ilheus virus-ILHV), alphavirus (Mayaro virus-MAYV) and orthobunyavirus (Oropouche virus-OROV). Principal Findings Only dengue viruses were detected in 260 patients (38.4%). Thirteen patients were co-infected with more than one DENV serotype and six (46.1%) of them had a more severe clinical presentation of the disease. Nucleotide sequencing showed that DENV-1 belonged to genotype V, DENV-2 to the Asian/American genotype, DENV-3 to genotype III and DENV-4 to genotype II. Conclusions Co-infection with more than one DENV serotype was observed. This finding should be warning signs to health authorities in situations of the large dispersal of serotypes that are occurring in the world. PMID:24978469

Martins, Valquiria do Carmo Alves; Bastos, Michele de Souza; Ramasawmy, Rajendranath; de Figueiredo, Regina Pinto; Gimaque, João Bosco Lima; Braga, Wornei Silva Miranda; Nogueira, Mauricio Lacerda; Nozawa, Sergio; Naveca, Felipe Gomes; Figueiredo, Luiz Tadeu Moraes; Mourão, Maria Paula Gomes

2014-01-01

28

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

29

Intra- and Interseasonal Autoregressive Prediction of Dengue Outbreaks Using Local Weather and Regional Climate for a Tropical Environment in Colombia  

PubMed Central

Dengue fever transmission results from complex interactions between the virus, human hosts, and mosquito vectors—all of which are influenced by environmental factors. Predictive models of dengue incidence rate, based on local weather and regional climate parameters, could benefit disease mitigation efforts. Time series of epidemiological and meteorological data for the urban environment of Cali, Colombia are analyzed from January of 2000 to December of 2011. Significant dengue outbreaks generally occur during warm-dry periods with extreme daily temperatures confined between 18°C and 32°C—the optimal range for mosquito survival and viral transmission. Two environment-based, multivariate, autoregressive forecast models are developed that allow dengue outbreaks to be anticipated from 2 weeks to 6 months in advance. These models have the potential to enhance existing dengue early warning systems, ultimately supporting public health decisions on the timing and scale of vector control efforts. PMID:24957546

Eastin, Matthew D.; Delmelle, Eric; Casas, Irene; Wexler, Joshua; Self, Cameron

2014-01-01

30

Preventive transfusion in dengue shock syndrome–is it necessary?  

Microsoft Academic Search

We compared 53 patients with dengue shock syndrome (DSS) who received preventive transfusions with 53 who did not. Significant differences in the development of pulmonary edema and length of hospitalization (P<.05) and none in hemorrhage (P=.136) were observed. Preventive transfusions did not produce sustained improvements in the coagulation status in DSS.

Lucy Chai See Lum; Mohammad El-Amin Abdel-Latif; Adrian Yu Teik Goh; Patrick Wai Keong Chan; Sai Kit Lam

2003-01-01

31

Dengue and Severe Dengue  

MedlinePLUS

... including insecticide products and application technologies; gathers official records of dengue and severe dengue from over 100 Member States; publishes guidelines and handbooks for case management, dengue prevention and control for Member States. Share ...

32

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

33

Underrecognition of leptospirosis during a dengue fever outbreak in Hawaii, 2001-2002.  

PubMed

During the 10-year period from 1997 through 2006, the reported mean annual incidence rate of leptospirosis in the state of Hawaii was 3.3/100,000 with a range of 22-60 infections reported each year. Because the clinical presentation is highly variable, however, leptospirosis illness is challenging to recognize and may be underdiagnosed. To assess whether the incidence may be substantially higher than reported figures indicate, we retrospectively studied the prevalence of anti-Leptospira IgM antibodies among specimens obtained over a 12-month period (May 2001 to April 2002) from patients presenting with febrile illness during a dengue fever outbreak in Hawaii. Of 1206 patients testing negative or indeterminate for dengue, 54 (4.5%; 95% confidence interval: 3.3%-5.7%) were positive for anti-Leptospira IgM antibodies using a commercially available dipstick enzyme-linked immunosorbent assay (ELISA). The most common clinical symptoms reported by laboratory-positive leptospirosis patients were fever (92%), headache (88%), and myalgia (83%). Three clinical symptoms were significantly less common among persons laboratory positive for leptospirosis when compared with the 122 patients who had been diagnosed with dengue fever during the outbreak: rash (p < 0.0001), chills (p = 0.05), and petechiae (p = 0.0005). Laboratory-positive leptospirosis infections were identified in persons exposed on each of the 5 most populous islands and illness onsets spanned a 10-month period, reflecting an endemic pattern of disease. If added to the figures obtained via routine passive surveillance, the number of leptospirosis infections identified through this study would more than double the annual incidence rate for Hawaii during 2001. These findings indicate that many leptospiral infections in Hawaii go undiagnosed. Physicians should maintain a high index of suspicion for leptospirosis when assessing patients presenting with acute febrile illness among residents and visitors to Hawaii. PMID:18447625

Ellis, Tania; Imrie, Allison; Katz, Alan R; Effler, Paul V

2008-08-01

34

Exploratory space-time analysis of reported dengue cases during an outbreak in Florida, Puerto Rico, 1991-1992.  

PubMed

The spatial and temporal distributions of dengue cases reported during a 1991-1992 outbreak in Florida, Puerto Rico (population = 8,689), were studied by using a Geographic Information System. A total of 377 dengue cases were identified from a laboratory-based dengue surveillance system and georeferenced by their residential addresses on digital zoning and U.S. Geological Survey topographic maps. Weekly case maps were generated for the period between June and December 1991, when 94.2% of the dengue cases were reported. The temporal evolution of the epidemic was rapid, affecting a wide geographic area within seven weeks of the first reported cases of the season. Dengue cases were reported in 217 houses; of these 56 (25.8%) had between two and six reported cases. K-function analysis was used to characterize the spatial clustering patterns for all reported dengue cases (laboratory-positive and indeterminate) and laboratory-positive cases alone, while the Barton and David and Knox tests were used to characterize spatio-temporal attributes of dengue cases reported during the 1991-1992 outbreak. For both sets of data significant case clustering was identified within individual households over short periods of time (three days or less), but in general, the cases had spatial pattern characteristics much like the population pattern as a whole. The rapid temporal and spatial progress of the disease within the community suggests that control measures should be applied to the entire municipality, rather than to the areas immediately surrounding houses of reported cases. The potential for incorporating Geographic Information System technologies into a dengue surveillance system and the limitations of using surveillance data for spatial studies are discussed. PMID:9546405

Morrison, A C; Getis, A; Santiago, M; Rigau-Perez, J G; Reiter, P

1998-03-01

35

Undesirable Consequences of Insecticide Resistance following Aedes aegypti Control Activities Due to a Dengue Outbreak  

PubMed Central

Background During a dengue outbreak with co-circulation of DENV-1 and -2 in the city of Boa Vista, one patient was diagnosed with DENV-4, a serotype supposed absent from Brazil for almost 30 years. The re-emergence of DENV-4 triggered the intensification of mechanical and chemical Aedes aegypti control activities in order to reduce vector density and avoid DENV-4 dissemination throughout the country. Methods/Principal Findings Vector control activities consisted of (a) source reduction, (b) application of diflubenzuron against larvae and (c) vehicle-mounted space spraying of 2% deltamethrin to eliminate adults. Control activity efficacy was monitored by comparing the infestation levels and the number of eggs collected in ovitraps before and after interventions, performed in 22 Boa Vista districts, covering an area of ?80% of the city and encompassing 56,837 dwellings. A total of 94,325 containers were eliminated or treated with diflubenzuron. The most frequently positive containers were small miscellaneous receptacles, which corresponded to 59% of all positive breeding sites. Insecticide resistance to deltamethrin was assessed before, during and after interventions by dose-response bioassays adopting WHO-based protocols. The intense use of the pyrethroid increased fourfold the resistance ratio of the local Ae. aegypti population only six months after the beginning of vector control. Curiously, this trend was also observed in the districts in which no deltamethrin was applied by the public health services. On the other hand, changes in the resistance ratio to the organophosphate temephos seemed less influenced by insecticide in Boa Vista. Conclusions Despite the intense effort, mosquito infestation levels were only slightly reduced. Besides, the median number of eggs in ovitraps remained unaltered after control activity intensification. The great and rapid increase in pyrethroid resistance levels of natural Ae. aegypti populations is discussed in the context of both public and domestic intensification of chemical control due to a dengue outbreak. PMID:24676277

Maciel-de-Freitas, Rafael; Avendanho, Fernando Campos; Santos, Rosangela; Sylvestre, Gabriel; Araújo, Simone Costa; Lima, José Bento Pereira; Martins, Ademir Jesus; Coelho, Giovanini Evelim; Valle, Denise

2014-01-01

36

Spatio-temporal dynamics of dengue 2009 outbreak in Córdoba City, Argentina.  

PubMed

During 2009 the biggest dengue epidemic to date occurred in Argentina, affecting almost half the country. We studied the spatio-temporal dynamics of the outbreak in the second most populated city of the country, Córdoba city. Confirmed cases and the results of an Aedes aegypti monitoring during the outbreak were geolocated. The imported cases began in January, and the autochthonous in March. Thirty-three percent of the 130 confirmed cases were imported, and occurred mainly at the center of the city. The autochthonous cases were more frequent in the outskirts, specially in the NE and SE. Aedes aegypti infestation showed no difference between neighborhoods with or without autochthonous cases, neither between neighborhoods with autochthonous vs. imported cases. The neighborhoods with imported cases presented higher population densities. The majority of autochthonous cases occurred at ages between 25 and 44 years old. Cases formed a spatio-temporal cluster of up to 20 days and 12km. According to a mathematical model that estimates the required number of days needed for transmission according to daily temperature, the number of cases begun to fall when more than 15.5 days were needed. This may be a coarse estimation of mean mosquito survival in the area, provided that the study area is close to the global distribution limit of the vector, and that cases prevalence was very low. PMID:24795212

Estallo, E L; Carbajo, A E; Grech, M G; Frías-Céspedes, M; López, L; Lanfri, M A; Ludueña-Almeida, F F; Almirón, W R

2014-08-01

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, Jürgen; Schmidt-Chanasit, Jonas; Rakotozandrindrainy, Raphael

2012-01-01

38

CDC Vital Signs: Preventing Norovirus Outbreaks  

MedlinePLUS

... outbreaks using genome sequencing and analysis. State and local governments can: Adopt and enforce all provisions of the ... against norovirus. Immediately block off, clean, and disinfect areas where ... to your local health department. Visit www.FoodSafety.gov for the ...

39

Lineage II of Southeast Asian/American DENV-2 is associated with a severe dengue outbreak in the Peruvian Amazon.  

PubMed

During 2010 and 2011, the Loreto region of Peru experienced a dengue outbreak of unprecedented magnitude and severity for the region. This outbreak coincided with the reappearance of dengue virus-2 (DENV-2) in Loreto after almost 8 years. Whole-genome sequence indicated that DENV-2 from the outbreak belonged to lineage II of the southeast Asian/American genotype and was most closely related to viruses circulating in Brazil during 2007 and 2008, whereas DENV-2 previously circulating in Loreto grouped with lineage I (DENV-2 strains circulating in South America since 1990). One amino acid substitution (NS5 A811V) in the 2010 and 2011 isolates resulted from positive selection. However, the 2010 and 2011 DENV-2 did not replicate to higher titers in monocyte-derived dendritic cells and did not infect or disseminate in a higher proportion of Aedes aegypti than DENV-2 isolates previously circulating in Loreto. These results suggest that factors other than enhanced viral replication played a role in the severity of this outbreak. PMID:25002298

Williams, Maya; Mayer, Sandra V; Johnson, William L; Chen, Rubing; Volkova, Evgeniya; Vilcarromero, Stalin; Widen, Steven G; Wood, Thomas G; Suarez-Ognio, Luis; Long, Kanya C; Hanley, Kathryn A; Morrison, Amy C; Vasilakis, Nikos; Halsey, Eric S

2014-09-01

40

Dengue  

MedlinePLUS

... endemic in Puerto Rico and in many popular tourist destinations in Latin America, Southeast Asia and the ... Education and Training Dengue educational tools... News & Highlights New! Need CME, CEU Credit? CDC announces a new ...

41

Low Sensitivity of NS1 Protein Tests Evidenced during a Dengue Type 2 Virus Outbreak in Santos, Brazil, in 2010  

PubMed Central

In 2010, a large outbreak of dengue occurred in Santos, Brazil. The detection of the NS1 antigen was used for diagnosis in addition to the detection of IgG, IgM, and RNA. A large number of NS1 false-negative results were obtained. A total of 379 RNA-positive samples were selected for thorough evaluation. NS1 was reactive in 37.7% of cases. Most of the cases were characterized as a secondary infection by dengue 2 virus. Sequencing of NS1 positive and negative isolates did not reveal any mutation that could justify the diagnostic failure. Use of existing NS1 tests in the Brazilian population may present a low negative predictive value, and they should be used with caution, preferentially after performing a validation with samples freshly obtained during the ongoing epidemic. PMID:23100478

Felix, Alvina Clara; Romano, Camila Malta; Centrone, Cristiane de Campos; Rodrigues, Célia Lima; Villas-Boas, Lucy; Araújo, Evaldo Stanislau; de Matos, Andréia Manso; Carvalho, Karina Inácio; Martelli, Celina Maria Turchi; Kallas, Èsper Georges; Pannuti, Claúdio Sérgio

2012-01-01

42

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; Méndez-Galván, Jorge; Burciaga-Zúñiga, Pierre

2012-01-01

43

Impact of climate and landuse variability based on dengue epidemic outbreak in Subang Jaya  

Microsoft Academic Search

Dengue disease has continually been a major public health problem in Malaysia. The numbers of cases have risen yearly and it had become more serious in the early of 21st century. Therefore, effort to reduce the number incidences must be taken seriously and should be supported from various agencies. Concerted effort from various agencies is vital effectively manage the dengue

C. D. Nazri; A. Abu Hassan; Z. Abd Latif; Rodziah Ismail

2011-01-01

44

Shellfish-associated enteric virus illness: virus localization, disease outbreaks and prevention  

Technology Transfer Automated Retrieval System (TEKTRAN)

Numerous outbreaks of shellfish-borne enteric virus illness have been reported worldwide. Most notable among the outbreaks are those involving norovirus illness and hepatitis A. Lessons learned from outbreak investigations indicate that most outbreaks are preventable. Anthropogenic sources of con...

45

Dengue Fever  

Technology Transfer Automated Retrieval System (TEKTRAN)

Dengue Fever” will be included in “Health Information for International Travel, 2007-2008” which will be published by the U.S. Centers for Disease Control and Prevention. Dengue and dengue hemorrhagic fever are viral diseases transmitted by Aedes mosquitoes. The disease is found in tropical and s...

46

An integrated ecosystem approach for sustainable prevention and control of dengue in Central Havana.  

PubMed

The authors developed and evaluated a comprehensive participatory ecosystem health approach for preventing the transmission of dengue, the most prevalent vector-borne disease in Cuba and the Latin America-Caribbean region. The integrated surveillance system central to this initiative encompassed three main subsystems (environmental; entomological; clinical-epidemiologic), relying on extensive community involvement. The study was conducted in Central Havana, Cuba. Indicators from each subsystem were selected and mapped using a GIS procedure providing instant visualization by city block in the municipality. To elucidate the factors affecting control and prevention efforts, perceived needs and risks, as well as knowledge, attitudes, and behaviors related to dengue, were assessed. Specific factors associated with the presence of mosquito breeding sites and risks of dengue were examined in a case-control study. PMID:17718176

Bonet, Mariano; Spiegel, Jerry M; Ibarra, Ana Maria; Kouri, Gustavo; Pintre, Alfredo; Yassi, Annalee

2007-01-01

47

Assessing Positivity and Circulating Levels of NS1 in Samples from a 2012 Dengue Outbreak in Rio de Janeiro, Brazil  

PubMed Central

Dengue virus (DENV) represents a major threat to public health worldwide. Early DENV diagnosis should not only detect the infection but also identify patients with a higher likelihood to develop severe cases. Previous studies have suggested the potential for NS1 to serve as a viral marker for dengue severity. However, further studies using different sera panels are required to confirm this hypothesis. In this context, we developed a lab-based ELISA to detect and quantitate NS1 protein from the four DENV serotypes and from primary and secondary cases. This approach was used to calculate the circulating NS1 concentration in positive samples. We also tested the NS1 positivity of DENV-positive samples according to the Platelia Dengue NS1 Ag assay. A total of 128 samples were positive for DENV infection and were classified according to the WHO guidelines. The overall NS1 positivity was 68% according to the Platelia assay, whereas all samples were NS1-positive when analyzed with our lab-based ELISA. Fifty-four samples were positive by PCR, revealing a co-circulation of DENV1 and DENV4, and the NS1 positivity for DENV4 samples was lower than that for DENV1. The circulating NS1 concentration ranged from 7 to 284 ng/mL. Our results support previous data indicating the low efficiency of the Platelia assay to detect DENV4 infection. Moreover, this work is the first to analyze NS1 antigenemia using retrospective samples from a Brazilian outbreak. PMID:25412084

Allonso, Diego; Meneses, Marcelo D. F.; Fernandes, Carlos A.; Ferreira, Davis F.; Mohana-Borges, Ronaldo

2014-01-01

48

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

49

Geo-visual Approach for Spatial Scan Statistics: An Analysis of Dengue Fever Outbreaks in Delhi  

Microsoft Academic Search

There are very few surveillance systems being used to detect disease outbreaks at present. In disease surveillance system, data related to cases and various risk factors are collected and then the collected data is transformed into meaningful information for effective disease control using statistical analysis tools. Disease outbreaks can be detected but for effective disease control, a visualization approach is

Raja Sengupta Shuchi Mala

2013-01-01

50

Historical Compilation and Georeferencing of Dengue and Chikungunya outbreak data for Disease Modeling  

Technology Transfer Automated Retrieval System (TEKTRAN)

The risk of vector-borne disease spread is increasing due to significant changes and variability in the global climate and increasing global travel and trade. Understanding the relationships between climate variability and disease outbreak patterns are critical to the design and construction of pred...

51

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. PMID:25302194

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

2014-01-01

52

The Dynamics, Causes and Possible Prevention of Hepatitis E Outbreaks  

PubMed Central

Rapidly spreading infectious diseases are a serious risk to public health. The dynamics and the factors causing outbreaks of these diseases can be better understood using mathematical models, which are fit to data. Here we investigate the dynamics of a Hepatitis E outbreak in the Kitgum region of northern Uganda during 2007 to 2009. First, we use the data to determine that is approximately 2.25 for the outbreak. Secondly, we use a model to estimate that the critical level of latrine and bore hole coverages needed to eradicate the epidemic is at least and respectively. Lastly, we further investigate the relationship between the co-infection factor for malaria and Hepatitis E on the value of for Hepatitis E. Taken together, these results provide us with a better understanding of the dynamics and possible causes of Hepatitis E outbreaks. PMID:22911752

Nannyonga, Betty; Sumpter, David J. T.; Mugisha, Joseph Y. T.; Luboobi, Livingstone S.

2012-01-01

53

Dengue Surveillance in Veterans Affairs Healthcare Facilities, 2007–2010  

PubMed Central

Background Although dengue is endemic in Puerto Rico (PR), 2007 and 2010 were recognized as epidemic years. In the continental United States (US), outside of the Texas-Mexico border, there had not been a dengue outbreak since 1946 until dengue re-emerged in Key West, Florida (FL), in 2009–2010. The objective of this study was to use electronic and manual surveillance systems to identify dengue cases in Veterans Affairs (VA) healthcare facilities and then to clinically compare dengue cases in Veterans presenting for care in PR and in FL. Methodology Outpatient encounters from 1/2007–12/2010 and inpatient admissions (only available from 10/2009–12/2010) with dengue diagnostic codes at all VA facilities were identified using VA's Electronic Surveillance System for Early Notification of Community-based Epidemics (ESSENCE). Additional case sources included VA data from Centers for Disease Control and Prevention BioSense and VA infection preventionists. Case reviews were performed. Categorical data was compared using Mantel-Haenszel or Fisher Exact tests and continuous variables using t-tests. Dengue case residence was mapped. Findings Two hundred eighty-eight and 21 PR and FL dengue cases respectively were identified. Of 21 FL cases, 12 were exposed in Key West and 9 were imported. During epidemic years, FL cases had significantly increased dengue testing and intensive care admissions, but lower hospitalization rates and headache or eye pain symptoms compared to PR cases. There were no significant differences in clinical symptoms, laboratory abnormalities or outcomes between epidemic and non-epidemic year cases in FL and PR. Confirmed/probable cases were significantly more likely to be hospitalized and have thrombocytopenia or leukopenia compared to suspected cases. Conclusions Dengue re-introduction in the continental US warrants increased dengue surveillance and education in VA. Throughout VA, under-testing of suspected cases highlights the need to emphasize use of diagnostic testing to better understand the magnitude of dengue among Veterans. PMID:23516642

Schirmer, Patricia L.; Lucero-Obusan, Cynthia A.; Benoit, Stephen R.; Santiago, Luis M.; Stanek, Danielle; Dey, Achintya; Martinez, Mirsonia; Oda, Gina; Holodniy, Mark

2013-01-01

54

Dengue: a continuing global threat  

PubMed Central

Dengue fever and dengue haemorrhagic fever are important arthropod-borne viral diseases. Each year, there are ~50 million dengue infections and ~500,000 individuals are hospitalized with dengue haemorrhagic fever, mainly in Southeast Asia, the Pacific and the Americas. Illness is produced by any of the four dengue virus serotypes. A global strategy aimed at increasing the capacity for surveillance and outbreak response, changing behaviours and reducing the disease burden using integrated vector management in conjunction with early and accurate diagnosis has been advocated. Antiviral drugs and vaccines that are currently under development could also make an important contribution to dengue control in the future. PMID:21079655

Guzman, Maria G.; Halstead, Scott B.; Artsob, Harvey; Buchy, Philippe; Farrar, Jeremy; Gubler, Duane J.; Hunsperger, Elizabeth; Kroeger, Axel; Margolis, Harold S.; Martínez, Eric; Nathan, Michael B.; Pelegrino, Jose Luis; Simmons, Cameron; Yoksan, Sutee; Peeling, Rosanna W.

2014-01-01

55

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, Valérie R.; Kittayapong, Pattamaporn; Wilder-Smith, Annelies

2014-01-01

56

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

Grönthal, Thomas; Moodley, Arshnee; Nykäsenoja, Suvi; Junnila, Jouni; Guardabassi, Luca; Thomson, Katariina; Rantala, Merja

2014-01-01

57

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

58

A rare case of dengue encephalitis  

PubMed Central

Dengue fever has a variable clinical spectrum ranging from asymptomatic infection to life-threatening dengue haemorrhagic fever and dengue shock syndrome. However, neurological complications, in general, are unusual. Dengue encephalopathy is not an unknown entity; however, dengue encephalitis, a direct neuronal infiltration by the dengue virus, is an extremely rare disease. Although dengue is classically considered a non-neurotropic virus, there is increasing evidence for dengue viral neurotropism, suggesting that, in a proportion of cases, there may be an element of direct viral encephalitis. An MRI brain rarely shows focal abnormalities in dengue encephalitis. We report an interesting case of dengue encephalitis during an outbreak in Delhi, India. The diagnosis was confirmed by blood and cerebrospinal fluid dengue serology and (NS1) antigen assay. The case showed extensive lesions involving the midbrain, cerebellum, thalamus and medial temporal region on both sides of the MRI brain, which is an uncommon manifestation of dengue fever. PMID:23413293

Rao, Sachin; Kumar, Manish; Ghosh, Soumik; Gadpayle, Adesh Kumar

2013-01-01

59

Protect Yourself and Your Baby from Dengue  

MedlinePLUS

Avoid mosquito bites during pregnancy to prevent dengue in your newborn baby • Dengue is transmitted by the bite of infected Aedes aegypti mosquitoes • A pregnant woman infected with dengue virus may ...

60

Dengue in the Pacific--an update of the current situation.  

PubMed

Dengue continues to be a threat to Pacific Island countries and territories (PICTs). The last DEN-1 epidemic reached 16 PICTs and in some of them it affected as much as 20 per cent of the population, aside from the massive impact on their fragile economies. Dengue is mostly introduced into PICTs from global travel, and many experts believe that it has a 3-4 year cyclical pattern of occurrence. All four virus serotypes (DEN-1, 2, 3 and 4) have caused epidemics, but those caused by DEN-1 and 2 have been somewhat larger. In light of this, dengue rightly remains a priority for the Pacific Public Health Surveillance Network (PPHSN). The paper updates the situation regarding dengue outbreaks in PICTs over the last four decades, describes the pattern of presentations in the recent past, and provides an update on the potential risk to PICTs for the near future. It follows on from an earlier dengue update written in 1998. The utility of PPHSN services is also demonstrated in the paper: PacNet for alerts and communication about dengue outbreaks (raising awareness and preparedness levels in the region) and LabNet for investigations relating to dengue. Creative interventions towards dengue control and prevention are being tried in PICTs and early assessment and evaluations of their effectiveness in the field are being examined. PMID:18181502

Singh, Narendra; Kiedrzynski, Tom; Lepers, Christelle; Benyon, Elise Kamisan

2005-09-01

61

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 César; Tibúrcio, Jacqueline Domingues; Silva, Mirna de Abreu e; Pereira, Lailah Horácio Sales; Dutra, Karina Rocha; Ferreira, Jaqueline Maria Siqueira; Lopes, Débora de Oliveira; dos Santos, Luciana Lara

2014-01-01

62

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

63

Spatial, environmental and entomological risk factors analysis on a rural dengue outbreak in Lundu District in Sarawak, Malaysia.  

PubMed

The objective of this study was to elucidate the association of various risk factors with dengue cases reported in Lundu district, Sarawak, by analyzing the interaction between environmental, entomological, socio-demographic factors. Besides conventional entomological, serological and house surveys, this study also used GIS technology to generate geographic and environmental data on Aedes albopictus and dengue transmission. Seven villages were chosen based on the high number of dengue cases reported. A total of 551 households were surveyed. An overall description of the socio-demographic background and basic facilities was presented together with entomological and geographical profiles. For serological and ovitrap studies, systematic random sampling was used. Serological tests indicated that 23.7% of the 215 samples had a history of dengue, either recent or previous infections. Two samples (0.9%) were confirmed by IgM ELISA and 49 samples (22.8%) had IgG responses. A total of 32,838 Aedes albopictus eggs were collected in 56 days of trapping. Cluster sampling was also done to determine whether any of the risk factors (entomological or geographical) were influenced by geographical location. These clusters were defined as border villages with East Kalimantan and roadside villages along Lundu/Biawas trunk road. The data collected were analyzed using SPSS version 10.01. Descriptive analysis using frequency, means, and median were used. To determine the association between variables and dengue cases reported, and to describe the differences between the two clusters of villages, two-sample t-test, and Pearson's Chi-Square were used. Accurate maps were produced with overlay and density function, which facilitates the map visualization and report generating phases. This study also highlights the use of differential Global Positioning System in mapping sites of 1m accuracy. Analysis of the data revealed there are significant differences in clusters of villages attributable to container density, house density, distance of the house from the main road, and number of Ae. albopictus eggs from ovitraps set indoor, outdoor and in dumping sites (Person's Chi-Square = 6.111, df = 1, p < 0.01). Further analysis using t-test showed that house density, container density, indoor mosquitoes egg count, outdoor mosquitoes egg count, and dumping sites mosquitoes egg count were higher at the roadside villages compared to border villages. A number of potential risk factors including those generated from GIS were investigated. None of the factors investigated in this study were associated with the dengue cases reported. PMID:17041556

Cheah, Whye Lian; Chang, Moh Seng; Wang, Yin Chai

2006-06-01

64

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

65

Evaluation of Compliance in Control and Prevention Study of Vancomycin Resistant Enterococcus Outbreak  

PubMed Central

Objective. Vancomycin resistant enterococci (VRE) colonization and the spread decrease with compliance and isolation guidelines. For the isolation methods to succeed, compliance with the isolation guidelines needs to be overseen. In this study, VRE outbreak among the Pediatric Ward patients, the preventative efforts to control this outbreak, and the impact of scoring tables used in controlling this outbreak on the success are explained. Design. Rectal swab cultures were taken from patients who were admitted to the Ward between October and December 2010 due to diagnoses of VRE and urinary tract infection. Results. VRE were isolated in the rectal swab samples of 34 patients. VRE infection findings were clinically detected in two of the cases with VRE isolation. Two isolations of VRE were detected on cultures from patient room door handle surface and the telephone in the room for common use. Close contact isolation was achieved and barrier precautions were taken for all cases, as soon as the detections were made. A scoring system was developed to evaluate the feasibility of and the compliance with the precautions to be taken. Conclusions. With the method presented in this study, the outbreak at our hospital was under control within two months. PMID:23476123

Kecik Bosnak, Vuslat; Namiduru, Mustafa; Karaoglan, Ilkay; Ozlem Mete, Ayse

2013-01-01

66

Integrating participatory community mobilization processes to improve dengue prevention: an eco-bio-social scaling up of local success in Machala, Ecuador  

PubMed Central

Background This project investigates the effectiveness and feasibility of scaling-up an eco-bio-social approach for implementing an integrated community-based approach for dengue prevention in comparison with existing insecticide-based and emerging biolarvicide-based programs in an endemic setting in Machala, Ecuador. Methods An integrated intervention strategy (IIS) for dengue prevention (an elementary school-based dengue education program, and clean patio and safe container program) was implemented in 10 intervention clusters from November 2012 to November 2013 using a randomized controlled cluster trial design (20 clusters: 10 intervention, 10 control; 100 households per cluster with 1986 total households). Current existing dengue prevention programs served as the control treatment in comparison clusters. Pupa per person index (PPI) is used as the main outcome measure. Particular attention was paid to social mobilization and empowerment with IIS. Results Overall, IIS was successful in reducing PPI levels in intervention communities versus control clusters, with intervention clusters in the six paired clusters that followed the study design experiencing a greater reduction of PPI compared to controls (2.2 OR, 95% CI: 1.2 to 4.7). Analysis of individual cases demonstrates that consideration for contexualizing programs and strategies to local neighborhoods can be very effective in reducing PPI for dengue transmission risk reduction. Conclusions In the rapidly evolving political climate for dengue control in Ecuador, integration of successful social mobilization and empowerment strategies with existing and emerging biolarvicide-based government dengue prevention and control programs is promising in reducing PPI and dengue transmission risk in southern coastal communities like Machala. However, more profound analysis of social determination of health is called for to assess sustainability prospects. PMID:25604763

Mitchell-Foster, Kendra; Ayala, Efraín Beltrán; Breilh, Jaime; Spiegel, Jerry; Wilches, Ana Arichabala; Leon, Tania Ordóñez; Delgado, Jefferson Adrian

2015-01-01

67

Reemergence of Dengue in Mauritius  

PubMed Central

Dengue reemerged in Mauritius in 2009 after an absence of >30 years, and >200 cases were confirmed serologically. Molecular studies showed that the outbreak was caused by dengue virus type 2. Phylogenetic analysis of the envelope gene identified 2 clades of the virus. No case of hemorrhagic fever was recorded. PMID:20350397

Pursem, Vidula N.; Barkham, Timothy M.S.; Ng, Lee-Ching; Inoue, Masafumi; Manraj, Shyam S.

2010-01-01

68

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

69

Dengue in children.  

PubMed

Dengue is a mosquito-borne viral disease of expanding geographical range and increasing incidence. The vast majority of dengue cases are children less than 15 years of age. Dengue causes a spectrum of illness from mild fever to severe disease with plasma leakage and shock. Infants and children with secondary heterologous dengue infections are most at risk for severe dengue disease. Laboratory diagnosis of dengue can be established within five days of disease onset by direct detection of viral components in serum. After day five, serologic diagnosis provides indirect evidence of dengue. Currently, no effective antiviral agents are available to treat dengue infection. Therefore, treatment remains supportive, with emphasis on close hematological monitoring, recognition of warning signs of severe disease and fluid-replacement therapy and/or blood transfusions when required. Development of a dengue vaccine is considered a high public health priority. A safe and efficacious dengue vaccine would also be important for travelers. This review highlights the current understanding of dengue in children, including its clinical manifestations, pathogenesis, diagnostic tests, management and prevention. PMID:25225163

Verhagen, Lilly M; de Groot, Ronald

2014-11-01

70

Gamma Interferon (IFN-?) Receptor Restricts Systemic Dengue Virus Replication and Prevents Paralysis in IFN-?/? Receptor-Deficient Mice  

PubMed Central

We previously reported that mice lacking alpha/beta and gamma interferon receptors (IFN-?/?R and -?R) uniformly exhibit paralysis following infection with the dengue virus (DENV) clinical isolate PL046, while only a subset of mice lacking the IFN-?R alone and virtually no mice lacking the IFN-?/?R alone develop paralysis. Here, using a mouse-passaged variant of PL046, strain S221, we show that in the absence of the IFN-?/?R, signaling through the IFN-?R confers approximately 140-fold greater resistance against systemic vascular leakage-associated dengue disease and virtually complete protection from dengue-induced paralysis. Viral replication in the spleen was assessed by immunohistochemistry and flow cytometry, which revealed a reduction in the number of infected cells due to IFN-?R signaling by 2 days after infection, coincident with elevated levels of IFN-? in the spleen and serum. By 4 days after infection, IFN-?R signaling was found to restrict DENV replication systemically. Clearance of DENV, on the other hand, occurred in the absence of IFN-?R, except in the central nervous system (CNS) (brain and spinal cord), where clearance relied on IFN-? from CD8+ T cells. These results demonstrate the roles of IFN-?R signaling in protection from initial systemic and subsequent CNS disease following DENV infection and demonstrate the importance of CD8+ T cells in preventing DENV-induced CNS disease. PMID:22973027

Prestwood, Tyler R.; Morar, Malika M.; Zellweger, Raphaël M.; Miller, Robyn; May, Monica M.; Yauch, Lauren E.; Lada, Steven M.

2012-01-01

71

Public knowledge and preventive behavior during a large-scale Salmonella outbreak: results from an online survey in the Netherlands  

PubMed Central

Background Food-borne Salmonella infections are a worldwide concern. During a large-scale outbreak, it is important that the public follows preventive advice. To increase compliance, insight in how the public gathers its knowledge and which factors determine whether or not an individual complies with preventive advice is crucial. Methods In 2012, contaminated salmon caused a large Salmonella Thompson outbreak in the Netherlands. During the outbreak, we conducted an online survey (n?=?1,057) to assess the general public’s perceptions, knowledge, preventive behavior and sources of information. Results Respondents perceived Salmonella infections and the 2012 outbreak as severe (m?=?4.21; five-point scale with 5 as severe). Their knowledge regarding common food sources, the incubation period and regular treatment of Salmonella (gastro-enteritis) was relatively low (e.g., only 28.7% knew that Salmonella is not normally treated with antibiotics). Preventive behavior differed widely, and the majority (64.7%) did not check for contaminated salmon at home. Most information about the outbreak was gathered through traditional media and news and newspaper websites. This was mostly determined by time spent on the medium. Social media played a marginal role. Wikipedia seemed a potentially important source of information. Conclusions To persuade the public to take preventive actions, public health organizations should deliver their message primarily through mass media. Wikipedia seems a promising instrument for educating the public about food-borne Salmonella. PMID:24479614

2014-01-01

72

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

73

Investigating an outbreak of acute fever in Chuuk, Federated States of Micronesia  

PubMed Central

Objective In September 2012, there was an unexpected increase of acute febrile illness (AFI) in Chuuk State of the Federated States of Micronesia. At the same time, dengue outbreaks were occurring in two of the Federated States of Micronesia’s other three states. The cause of AFI was suspected to be dengue; however, by the end of October, only one of 39 samples was positive for dengue. The objective of the investigation was to establish the cause of the outbreak. Methods A line list was created and data analysed by time, place, person and clinical features. Reported symptoms were compared with the published symptoms of several diagnoses and laboratory testing undertaken. Results Of the 168 suspected cases, 62% were less than 20 years of age and 60% were male. The clinical features of the cases were not typical for dengue but suggestive of respiratory illness. Nasopharyngeal swabs were subsequently collected and found to be positive for influenza. Public health measures were undertaken and the AFI returned to expected levels. Discussion Clinical diagnosis of acute febrile illness (AFI) can often be difficult and misleading. This can mean that opportunities for preventive measures early on in an outbreak are missed. In any outbreak, descriptive epidemiological analyses are valuable in helping to ascertain the cause of the outbreak. PMID:25685599

Yichiro, Yoster; Otoko, Kasian; Heldart, Helden; Meyshine, Andita; Assito, Prisca; Pretrick, Moses; Souares, Yvan; Hancock, Thane; Durand, Mark; Roth, Adam

2014-01-01

74

Improved dengue fever prevention through innovative intervention methods in the city of Salto, Uruguay  

PubMed Central

Background Uruguay is located at the southern border of Aedes aegypti distribution on the South American sub-continent. The reported dengue cases in the country are all imported from surrounding countries. One of the cities at higher risk of local dengue transmission is Salto, a border city with heavy traffic from dengue endemic areas. Methods We completed an intervention study using a cluster randomized trial design in 20 randomly selected ‘clusters’ in Salto. The clusters were located in neighborhoods of differing geography and economic, cultural and social aspects. Results Entomological surveys were carried out to measure the impact of the intervention on vector densities. Through participatory processes of all stakeholders, an appropriate ecosystem management intervention was defined. Residents collected the abundant small water holding containers and the Ministry of Public Health and the Municipality of Salto were responsible for collecting and eliminating them. Additional vector breeding places were large water tanks; they were either altered so that they could not hold water any more or covered so that oviposition by mosquitoes could not take place. Conclusions The response from the community and national programme managers was encouraging. The intervention evidenced opportunities for cost savings and reducing dengue vector densities (although not to statistically significant levels). The observed low vector density limits the potential reduction due to the intervention. A larger sample size is needed to obtain a statistically significant difference. PMID:25604764

Basso, César; García da Rosa, Elsa; Romero, Sonnia; González, Cristina; Lairihoy, Rosario; Roche, Ingrid; Caffera, Ruben M.; da Rosa, Ricardo; Calfani, Marisel; Alfonso-Sierra, Eduardo; Petzold, Max; Kroeger, Axel; Sommerfeld, Johannes

2015-01-01

75

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

76

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

77

Innovative community-based ecosystem management for dengue and Chagas disease prevention in low and middle income countries in Latin America and the Caribbean  

PubMed Central

In 2009, the WHO Special Programme for Research and Training in Tropical Diseases (TDR) and the International Development Research Centre (IDRC) launched a call for innovative community-based ecosystem management research projects for dengue and Chagas disease prevention in low and middle income countries in Latin America and the Caribbean. Eight research institutions were selected. The outputs of these projects led to a better understanding of the interaction between ecological, biological, social and economic (eco-bio-social) determinants of dengue and Chagas disease in Latin America and the Caribbean. Both diseases are considered highly relevant in the regional health agendas. PMID:25604758

Finkelman, Jacobo

2015-01-01

78

Innovative community-based ecosystem management for dengue and Chagas disease prevention in low and middle income countries in Latin America and the Caribbean.  

PubMed

In 2009, the WHO Special Programme for Research and Training in Tropical Diseases (TDR) and the International Development Research Centre (IDRC) launched a call for innovative community-based ecosystem management research projects for dengue and Chagas disease prevention in low and middle income countries in Latin America and the Caribbean. Eight research institutions were selected. The outputs of these projects led to a better understanding of the interaction between ecological, biological, social and economic (eco-bio-social) determinants of dengue and Chagas disease in Latin America and the Caribbean. Both diseases are considered highly relevant in the regional health agendas. PMID:25604758

Finkelman, Jacobo

2015-02-01

79

A Statistical Model of the International Spread of Wild Poliovirus in Africa Used to Predict and Prevent Outbreaks  

PubMed Central

Background Outbreaks of poliomyelitis in African countries that were previously free of wild-type poliovirus cost the Global Polio Eradication Initiative US$850 million during 2003–2009, and have limited the ability of the program to focus on endemic countries. A quantitative understanding of the factors that predict the distribution and timing of outbreaks will enable their prevention and facilitate the completion of global eradication. Methods and Findings Children with poliomyelitis in Africa from 1 January 2003 to 31 December 2010 were identified through routine surveillance of cases of acute flaccid paralysis, and separate outbreaks associated with importation of wild-type poliovirus were defined using the genetic relatedness of these viruses in the VP1/2A region. Potential explanatory variables were examined for their association with the number, size, and duration of poliomyelitis outbreaks in 6-mo periods using multivariable regression analysis. The predictive ability of 6-mo-ahead forecasts of poliomyelitis outbreaks in each country based on the regression model was assessed. A total of 142 genetically distinct outbreaks of poliomyelitis were recorded in 25 African countries, resulting in 1–228 cases (median of two cases). The estimated number of people arriving from infected countries and <5-y childhood mortality were independently associated with the number of outbreaks. Immunisation coverage based on the reported vaccination history of children with non-polio acute flaccid paralysis was associated with the duration and size of each outbreak, as well as the number of outbreaks. Six-month-ahead forecasts of the number of outbreaks in a country or region changed over time and had a predictive ability of 82%. Conclusions Outbreaks of poliomyelitis resulted primarily from continued transmission in Nigeria and the poor immunisation status of populations in neighbouring countries. From 1 January 2010 to 30 June 2011, reduced transmission in Nigeria and increased incidence in reinfected countries in west and central Africa have changed the geographical risk of polio outbreaks, and will require careful immunisation planning to limit onward spread. Please see later in the article for the Editors' Summary PMID:22028632

O'Reilly, Kathleen M.; Chauvin, Claire; Aylward, R. Bruce; Maher, Chris; Okiror, Sam; Wolff, Chris; Nshmirimana, Deo; Donnelly, Christl A.; Grassly, Nicholas C.

2011-01-01

80

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

81

Challenges encountered using standard vector control measures for dengue in Boa Vista, Brazil  

PubMed Central

Abstract Problem In 2010, dengue virus (DENV) serotype–4 was detected during a dengue outbreak in the Amazonian city of Boa Vista. At that time Brazil was already endemic for DENV-1, DENV-2 and DENV-3. This was the first time DENV-4 was observed in the country after it was initially detected and eliminated in 1981. Approach To hinder the spread of DENV-4 throughout Brazil, standard vector control measures were intensified. Vector control professionals visited 56?837 households in 22 out of 31 districts of Boa Vista, to eliminate mosquito-breeding sites. Water storage containers were treated with the larvicide diflubenzuron, and deltamethrin was sprayed for adult Aedes aegypti mosquitoes. Fifteen days later, a second larvae survey and additional deltamethrin applications were performed. Local setting In Brazil, dengue vector control is managed at all three government levels. Regular surveillance of Aedes aegypti is done four to six times a year to strengthen mosquito control activities in areas with high-vector density. Educational dengue control campaigns in communities are scarce, especially between outbreaks. Relevant changes In spite of extensive implementation of all standard control actions recommended by the Brazilian dengue control programme, only a slight decrease in mosquito density was detected. Lessons learnt There is a need to redesign all levels of dengue control. Public consultation and engagement, behaviour change and actions that go beyond technical impositions are required. Vector control programme managers need to reflect on what constitutes good practices and whether intermittent information campaigns are effective measures for dengue prevention and control. PMID:25378760

Valle, Denise

2014-01-01

82

Molecular epidemiology of dengue type 2 virus in Venezuela: evidence for in situ virus evolution and recombination  

Microsoft Academic Search

Epidemic outbreaks of dengue fever (DF) were first recorded in Venezuela in 1978 and were followed by the emergence of dengue haemorrhagic fever (DHF) outbreaks in 1989. To gain a better understanding of the nature of these epidemics, the complete envelope (E) gene sequence of 34 Venezuelan dengue type 2 (DEN-2) viruses, isolated between 1997 and 2000 was determined. Of

N. Y. Uzcategui; D. Camacho; G. Comach; R. Cuello de Uzcategui; E. C. Holmes; E. A. Gould

2001-01-01

83

[Prevention of an outbreak of Acinetobacter baumannii in intensive care units: study of the efficacy of different mathematical methods].  

PubMed

Introduction. Although in past decades, Acinetobacter baumanni infections have been sporadically identified in hospitals, nowadays the nosocomial infections due to this pathogen have notably increased. Its importance is due to its multidrug- resistance, morbidity and mortatility in healthcare settings. Consequently, it is important to predict the evolution of these outbreaks in order to stablish the most efficient control measures. There are several experimental studies shown that the compliance with hand and environmental hygiene and the efficient management of the healthcare work help to control the evolution of these outbreaks. The goal of this work is to formally proof these experimental results by means of the analysis of the results provided by the model. Methods. A stochastic mathematical model based on cellular automata was developed. The variables and parameters involved in it have been identified from the knowledge of the epidemiology and main characteristics of Acinetobacter infections. Results. The model provides several simulations from different initial conditions. The analysis of these results proofs in a formal way that the compliance with hand and environmental hygiene and an efficient plannification of the work of healtcare workers yield a decrease in the colonized patients. Moreover, this is the unique model proposed studying the dynamics of an outbreak of A. baumanni. Conclusions. The computational implementation of the model provides us an efficient tool in the management of outbreaks due to A. baumanni. The analysis of the simulations obtained allows us to obtain a formal proof of the behaviour of the measures for control and prevention. PMID:25690140

Fresnadillo-Martínez, M J; García-Merino, E; García-Sánchez, E; Martín-Del Rey, A; Rodríguez-Encinas, A; Rodríguez-Sánchez, G; García-Sánchez, J E

2015-02-01

84

Climate and Dengue Transmission: Evidence and Implications  

PubMed Central

Background: Climate influences dengue ecology by affecting vector dynamics, agent development, and mosquito/human interactions. Although these relationships are known, the impact climate change will have on transmission is unclear. Climate-driven statistical and process-based models are being used to refine our knowledge of these relationships and predict the effects of projected climate change on dengue fever occurrence, but results have been inconsistent. Objective: We sought to identify major climatic influences on dengue virus ecology and to evaluate the ability of climate-based dengue models to describe associations between climate and dengue, simulate outbreaks, and project the impacts of climate change. Methods: We reviewed the evidence for direct and indirect relationships between climate and dengue generated from laboratory studies, field studies, and statistical analyses of associations between vectors, dengue fever incidence, and climate conditions. We assessed the potential contribution of climate-driven, process-based dengue models and provide suggestions to improve their performance. Results and Discussion: Relationships between climate variables and factors that influence dengue transmission are complex. A climate variable may increase dengue transmission potential through one aspect of the system while simultaneously decreasing transmission potential through another. This complexity may at least partly explain inconsistencies in statistical associations between dengue and climate. Process-based models can account for the complex dynamics but often omit important aspects of dengue ecology, notably virus development and host–species interactions. Conclusion: Synthesizing and applying current knowledge of climatic effects on all aspects of dengue virus ecology will help direct future research and enable better projections of climate change effects on dengue incidence. Citation: Morin CW, Comrie AC, Ernst KC. 2013. Climate and dengue transmission: evidence and implications. Environ Health Perspect 121:1264–1272;?http://dx.doi.org/10.1289/ehp.1306556 PMID:24058050

Comrie, Andrew C.; Ernst, Kacey

2013-01-01

85

Clinical Manifestations and Management of Dengue/DHF/DSS.  

PubMed

Dengue is one of the most important mosquito-borne viral illnesses. The first DHF outbreak was reported from the Philippines in 1953. Initially it was endemic only in Southeast Asia and the Western Pacific regions. After about 50 years from the first outbreak, it spread globally to almost every continent including North and South America, Australia and Africa. The majority of cases during the 50s to 80s were children, but today the disease affects both children and adults of all age groups. The disease is caused by dengue viruses that have four serotypes: dengue 1, dengue 2, dengue 3 and dengue 4. Primary infection usually results in milder illness, while more severe disease occurs in cases of repeated infection with different serotypes. In this paper clinical manifestations and management of dengue/DHF/DSS are summarized. PMID:22500140

Kalayanarooj, Siripen

2011-12-01

86

Clinical Manifestations and Management of Dengue/DHF/DSS  

PubMed Central

Dengue is one of the most important mosquito-borne viral illnesses. The first DHF outbreak was reported from the Philippines in 1953. Initially it was endemic only in Southeast Asia and the Western Pacific regions. After about 50 years from the first outbreak, it spread globally to almost every continent including North and South America, Australia and Africa. The majority of cases during the 50s to 80s were children, but today the disease affects both children and adults of all age groups. The disease is caused by dengue viruses that have four serotypes: dengue 1, dengue 2, dengue 3 and dengue 4. Primary infection usually results in milder illness, while more severe disease occurs in cases of repeated infection with different serotypes. In this paper clinical manifestations and management of dengue/DHF/DSS are summarized. PMID:22500140

Kalayanarooj, Siripen

2011-01-01

87

Current perspectives on the spread of dengue in India  

PubMed Central

Dengue fever (DF) and dengue hemorrhagic fever (DHF) are important arthropod-borne viral diseases. Each year, there are ~50 million dengue infections and ~500,000 individuals are hospitalized with DHF, mainly in Southeast Asia. Dengue in India has dramatically expanded over the last few decades, with rapidly changing epidemiology. The first major DHF outbreak in the entire nation occurred in 1996 by dengue virus serotype 2, and after a gap of almost a decade, the country faced yet another DF outbreak in the year 2003 by dengue virus serotype 3. A dramatic increase in the number and frequency of outbreaks followed, and, at present, in most of the states of India, dengue is almost endemic. At present, all the four serotypes are seen in circulation, but the predominant serotype keeps changing. Despite this trend, surveillance, reporting, and diagnosis of dengue remain largely passive in India. More active community-based epidemiological studies with intensive vector control and initiatives for dengue vaccine development should be geared up to control the spread of dengue in India. We review here the factors that may have contributed to the changing epidemiology of dengue in India. PMID:25525374

Gupta, Ekta; Ballani, Neha

2014-01-01

88

[Health education actions for the prevention and control of dengue fever: a study at Icaraí, Caucaia, Ceará State, Brazil].  

PubMed

This study analyses education actions and their strategies for preventing and controlling dengue fever, highlighting constraints and difficulties. Conducted through a qualitative approach at the Primary Care Unit and 8 properties in Icaraí, Ceará State, Brazil, its 17 subjects are divided into groups: I (8 PCU users); II (4 Endemic Disease Control Agents); and III (5 healthcare practitioners). The data was collected through semi-structured interviews; participative observation and documentary analyses, using a hermeneutic dialectic analysis method. The findings indicate that health education actions are divergent, while transforming actions are ineffective in terms of impacts on the disease. Difficulties include: weak location-specific actions; educational messages whose contents are not tailored to their contexts; authoritarian and coercive strategies; absence of public policies; gaps between PCU and local population; stress on public health campaigns; practitioners who do not listen to the population and vice-versa; with technical expertise still prevailing over users. The evidence underscores the need for actions strengthening the possibilities of empowering the subjects, helping them become responsible for their own lives and citizenship construction processes. PMID:18813532

Sales, Fátima Maria de Sousa

2008-01-01

89

Policymakers' views on dengue fever/dengue haemorrhagic fever and the need for dengue vaccines in four southeast Asian countries.  

PubMed

A survey of policymakers and other influential professionals in four southeast Asian countries (Cambodia, Indonesia, Philippines and Vietnam) was conducted to determine policymakers' views on the public health importance of dengue fever and dengue haemorrhagic fever (DHF), the need for a vaccine and the determinants influencing its potential introduction. The survey, which involved face-to-face interviews with policymakers, health programme managers, researchers, opinion leaders and other key informants, revealed an almost uniformly high level of concern about dengue fever/DHF and a high perceived need for a dengue vaccine. Several characteristics of the disease contribute to this high sense of priority, including its geographic spread, occurrence in outbreaks, the recurrent risk of infection each dengue season, its severity and the difficulty in diagnosis and management, its urban predominance, its burden on hospitals, and its economic toll on governments and families. Research felt to be key to future decision-making regarding dengue vaccine introduction include: disease surveillance studies, in-country vaccine trials or pilot projects, and studies on the economic burden of dengue and the cost-effectiveness of dengue vaccines. The results suggest favourable conditions for public and private sector markets for dengue vaccines and the need for creative financing strategies to ensure their accessibility to poor children in dengue-endemic countries. PMID:14604579

DeRoeck, Denise; Deen, Jacqueline; Clemens, John D

2003-12-01

90

Analyzing the spatio-temporal relationship between dengue vector larval density and land-use using factor analysis and spatial ring mapping  

PubMed Central

Background Dengue, a mosquito-borne febrile viral disease, is found in tropical and sub-tropical regions and is now extending its range to temperate regions. The spread of the dengue viruses mainly depends on vector population (Aedes aegypti and Aedes albopictus), which is influenced by changing climatic conditions and various land-use/land-cover types. Spatial display of the relationship between dengue vector density and land-cover types is required to describe a near-future viral outbreak scenario. This study is aimed at exploring how land-cover types are linked to the behavior of dengue-transmitting mosquitoes. Methods Surveys were conducted in 92 villages of Phitsanulok Province Thailand. The sampling was conducted on three separate occasions in the months of March, May and July. Dengue indices, i.e. container index (C.I.), house index (H.I.) and Breteau index (B.I.) were used to map habitats conducible to dengue vector growth. Spatial epidemiological analysis using Bivariate Pearson’s correlation was conducted to evaluate the level of interdependence between larval density and land-use types. Factor analysis using principal component analysis (PCA) with varimax rotation was performed to ascertain the variance among land-use types. Furthermore, spatial ring method was used as to visualize spatially referenced, multivariate and temporal data in single information graphic. Results Results of dengue indices showed that the settlements around gasoline stations/workshops, in the vicinity of marsh/swamp and rice paddy appeared to be favorable habitat for dengue vector propagation at highly significant and positive correlation (p = 0.001) in the month of May. Settlements around the institutional areas were highly significant and positively correlated (p = 0.01) with H.I. in the month of March. Moreover, dengue indices in the month of March showed a significant and positive correlation (p <= 0.05) with deciduous forest. The H.I. of people living around horticulture land were significantly and positively correlated (p = 0.05) during the month of May, and perennial vegetation showed a highly significant and positive correlation (p = 0.001) in the month of March with C.I. and significant and positive correlation (p <= 0.05) with B.I., respectively. Conclusions The study concluded that gasoline stations/workshops, rice paddy, marsh/swamp and deciduous forests played highly significant role in dengue vector growth. Thus, the spatio-temporal relationships of dengue vector larval density and land-use types may help to predict favorable dengue habitat, and thereby enables public healthcare managers to take precautionary measures to prevent impending dengue outbreak. PMID:23043443

2012-01-01

91

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

92

Cardiac tamponade presenting as early manifestation in dengue fever.  

PubMed

Dengue fever (DF) is an outbreak prone viral disease transmitted by aedes mosquitoes. It is often associated with evidence of plasma leakage due to increased vascular permeability manifested by pleural effusion, ascites, hypoproteinaemia and pericardial effusion. Cases of small pericardial effusion have been reported in association with dengue fever, largely with dengue haemorrhagic fever (DHF) during epidemic outbreaks. Dengue may rarely present with cardiac tamponade as early manifestation and urgent pericardiocentesis is life saving. A 34 year old male presented with low grade fever, headache, myalgia and breathlessness. Echocardiography revealed large pericardial effusion with right ventricular diagnostic collapse requiring urgent drainage. Subsequently patient improved. Dengue serology (both IgM and IgG) was reported as markedly elevated supporting a diagnosis of classic dengue fever. PMID:25327070

Bendwal, Suresh; Malviya, Kavita; Jatav, O P; Malviya, Kapil

2014-03-01

93

Fractional Derivatives in Dengue Epidemics  

NASA Astrophysics Data System (ADS)

We introduce the use of fractional calculus, i.e., the use of integrals and derivatives of non-integer (arbitrary) order, in epidemiology. The proposed approach is illustrated with an outbreak of dengue disease, which is motivated by the first dengue epidemic ever recorded in the Cape Verde islands off the coast of west Africa, in 2009. Numerical simulations show that in some cases the fractional models fit better the reality when compared with the standard differential models. The classical results are obtained as particular cases by considering the order of the derivatives to take an integer value.

Pooseh, Shakoor; Rodrigues, Helena Sofia; Torres, Delfim F. M.

2011-09-01

94

An Epidemic of Dengue-1 in a Remote Village in Rural Laos  

PubMed Central

In the Lao PDR (Laos), urban dengue is an increasingly recognised public health problem. We describe a dengue-1 virus outbreak in a rural northwestern Lao forest village during the cool season of 2008. The isolated strain was genotypically “endemic” and not “sylvatic,” belonging to the genotype 1, Asia 3 clade. Phylogenetic analyses of 37 other dengue-1 sequences from diverse areas of Laos between 2007 and 2010 showed that the geographic distribution of some strains remained focal overtime while others were dispersed throughout the country. Evidence that dengue viruses have broad circulation in the region, crossing country borders, was also obtained. Whether the outbreak arose from dengue importation from an urban centre into a dengue-naïve community or crossed into the village from a forest cycle is unknown. More epidemiological and entomological investigations are required to understand dengue epidemiology and the importance of rural and forest dengue dynamics in Laos. PMID:23951379

Dubot-Pérès, Audrey; Vongphrachanh, Phengta; Denny, Justin; Phetsouvanh, Rattanaphone; Linthavong, Singharath; Sengkeopraseuth, Bounthanom; Khasing, Amphai; Xaythideth, Vimattha; Moore, Catrin E.; Vongsouvath, Manivanh; Castonguay-Vanier, Josée; Sibounheuang, Bountoy; Chanthongthip, Anisone; de Lamballerie, Xavier; Newton, Paul N.

2013-01-01

95

Geographical information system (GIS) in investigation of an outbreak.  

PubMed

An outbreak of fever in a village in southern India was reported on 1st September, 2001. The first reported case presented with epistaxis and a platelet count of 27000h(1)/mm3. Clinical, laboratory and entomological evidence supported a diagnosis of dengue fever. One third of the village was affected and 3.7 % of the population presented with haemorrhagic symptoms; none were fatal. Five acute cases tested for dengue specific IgM showed that two were positive. The larvae of Aedes aegypti were discovered from domestic water collections in the village. Spatial analysis done with the help of Geographical Information Systems software (GIS) demonstrated a centrifugal spread of cases from the most affected street until it involved the entire village. Spatial analysis revealed that cases occurred in clusters and that these could not have occurred by chance. This was our first experience in producing a geo-referenced map of a village area and in spatial analysis. GIS is a novel and simple tool for outbreak investigations and the spatial analyst adds additional information to the data collected. Control of adult mosquitoes and larvae prevented the outbreak from spreading to an adjacent village. PMID:16637399

Nisha, V; Gad, Santosh S; Selvapandian, David; Suganya, V; Rajagopal, V; Suganti, Pearlin; Balraj, V; Devasundaram, Jayanth

2005-03-01

96

Dengue hemorrhagic fever  

MedlinePLUS

Hemorrhagic dengue; Dengue shock syndrome; Philippine hemorrhagic fever; Thai hemorrhagic fever; Singapore hemorrhagic fever ... Yellow Fever, Dengue, Dengue Hemorrhagic Fever, Japanese ... Encephalitis, St. Louis Encephalitis, Tick-Borne Encephalitis). ...

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.

0000-00-00

98

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

99

Dengue Fever  

MedlinePLUS

... and subtropical areas of Africa Southeast Asia and China India Middle East Caribbean and Central and South ... the disease. In the Western hemisphere, the estimated economic burden of dengue is about $2.1 billion ...

100

Emergence of dengue virus type-3 in northern India.  

PubMed

During the last few decades dengue has reemerged in several parts of Southeast Asia, including India. A major outbreak of dengue infection occurred in northern India during October to December 2003. To determine the etiology, we carried out serological, virological and molecular investigations of this outbreak. A total of 76 dengue suspected patient blood samples were collected from Gwalior, Madhya Pradesh and Delhi, India. Serological investigations carried out using an in-house Dipstick ELISA protocol revealed the presence of anti-dengue antibodies in 53 patients. Twelve of them (22%) had a positive IgM response, indicative of primary infection, and 22 of them (42%) revealed only IgG antibodies, indicative of secondary infection. RT-PCR analysis employing dengue group specific amplimer revealed the presence of dengue specific RNA in four acute phase samples. These four RT-PCR positive samples were further processed for virus isolation in C6/36 cells and suckling mice, yielding four dengue virus isolates. The Nested PCR analysis employing serotype specific amplimer revealed the presence of dengue-3 specific 389 bp amplicon. This study confirmed the reemergence of dengue virus type-3 in a dominant form in India after a gap of nine years. Earlier, dengue virus type-2 was implicated as the etiology of a major dengue epidemic in Delhi in 1996 and Gwalior in 2001. The implication of dengue type-3 as etiology of a DHF epidemic in neighboring Sri Lanka and Bangladesh recently confirms the reemergence of dengue type-3 as the dominant form on the Indian subcontinent. PMID:15916043

Dash, Paban Kumar; Saxena, Parag; Abhyankar, Ajay; Bhargava, Rakesh; Jana, Asha Mukul

2005-03-01

101

Recent progress in dengue vaccine development.  

PubMed

Dengue virus (DENV) has four distinct serotypes. DENV infection can result in classic dengue fever and life-threatening dengue hemorrhagic fever/dengue shock syndrome. In recent decades, DENV infection has become an important public health concern in epidemic-prone areas. Vaccination is the most effective measure to prevent and control viral infections. However, several challenges impede the development of effective DENV vaccines, such as the lack of suitable animal models and the antibody-dependent enhancement phenomenon. Although no licensed DENV vaccine is available, significant progress has been made. This review summarizes candidate DENV vaccines from recent investigations. PMID:25547681

Wei, Jianchun; Chen, Hui; An, Jing

2014-12-01

102

Dengue specific immunoglobulins M, A, and E in primary and secondary dengue 4 infected Salvadorian children.  

PubMed

El Salvador is a Central American country that has been affected by several dengue outbreaks. This study investigated the levels of IgM, IgA, and IgE anti-dengue antibodies in serum samples from children in El Salvador, with a clinical and serological diagnosis of dengue infection during the dengue 4 outbreak in 2002-2003. Seventy one serum samples were tested by ELISA and cases were classified in three groups: 13 primary dengue fever (PDF), 21 secondary dengue fever (SDF), and 37 secondary dengue hemorrhagic fever (SDHF). Also, the specificity of anti-dengue IgM for the different serotypes was tested. No significant differences in the IgM response were found between PDF and SDF, but these were detected between PDF and SDHF (P?=?0.0053) and between SDF and SDHF (P?=?0.0003). The IgA and IgE values showed a statistically significant difference between primary and secondary groups. The highest positivity percentage of IgA was between 95% (SDF) and 100% (SDHF) towards day 7 of onset of fever. All secondary cases were positive for IgE antibodies. The specificity of IgM was determined for DENV-4 virus in primary and secondary DF groups. This is the first study on dengue cases in Salvadorian children related to the immune response of different immunoglobulins to the type of infection and the clinical picture. Further prospective studies are needed to define if the pattern of immunoglobulins can determine early dengue infection and/or severity. PMID:24615872

Vazquez, Susana; Lozano, Celina; Perez, Ana Beatriz; Castellanos, Yinet; Ruiz, Didye; Calzada, Naifi; Guzmán, Maria Guadalupe

2014-09-01

103

Confusion, knock-down and kill of Aedes aegypti using metofluthrin in domestic settings: a powerful tool to prevent dengue transmission?  

PubMed Central

Background Dengue control methods are reliant upon control of the vector, primarily Aedes aegypti. Current adulticiding methods in North Queensland include treating premises with residual synthetic pyrethroid insecticides (interior residual spraying; IRS), a laborious, intrusive task. The vapor active synthetic pyrethroid metofluthrin might offer an efficient alternative as some studies indicate that it prevents biting and has strong knockdown effects. However, its expellant and/or irritant effects, longevity, residual activity and the speed with which biting behavior is disrupted have not yet been characterized. Methods We exposed cohorts of Cairns colony (F2-4) Ae. aegypti to rooms (17–24 m3) treated with 5% and 10% AI metofluthrin emanators. Using free-flying and caged populations we measured biting (human landing rate), expulsion through unscreened windows, knockdown and death over periods ranging between a few minutes and 24 hrs. Observations of the behavior of single female Ae. aegypti exposed to metofluthrin were also made. Results Female Ae. aegypti exposed to 5% or 10% metofluthrin formulations were almost entirely inhibited from biting. This was the result of rapid knockdown and mortality (80-90% in less than one hour) and to the behavioral impacts of exposure that, within minutes, caused female Ae. aegypti to become disoriented, stop landing on hosts, and seek resting sites. Exposed mosquitoes did not exhibit any increased propensity to exit treated rooms and the 10% AI resin remained fully active for at least 20 days. Conclusion The new, high-dose, resin formulations of metofluthrin act quickly to prevent biting and to knockdown and kill free-flying female Ae. aegypti in our experimental rooms. There was no evidence that metofluthrin induced escape from treated areas. Resin-based metofluthrin emanators show great potential as a replacement for labor intensive IRS for dengue vector control. PMID:24025232

2013-01-01

104

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

105

Neurological manifestations of dengue infection: a review.  

PubMed

Dengue is a common arboviral infection in tropical and sub-tropical areas of the world transmitted by Aedes mosquitoes and caused by infection with one of the 4 serotypes of dengue virus. Neurologic manifestations are increasingly recognised but the exact incidence is unknown. Dengue infection has a wide spectrum of neurological complications such as encephalitis, myositis, myelitis, Guillain-Barré syndrome (GBS) and mononeuropathies. Encephalopathy is the most common reported complication. In endemic regions, dengue infection should be considered as one of the aetiologies of encephalitis. Even for other neurological syndromes like myelitis, myositis, GBS etc., dengue infection should be kept in differential diagnosis and should be ruled out especially so in endemic countries during dengue outbreaks and in cases where the aetiology is uncertain. A high degree of suspicion in endemic areas can help in picking up more cases thereby helping in understanding the true extent of neurological complications in dengue fever. Also knowledge regarding the various neurological complications helps in looking for the warning signs and early diagnosis thereby improving patient outcome. PMID:25220113

Verma, Rajesh; Sahu, Ritesh; Holla, Vikram

2014-11-15

106

Dengue vaccines: Challenges, development, current status and prospects.  

PubMed

Infection with dengue virus (DENV) is the most rapidly spreading mosquito-borne viral disease in the world. The clinical spectrum of dengue, caused by any of the four serotypes of DENV, ranges from mild self-limiting dengue fever to severe dengue, in the form dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Increased rates of hospitalization due to severe dengue, during outbreaks, result in massive economic losses and strained health services. In the absence of specific antiviral therapy, control of transmission of DENV by vector management is the sole method available for decreasing dengue-associated morbidity. Since vector control strategies alone have not been able to satisfactorily achieve reduction in viral transmission, the implementation of a safe, efficacious and cost-effective dengue vaccine as a supplementary measure is a high public health priority. However, the unique and complex immunopathology of dengue has complicated vaccine development. Dengue vaccines have also been challenged by critical issues like lack of animal models for the disease and absence of suitable markers of protective immunity. Although no licensed dengue vaccine is yet available, several vaccine candidates are under phases of development, including live attenuated virus vaccines, live chimeric virus vaccines, inactivated virus vaccines, subunit vaccines, DNA vaccines and viral-vectored vaccines. Although some vaccine candidates have progressed from animal trials to phase II and III in humans, a number of issues regarding implementation of dengue vaccine in countries like India still need to be addressed. Despite the current limitations, collaborative effects of regulatory bodies like World Health Organization with vaccine manufacturers and policy makers, to facilitate vaccine development and standardize field trials can make a safe and efficacious dengue vaccine a reality in near future. PMID:25559995

Ghosh, A; Dar, L

2015-01-01

107

Dengue disease status in Chennai (2006-2008): A retrospective analysis  

PubMed Central

Background & objectives: Dengue is one of the most important Arboviral diseases in man with outbreaks in Southeast Asia and India. We report a retrospective analysis of the dengue positivity in the referred samples for three years period (2006 to 2008) at the Department of Virology, King Institute of Preventive Medicine, Chennai, Tamil Nadu, India. Methods: Serum samples from 1593 suspected cases (968 male and 625 female) were obtained. Of the 1593 cases screened, 1204 (75.5%) were paediatric cases and 389 (24.4%) adults. The samples were subjected to MAC ELISA and IgG ELISA. Results: Of the 968 patients, 686 (43.0%) were positive, of which 579 (84.0%) were in the paediatric age group (<14 yr) and 107 (15.5%) were adults. The IgM positivity being 356 (36.7%) in males and 330 (52.8%) in females. Of the 686 positives, 113 (16.47%) were positive for both IgM and IgG denoting secondary infection. There was a noticeable increased occurrence during the cooler months and during the monsoon and post-monsoon months. Interpretation & conclusions: The dengue IgM seropositivity among the suspected cases indicates active dengue virus activity. Increase in the probable secondary infections especially in a country like ours where multiple serotypes are prevalent raises concern over probable increase in the incidence of the more serious DHF/DSS. Studies need to be done to identify circulating serotypes of dengue virus to design preventive strategies. PMID:21441688

Gunasekaran, P.; Kaveri, K.; Mohana, S.; Arunagiri, Kavita; Babu, B.V. Suresh; Priya, P. Padma; Kiruba, R.; Kumar, V. Senthil; Sheriff, A. Khaleefathullah

2011-01-01

108

Climate-Based Models for Understanding and Forecasting Dengue Epidemics  

PubMed Central

Background Dengue dynamics are driven by complex interactions between human-hosts, mosquito-vectors and viruses that are influenced by environmental and climatic factors. The objectives of this study were to analyze and model the relationships between climate, Aedes aegypti vectors and dengue outbreaks in Noumea (New Caledonia), and to provide an early warning system. Methodology/Principal Findings Epidemiological and meteorological data were analyzed from 1971 to 2010 in Noumea. Entomological surveillance indices were available from March 2000 to December 2009. During epidemic years, the distribution of dengue cases was highly seasonal. The epidemic peak (March–April) lagged the warmest temperature by 1–2 months and was in phase with maximum precipitations, relative humidity and entomological indices. Significant inter-annual correlations were observed between the risk of outbreak and summertime temperature, precipitations or relative humidity but not ENSO. Climate-based multivariate non-linear models were developed to estimate the yearly risk of dengue outbreak in Noumea. The best explicative meteorological variables were the number of days with maximal temperature exceeding 32°C during January–February–March and the number of days with maximal relative humidity exceeding 95% during January. The best predictive variables were the maximal temperature in December and maximal relative humidity during October–November–December of the previous year. For a probability of dengue outbreak above 65% in leave-one-out cross validation, the explicative model predicted 94% of the epidemic years and 79% of the non epidemic years, and the predictive model 79% and 65%, respectively. Conclusions/Significance The epidemic dynamics of dengue in Noumea were essentially driven by climate during the last forty years. Specific conditions based on maximal temperature and relative humidity thresholds were determinant in outbreaks occurrence. Their persistence was also crucial. An operational model that will enable health authorities to anticipate the outbreak risk was successfully developed. Similar models may be developed to improve dengue management in other countries. PMID:22348154

Descloux, Elodie; Mangeas, Morgan; Menkes, Christophe Eugène; Lengaigne, Matthieu; Leroy, Anne; Tehei, Temaui; Guillaumot, Laurent; Teurlai, Magali; Gourinat, Ann-Claire; Benzler, Justus; Pfannstiel, Anne; Grangeon, Jean-Paul; Degallier, Nicolas; De Lamballerie, Xavier

2012-01-01

109

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

110

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; Rocklöv, Joacim; Byass, Peter; Louis, Valérie R.; Tozan, Yesim; Massad, Eduardo; Tenorio, Antonio; Lagneau, Christophe; L'Ambert, Grégory; Brooks, David; Wegerdt, Johannah; Gubler, Duane

2012-01-01

111

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

112

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

113

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

114

Community beliefs and practices about dengue in Puerto Rico  

Technology Transfer Automated Retrieval System (TEKTRAN)

In spite of long-term endemicity and repeated government and private efforts, effective, sustained community participation for dengue prevention is still a challenge in Puerto Rico. This study explored differences found in interviews conducted in 2001 in attitudes toward dengue and its prevention by...

115

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

116

Co-infections with Chikungunya Virus and Dengue Virus in Delhi, India  

PubMed Central

Aedes aegypti mosquitoes are common vectors for dengue virus and chikungunya virus. In areas where both viruses cocirculate, they can be transmitted together. During a dengue outbreak in Delhi in 2006, 17 of 69 serum samples were positive for chikungunya virus by reverse transcription–PCR; 6 samples were positive for both viruses. PMID:19624923

Chahar, Harendra S.; Bharaj, Preeti; Dar, Lalit; Guleria, Randeep; Kabra, Sushil K.

2009-01-01

117

Neutralizing Dengue Antibody in Pregnant Thai Women and Cord Blood  

PubMed Central

Background The WHO ‘Global Strategy for Dengue Prevention and Control, 2012–2020’ addresses the growing need for the treatment of dengue, and targets a 25% reduction in morbidity and 50% in mortality (using 2010 estimates as baseline). Achieving these goals requires future dengue prevention strategies that will employ both potential vaccines and sustainable vector-control measures. Maternally transferred dengue antibody is an important factor in determining the optimal age for dengue vaccination. Objectives To estimate the seroprevalence of dengue antibodies among mothers living in an area of high endemicity – Ban Pong, Ratchaburi Province – and to assess maternal dengue antibodies transferred to cord blood. Materials & Methods A cross-sectional study was conducted with 141 pregnant women who delivered at Ban Pong Hospital, Ratchaburi, Thailand. Maternal-cord paired sera were tested for dengue neutralizing (NT) antibody by PRNT50 assay. A ratio of ? 1:10 NT titer to dengue serotype was considered seropositive. Results Most mothers (137/141, 97.2%) had NT antibodies to at least one dengue serotype in their sera. At birth, the proportion of cord sera with NT antibodies to DEN-1, DEN-2, DEN-3, and DEN-4, were high and similar to the sera of their mothers, at 93.6%, 97.2%, 97.9%, and 92.2%, respectively. The dengue geometric mean titers (GMT) in cord blood were significantly higher than the maternal antibodies (p<0.001): highest in DEN-2, followed by DEN-3, and then DEN-1. The GMT of DEN-4 was the lowest among all four serotypes. Conclusions Dengue infection is highly prevalent among pregnant women in this dengue-endemic area. Most of the cord blood had transferred dengue antibodies, which may have an impact on the disease burden in this population. PMID:25658481

Khamim, Kriangsak; Hattasingh, Weerawan; Nisalak, Ananda; Kaewkungwal, Jaranit; Fernandez, Stefan; Thaisomboonsuk, Butsaya; Pengsaa, Krisana; Thisyakorn, Usa

2015-01-01

118

Identification of the prediction model for dengue incidence in Can Tho city, a Mekong Delta area in Vietnam.  

PubMed

The Mekong Delta is highly vulnerable to climate change and a dengue endemic area in Vietnam. This study aims to examine the association between climate factors and dengue incidence and to identify the best climate prediction model for dengue incidence in Can Tho city, the Mekong Delta area in Vietnam. We used three different regression models comprising: standard multiple regression model (SMR), seasonal autoregressive integrated moving average model (SARIMA), and Poisson distributed lag model (PDLM) to examine the association between climate factors and dengue incidence over the period 2003-2010. We validated the models by forecasting dengue cases for the period of January-December, 2011 using the mean absolute percentage error (MAPE). Receiver operating characteristics curves were used to analyze the sensitivity of the forecast of a dengue outbreak. The results indicate that temperature and relative humidity are significantly associated with changes in dengue incidence consistently across the model methods used, but not cumulative rainfall. The Poisson distributed lag model (PDLM) performs the best prediction of dengue incidence for a 6, 9, and 12-month period and diagnosis of an outbreak however the SARIMA model performs a better prediction of dengue incidence for a 3-month period. The simple or standard multiple regression performed highly imprecise prediction of dengue incidence. We recommend a follow-up study to validate the model on a larger scale in the Mekong Delta region and to analyze the possibility of incorporating a climate-based dengue early warning method into the national dengue surveillance system. PMID:25447266

Phung, Dung; Huang, Cunrui; Rutherford, Shannon; Chu, Cordia; Wang, Xiaoming; Nguyen, Minh; Nguyen, Nga Huy; Manh, Cuong Do

2015-01-01

119

Preventive behaviors, beliefs, and anxieties in relation to the swine flu outbreak among college students aged 18–24 years  

Microsoft Academic Search

Aim  The objective of this study was to assess beliefs, misconception, and anxiety in relation to swine flu outbreak and whether\\u000a perception of the outbreak predicted changes in behavior.\\u000a \\u000a \\u000a \\u000a \\u000a Subject and methods  In November 2009, we conducted an Internet-based cross-sectional survey of college students aged 18–24 years in a Midwestern\\u000a State in the USA. We collected information on swine flu knowledge, perception on

Mehulkumar K. Kanadiya; Anthony M. Sallar

2011-01-01

120

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

121

Quantifying the Emergence of Dengue in Hanoi, Vietnam: 1998–2009  

PubMed Central

Background An estimated 2.4 billion people live in areas at risk of dengue transmission, therefore the factors determining the establishment of endemic dengue in areas where transmission suitability is marginal is of considerable importance. Hanoi, Vietnam is such an area, and following a large dengue outbreak in 2009, we set out to determine if dengue is emerging in Hanoi. Methods and Principal Findings We undertook a temporal and spatial analysis of 25,983 dengue cases notified in Hanoi between 1998 and 2009. Age standardized incidence rates, standardized age of infection, and Standardized Morbidity Ratios (SMR) were calculated. A quasi-Poisson regression model was used to determine if dengue incidence was increasing over time. Wavelet analysis was used to explore the periodicity of dengue transmission and the association with climate variables. After excluding the two major outbreak years of 1998 and 2009 and correcting for changes in population age structure, we identified a significant annual increase in the incidence of dengue cases over the period 1999–2008 (incidence rate ratio ?=?1.38, 95% confidence interval ?=?1.20–1.58, p value ?=?0.002). The age of notified dengue cases in Hanoi is high, with a median age of 23 years (mean 26.3 years). After adjusting for changes in population age structure, there was no statistically significant change in the median or mean age of dengue cases over the period studied. Districts in the central, highly urban, area of Hanoi have the highest incidence of dengue (SMR>3). Conclusions Hanoi is a low dengue transmission setting where dengue incidence has been increasing year on year since 1999. This trend needs to be confirmed with serological surveys, followed by studies to determine the underlying drivers of this emergence. Such studies can provide insights into the biological, demographic, and environmental changes associated with vulnerability to the establishment of endemic dengue. PMID:21980544

Cuong, Hoang Quoc; Hien, Nguyen Tran; Duong, Tran Nhu; Phong, Tran Vu; Cam, Nguyen Nhat; Farrar, Jeremy; Nam, Vu Sinh; Thai, Khoa T. D.; Horby, Peter

2011-01-01

122

Spatio-Temporal Diffusion Pattern and Hotspot Detection of Dengue in Chachoengsao Province, Thailand  

PubMed Central

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

123

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

124

Dengue in China: a clinical review.  

PubMed Central

Three etiologically proven outbreaks of dengue fever and one etiologically confirmed epidemic of dengue haemorrhagic fever have occurred in south China since 1978. The first of these, an epidemic of dengue due to virus type 4 took place in Shiwan town, Foshan city, Guangdong Province, in 1978; the epidemic began in May and ended in November. The clinical manifestations of 583 hospitalized patients were observed from August to October. The majority (81.3%) of patients were aged 21-50 years (male:female = 1.2:1). The course of illness was about 1 week in most cases; three patients (0.5%) died. A local outbreak of dengue due to virus type 1 occurred in Shiqi town, Zhongshan County, Guangdong Province, from September to November 1979. The majority of patients were older children and adolescents. There was no marked difference between males and females in terms of the course of the illness, and there were no complications or deaths. A large epidemic of dengue due to virus type 3 occurred on Hainan Island in 1980. The clinical manifestations of 510 hospitalized patients (mostly adolescents and adults) were observed from April to September. Some patients developed rare complications, such as loss of hair, acute intravascular haemolysis, and multiple peripheral paralysis; there were four deaths (0.78%). The first known epidemic of dengue haemorrhagic fever in China occurred among 10-29-year-olds on Hainan Island in 1985 and 1986. There were no essential differences between males and females. Some cases had rare complications such as acute intravascular haemolysis, while others had diffuse intravascular coagulation and altered mental status; 10 patients (6.5%) died. PMID:8324854

Qiu, F. X.; Gubler, D. J.; Liu, J. C.; Chen, Q. Q.

1993-01-01

125

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

126

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

127

Insecticide Control in a Dengue Epidemics Model  

NASA Astrophysics Data System (ADS)

A model for the transmission of dengue disease is presented. It consists of eight mutually-exclusive compartments representing the human and vector dynamics. It also includes a control parameter (insecticide) in order to fight the mosquitoes. The main goal of this work is to investigate the best way to apply the control in order to effectively reduce the number of infected humans and mosquitoes. A case study, using data of the outbreak that occurred in 2009 in Cape Verde, is presented.

Rodrigues, Helena Sofia; Monteiro, M. Teresa T.; Torres, Delfim F. M.

2010-09-01

128

Developing a Social Autopsy Tool for Dengue Mortality: A Pilot Study  

PubMed Central

Background Dengue fever is a public health problem in the tropical and sub-tropical world. Dengue cases have grown dramatically in recent years as well as dengue mortality. Colombia has experienced periodic dengue outbreaks with numerous dengue related-deaths, where the Santander department has been particularly affected. Although social determinants of health (SDH) shape health outcomes, including mortality, it is not yet understood how these affect dengue mortality. The aim of this pilot study was to develop and pre-test a social autopsy (SA) tool for dengue mortality. Methods and Findings The tool was developed and pre-tested in three steps. First, dengue fatal cases and ‘near misses’ (those who recovered from dengue complications) definitions were elaborated. Second, a conceptual framework on determinants of dengue mortality was developed to guide the construction of the tool. Lastly, the tool was designed and pre-tested among three relatives of fatal cases and six near misses in 2013 in the metropolitan zone of Bucaramanga. The tool turned out to be practical in the context of dengue mortality in Colombia after some modifications. The tool aims to study the social, individual, and health systems determinants of dengue mortality. The tool is focused on studying the socioeconomic position and the intermediary SDH rather than the socioeconomic and political context. Conclusions The SA tool is based on the scientific literature, a validated conceptual framework, researchers’ and health professionals’ expertise, and a pilot study. It is the first time that a SA tool has been created for the dengue mortality context. Our work furthers the study on SDH and how these are applied to neglected tropical diseases, like dengue. This tool could be integrated in surveillance systems to provide complementary information on the modifiable and avoidable death-related factors and therefore, be able to formulate interventions for dengue mortality reduction. PMID:25658485

Arauz, María José; Ridde, Valéry; Hernández, Libia Milena; Charris, Yaneth; Carabali, Mabel; Villar, Luis Ángel

2015-01-01

129

Dengue Fever Treatment  

MedlinePLUS

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

130

The dengue viruses.  

PubMed Central

Dengue, a major public health problem throughout subtropical and tropical regions, is an acute infectious disease characterized by biphasic fever, headache, pain in various parts of the body, prostration, rash, lymphadenopathy, and leukopenia. In more severe or complicated dengue, patients present with a severe febrile illness characterized by abnormalities of hemostasis and increased vascular permeability, which in some instances results in a hypovolemic shock. Four distinct serotypes of the dengue virus (dengue-1, dengue-2, dengue-3, and dengue-4) exist, with numerous virus strains found worldwide. Molecular cloning methods have led to a greater understanding of the structure of the RNA genome and definition of virus-specific structural and nonstructural proteins. Progress towards producing safe, effective dengue virus vaccines, a goal for over 45 years, has been made. Images PMID:2224837

Henchal, E A; Putnak, J R

1990-01-01

131

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.

132

Genetic and biological differentiation of dengue 3 isolates obtained from clinical cases in Java, Indonesia, 1976–1978  

Microsoft Academic Search

Summary Previous epidemiological, virological and clinical studies have documented a series of outbreaks of dengue fever and dengue haemorrhagic fever\\/dengue shock syndrome which occured in Java, Indonesia in 1976–1978. In the current study we compare growth characteristics in cell culture, and nucleotide sequence data for the viral prM and E genes, of five low passage DEN-3 isolates obtained during these

E. Lee; D. J. Gubler; R. C. Weir; L. Dalgarno

1993-01-01

133

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

134

A new challenge for hospitals in southeast France: monitoring local populations of Aedes albopictus to prevent nosocomial transmission of dengue or chikungunya.  

PubMed

Aedes albopictus was first identified in southern France in 2004, inducing an emerging risk for autochthonous transmission around imported cases of dengue or chikungunya, and also for mosquito-borne nosocomial transmission in hospitals. Aedes albopictus has been present in Marseille since September 2009 and in Aix-en-Provence since August 2010. Because of the possible admission of viremic patients with dengue or chikungunya in the hospitals of these cities, a mosquito survey was conducted in 2011 in 2 of the hospitals, with the use of mosquito traps. Aedes albopictus was detected with Eisenhans II traps and egg traps in both hospitals during the warm season. PMID:23687863

Cotteaux-Lautard, Christelle; Berenger, Jean-Michel; Fusca, François; Chardon, Hubert; Simon, Fabrice; Pagès, Frederic

2013-03-01

135

Dengue in Cape Verde: vector control and vaccination  

E-print Network

In 2009, for the first time in Cape Verde, an outbreak of dengue was reported and over twenty thousand people were infected. Only a few prophylactic measures were taken. The effects of vector control on disease spreading, such as insecticide (larvicide and adulticide) and mechanical control, as well as an hypothetical vaccine, are estimated through simulations with the Cape Verde data.

Rodrigues, Helena Sofia; Torres, Delfim F M

2012-01-01

136

Effective suppression of Dengue fever virus in mosquito cell cultures using retroviral transduction of hammerhead ribozymes targeting the viral genome  

Microsoft Academic Search

Outbreaks of Dengue impose a heavy economic burden on developing countries in terms of vector control and human morbidity. Effective vaccines against all four serotypes of Dengue are in development, but population replacement with transgenic vectors unable to transmit the virus might ultimately prove to be an effective approach to disease suppression, or even eradication. A key element of the

Pruksa Nawtaisong; James Keith; Tresa Fraser; Velmurugan Balaraman; Andrey Kolokoltsov; Robert A Davey; Stephen Higgs; Ahmed Mohammed; Yupha Rongsriyam; Narumon Komalamisra; Malcolm J Fraser Jr

2009-01-01

137

Chapter 3. Integration of botanicals and microbial pesticides for the control of dengue vector, Aedes aegypti (Insecta: Diptera: Culicidae)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Mosquitoes are the single most important group of insects in terms of public health significance and causing diseases such as malaria, filariasis, dengue fever, Japanese encephalitis and other fevers. There has been an outbreak of Chikungunya and dengue all over the India from 2006 – 2009. Aedes ae...

138

Dengue vaccines: Problems & prospects  

Microsoft Academic Search

The extent of cumulative disease burden caused by dengue virus has attained an unprecedented level in recent times with sharp increase in the size of human population at risk. Dengue disease presents highly complex medical, economic and ecologic problems. The surge in publications on the development of dengue vaccines, taking advantage of new generation of biotechnology techniques indicates the profound

U. C. Chaturvedi; Richa Shrivastava; Rachna Nagar

2005-01-01

139

Spotlight on measles in Italy: why outbreaks of a vaccine-preventable infection continue in the 21st century.  

PubMed

Measles is a serious infectious disease that can lead to significant morbidity and mortality. Remarkable progress has been made through measles vaccination in reducing the number of people dying from measles. In the last years, concerns about the safety of vaccines have led to decline in immunization coverage rates and new outbreaks of measles in many European countries, including Italy. We believe that it is important to reinforce the message that measles vaccine is safe and highly effective through appropriate information campaigns and public awareness. PMID:25612664

Piccirilli, Giulia; Lazzarotto, Tiziana; Chiereghin, Angela; Serra, Laura; Gabrielli, Liliana; Lanari, Marcello

2015-03-01

140

The Clinical, Serological and Molecular Diagnosis of Emerging Dengue Infection at a Tertiary Care Institute in Southern, India  

PubMed Central

Introduction: Dengue is an acute viral infection which presents as uneventful pyrexia to a fatal complication. This infection is increasingly being recognized as the world’s major emerging tropical disease and an important public health problem. This article highlights the clinical manifestations of Dengue virus infection and the various molecular tests that were used for its laboratory diagnosis. Methods: Serum samples from 713 suspected cases of Dengue were collected between August and December 2007. The clinical profiles of 123 hospitalized patients were analyzed. Serology, RT- PCR, virus isolation and sequencing were done. Results: The most common clinical symptoms were fever, thrombocytopenia, rash and elevated liver enzymes. The demonstration of the Dengue RNA in 5.16% samples, the detection of Dengue specific IgM antibodies in 18% samples and the isolation of the DENV-4 and the DENV-3 viruses from the clinical samples confirmed this Dengue outbreak. A co -infection with Chikungunya was observed in 2.06% of the cases. The phylogenetic analysis revealed that the Indian Dengue-4 isolates from this outbreak belonged to the genotype I. This study clearly indicated the sudden dominance of DENV-4 in an Indian Dengue outbreak. Conclusion: The surveillance of the Dengue viruses needs to be closely monitored for the emergence of newer serotype(s) in hitherto unknown areas. PMID:23634396

Neeraja, Mamidi; Lakshmi, Vemu; Dash, P.K.; Parida, M.M.; Rao, P.V.L.

2013-01-01

141

[Epidemiology of dengue fever in China since 1978].  

PubMed

Since 1978, dengue fever occurred endemically and epidemically every 4 to 7 years in China, affecting commonly people aged between 20 and 60 years with similar incidences in males and females. Four serotypes of dengue virus have been identified in China, with DENV-1 as the predominant serotype. The incidence of dengue fever became gradually decreased after 1997 but increased significantly in the recent two years, especially in 2014, where, up to November, a total of 44894 cases had been reported in Guangdong Province. In this review, the authors summarize the epidemiology, geographical and population distribution of dengue fever in China since 1978 and analyze the factors contributing to the outbreak in 2014. PMID:25537911

Xiong, Yi-Quan; Chen, Qing

2014-12-20

142

Natural or deliberate outbreak in Pakistan: how to prevent or detect and trace its origin: biosecurity, surveillance, forensics.  

PubMed

Over the last few decades biosecurity and biosafety have emerged as a prominent public health concern due to some high-profile accidents. Effective strategies to deal with the outbreak, whether deliberate or non-deliberate requires a multidisciplinary approach and coordinated decision-making by various state departments such as health, forensics, agriculture, environment, intelligence, law and enforcement, etc. In a dynamic global environment and the overwhelming asymmetric threats from the non-state actors, it is of utmost importance to understand the biosecurity issues and initiate a coordinated global effort to cope with biosecurity and biosafety breaches and develop an as effective response mechanism. An attractive choice for the terrorists, state enemies and non-state actors is the use of biological weapons. An unwanted incident may not only bring chaos to the people, but also can inflict severe economic damage industrially and locally as was in the notorious foot-and-mouth disease outbreak. Because of special geopolitical compulsion, Pakistan is one of the hot spots where special action needs to be taken. The current review focuses on the various approaches, technologies that can be used to alleviate the chances of biosafety and biosecurity incident and emphasizes the role of modern technology that can be used in this regard. PMID:24942803

Shinwari, Zabta Khan; Khalil, Ali Talha; Nasim, Anwar

2014-08-01

143

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

144

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

145

Dengue Viral Infection of Endothelial Cells and Dengue Hemorrhagic Fever.  

E-print Network

??Dengue virus (DENV) is the etiological agent responsible for the severe and potentially fatal illnesses known as dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). Microvascular plasma… (more)

Arevalo, Maria Teresa; Jin, Xia

2011-01-01

146

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

147

Health Beliefs and Practices Related to Dengue Fever: A Focus Group Study  

PubMed Central

Background This qualitative study aimed to provide an in-depth understanding of the meaning of dengue fever (DF) amongst people living in a dengue endemic region, dengue prevention and treatment-seeking behaviours. The Health Belief Model was used as a framework to explore and understand dengue prevention behaviours. Methods A total of 14 focus group discussions were conducted with 84 Malaysian citizens of different socio-demographic backgrounds between 16th December, 2011 and 12th May, 2012. Results The study revealed that awareness about DF and prevention measures were high. The pathophysiology of dengue especially dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS) were rarely known; as a result, it was seen as deadly by some but was also perceived as easily curable by others without a basis of understanding. Young adults and elderly participants had a low perception of susceptibility to DF. In general, the low perceived susceptibility emerged as two themes, namely a perceived natural ability to withstand infection and a low risk of being in contact with the dengue virus vector, Aedes spp. mosquitoes. The barriers to sustained self-prevention against dengue prevention that emerged in focus groups were: i) lack of self-efficacy, ii) lack of perceived benefit, iii) low perceived susceptibility, and iv) unsure perceived susceptibility. Low perceived benefit of continued dengue prevention practices was a result of lack of concerted action against dengue in their neighborhood. Traditional medical practices and home remedies were widely perceived and experienced as efficacious in treating DF. Conclusion Behavioural change towards attaining sustainability in dengue preventive practices may be enhanced by fostering comprehensive knowledge of dengue and a change in health beliefs. Wide use of unconventional therapy for DF warrants the need to enlighten the public to limit their reliance on unproven alternative treatments. PMID:23875045

Wong, Li Ping; AbuBakar, Sazaly

2013-01-01

148

Agent-based modeling to simulate the dengue spread  

NASA Astrophysics Data System (ADS)

In this paper, we introduce a novel method ABM in simulating the unique process for the dengue spread. Dengue is an acute infectious disease with a long history of over 200 years. Unlike the diseases that can be transmitted directly from person to person, dengue spreads through a must vector of mosquitoes. There is still no any special effective medicine and vaccine for dengue up till now. The best way to prevent dengue spread is to take precautions beforehand. Thus, it is crucial to detect and study the dynamic process of dengue spread that closely relates to human-environment interactions where Agent-Based Modeling (ABM) effectively works. The model attempts to simulate the dengue spread in a more realistic way in the bottom-up way, and to overcome the limitation of ABM, namely overlooking the influence of geographic and environmental factors. Considering the influence of environment, Aedes aegypti ecology and other epidemiological characteristics of dengue spread, ABM can be regarded as a useful way to simulate the whole process so as to disclose the essence of the evolution of dengue spread.

Deng, Chengbin; Tao, Haiyan; Ye, Zhiwei

2008-10-01

149

Failure of influenza vaccine to prevent two successive outbreaks of influenza A H1N1 in a school community.  

PubMed Central

Forty nine of the 149 boys (33%) at a preparatory school fell ill at the beginning of the autumn term 1986 with symptoms of influenza. One hundred and eighty two of the 470 pupils (39%) in the senior part of the same school had similar symptoms of influenza at the beginning of the spring term 1987. A new variant of influenza A H1N1 virus was isolated from both outbreaks and shown to be antigenically similar to A/Taiwan/1/86. The attack rate among pupils who had previously received trivalent influenza vaccine containing A/Chile/1/83 H1N1 antigen was not significantly different from the rate among those who had never been vaccinated. It is concluded that annual vaccination of all boarding school pupils may be inappropriate. PMID:2107831

Teare, E L; Rawes, J C; Chakraverty, P; Noah, N D; Webster, D; Corcoran, T; Oxford, J

1990-01-01

150

[Dengue fever in mainland France].  

PubMed

Dengue fever is the most widespread distributed vector borne viral disease. It is transmitted through the bites of Aedes aegypti and Aedes albopictus mosquitoes. With the expansion of Aedes albopictus and increasing travel exchange, it is no longer limited to the tropical zone and transmission has been documented in temperate areas. In mainland France, where Aedes albopictus has been present and disseminating since 2004, 2 episodes of autochthonous transmission occurred in 2010 and in 2013. Control measures against dengue and chikungunya, which shares the same vector, are implemented every year since 2006, in the areas where the vector is present. They aim at preventing or limiting local transmission of these diseases. They are based on epidemiological and entomological surveillance and vector control measures. The diagnosis of dengue, and chikungunya should be considered in case of suggestive symptoms in patients returning from an area of virus circulation. It should also be considered for patients living or having stayed in areas of mainland France where Aedes albopictus is present, during its activity period from May 1 to November 30. The prevention and control system, including vector control measures and the notification of cases to the local health authority should be known, as the risk of autochthonous transmission increases every year. PMID:25080833

Paty, M-C

2014-11-01

151

Mosquito habitat and dengue risk potential in Kenya: alternative methods to traditional risk mapping techniques.  

PubMed

Outbreaks, epidemics and endemic conditions make dengue a disease that has emerged as a major threat in tropical and sub-tropical countries over the past 30 years. Dengue fever creates a growing burden for public health systems and has the potential to affect over 40% of the world population. The problem being investigated is to identify the highest and lowest areas of dengue risk. This paper presents "Similarity Search", a geospatial analysis aimed at identifying these locations within Kenya. Similarity Search develops a risk map by combining environmental susceptibility analysis and geographical information systems, and then compares areas with dengue prevalence to all other locations. Kenya has had outbreaks of dengue during the past 3 years, and we identified areas with the highest susceptibility to dengue infection using bioclimatic variables, elevation and mosquito habitat as input to the model. Comparison of the modelled risk map with the reported dengue epidemic cases obtained from the open source reporting ProMED and Government news reports from 1982-2013 confirmed the high-risk locations that were used as the Similarity Search presence cells. Developing the risk model based upon the bioclimatic variables, elevation and mosquito habitat increased the efficiency and effectiveness of the dengue fever risk mapping process. PMID:25545930

Attaway, David F; Jacobsen, Kathryn H; Falconer, Allan; Manca, Germana; Rosenshein Bennett, Lauren; Waters, Nigel M

2014-11-01

152

Dengue disease, basic reproduction number and control  

E-print Network

Dengue is one of the major international public health concerns. Although progress is underway, developing a vaccine against the disease is challenging. Thus, the main approach to fight the disease is vector control. A model for the transmission of Dengue disease is presented. It consists of eight mutually exclusive compartments representing the human and vector dynamics. It also includes a control parameter (insecticide) in order to fight the mosquito. The model presents three possible equilibria: two disease-free equilibria (DFE) and another endemic equilibrium. It has been proved that a DFE is locally asymptotically stable, whenever a certain epidemiological threshold, known as the basic reproduction number, is less than one. We show that if we apply a minimum level of insecticide, it is possible to maintain the basic reproduction number below unity. A case study, using data of the outbreak that occurred in 2009 in Cape Verde, is presented.

Rodrigues, Helena Sofia; Torres, Delfim F M; Zinober, Alan; 10.1080/00207160.2011.554540

2011-01-01

153

Dengue/dengue haemorrhagic fever: history and current status.  

PubMed

Dengue fever (DF) is an old disease; the first record of a clinically compatible disease being recorded in a Chinese medical encyclopaedia in 992. As the global shipping industry expanded in the 18th and 19th centuries, port cities grew and became more urbanized, creating ideal conditions for the principal mosquito vector, Aedes aegypti. Both the mosquitoes and the viruses were thus spread to new geographic areas causing major epidemics. Because dispersal was by sailing ship, however, there were long intervals (10-40 years) between epidemics. In the aftermath of World War II, rapid urbanization in Southeast Asia led to increased transmission and hyperendemicity. The first major epidemics of the severe and fatal form of disease, dengue haemorrhagic fever (DHF), occurred in Southeast Asia as a direct result of this changing ecology. In the last 25 years of the 20th century, a dramatic global geographic expansion of epidemic DF/DHF occurred, facilitated by unplanned urbanization in tropical developing countries, modern transportation, lack of effective mosquito control and globalization. As we go into the 21st century, epidemic DF/DHF is one of the most important infectious diseases affecting tropical urban areas. Each year there are an estimated 50-100 million dengue infections, 500000 cases of DHF that must be hospitalized and 20000-25 000 deaths, mainly in children. Epidemic DF/DHF has an economic impact on the community of the same order of magnitude as malaria and other important infectious diseases. There are currently no vaccines nor antiviral drugs available for dengue viruses; the only effective way to prevent epidemic DF/DHF is to control the mosquito vector, Aedes aegypti. PMID:17319151

Gubler, Duane J

2006-01-01

154

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, Cláudio 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

155

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; Leitão, Pedro J.; Lakes, Tobia

2013-01-01

156

Dengue in the health transition.  

PubMed

The "Health Transition" describes the medical consequences which accompany the demographic transition and development. In many Asian countries, as the infectious diseases of infancy decline, such as diarrhea, acute respiratory disease, measles and malaria, so too, do infant mortality rates. As a consequence of falling infant mortality rates and declines in fertility, the age pyramid has become more rectangular. No longer is nearly half of the population under the age of 15 years. Diseases of adults are beginning to become predominant: trauma, heart disease, cancer, stroke and diabetes. Life expectancy has increased along with costs of the health care system. As a fraction of per capita gross domestic product, health care is beginning to become a major national expense. It is ironic that the one vector-borne infectious disease likely to bridge the health transition in tropical countries is dengue. As evidenced by the experience of Singapore and Taiwan, modern housing and commercial development provide more, rather than fewer breeding places for Aedes aegypti. Greater affluence often means less compliance with mosquito control programs. Meanwhile, the dengue viruses, heeding some unknown genetic imperative, cause ever more severe disease. Modern Asian societies must count dengue as a real and enduring threat. To prevent costly hospitalizations and a sense of social disorder, effective measures must be adopted to achieve a significant reduction of Aedes aegypti populations. Sustained dengue control requires source reduction which, in turn depends upon imaginative leadership, skilled man power, legislative authority, an authentic national research program and intersectoral cooperation. A leadership role beckons for new actors in the control of Aedes aegypti: large municipalities, environmental agencies and the private sector. PMID:7844846

Halstead, S B

1994-12-01

157

Lineage shift of dengue virus in Eastern India: an increased implication for DHF/DSS.  

PubMed

SUMMARY Dengue fever, a mosquito-borne viral disease, has become a major public health problem with marked expansion in recent decades. Dengue has now become hyperendemic in India with co-circulation of all the four serotypes. Herein, we report an unprecedented outbreak which occurred during August to October 2011 in Odisha, eastern India. This is the first report of a large epidemic in Odisha. Detailed serological and molecular investigation was carried out to identify the aetiology. Almost half of the samples were found to be dengue antigen (NS1) positive. Further molecular assays revealed circulation of mixed dengue serotypes (DENV-2 and DENV-3). Cosmopolitan genotype of DENV-2 and -3 were identified as the aetiology by phylogenetic analysis. Interestingly, a new lineage of DENV-3 within cosmopolitan genotype was incriminated in this outbreak. The emergence of the unprecedented magnitude of the dengue outbreak with the involvement of a novel lineage of DENV in a newer state of India is a major cause for concern. There is an urgent need to monitor phylodynamics of dengue viruses in other endemic areas. PMID:25314901

Shrivastava, A; Soni, M; Shrivastava, S; Sharma, S; Dash, P K; Gopalan, N; Behera, P K; Parida, M M

2014-10-15

158

Live attenuated tetravalent dengue vaccine  

Microsoft Academic Search

The development of a live attenuated tetravalent dengue vaccine is currently the best strategy to obtain a vaccine against dengue viruses. The Mahidol University group developed candidate live attenuated vaccines by attenuation through serial passages in certified primary cell cultures. Dengue serotype 1, 2 and 4 viruses were developed in primary dog kidney cells, whereas dengue serotype 3 was serially

N Bhamarapravati; Y Sutee

2000-01-01

159

Weather-Driven Variation in Dengue Activity in Australia Examined Using a Process-Based Modeling Approach  

PubMed Central

The impact of weather variation on dengue transmission in Cairns, Australia, was determined by applying a process-based dengue simulation model (DENSiM) that incorporated local meteorologic, entomologic, and demographic data. Analysis showed that inter-annual weather variation is one of the significant determinants of dengue outbreak receptivity. Cross-correlation analyses showed that DENSiM simulated epidemics of similar relative magnitude and timing to those historically recorded in reported dengue cases in Cairns during 1991–2009, (r = 0.372, P < 0.01). The DENSiM model can now be used to study the potential impacts of future climate change on dengue transmission. Understanding the impact of climate variation on the geographic range, seasonality, and magnitude of dengue transmission will enhance development of adaptation strategies to minimize future disease burden in Australia. PMID:23166197

Bannister-Tyrrell, Melanie; Williams, Craig; Ritchie, Scott A.; Rau, Gina; Lindesay, Janette; Mercer, Geoff; Harley, David

2013-01-01

160

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

161

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. PMID:24889214

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

2015-01-01

162

Dengue and dengue vectors in the WHO European region: past, present, and scenarios for the future.  

PubMed

After 55 years of absence, dengue has re-emerged in the WHO European region both as locally transmitted sporadic cases and as an outbreak in Madeira, driven by the introduction of people infected with the virus and the invasion of the vector mosquito species Aedes aegypti and Aedes albopictus. Models predict a further spread of A albopictus, particularly under climate change conditions. Dengue transmission models suggest a low risk in Europe, but these models too rarely include transmission by A albopictus (the main established vector). Further information gaps exist with regard to the Caucasus and central Asian countries of the WHO European region. Many European countries have implemented surveillance and control measures for invasive mosquitoes, but only a few include surveillance for dengue. As long as no dengue-specific prophylaxis or therapeutics are available, integrated vector management is the most sustainable control option. The rapid elimination of newly introduced A aegypti populations should be targeted in the European region, particularly in southern Europe and the Caucasus, where the species was present for decades until the 1950s. PMID:25172160

Schaffner, Francis; Mathis, Alexander

2014-12-01

163

77 FR 4048 - Disease, Disability, and Injury Prevention and Control Special Emphasis Panel (SEP): Initial Review  

Federal Register 2010, 2011, 2012, 2013, 2014

...Initial Review The meeting announced below concerns Evaluation of Dengue Epidemiology, Outcomes, and Prevention in Sentinel Surveillance...evaluation of applications received in response to ``Evaluation of Dengue Epidemiology, Outcomes and Prevention in Sentinel...

2012-01-26

164

Dengue Spatial and Temporal Patterns, French Guiana, 2001  

PubMed Central

To study a 2001 dengue fever outbreak in Iracoubo, French Guiana, we recorded the location of all patients’ homes and the date when symptoms were first observed. A geographic information system was used to integrate the patient-related information. The Knox test, a classic space-time analysis technique, was used to detect spatiotemporal clustering. Analysis of the relative-risk (RR) variations when space and time distances vary, highlighted the maximum space and time extent of a dengue transmission focus. The results show that heterogeneity in the RR variations in space and time corresponds to known entomologic and epidemiologic factors, such as the mosquito feeding cycle and host-seeking behavior. This finding demonstrates the relevance and potential of the use of GIS and spatial statistics for elaborating a dengue fever surveillance strategy. PMID:15200850

Deparis, Xavier; Dussart, Philippe; Morvan, Jacques; Rabarison, Patrick; Remy, Franck; Polidori, Laurent; Gardon, Jacques

2004-01-01

165

Dengue spatial and temporal patterns, French Guiana, 2001.  

PubMed

To study a 2001 dengue fever outbreak in Iracoubo, French Guiana, we recorded the location of all patients' homes and the date when symptoms were first observed. A geographic information system (GIS) was used to integrate the patient-related information. The Knox test, a classic space-time analysis technique, was used to detect spatiotemporal clustering. Analysis of the relative-risk (RR) variations when space and time distances vary, highlighted the maximum space and time extent of a dengue transmission focus. The results show that heterogeneity in the RR variations in space and time corresponds to known entomologic and epidemiologic factors, such as the mosquito feeding cycle and host-seeking behavior. This finding demonstrates the relevance and potential of the use of GIS and spatial statistics for elaborating a dengue fever surveillance strategy. PMID:15200850

Tran, Annelise; Deparis, Xavier; Dussart, Philippe; Morvan, Jacques; Rabarison, Patrick; Remy, Franck; Polidori, Laurent; Gardon, Jacques

2004-04-01

166

Dengue virus envelope protein domain I/II hinge: a key target for dengue virus vaccine design?  

PubMed

Dengue virus is the most significant arboviral pathogen worldwide with nearly 400 million infections annually and half the global population at risk of disease. Despite this tremendous public health burden, there are no licensed treatments or vaccines to prevent dengue in humans. Results from clinical trials of leading vaccine candidates have demonstrated that our current understanding of the correlates of protection from dengue is incomplete, and as such vaccine performance has been moderate, but with considerable room for improvement. Here we highlight new findings revealing key neutralizing epitopes that regulate serotype-specific immunity, and discuss their implications for design and evaluation of future vaccine candidates. PMID:25249440

Widman, Douglas G; Baric, Ralph S

2015-01-01

167

Utility of the Tourniquet Test and the White Blood Cell Count to Differentiate Dengue among Acute Febrile Illnesses in the Emergency Room  

PubMed Central

Dengue often presents with non-specific clinical signs, and given the current paucity of accurate, rapid diagnostic laboratory tests, identifying easily obtainable bedside markers of dengue remains a priority. Previous studies in febrile Asian children have suggested that the combination of a positive tourniquet test (TT) and leucopenia can distinguish dengue from other febrile illnesses, but little data exists on the usefulness of these tests in adults or in the Americas. We evaluated the diagnostic accuracy of the TT and leucopenia (white blood cell count <5000/mm3) in identifying dengue as part of an acute febrile illness (AFI) surveillance study conducted in the Emergency Department of Saint Luke's Hospital in Ponce, Puerto Rico. From September to December 2009, 284 patients presenting to the ED with fever for 2–7 days and no identified source were enrolled. Participants were tested for influenza, dengue, leptospirosis and enteroviruses. Thirty-three (12%) patients were confirmed as having dengue; 2 had dengue co-infection with influenza and leptospirosis, respectively. An infectious etiology was determined for 141 others (136 influenza, 3 enterovirus, 2 urinary tract infections), and 110 patients had no infectious etiology identified. Fifty-two percent of laboratory-positive dengue cases had a positive TT versus 18% of patients without dengue (P<0.001), 87% of dengue cases compared to 28% of non-dengue cases had leucopenia (P<0.001). The presence of either a positive TT or leucopenia correctly identified 94% of dengue patients. The specificity and positive predictive values of these tests was significantly higher in the subset of patients without pandemic influenza A H1N1, suggesting improved discriminatory performance of these tests in the absence of concurrent dengue and influenza outbreaks. However, even during simultaneous AFI outbreaks, the absence of leucopenia combined with a negative tourniquet test may be useful to rule out dengue. PMID:22163057

Gregory, Christopher J.; Lorenzi, Olga D.; Colón, Lisandra; Sepúlveda García, Arleene; Santiago, Luis M.; Cruz Rivera, Ramón; Cuyar Bermúdez, Liv Jossette; Ortiz Báez, Fernando; Vázquez Aponte, Delanor; Tomashek, Kay M.; Gutierrez, Jorge; Alvarado, Luisa

2011-01-01

168

An update on the incidence of dengue gaining strength in Saudi Arabia and current control approaches for its vector mosquito  

PubMed Central

Background The cases of dengue reported earlier in the late 1990s from the Kingdom of Saudi Arabia (KSA) occurred in the cities of Jeddah and Makkah. Although the kingdom has ample financial resources to establish effective control measures for the dengue vector, numerous cases of dengue occur and fluctuate in numbers from year to year. This necessitates a serious review of the current vector control strategies being practiced in order to identify the existing shortcomings. This short report provides an update on epidemiology of dengue in KSA (specifically in cities of Jeddah and Makkah) with a critical look at the current vector control strategies. Findings In 2013, 4411 cases of dengue were reported, with 8 cases of mortality. This number of dengue incidence was four times higher compared to 2012. In 2013, the highest number of 1272 dengue cases was reported in May, while the lowest number (37) of cases was reported in September. Conclusions It is evident that the control strategies of the dengue vector presently employed are inadequate. There seems to be serious deficiencies in following proper scientific procedures during field application(s) of control materials against the vector as is evident by the increases in the number of dengue cases as well as frequent outbreaks of the vector mosquito populations. In this review, some specific suggestions are made to draw attention to the relevant KSA authorities of the possible reasons behind unsuccessful control results and as to how to improve the strategy of dengue vector control in the kingdom. PMID:24890567

2014-01-01

169

Novel Strategies to Control Aedes aegypti and Dengue  

Microsoft Academic Search

\\u000a Vector-borne diseases are resurgent throughout the world. There are critical needs to develop novel approaches and strategies\\u000a and improved public health capacity to prevent and control these diseases. Dengue is an archetypical resurging and emerging\\u000a disease. At the Arthropod-Borne and Infectious Diseases Laboratory, we are investigating novel strategies for Aedes aegypti and dengue control; including development of (1) transgenic Ae.

Barry Beaty; Scott Bernhardt; William Black; Carol Blair; Lars Eisen; Darwin Elizondo-Quiroga; Jose Farfan-Ale; Saul Lozano-Fuentes; Alexander Franz; Ken E. Olson; Irma Sanchez-Vargas

170

Dengue and Calcium  

PubMed Central

Dengue is potentially fatal unless managed appropriately. No specific treatment is available and the mainstay of treatment is fluid management with careful monitoring, organ support, and correction of metabolic derangement. Evidence with regards to the role of calcium homeostasis in dengue is limited. Low blood calcium levels have been demonstrated in dengue infection and hypocalcemia maybe more pronounced in more severe forms. The cause of hypocalcemia is likely to be multifactorial. Calcium has been also implicated in the immuopathogenesis of dengue; however, the precise clinical implications of these interactions are yet not clearly defined. Derangements of calcium homeostasis are likely to be associated with myocardial dysfunction and cardiac arrhythmias observed in dengue as suggested by in vitro studies. Calcium also plays a role in platelet aggregation. Studies evaluating the therapeutic use of calcium in dengue have been underpowered and poorly designed to make any firm recommendations. Further studies are needed to explore the role and usefulness of maintenance of calcium homeostasis in modulating cardiac dysfunction, immunopathogenesis, and platelet abnormalities related to dengue. PMID:25625064

Shivanthan, Mitrakrishnan C; Rajapakse, Senaka

2014-01-01

171

Dengue Spatial and Temporal Patterns, French Guiana, 2001  

Microsoft Academic Search

To study a 2001 dengue fever outbreak in Iracoubo, French Guiana, we recorded the location of all patients' homes and the date when symptoms were first observed. A geographic information system (GIS) was used to integrate the patient-related information. The Knox test, a classic space-time analysis technique, was used to detect spa- tiotemporal clustering. Analysis of the relative-risk (RR) variations

Annelise Tran; Xavier Deparis; Philippe Dussart; Jacques Morvan; Patrick Rabarison; Franck Remy; Laurent Polidori; Jacques Gardon

2004-01-01

172

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

173

Temporal Correlations Between Mosquito-Based Dengue Virus Surveillance Measures or Indoor Mosquito Abundance and Dengue Case Numbers in Mérida City, México  

PubMed Central

Surveillance of dengue virus (DENV) in Aedes (Stegomyia) aegypti (L.) females is of potential interest because human DENV infections are commonly asymptomatic, which decreases the effectiveness of dengue case surveillance to provide early warning of building outbreaks. Our primary aim was to examine if mosquito-based virological measures – monthly percentages of examined Ae. aegypti females infected with DENV or examined homes from which ?1 DENV-infected Ae. aegypti female was collected – are correlated with reported dengue cases in the same or subsequent months within study neighborhoods in Mérida City, México. The study encompassed ~30 neighborhoods in the southern and eastern parts of the city. Mosquitoes were collected monthly over a 15-month period within study homes (average of 145 homes examined per month); this produced ~5,800 Ae. aegypti females subsequently examined for DENV RNA. Although monthly dengue case numbers in the study neighborhoods varied more than 100-fold during the study period, we did not find statistically significant positive correlations between monthly data for mosquito-based DENV surveillance measures and reported dengue cases in the same or subsequent months. Monthly average temperature, rainfall, and indoor abundance of Ae. aegypti females were positively correlated (P ? 0.001) with dengue case numbers in subsequent months with lag times of 3–5, 2, and 1–2 months, respectively. However, because dengue outbreak risk is strongly influenced by serotype-specific susceptibility of the human population to DENV, the value of weather conditions and entomological indices to predict outbreaks is very limited. Potential ways to improve the sensitivity of mosquito-based DENV surveillance are discussed. PMID:25118425

EISEN, LARS; GARCÍA-REJÓN, JULIÁN E.; GÓMEZ-CARRO, SALVADOR; VÁSQUEZ, MARÍA DEL ROSARIO NÁJERA; KEEFE, THOMAS J.; BEATY, BARRY J.; LOROÑO-PINO, MARÍA ALBA

2014-01-01

174

Acute Pancreatitis Complicating Severe Dengue  

PubMed Central

Dengue is an arthropod borne viral infection endemic in tropical and subtropical continent. Severe dengue is life threatening. Various atypical presentations of dengue have been documented. But we present a rare and fatal complication of severe dengue in form of acute pancreatitis. A 27-year-old male had presented with severe dengue in decompensated shock and with pain in abdomen due to pancreatitis. The pathogenesis of acute pancreatitis in dengue is not clearly understood, but various mechanisms are postulated. The awareness and timely recognition of this complication is very important for proper management. PMID:24926168

Jain, Vishakha; Gupta, OP; Rao, Tarun; Rao, Siddharth

2014-01-01

175

Anti-GBM disease and ANCA during dengue infection.  

PubMed

Anti-glomerular basement membrane (GBM) disease is a severe inflammatory renal disorder due to pathogenic autoantibodies directed mainly against the ?3 chain of type IV collagen. In ~ 1/4 of patients with anti-GBM disease, antineutrophil cytoplasmic antibodies (ANCA) predominantly with myeloperoxidase (MPO) specificity can be detected. Although the inciting stimuli leading to the development of an immune response against the type IV collagen and neutrophils are unknown, evidence indicates that both genetic and environmental factors play a role. Of note, molecular mimicry between self-antigens and nonself-antigens such as antigenic determinants of microorganisms has been implicated in the pathogenesis of anti-GBM disease and ANCA-associated vasculitis. A mosquito-borne viral illness highly prevalent in the tropics and subtropics, dengue can be complicated by acute renal failure, proteinuria, hematuria and glomerulonephritis. We present a 66-yearold woman who was diagnosed with dengue infection and rapidly progressive glomerulonephritis during an outbreak of dengue in Honduras in the summer of 2013. Renal biopsy revealed severe crescentic glomerulonephritis. Immunofluorescence examination demonstrated strong linear IgG deposition along glomerular capillary walls. Serologic tests demonstrated antibodies against GBM, MPO and platelet glycoproteins. The patient was diagnosed with anti-GBM disease associated with p-ANCA with MPO specificity. Despite heavy immunosuppression and plasmapheresis, IgG titers against dengue virus continued to rise confirming the diagnosis of acute dengue infection. We present the first reported case of anti-GBM disease associated with p-ANCA with MPO specificity during dengue infection. This report calls for a heightened awareness of autoimmunity leading to crescentic glomerulonephritis in patients with dengue infection. PMID:24691016

Lizarraga, Karlo J; Florindez, Jorge A; Daftarian, Pirouz; Andrews, David M; Ortega, Luis M; Mendoza, Jair Munoz; Contreras, Gabriel N; Nayer, Ali

2015-02-01

176

Impact of Dengue  

MedlinePLUS

... in the Americas, South-East Asia, the Eastern Mediterranean and the Western Pacific and dengue fever is ... East Asia Region WHO European Region WHO Eastern Mediterranean Region WHO Western Pacific Region RSS Feeds WHO ...

177

Travelers' Health: Dengue Fever  

MedlinePLUS

... onset), IgM anti-DENV can be detected with ELISA. For patients presenting during the first week after ... laboratory confirmation of dengue. IgG anti-DENV by ELISA in a single serum sample is not useful ...

178

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

179

International Dispersal of Dengue through Air Travel: Importation Risk for Europe  

PubMed Central

Background The worldwide distribution of dengue is expanding, in part due to globalized traffic and trade. Aedes albopictus is a competent vector for dengue viruses (DENV) and is now established in numerous regions of Europe. Viremic travellers arriving in Europe from dengue-affected areas of the world can become catalysts of local outbreaks in Europe. Local dengue transmission in Europe is extremely rare, and the last outbreak occurred in 1927–28 in Greece. However, autochthonous transmission was reported from France in September 2010, and from Croatia between August and October 2010. Methodology We compiled data on areas affected by dengue in 2010 from web resources and surveillance reports, and collected national dengue importation data. We developed a hierarchical regression model to quantify the relationship between the number of reported dengue cases imported into Europe and the volume of airline travellers arriving from dengue-affected areas internationally. Principal Findings In 2010, over 5.8 million airline travellers entered Europe from dengue-affected areas worldwide, of which 703,396 arrived at 36 airports situated in areas where Ae. albopictus has been recorded. The adjusted incidence rate ratio for imported dengue into European countries was 1.09 (95% CI: 1.01–1.17) for every increase of 10,000 travellers; in August, September, and October the rate ratios were 1.70 (95%CI: 1.23–2.35), 1.46 (95%CI: 1.02–2.10), and 1.35 (95%CI: 1.01–1.81), respectively. Two Italian cities where the vector is present received over 50% of all travellers from dengue-affected areas, yet with the continuing vector expansion more cities will be implicated in the future. In fact, 38% more travellers arrived in 2013 into those parts of Europe where Ae. albopictus has recently been introduced, compared to 2010. Conclusions The highest risk of dengue importation in 2010 was restricted to three months and can be ranked according to arriving traveller volume from dengue-affected areas into cities where the vector is present. The presence of the vector is a necessary, but not sufficient, prerequisite for DENV onward transmission, which depends on a number of additional factors. However, our empirical model can provide spatio-temporal elements to public health interventions. PMID:25474491

Semenza, Jan C.; Sudre, Bertrand; Miniota, Jennifer; Rossi, Massimiliano; Hu, Wei; Kossowsky, David; Suk, Jonathan E.; Van Bortel, Wim; Khan, Kamran

2014-01-01

180

Use of Insecticide-Treated House Screens to Reduce Infestations of Dengue Virus Vectors, Mexico  

PubMed Central

Dengue prevention efforts rely on control of virus vectors. We investigated use of insecticide-treated screens permanently affixed to windows and doors in Mexico and found that the screens significantly reduced infestations of Aedes aegypti mosquitoes in treated houses. Our findings demonstrate the value of this method for dengue virus vector control. PMID:25625483

Manrique-Saide, Pablo; Che-Mendoza, Azael; Barrera-Perez, Mario; Guillermo-May, Guillermo; Herrera-Bojorquez, Josue; Dzul-Manzanilla, Felipe; Gutierrez-Castro, Cipriano; Lenhart, Audrey; Vazquez-Prokopec, Gonzalo; Sommerfeld, Johannes; McCall, Philip J.; Kroeger, Axel

2015-01-01

181

Use of insecticide-treated house screens to reduce infestations of dengue virus vectors, Mexico.  

PubMed

Dengue prevention efforts rely on control of virus vectors. We investigated use of insecticide-treated screens permanently affixed to windows and doors in Mexico and found that the screens significantly reduced infestations of Aedes aegypti mosquitoes in treated houses. Our findings demonstrate the value of this method for dengue virus vector control. PMID:25625483

Manrique-Saide, Pablo; Che-Mendoza, Azael; Barrera-Perez, Mario; Guillermo-May, Guillermo; Herrera-Bojorquez, Josue; Dzul-Manzanilla, Felipe; Gutierrez-Castro, Cipriano; Lenhart, Audrey; Vazquez-Prokopec, Gonzalo; Sommerfeld, Johannes; McCall, Philip J; Kroeger, Axel; Arredondo-Jimenez, Juan I

2015-02-01

182

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

183

Acute renal failure due to rhabdomyolysis following dengue viral infection: a case report  

PubMed Central

Introduction With more than one-third of the world’s population living in areas at risk for transmission, dengue fever is a leading cause of illness and death in the tropics and subtropics. Despite the high incidence of dengue fever, rhabdomyolysis leading to acute renal failure is an extremely rare complication of dengue fever. Only a few such cases have been reported in the literature. Case presentation We describe the case of a 42-year-old, previously healthy Sri Lankan Sinhalese man who developed acute renal failure due to rhabdomyolysis following dengue virus infection. He was transferred to our institution with a five-day history of fever, headache, myalgia, impaired level of consciousness, and reduced urinary output. He was hemodynamically stable and did not have evidence of plasma leakage. His serology for dengue immunoglobulin M and immunoglobulin G was positive, and biochemical investigations disclosed evidence of rhabdomyolysis and acute renal failure. He was treated with induced alkaline diuresis and hemodialysis, and he experienced an uncomplicated recovery. Conclusion The occurrence of acute renal failure significantly increases the mortality of patients with dengue fever. Therefore, early diagnosis and early management are crucial in rhabdomyolysis complicating dengue fever to prevent established acute renal failure. It should be kept in mind that the threshold for suspecting rhabdomyolysis is very low in dengue fever. Creatinine phosphokinase levels should routinely be measured in all patients with severe dengue fever for early detection of rhabdomyolysis to prevent acute renal failure. PMID:23889764

2013-01-01

184

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

185

Dengue Incidence in Urban and Rural Cambodia: Results from Population-Based Active Fever Surveillance, 2006  

E-print Network

Dengue Incidence in Urban and Rural Cambodia: Results from Population-Based Active Fever in rural villages and urban areas during 2006­2008. Methods and Findings: Active surveillance for febrile.5­211.5/1,000 person-seasons (median 36.5). During a DENV-3 outbreak in 2007, rural areas were affected more than urban

Paris-Sud XI, Université de

186

Reemergence of Dengue Virus Type  

E-print Network

Reemergence of Dengue Virus Type 4, French Antilles and French Guiana, 2004­2005 Philippe Dussart After 10 years of absence, dengue virus type 4 (DENV- 4) has recently reemerged in Martinique is a viral disease transmitted by mosquitoes. It is caused by any of the 4 viral serotypes of dengue virus

Paris-Sud XI, Université de

187

Evaluation of four methods for detection of immunoglobulin M antibodies to dengue virus.  

PubMed

Dengue has become hyperendemic in many islands of the Caribbean region. The performance in a diagnostic laboratory of four commercial assays for detection of immunoglobulin M (IgM) antibodies was evaluated. Sera from 62 patients with dengue virus infection were studied. These included 18 patients from whom dengue virus type 2 was isolated in a 1997 outbreak (specimens collected a mean of 14 days after onset of symptoms), 8 patients with dengue hemorrhagic fever (mean time after onset, 11 days), and 36 patients in whom dengue was previously confirmed by serology (mean time after onset, 10 days). Thirty serum specimens from blood donors in a country where dengue is not endemic were used as negative controls. The methods evaluated were two IgM-capture enzyme-linked immunosorbent assays (ELISA) (MRL Diagnostics, Cypress, Calif., and PanBio, Queensland, Australia), a dot ELISA dipstick assay (Integrated Diagnostics, Baltimore, Md.), and a rapid immunochromatographic assay for dengue IgG and IgM (PanBio IC). IgG antibodies were also detected by an ELISA method (MRL Diagnostics). The sensitivities of the four assays were as follows: MRL Diagnostics IgM ELISA, 98.4%; PanBio IgM ELISA, 85.5%; Integrated Diagnostics IgM dot ELISA, 96. 8%; and PanBio IC, 83.9%. The specificities of all tests were 100%. Evidence of secondary dengue was found in all patients with dengue hemorrhagic fever and in 83% of the remaining patients. The MRL Diagnostics IgM ELISA appears to be more sensitive than the PanBio IgM ELISA, and this may be significant when IgM titers are low, particularly in patients with secondary dengue infections. The dot ELISA dipstick assay is equally sensitive and may be more appropriate for use in laboratories with lower workloads. PMID:10391862

Branch, S L; Levett, P N

1999-07-01

188

Simultaneous circulation of genotypes I and III of dengue virus 3 in Colombia  

PubMed Central

Background Dengue is a major health problem in tropical and subtropical regions. In Colombia, dengue viruses (DENV) cause about 50,000 cases annually, 10% of which involve Dengue Haemorrhagic Fever/Dengue Shock Syndrome. The picture is similar in other surrounding countries in the Americas, with recent outbreaks of severe disease, mostly associated with DENV serotype 3, strains of the Indian genotype, introduced into the Americas in 1994. Results The analysis of the 3'end (224 bp) of the envelope gene from 32 DENV-3 strains recently recovered in Colombia confirms the circulation of the Indian genotype, and surprisingly the co-circulation of an Asian-Pacific genotype only recently described in the Americas. Conclusion These results have important implications for epidemiology and surveillance of DENV infection in Central and South America. Molecular surveillance of the DENV genotypes infecting humans could be a very valuable tool for controlling/mitigating the impact of the DENV infection. PMID:18764951

Usme-Ciro, Jose A; Mendez, Jairo A; Tenorio, Antonio; Rey, Gloria J; Domingo, Cristina; Gallego-Gomez, Juan C

2008-01-01

189

[Dengue fever: from disease to vaccination].  

PubMed

Dengue is a tropical disease affecting 110 countries throughout the world and placing over 3 billion people at risk of infection. According the World Health Organization 70 to 500 million persons are infected every year including 2 million who develop hemorrhagic form and 20,000 who die. Children are at highest risk for death. Due to the absence of specialized laboratories in most endemic regions and to the lack of specifici clinical presentation, the incidence of dengue and its economic costs are certainly underestimated. Dengue iscaused by an arbovirus belonging to the Flavivirus genus of the family Flaviviridae. There are four dengue virus serotypes and no cross protection between them. The disease is transmitted through the bites of mosquitoes belonging to the Aedes genus, mainly Aedes aegypti. However A. albopictus has played an important role in the spread of the disease and other species may be involved in specific locations (e.g., A. polynesiensis in the South Pacific). There is no specific treatment for dengue. Management of severe forms depends on symptomatic treatment of hemorrhagic complications and hypovolemic shock. Prevention requires control of vector mosquitoes that is difficult to implement and maintain. Dengue is a major emerging infectious disease with a heavy impact on public health. The high human and economic costs as well as the absence of specific preventive measures underscore the need to develop a vaccine. However finding and distributing such a vaccine to populations at risk is hampered by numerous obstacles. The most notable challenges standing in the way of development of a candidate vaccine are as follows: absence of an animal model, which has important implications for the preclinical development strategy; need to develop a live attenuated vaccine; existence of 4 antigenically distinct serotypes with the resulting risk of competition between vaccine strains; immunologic risks related to antibody-dependent enhancement that has been hypothesized to be the cause of severe forms of the illness; absence of a well defined correlate of protection and preexisting vaccine, which will require the organization of large-scale pre-clinical trials to demonstrate the efficacy of the virus; complexity associated with industrial production of a tetravalent vaccine. Development and production of a safe and reliable vaccine are only the first steps to ensuring protection of the populations at risk, It twill also be necessary to identify and take into account a variety of geographic, economic, regulatory, and logistic factors: The epidemiological profile of dengue is variable. For example the age at which the likelihood of developing the disease is highest is not the same in Asia and Latin America. Vaccination programs must be tailored to regional and national epidemiological specificities. Introduction of dengue vaccination in the national immunization programs must take into account the special features of each country without jeopardizing the existing vaccines already in use. The need for an additional visit can represent a hardship both economically and logistically. Alternative funding will be needed to finance vaccination programs in some countries located in endemic zones, Long-term phase 4 effectiveness and tolerance field studies must be planned in collaboration with national authorities. All these challenges and obstacles have been taken into account in the development of Sanofi Pasteur's live attenuated tetravalent vaccine. Research for development of a dengue vaccine began during the 1990s. Clinical studies with the most promising tetravalent vaccine were started in the 2000s. A trial carried out in adults in the United States has shown that administration of three doses of the tetravalent candidate vaccine was 100% successful in inducing an antibody response capable of neutralizing all four dengue virus serotypes. Phase II clinical trials are now under way in children and adults in Mexico, Peru, and the Philippines. The first efficacy trial in children began in Thailand in February 2009. The purp

Teyssou, R

2009-08-01

190

Dengue—How Best to Classify It  

PubMed Central

Dengue has emerged as a major public health problem worldwide. Dengue virus infection causes a wide range of clinical manifestations. Since the 1970s, clinical dengue has been classified according to the World Health Organization guideline as dengue fever and dengue hemorrhagic fever. The classification has been criticized with regard to its usefulness and its applicability. In 2009, the World Health Organization issued a new guideline that classifies clinical dengue as dengue and severe dengue. The 2009 classification differs significantly from the previous classification in both conceptual and practical levels. The impacts of the new classification on clinical practice, dengue research, and public health policy are discussed. PMID:21832264

Rothman, Alan L.; Gibbons, Robert V.; Sittisombut, Nopporn; Malasit, Prida; Ennis, Francis A.; Nimmannitya, Suchitra; Kalayanarooj, Siripen

2011-01-01

191

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.

192

Sulfated Polysaccharide, Curdlan Sulfate, Efficiently Prevents Entry/Fusion and Restricts Antibody-Dependent Enhancement of Dengue Virus Infection In Vitro: A Possible Candidate for Clinical Application  

PubMed Central

Curdlan sulfate (CRDS), a sulfated 1?3-?-D glucan, previously shown to be a potent HIV entry inhibitor, is characterized in this study as a potent inhibitor of the Dengue virus (DENV). CRDS was identified by in silico blind docking studies to exhibit binding potential to the envelope (E) protein of the DENV. CRDS was shown to inhibit the DENV replication very efficiently in different cells in vitro. Minimal effective concentration of CRDS was as low as 0.1 µg/mL in LLC-MK2 cells, and toxicity was observed only at concentrations over 10 mg/mL. CRDS can also inhibit DENV-1, 3, and 4 efficiently. CRDS did not inhibit the replication of DENV subgenomic replicon. Time of addition experiments demonstrated that the compound not only inhibited viral infection at the host cell binding step, but also at an early post-attachment step of entry (membrane fusion). The direct binding of CRDS to DENV was suggested by an evident reduction in the viral titers after interaction of the virus with CRDS following an ultrafiltration device separation, as well as after virus adsorption to an alkyl CRDS-coated membrane filter. The electron microscopic features also showed that CRDS interacted directly with the viral envelope, and caused changes to the viral surface. CRDS also potently inhibited DENV infection in DC-SIGN expressing cells as well as the antibody-dependent enhancement of DENV-2 infection. Based on these data, a probable binding model of CRDS to DENV E protein was constructed by a flexible receptor and ligand docking study. The binding site of CRDS was predicted to be at the interface between domains II and III of E protein dimer, which is unique to this compound, and is apparently different from the ?-OG binding site. Since CRDS has already been tested in humans without serious side effects, its clinical application can be considered. PMID:23658845

Zhang, Li Feng; Chin, Wei Xin; Muschin, Tegshi; Heinig, Lars; Suzuki, Youichi; Nanjundappa, Haraprasad; Yoshinaka, Yoshiyuki; Ryo, Akihide; Nomura, Nobuo; Ooi, Eng Eong; Vasudevan, Subhash G.; Yoshida, Takashi; Yamamoto, Naoki

2013-01-01

193

Detection of dengue viruses in field-caught Aedes aegypti (Diptera: Culicidae) in Maracay, Aragua state, Venezuela by type-specific polymerase chain reaction.  

PubMed

Virological surveillance of dengue viruses in Aedes aegypti populations constitutes a powerful tool for early prediction of dengue outbreaks. We have standardized a protocol for viral RNA extraction from individual and pools of mosquitoes that permits a sensitive detection of dengue virus without RNA degradation or PCR inhibition when we apply a semi-nested RT-PCR. The limit of detection for each dengue serotype was 0.1 PFU. In a prospective field study conducted from November 2000 to December 2001, adult female A. aegypti mosquitoes from several municipalities with high dengue transmission in Maracay, Aragua State, Venezuela were collected and screened for dengue viruses using RT-PCR. We analyzed a total of 296 A. aegypti pools (1,632 mosquitoes); of these, 154 pools (469 mosquitoes) were collected from houses with persons with clinical diagnosis of dengue (dengue houses), and 142 pools (1,163 mosquitoes) from adjacent residences (neighbour houses). From the dengue houses, eight mosquito pools (5.2%) were positive for DENV-1 (0.7%), DENV-3 (3.2%) and DENV-4 (1.3%) viruses. From the neighbour houses, 18 mosquito pools (12.7%) were positive for DENV-3 (12%) and DENV-4 (0.7%) viruses. From these 26 RT-PCR positive mosquito pools (containing 1-25 mosquitoes each), 22 pools (84.6%) were positive for DENV-3. The most prevalent serotype in the 2001 dengue outbreak was also DENV-3. The minimum infection rate in both A. aegypti collections, from dengue houses and neighbour houses was 17 and 15 per 1,000, respectively. The relevance of these results for dengue surveillance is discussed. PMID:15639750

Urdaneta, Ludmel; Herrera, Flor; Pernalete, Martha; Zoghbi, Normig; Rubio-Palis, Yasmín; Barrios, Roybel; Rivero, José; Comach, Guillermo; Jiménez, Matilde; Salcedo, Maria

2005-03-01

194

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

195

[Modern immunological and clinical determinants of virus dengue infection].  

PubMed

The growing problem of widespread viral infections is a challenge for modern medicine. Emerging reports of dengue virus infections in Europe create a new epidemic problem. The virus responsible for causing the symptoms of the disease is transmitted by mosquitoes. Over 50% of the world's population lives in areas where the risk of dengue feveris high. In total, according to WHO, infected with dengue is 2.4 million people and outbreaks of endemic diseases are present in 100 countries that threaten the 2.5 billion population. There are four serotypes of dengue virus, which belong to the family Flaviviridae and the type of Flavirus. Serotypes are known as DENV-1, DENV-2, DENV-3 and DENV-4. Contact each of the serotypes of the virus causes long-lasting resistance to the other, and each of them is responsible for the induction of disease epidemics, including severe cases. In the first stage of the disease should seek to replace lost fluids and electrolytes. Because of the elevated body temperature is recommended to administer paracetamol formulations and the use of cold compresses. Contraindicated is the use of aspirin and non-steroidal anti-inflammatory drugs. In severe forms of dengue patients absolutely should be hospitalized and treatment in the intensive care centers. In the treatment of shock, it is recommended that the administration of isotonic crystalloid fluids at 5-10 ml/kg/hr. under the control of hematocrit and fill peripheral microcirculation. The administration of blood products for the large current is required to control bleeding. Dengue vaccine containing DEN-DEN chimeras is still at the stage of preclinical studies. PMID:25546995

P?usa, Tadeusz

2014-11-01

196

Describing the Breakbone Fever: IDODEN, an Ontology for Dengue Fever  

PubMed Central

Background Ontologies represent powerful tools in information technology because they enhance interoperability and facilitate, among other things, the construction of optimized search engines. To address the need to expand the toolbox available for the control and prevention of vector-borne diseases we embarked on the construction of specific ontologies. We present here IDODEN, an ontology that describes dengue fever, one of the globally most important diseases that are transmitted by mosquitoes. Methodology/Principal Findings We constructed IDODEN using open source software, and modeled it on IDOMAL, the malaria ontology developed previously. IDODEN covers all aspects of dengue fever, such as disease biology, epidemiology and clinical features. Moreover, it covers all facets of dengue entomology. IDODEN, which is freely available, can now be used for the annotation of dengue-related data and, in addition to its use for modeling, it can be utilized for the construction of other dedicated IT tools such as decision support systems. Conclusions/Significance The availability of the dengue ontology will enable databases hosting dengue-associated data and decision-support systems for that disease to perform most efficiently and to link their own data to those stored in other independent repositories, in an architecture- and software-independent manner. PMID:25646954

Mitraka, Elvira; Topalis, Pantelis; Dritsou, Vicky; Dialynas, Emmanuel; Louis, Christos

2015-01-01

197

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

198

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

199

Optimization model of vaccination strategy for dengue transmission  

NASA Astrophysics Data System (ADS)

Dengue fever is emerging tropical and subtropical disease caused by dengue virus infection. The vaccination should be done as a prevention of epidemic in population. The host-vector model are modified with consider a vaccination factor to prevent the occurrence of epidemic dengue in a population. An optimal vaccination strategy using non-linear objective function was proposed. The genetic algorithm programming techniques are combined with fourth-order Runge-Kutta method to construct the optimal vaccination. In this paper, the appropriate vaccination strategy by using the optimal minimum cost function which can reduce the number of epidemic was analyzed. The numerical simulation for some specific cases of vaccination strategy is shown.

Widayani, H.; Kallista, M.; Nuraini, N.; Sari, M. Y.

2014-02-01

200

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

201

Dengue Virus Tropism in Humanized Mice Recapitulates Human Dengue Fever  

PubMed Central

Animal models of dengue virus disease have been very difficult to develop because of the virus' specificity for infection and replication in certain human cells. We developed a model of dengue fever in immunodeficient mice transplanted with human stem cells from umbilical cord blood. These mice show measurable signs of dengue disease as in humans (fever, viremia, erythema and thrombocytopenia), and after infection with the most virulent strain of dengue serotype 2, humanized mice showed infection in human cells in bone marrow, spleen and blood. Cytokines and chemokines were secreted by these human cells into the mouse bloodstream. We demonstrated that the pathology of dengue virus infection in these mice follows that reported in human patients, making this the first valid and relevant model for studying dengue fever pathogenesis in humans. PMID:21695193

Mota, Javier; Rico-Hesse, Rebeca

2011-01-01

202

Environmental data analysis and remote sensing for early detection of dengue and malaria  

NASA Astrophysics Data System (ADS)

Malaria and dengue fever are the two most common mosquito-transmitted diseases, leading to millions of serious illnesses and deaths each year. Because the mosquito vectors are sensitive to environmental conditions such as temperature, precipitation, and humidity, it is possible to map areas currently or imminently at high risk for disease outbreaks using satellite remote sensing. In this paper we propose the development of an operational geospatial system for malaria and dengue fever early warning; this can be done by bringing together geographic information system (GIS) tools, artificial neural networks (ANN) for efficient pattern recognition, the best available ground-based epidemiological and vector ecology data, and current satellite remote sensing capabilities. We use Vegetation Health Indices (VHI) derived from visible and infrared radiances measured by satellite-mounted Advanced Very High Resolution Radiometers (AVHRR) and available weekly at 4-km resolution as one predictor of malaria and dengue fever risk in Bangladesh. As a study area, we focus on Bangladesh where malaria and dengue fever are serious public health threats. The technology developed will, however, be largely portable to other countries in the world and applicable to other disease threats. A malaria and dengue fever early warning system will be a boon to international public health, enabling resources to be focused where they will do the most good for stopping pandemics, and will be an invaluable decision support tool for national security assessment and potential troop deployment in regions susceptible to disease outbreaks.

Rahman, Md Z.; Roytman, Leonid; Kadik, Abdelhamid; Rosy, Dilara A.

2014-06-01

203

OUTBREAK OF TICK-BORNE RELAPSING FEVER AT THE NORTH RIM OF THE GRAND CANYON: EVIDENCE FOR EFFECTIVENESS OF PREVENTIVE MEASURES  

Microsoft Academic Search

An outbreak of tick-borne relapsing fever (TBRF) originating at the North Rim of Grand Canyon National Park was investigated in 1990. To determine risk factors for the disease, almost 7,000 parties of visitors were surveyed; over half responded, representing 10,000 people. Fifteen cases of confirmed or probable TBRF were identified in visitors and 2 in employees. All patients except one

W. S. PAUL; G. MAUPIN; A. O. SCOTT-WRIGHT; R. B. CRAVEN; D. T. DENNIS

204

Multiyear Climate Variability and Dengue—El Niño Southern Oscillation, Weather, and Dengue Incidence in Puerto Rico, Mexico, and Thailand: A Longitudinal Data Analysis  

PubMed Central

Background The mosquito-borne dengue viruses are a major public health problem throughout the tropical and subtropical regions of the world. Changes in temperature and precipitation have well-defined roles in the transmission cycle and may thus play a role in changing incidence levels. The El Niño Southern Oscillation (ENSO) is a multiyear climate driver of local temperature and precipitation worldwide. Previous studies have reported varying degrees of association between ENSO and dengue incidence. Methods and Findings We analyzed the relationship between ENSO, local weather, and dengue incidence in Puerto Rico, Mexico, and Thailand using wavelet analysis to identify time- and frequency-specific association. In Puerto Rico, ENSO was transiently associated with temperature and dengue incidence on multiyear scales. However, only local precipitation and not temperature was associated with dengue on multiyear scales. In Thailand, ENSO was associated with both temperature and precipitation. Although precipitation was associated with dengue incidence, the association was nonstationary and likely spurious. In Mexico, no association between any of the variables was observed on the multiyear scale. Conclusions The evidence for a relationship between ENSO, climate, and dengue incidence presented here is weak. While multiyear climate variability may play a role in endemic interannual dengue dynamics, we did not find evidence of a strong, consistent relationship in any of the study areas. The role of ENSO may be obscured by local climate heterogeneity, insufficient data, randomly coincident outbreaks, and other, potentially stronger, intrinsic factors regulating transmission dynamics. Please see later in the article for the Editors' Summary PMID:19918363

Johansson, Michael A.; Cummings, Derek A. T.; Glass, Gregory E.

2009-01-01

205

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

206

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

207

Susceptibility of Florida Aedes aegypti and Aedes albopictus to dengue viruses from Puerto Rico.  

PubMed

Locally acquired dengue cases in the continental U.S. are rare. However, outbreaks of dengue-1 during 2009, 2010, and 2013 in Florida and dengue-1 and -2 in Texas suggest vulnerability to transmission. Travel and commerce between Puerto Rico and the U.S. mainland is common, which may pose a risk for traveler-imported dengue cases. Mosquitoes were collected in Florida and used to evaluate their susceptibility to dengue viruses (DENV) from Puerto Rico. Aedes aegypti and Ae. albopictus were susceptible to virus infection with DENV-1 and -2. No significant differences were observed in rates of midgut infection or dissemination between Ae. aegypti or Ae. albopictus for DENV-1 (6-14%). Aedes aegypti was significantly more susceptible to midgut infection with DENV-2 than Ae. albopictus (Ae. aegypti, ?28%; Ae. albopictus, ?9%). The dissemination rate with dengue-2 virus for Ae. aegypti (23%) was greater than Ae. albopictus (0%), suggesting that Ae. albopictus is not likely to be an important transmitter of the DENV-2 isolate from Puerto Rico. These results are discussed in light of Florida's vulnerability to DENV transmission. PMID:25424270

Alto, Barry W; Smartt, Chelsea T; Shin, Dongyoung; Bettinardi, David; Malicoate, Jolene; Anderson, Sheri L; Richards, Stephanie L

2014-12-01

208

Dengue Fever Occurrence and Vector Detection by Larval Survey, Ovitrap and MosquiTRAP: A Space-Time Clusters Analysis  

PubMed Central

The use of vector surveillance tools for preventing dengue disease requires fine assessment of risk, in order to improve vector control activities. Nevertheless, the thresholds between vector detection and dengue fever occurrence are currently not well established. In Belo Horizonte (Minas Gerais, Brazil), dengue has been endemic for several years. From January 2007 to June 2008, the dengue vector Aedes (Stegomyia) aegypti was monitored by ovitrap, the sticky-trap MosquiTRAP™ and larval surveys in an study area in Belo Horizonte. Using a space-time scan for clusters detection implemented in SaTScan software, the vector presence recorded by the different monitoring methods was evaluated. Clusters of vectors and dengue fever were detected. It was verified that ovitrap and MosquiTRAP vector detection methods predicted dengue occurrence better than larval survey, both spatially and temporally. MosquiTRAP and ovitrap presented similar results of space-time intersections to dengue fever clusters. Nevertheless ovitrap clusters presented longer duration periods than MosquiTRAP ones, less acuratelly signalizing the dengue risk areas, since the detection of vector clusters during most of the study period was not necessarily correlated to dengue fever occurrence. It was verified that ovitrap clusters occurred more than 200 days (values ranged from 97.0±35.35 to 283.0±168.4 days) before dengue fever clusters, whereas MosquiTRAP clusters preceded dengue fever clusters by approximately 80 days (values ranged from 65.5±58.7 to 94.0±14. 3 days), the former showing to be more temporally precise. Thus, in the present cluster analysis study MosquiTRAP presented superior results for signaling dengue transmission risks both geographically and temporally. Since early detection is crucial for planning and deploying effective preventions, MosquiTRAP showed to be a reliable tool and this method provides groundwork for the development of even more precise tools. PMID:22848729

de Melo, Diogo Portella Ornelas; Scherrer, Luciano Rios; Eiras, Álvaro Eduardo

2012-01-01

209

Overview of current situation of dengue and dengue vector control  

Technology Transfer Automated Retrieval System (TEKTRAN)

Dengue is the most important arbovirus of humans in the world. It is caused by one of four closely related virus serotypes whose primary vector is Aedes aegypti and secondarily by Ae. albopictus. A global dengue pandemic began in Southeast Asia after World War II and has intensified during the las...

210

Dengue vaccine design: issues and challenges  

Microsoft Academic Search

Dengue virus infection is now a global problem affecting tens of millions of people. The spread of the four dengue virus serotypes had led to increased incidence of dengue haemorrhagic fever (DHF) reported and with 2.5 billion people at risk, efforts towards the development of safe and effective vaccines against dengue must be accelerated. This chapter reviews some of the

M J Cardosa

211

Dengue: update on epidemiology.  

PubMed

The epidemiology of dengue fever has undergone major shifts in recent decades. The global distribution has expanded to include more geographic areas. The intensity of transmission and the severity of infections have increased in areas where infection was already endemic. Multiple studies provide a clearer picture of the epidemiology and allow mapping of its distribution and change over time. Despite major efforts to control transmission, competent vectors now infest most tropical and subtropical regions; Aedes albopictus, also a competent vector, is able to survive in temperate areas, placing parts of Europe and North America at risk for local transmission. Many research teams in dengue-endemic areas are working to identify key local weather, vector, and other variables that would allow prediction of a likely epidemic early enough to permit interventions to avert it or blunt its impact. PMID:25475383

Wilson, Mary Elizabeth; Chen, Lin H

2015-01-01

212

Dengue eye disease.  

PubMed

Dengue fever, a viral disease epidemic in some parts of the world, is of considerable international concern, with a growing incidence owing to developing urbanization, tourism, and trade. Ocular manifestations of dengue fever are uncommon, but of great significance. Proposed mechanisms include direct viral infection as well as immunologic phenomena. Common manifestations include subconjunctival, vitreous, and retinal hemorrhages; posterior uveitis; optic neuritis; and maculopathies such as foveolitis, hemorrhage, and edema. Main symptoms include blurring of vision, scotomata, metamorphopsia, and floaters. Diagnostic and monitoring investigations described included optical coherence tomography, fundus fluorescein and indocyanine green angiography, visual field analysis, and electrophysiologic tests. Management is based on clinical presentation and includes active surveillance as well as various anti-inflammatory and immunosuppressive therapies. There have been no prospective, randomized therapeutic trials, and it is unclear if the disease is self-limiting or if treatment is actually beneficial. Prognosis varies, ranging from full resolution to permanent vision loss despite intervention. PMID:25223497

Ng, Aaron W; Teoh, Stephen C

2014-08-12

213

The geographic information system as an epidemiological tool in the surveillance of dengue virus-infected Aedes mosquitos.  

PubMed

A Geographic Information System (GIS) was used as analysis tool to study the spatial distribution of dengue virus-infected Aedes mosquitos in Thailand. Global Positioning System (GPS) instruments were used to map villages involved in dengue epidemiological studies in Ratchaburi Province, Thailand. Differentially processed GPS data, with a spatial resolution of approximately 1 meter, were incorporated into a GIS for analysis and mapping. Databases associated with a village GIS included village number, Aedes aegypti populations, and test results. Epidemiological surveillance for dengue infection through the detection of the dengue virus type(s) infecting Aedes mosquitos during epidemic periods constitutes a reliable sentinel system for dengue outbreaks. Various techniques were applied including: enzyme linked immunosorbent assay (ELISA), indirect immunofluorescent assay (IFA), and reverse transcriptase-polymerase chain reaction (RT-PCR) assay for the virologic surveillance of the type-specific detection of dengue viruses in artificially infected and in field-caught adult Aedes mosquitos. In laboratory experiments, all assays showed sufficient sensitively to detect one virus infected mosquito and the rapid RT-PCR clearly showed serotype-specificity with very high detection sensitivity. In the field study conducted from April to September 2000, female adult Aedes mosquitos were collected from selected dengue-sensitive areas in Chom Bung district, Ratchaburi Province and assayed by ELISA, IFA and RT-PCR with 18.3% (44/240), 28.98% (20/69) and 15% (3/20) positive for dengue virus, respectively. Geographic distribution of the virus-infected Aedes mosquitos and household locations were demonstrated by the GPS and the GIS. The development of disease mapping data coupled with RT-PCR laboratory-based surveillance of dengue virus infection can successfully serve as epidemiologic tools in an early warning system for dengue hemorrhagic fever (DHF) epidemics. PMID:15916091

Sithiprasasna, Ratana; Patpoparn, Somboon; Attatippaholkun, Watcharee; Suvannadabba, Saravudh; Srisuphanunt, Mayuna

2004-12-01

214

DENGUE IN PREGNANCY  

Microsoft Academic Search

This was a retrospective study of patients with dengue infection in pregnancy from year 2000 till 2004. Data were analyzed by looking at the presentation, complications of pa- tient and fetus, and pregnancy outcomes. There was a total of 16 cases with an increasing trend (0.12% in 2003 vs 0.25% in 2004). The mean age of patients was 30.19 ±

Nor Azlin Mohamed Ismail; Nirmala Kampan; Muhammad Abdul Jamil; Zainul Rashid Mohd Razi

215

TDR research on dengue: recommendations of a scientific working group.  

PubMed

Based on a scientific working group meeting in April 2000, this paper highlights the role of the UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR) in dengue fever prevention and control. Data showed that dengue infection is found in over 100 countries and territories and causes an estimated 50-100 million cases a year. TDR is expected to promote multicenter studies for developing and evaluating community-based mosquito control strategies. On the other hand, in Product Research and Development, a high priority is to develop tests to detect primary or secondary dengue infections early in the course of infection. It was recommended that TDR accelerate development of the current candidates, in collaboration with the current research groups, by appointing a task force with responsibilities for the design and conduct of Phase I-III trials. Finally, it was recommended that other important needed research on dengue, such as case management, clinico-epidemiological diagnosis, and surveillance, should be addressed by other players in the dengue research arena. PMID:12296148

2000-06-01

216

[Detection of dengue virus antigen in post-mortem tissues].  

PubMed

The epidemiological situation of dengue has worsened over the last decade. The difficulties in preventing its transmission and the absence of a vaccine or specific treatment have made dengue a serious risk to public health, health centers and research systems at different levels. Currently, most studies on the pathogenesis of dengue infection focus on the T-cell immune response almost exclusively in secondary infections and are aimed at identifying the mechanisms involved in the development of vascular permeability and bleeding events that accompany the infection. This report describes the case of a baby girl less than 45 days of age with clinical signs of severe dengue, whose diagnosis was confirmed by reverse transcription polymerase chain reaction in post-mortem tissue samples and by the ancillary diagnostic use of immunohistochemistry, which detected viral antigens in all organs obtained at autopsy. This case highlights the importance of studying primary infections associated with severe dengue, particularly in children, who are more likely to develop the severe form of the disease without previous infection, and it further stresses the importance of a diagnosis that should not be based solely on the examination of liver tissue samples when studying the pathogenesis of the viral infection. PMID:25504239

Rivera, Jorge; Neira, Marcela; Parra, Edgar; Méndez, Jairo; Sarmiento, Ladys; Caldas, María Leonor

2014-01-01

217

Corticosteroids in the treatment of dengue shock syndrome  

PubMed Central

Dengue infection causes significant morbidity and mortality in over 100 countries worldwide, and its incidence is on the rise. The pathophysiological basis for the development of severe dengue, characterized by plasma leakage and the “shock syndrome” are poorly understood. No specific treatment or vaccine is available, and careful monitoring and judicious administration of fluids forms the mainstay of management at present. It is postulated that vascular endothelial dysfunction, induced by cytokine and chemical mediators, is an important mechanism of plasma leakage. Although corticosteroids are potent modulators of the immune system, their role in pharmacological doses in modulating the purported immunological effects that take place in severe dengue has been a subject of controversy. The key evidence related to the role of corticosteroids for various manifestations of dengue are reviewed here. In summary, there is currently no high-quality evidence supporting the beneficial effects of corticosteroids for treatment of shock, prevention of serious complications, or increasing platelet counts. Non-randomized trials of corticosteroids given as rescue medication for severe shock have shown possible benefit. Nonetheless, the evidence base is small, and good-quality trials are lacking. We reiterate the need for well-designed and adequately powered randomized controlled trials of corticosteroids for the treatment of dengue shock. PMID:24899817

Rajapakse, Senaka; Rodrigo, Chaturaka; Maduranga, Sachith; Rajapakse, Anoja Chamarie

2014-01-01

218

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

219

Micronutrients and dengue.  

PubMed

Dengue virus infection is the most widespread mosquito-borne viral infection in humans and has emerged as a serious global health challenge. In the absence of effective treatment and vaccine, host factors including nutritional status, which may alter disease progression, need investigation. The interplay between nutrition and other infections is well-established, and modulation of nutritional status often presents a simple low-cost method of interrupting transmission, reducing susceptibility, and/or ameliorating disease severity. This review examines the evidence on the role of micronutrients in dengue virus infection. We found critical issues and often inconsistent results across studies; this finding along with the lack of sufficient literature in this field have limited our ability to make any recommendations. However, vitamins D and E have shown promise in small supplementation trials. In summary, the role of micronutrients in dengue virus infection is an exciting research area and needs to be examined in well-designed studies with larger samples. PMID:25200269

Ahmed, Sundus; Finkelstein, Julia L; Stewart, Anna M; Kenneth, John; Polhemus, Mark E; Endy, Timothy P; Cardenas, Washington; Mehta, Saurabh

2014-11-01

220

Synthetic 1,4-pyran naphthoquinones are potent inhibitors of dengue virus replication.  

PubMed

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; da Costa, Luciana J; Ferreira, Sabrina B

2013-01-01

221

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

222

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

223

[Paediatric features of Dengue and Chikungunya fevers].  

PubMed

Dengue (Df) and Chikungunya fever (Cf) arbovirosis are booming in the world, because of the plasticity of their pathogens, mutant RNA viruses making the acquisition of sustainable herd immunity and vaccination difficult in humans, and the plasticity of their vectors, the female mosquitoes of the genus Aedes (Stegomya), capable of adapting to different environments. This review summarizes the viral life cycle and epidemiology of these arboviruses, pathogenesis and pediatric aspects of their clinical forms and the basic principles of their treatment and prevention. PMID:19815395

Gérardin, P

2010-01-01

224

High Level of Awareness but Poor Practices Regarding Dengue Fever Control: A Cross-sectional Study from North India  

PubMed Central

Background: Delhi, the capital of India, has suffered many outbreaks of dengue in recent past and despite the obvious magnitude of problem, very scarce evidence exists that documents the knowledge, awareness and practices of the people regarding dengue. Aim: To assess the knowledge and practices related to control of dengue fever and to assess the differences in knowledge and practices based on sex and literacy. Materials and Methods: A cross-sectional study was conducted among persons visiting a tertiary care hospital in New Delhi. A systematic sampling procedure was adopted and a pretested questionnaire was used. Results: A total of 215 individuals were interviewed. Majority of the respondents (96.3%) had heard about dengue. The important sources of information were television (54.9%) and newspaper/magazines (51.7%). Around 89% of the study participants considered dengue as “serious problem”. Nearly 86% participants were aware of the spread of dengue by mosquitoes while 73% were aware of one of the correct breeding sites of Aedes mosquito. Mosquito mats/liquidators were used by 61% of respondents, coils by 56% and repellant creams by 22%. Conclusion: The awareness regarding dengue and mosquito control measures was satisfactory to an extent. Programs should focus that this knowledge gets translated into practice. PMID:22754880

Chinnakali, Palanivel; Gurnani, Nishant; Upadhyay, Ravi Prakash; Parmar, Komal; Suri, Tejas M; Yadav, Kapil

2012-01-01

225

Monoclonal antibody to dengue capsid protein  

PubMed Central

Dengue fever (DF) and dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) are considered the most important arthropod-borne viral diseases in terms of morbidity and mortality. The emergency and severity of dengue (Den) infections increase the necessity of an early, quick and effective dengue laboratory diagnostic. Viral isolation is considered a gold standard for diagnosis of dengue infection using monoclonal antibodies (mAbs) as a tool for determining serotype specificity. Alternatives have been used to improve sensitivity and time to dengue diagnosis. Based on the early expression of dengue C protein in the life cycle, we focused our study on the application of an anti-dengue 2 virus capsid protein mAb in dengue diagnosis. The kinetic expression of dengue-2 capsid in mosquito cells and its immuno-localization in experimentally infected suckling albin Swiss (OF-1) mice brain tissues was established. The results demonstrate the possible utility of this mAb in early dengue diagnosis versus traditional isolation. In addition, a preliminary study of an enzyme immunoassay method using 8H8 mAb for specific detection of dengue C protein antigen was performed, making possible recombinant C protein quantification. The results suggest that detection of dengue capsid protein could be useful in the diagnosis of early dengue infection. PMID:20061827

Vazquez, Y; Vazquez, S V; Capó; Torres, G; Caballero, Y; Sánchez, A; Limonta, D; Alvarez, M; Guzmán, MG

2009-01-01

226

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

227

High Content Screening of a Kinase-Focused Library Reveals Compounds Broadly-Active against Dengue Viruses  

PubMed Central

Dengue virus is a mosquito-borne flavivirus that has a large impact in global health. It is considered as one of the medically important arboviruses, and developing a preventive or therapeutic solution remains a top priority in the medical and scientific community. Drug discovery programs for potential dengue antivirals have increased dramatically over the last decade, largely in part to the introduction of high-throughput assays. In this study, we have developed an image-based dengue high-throughput/high-content assay (HT/HCA) using an innovative computer vision approach to screen a kinase-focused library for anti-dengue compounds. Using this dengue HT/HCA, we identified a group of compounds with a 4-(1-aminoethyl)-N-methylthiazol-2-amine as a common core structure that inhibits dengue viral infection in a human liver-derived cell line (Huh-7.5 cells). Compounds CND1201, CND1203 and CND1243 exhibited strong antiviral activities against all four dengue serotypes. Plaque reduction and time-of-addition assays suggests that these compounds interfere with the late stage of viral infection cycle. These findings demonstrate that our image-based dengue HT/HCA is a reliable tool that can be used to screen various chemical libraries for potential dengue antiviral candidates. PMID:23437413

Li, Xiaolan; Milan Bonotto, Rafaela; No, Joo Hwan; Kim, Keum Hyun; Baek, Sungmin; Kim, Hee Young; Windisch, Marc Peter; Pamplona Mosimann, Ana Luiza; de Borba, Luana; Liuzzi, Michel; Hansen, Michael Adsetts Edberg; Nunes Duarte dos Santos, Claudia; Freitas-Junior, Lucio Holanda

2013-01-01

228

The effect of temperature and humidity on dengue virus propagation in Aedes aegypti mosquitos.  

PubMed

The effect of temperature and relative humidity on dengue virus propagation in the mosquito as one of the possible contributing factors to dengue hemorrhagic fever (DHF) outbreaks was studied. Ae. aegypti mosquitos were reared under standard conditions and inoculated intrathoracically with dengue virus. Virus propagation in the mosquitos was determined at the temperature and relative humidity of all 3 seasons of Yangon and for the simulated temperature and relative humidity of Singapore. The virus propagation was detected by direct fluorescent antibody technique (DFAT) with mosquito head squash and the virus titer was determined by plaque forming unit test (PFUT) in baby hamster kidney-21 cells. The results show that the infected mosquitos kept under the conditions of the rainy season and under the simulated conditions of Singapore had a significantly higher virus titer (p=<0.05) when compared with the other 2 seasons of Yangon. So it is thought that the temperature and relative humidity of the rainy season of Yangon and that of Singapore favors dengue virus propagation in the mosquito and is one of the contributing factors to the occurence of DHF outbreaks. PMID:9886113

Thu, H M; Aye, K M; Thein, S

1998-06-01

229

‘We do not do any activity until there is an outbreak’: barriers to disease prevention and health promotion at the community level in Kongwa District, Tanzania  

PubMed Central

Background Little is known about the barriers to disease prevention and health promotion at the community level – within a decentralized health system. Objective This paper, therefore, presents and discusses findings on barriers (and opportunities) for instituting disease prevention and health promotion activities. Design The study was conducted in Kongwa District, Tanzania, using an explorative case study approach. Data were collected through document reviews and in-depth interviews with key informants at district, ward, and village levels. A thematic approach was used in the analysis of the data. Results This study has identified several barriers, namely decision-makers at the national and district levels lack the necessary political will in prioritizing prevention and health promotion; the gravity of prevention and health promotion stated in the national health policy is not reflected in the district health plans; gross underfunding of community-level disease prevention and health promotion activities; and limited community participation. Conclusion In this era, when Tanzania is burdened with both communicable and non-communicable diseases, prevention and health promotion should be at the top of the health care agenda. Despite operating in a neoliberal climate, a stronger role of the state is called for. Accordingly, the government should prioritize higher health-protecting physical, social, and economic environments. This will require a national health promotion policy that will clearly chart out how multisectoral collaboration can be put into practice. PMID:25084832

Nyamhanga, Tumaini; Frumence, Gasto; Mwangu, Mughwira; Hurtig, Anna-Karin

2014-01-01

230

Cholera outbreaks in Africa.  

PubMed

During the current seventh cholera pandemic, Africa bore the major brunt of global disease burden. More than 40 years after its resurgence in Africa in 1970, cholera remains a grave public health problem, characterized by large disease burden, frequent outbreaks, persistent endemicity, and high CFRs, particularly in the region of the central African Great Lakes which might act as reservoirs for cholera. There, cases occur year round with a rise in incidence during the rainy season. Elsewhere in sub-Saharan Africa, cholera occurs mostly in outbreaks of varying size with a constant threat of widespread epidemics. Between 1970 and 2011, African countries reported 3,221,050 suspected cholera cases to the World Health Organization, representing 46 % of all cases reported globally. Excluding the Haitian epidemic, sub-Saharan Africa accounted for 86 % of reported cases and 99 % of deaths worldwide in 2011. The number of cholera cases is possibly much higher than what is reported to the WHO due to the variation in modalities, completeness, and case definition of national cholera data. One source on country specific incidence rates for Africa, adjusting for underreporting, estimates 1,341,080 cases and 160,930 deaths (52.6 % of 2,548,227 estimated cases and 79.6 % of 209,216 estimated deaths worldwide). Another estimates 1,411,453 cases and 53,632 deaths per year, respectively (50 % of 2,836,669 estimated cases and 58.6 % of 91,490 estimated deaths worldwide). Within Africa, half of all cases between 1970 and 2011 were notified from only seven countries: Angola, Democratic Republic of the Congo, Mozambique, Nigeria, Somalia, Tanzania, and South Africa. In contrast to a global trend of decreasing case fatality ratios (CFRs), CFRs have remained stable in Africa at approximately 2 %. Early propagation of cholera outbreaks depends largely on the extent of individual bacterial shedding, host and organism characteristics, the likelihood of people coming into contact with an infectious dose of Vibrio cholerae and on the virulence of the implicated strain. Cholera transmission can then be amplified by several factors including contamination of human water- or food sources; climate and extreme weather events; political and economic crises; high population density combined with poor quality informal housing and poor hygiene practices; spread beyond a local community through human travel and animals, e.g., water birds. At an individual level, cholera risk may increase with decreasing immunity and hypochlorhydria, such as that induced by Helicobacter pylori infection, which is endemic in much of Africa, and may increase individual susceptibility and cholera incidence. Since contaminated water is the main vehicle for the spread of cholera, the obvious long-term solution to eradicate the disease is the provision of safe water to all African populations. This requires considerable human and financial resources and time. In the short and medium term, vaccination may help to prevent and control the spread of cholera outbreaks. Regardless of the intervention, further understanding of cholera biology and epidemiology is essential to identify populations and areas at increased risk and thus ensure the most efficient use of scarce resources for the prevention and control of cholera. PMID:24827501

Mengel, Martin A; Delrieu, Isabelle; Heyerdahl, Leonard; Gessner, Bradford D

2014-01-01

231

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

232

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, Maïna; Taurel, Anne-Frieda; Flamand, Claude; Quénel, Philippe

2014-01-01

233

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

234

Viral Immune Evasion in Dengue: Toward Evidence-Based Revisions of Clinical Practice Guidelines  

PubMed Central

Dengue, a leading cause of illness and death in the tropics and subtropics since the 1950?s, is fast spreading in the Western hemisphere. Over 30% of the world?s population is at risk for the mosquitoes that transmit any one of four related Dengue viruses (DENV). Infection induces lifetime protection to a particular serotype, but successive exposure to a different DENV increases the likelihood of severe form of dengue fever (DF), dengue hemorrhagic fever (DHF), or dengue shock syndrome (DSS). Prompt supportive treatment lowers the risk of developing the severe spectrum of Dengue-associated physiopathology. Vaccines are not available, and the most effective protective measure is to prevent mosquito bites. Here, we discuss selected aspects of the syndemic nature of Dengue, including its potential for pathologies of the central nervous system (CNS). We examine the fundamental mechanisms of cell-mediated and humoral immunity to viral infection in general, and the specific implications of these processes in the regulatory control of DENV infection, including DENV evasion from immune surveillance. In line with the emerging model of translational science in health care, which integrates translational research (viz., going from the patient to the bench and back to the patient) and translational effectiveness (viz., integrating and utilizing the best available evidence in clinical settings), we examine novel and timely evidence-based revisions of clinical practice guidelines critical in optimizing the management of DENV infection and Dengue pathologies. We examine the role of tele-medicine and stakeholder engagement in the contemporary model of patient centered, effectiveness-focused and evidence-based health care. Abbreviations BBB - blood-brain barrier, CNS - central nervous system, DAMP - damage-associated molecular patterns, DENV - dengue virus, DF - dengue fever, DHF - dengue hemorrhagic fever, DSS - dengue shock syndrome, DALYs - isability adjusted life years, IFN-g - interferon-gamma, ILX - interleukinX, JAK/STAT - janus kinase (JAK) / Signal transducer and activator of transcription (STAT), LT - Escherichia coli heat-labile enterotoxin formulations deficient in GM1 binding by mutation (LT[G33D]), MCP-1 - monocyte chemotactic protein 1, M-CSF - macrophage colony-stimulating fact, MHC - major histocompatibility complex, MIF - macrophage migration inhibitory factor, [MIP-1]-? / -? - macrophage inflammatory protein-1 alpha and beta, mAb - monoclonal antibody, NS1 - non-structural protein 1 of dengue virus, NK - natural killer cells, PAMP - pathogen-associated molecular patterns, PBMC - peripheral blood mononuclear cells, TBF-b - transforming growth factor-beta, TNF-? - tumor necrosis-alpha, VHFs - virus hemorrhagic fevers, WHO - World Health Organization. PMID:25670874

Chiappelli, Francesco; Santos, Silvana Maria Eloi; Caldeira Brant, Xenia Maria; Bakhordarian, Andre; Thames, April D; Maida, Carl A; Du, Angela M; Jan, Allison L; Nahcivan, Melissa; Nguyen, Mia T; Sama, Nateli

2014-01-01

235

Dengue fever and dengue haemorrhagic fever in adolescents and adults  

PubMed Central

Dengue fever (DF) is endemic in tropical and subtropical zones and the prevalence is increasing across South-east Asia, Africa, the Western Pacific and the Americas. In recent years, the spread of unplanned urbanisation, with associated substandard housing, overcrowding and deterioration in water, sewage and waste management systems, has created ideal conditions for increased transmission of the dengue virus in tropical urban centres. While dengue infection has traditionally been considered a paediatric disease, the age distribution of dengue has been rising and more cases have been observed in adolescents and adults. Furthermore, the development of tourism in the tropics has led to an increase in the number of tourists who become infected, most of whom are adults. Symptoms and risk factors for dengue haemorrhagic fever (DHF) and severe dengue differ between children and adults, with co-morbidities and incidence in more elderly patients associated with greater risk of mortality. Treatment options for DF and DHF in adults, as for children, centre round fluid replacement (either orally or intravenously, depending on severity) and antipyretics. Further data are needed on the optimal treatment of adult patients. PMID:22668446

Tantawichien, Terapong

2012-01-01

236

Knowledge, Attitude and Practice Regarding Dengue Fever among the Healthy Population of Highland and Lowland Communities in Central Nepal  

PubMed Central

Background Dengue fever (DF) is the most rapidly spreading mosquito-borne viral disease in the world. In this decade it has expanded to new countries and from urban to rural areas. Nepal was regarded DF free until 2004. Since then dengue virus (DENV) has rapidly expanded its range even in mountain regions of Nepal, and major outbreaks occurred in 2006 and 2010. However, no data on the local knowledge, attitude and practice (KAP) of DF in Nepal exist although such information is required for prevention and control measures. Methods We conducted a community based cross-sectional survey in five districts of central Nepal between September 2011 and February 2012. We collected information on the socio-demographic characteristics of the participants and their knowledge, attitude and practice regarding DF using a structured questionnaire. We then statistically compared highland and lowland communities to identify possible causes of observed differences. Principal Findings Out of 589 individuals interviewed, 77% had heard of DF. Only 12% of the sample had good knowledge of DF. Those living in the lowlands were five times more likely to possess good knowledge than highlanders (P<0.001). Despite low knowledge levels, 83% of the people had good attitude and 37% reported good practice. We found a significantly positive correlation among knowledge, attitude and practice (P<0.001). Among the socio-demographic variables, the education level of the participants was an independent predictor of practice level (P<0.05), and education level and interaction between the sex and age group of the participants were independent predictors of attitude level (P<0.05). Conclusion Despite the rapid expansion of DENV in Nepal, the knowledge of people about DF was very low. Therefore, massive awareness programmes are urgently required to protect the health of people from DF and to limit its further spread in this country. PMID:25007284

Dhimal, Meghnath; Aryal, Krishna Kumar; Dhimal, Mandira Lamichhane; Gautam, Ishan; Singh, Shanker Pratap; Bhusal, Chop Lal; Kuch, Ulrich

2014-01-01

237

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

238

Fusion of Protegrin-1 and Plectasin to MAP30 Shows Significant Inhibition Activity against Dengue Virus Replication  

PubMed Central

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

239

MUCOCUTANEOUS MANIFESTATIONS OF DENGUE FEVER  

PubMed Central

Dengue viral infection is a cause of considerable morbidity and mortality and may be associated with a variety of mucocutaneous manifestations that may provide important early clues to the diagnosis of this condition. Cutaneous and mucosal findings like confluent erythema, morbilliform eruptions, and hemorrhagic lesions may figure prominently in the clinical features of dengue. The differential diagnoses include a large number of bacterial and viral exanthems as well as drug rash. PMID:20418984

Thomas, Emy Abi; John, Mary; Kanish, Bimal

2010-01-01

240

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, Estefanía; Mistchenko, Alicia S.

2014-01-01

241

Dengue virus 1 in Buenos Aires from 1999 to 2010: towards local spread.  

PubMed

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, Estefanía; Mistchenko, Alicia S; Barrero, Paola R

2014-01-01

242

Dot enzyme immunoassay: an alternative diagnostic aid for dengue fever and dengue haemorrhagic fever.  

PubMed Central

A dot enzyme immunoassay (DEIA) for the detection of antibodies to dengue virus was tested for use as a tool in the presumptive diagnosis of dengue fever and dengue haemorrhagic fever. Paired sera from the following groups of patients were tested using the DEIA and the haemagglutination inhibition (HI) test: those with primary dengue fever; those experiencing a second dengue infection; and febrile patients who did not have dengue. The data obtained show that the DEIA can be effectively used at a serum dilution of 1:1000 to confirm presumptive recent dengue in patients with a second dengue infection. However, demonstration of seroconversion proved necessary for patients with primary dengue. At a serum dilution of 1:1000 the DEIA has a specificity of 97.3%. The role of this simple and rapid test in improving the effectivity of programmes for the control of dengue virus infection is discussed. PMID:1786623

Cardosa, M. J.; Tio, P. H.

1991-01-01

243

[Identification of places with potential transmission of dengue fever in Porto Alegre using Geographical Information Systems].  

PubMed

The social-environmental conditions that promote the continuity of Aedes aegypti in urban areas and its capacity for dengue transmission have yet to be determined. The aim of this work was to locate dengue cases and vector presence, then to identify social-environmental factors that characterize these sites, through Geographical Information Systems (GIS), with a view to developing a dengue fever prevention model. The vector was mainly located in south and east areas of the city, with a broad dispersion, while most of the cases were located in the central region of the city. The sectors with cases present characteristics of high income. Otherwise, sectors with vector present a predominance of houses and good sanitation infrastructure. The difference between cases and vector spatial patterns ensured for 2002 an absence of dengue transmission in the city. PMID:15895177

Barcellos, Christovam; Pustai, Adelaide Kreutz; Weber, Maria Angélica; Brito, Maria Regina Varnieri

2005-01-01

244

Identification of dengue fever cases in Houston, Texas, with evidence of autochthonous transmission between 2003 and 2005.  

PubMed

Houston, Texas, maintains an environment conducive to dengue virus (DENV) emergence; however, surveillance is passive and diagnostic testing is not readily available. To determine if DENV is present in the area, we tested 3768 clinical specimens (2138 cerebrospinal fluid [CSF] and 1630 serum) collected from patients with suspected mosquito-borne viral disease between 2003 and 2005. We identified 47 immunoglobulin M (IgM)-positive dengue cases, including two cases that were positive for viral RNA in serum for dengue serotype 2. The majority of cases did not report any history of travel outside the Houston area prior to symptom onset. The epidemic curve suggests an outbreak occurred in 2003 with continued low-level transmission in 2004 and 2005. Chart abstractions were completed for 42 of the 47 cases; 57% were diagnosed with meningitis and/or encephalitis, and 43% met the case definition for dengue fever. Two of the 47 cases were fatal, including one with illness compatible with dengue shock syndrome. Our results support local transmission of DENV during the study period. These findings heighten the need for dengue surveillance in the southern United States. PMID:24107180

Murray, Kristy O; Rodriguez, Liliana F; Herrington, Emily; Kharat, Vineetkumar; Vasilakis, Nikolaos; Walker, Christopher; Turner, Cynthia; Khuwaja, Salma; Arafat, Raouf; Weaver, Scott C; Martinez, Diana; Kilborn, Cindy; Bueno, Rudy; Reyna, Martin

2013-12-01

245

Measles (Rubeola) Cases and Outbreaks  

MedlinePLUS

... ongoing outbreak linked to an amusement park in California . On January 23, 2015, CDC issued a Health ... ongoing outbreak linked to an amusement park in California . 2014: The U.S. experienced 23 measles outbreaks in ...

246

Geographical information systems for dengue surveillance.  

PubMed

This review provides details on the role of Geographical Information Systems (GIS) in current dengue surveillance systems and focuses on the application of open access GIS technology to emphasize its importance in developing countries, where the dengue burden is greatest. It also advocates for increased international collaboration in transboundary disease surveillance to confront the emerging global challenge of dengue. PMID:22556070

Duncombe, Jennifer; Clements, Archie; Hu, Wenbiao; Weinstein, Philip; Ritchie, Scott; Espino, Fe Esperanza

2012-05-01

247

Direct Costs of Dengue Hospitalization in Brazil: Public and Private Health Care Systems and Use of WHO Guidelines  

PubMed Central

Background Dengue, an arboviral disease, is a public health problem in tropical and subtropical regions worldwide. In Brazil, epidemics have become increasingly important, with increases in the number of hospitalizations and the costs associated with the disease. This study aimed to describe the direct costs of hospitalized dengue cases, the financial impact of admissions and the use of blood products where current protocols for disease management were not followed. Methods and Results To analyze the direct costs of dengue illness and platelet transfusion in Brazil based on the World Health Organization (WHO) guidelines, we conducted a retrospective cross-sectional census study on hospitalized dengue patients in the public and private Brazilian health systems in Dourados City, Mato Grosso do Sul State, Brazil. The analysis involved cases that occurred from January through December during the 2010 outbreak. In total, we examined 8,226 mandatorily reported suspected dengue cases involving 507 hospitalized patients. The final sample comprised 288 laboratory-confirmed dengue patients, who accounted for 56.8% of all hospitalized cases. The overall cost of the hospitalized dengue cases was US $210,084.30, in 2010, which corresponded to 2.5% of the gross domestic product per capita in Dourados that year. In 35.2% of cases, blood products were used in patients who did not meet the blood transfusion criteria. The overall median hospitalization cost was higher (p?=?0.002) in the group that received blood products (US $1,622.40) compared with the group that did not receive blood products (US $550.20). Conclusion The comparative costs between the public and the private health systems show that both the hospitalization of and platelet transfusion in patients who do not meet the WHO and Brazilian dengue guidelines increase the direct costs, but not the quality, of health care. PMID:25188295

Vieira Machado, Alessandra A.; Estevan, Anderson Oliveira; Sales, Antonio; Brabes, Kelly Cristina da Silva; Croda, Júlio; Negrão, Fábio Juliano

2014-01-01

248

Waterborne outbreaks of cryptosporidiosis.  

PubMed

Water is the most commonly reported vehicle of transmission in Cryptosporidium outbreaks. While mains drinking water quality is highly regulated in industrialised countries, treated recreational water venues remain highly variable and these have emerged as important settings in the transmission of cryptosporidiosis. Epidemiological investigations of outbreaks benefit from supplementary microbiological evidence and, more recently, the application of molecular typing data to link isolates from cases to each other and to suspected sources. This article documents how waterborne Cryptosporidium outbreaks are identified and reported, how such outbreaks have acted as drivers of regulatory change, and some of the recent developments in the detection and investigation of these outbreaks and their spread, especially the application of molecular typing assays. PMID:23247139

Chalmers, Rachel M

2012-01-01

249

Of cascades and perfect storms: the immunopathogenesis of dengue haemorrhagic  

E-print Network

REVIEW Of cascades and perfect storms: the immunopathogenesis of dengue haemorrhagic fever-dengue witnessed a consolidation of the original observations made in the 1970s that dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS) have an immunological basis. Following reinfection with a dengue virus

Cai, Long

250

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

251

Spatiotemporal Dynamics of Dengue Epidemics, Southern Vietnam  

PubMed Central

An improved understanding of heterogeneities in dengue virus transmission might provide insights into biological and ecologic drivers and facilitate predictions of the magnitude, timing, and location of future dengue epidemics. To investigate dengue dynamics in urban Ho Chi Minh City and neighboring rural provinces in Vietnam, we analyzed a 10-year monthly time series of dengue surveillance data from southern Vietnam. The per capita incidence of dengue was lower in Ho Chi Minh City than in most rural provinces; annual epidemics occurred 1–3 months later in Ho Chi Minh City than elsewhere. The timing and the magnitude of annual epidemics were significantly more correlated in nearby districts than in remote districts, suggesting that local biological and ecologic drivers operate at a scale of 50–100 km. Dengue incidence during the dry season accounted for 63% of variability in epidemic magnitude. These findings can aid the targeting of vector-control interventions and the planning for dengue vaccine implementation. PMID:23735713

Cuong, Hoang Quoc; Vu, Nguyen Thanh; Cazelles, Bernard; Boni, Maciej F.; Thai, Khoa T.D.; Rabaa, Maia A.; Quang, Luong Chan; Simmons, Cameron P.; Huu, Tran Ngoc

2013-01-01

252

Spatiotemporal dynamics of dengue epidemics, southern Vietnam.  

PubMed

An improved understanding of heterogeneities in dengue virus transmission might provide insights into biological and ecologic drivers and facilitate predictions of the magnitude, timing, and location of future dengue epidemics. To investigate dengue dynamics in urban Ho Chi Minh City and neighboring rural provinces in Vietnam, we analyzed a 10-year monthly time series of dengue surveillance data from southern Vietnam. The per capita incidence of dengue was lower in Ho Chi Minh City than in most rural provinces; annual epidemics occurred 1-3 months later in Ho Chi Minh City than elsewhere. The timing and the magnitude of annual epidemics were significantly more correlated in nearby districts than in remote districts, suggesting that local biological and ecologic drivers operate at a scale of 50-100 km. Dengue incidence during the dry season accounted for 63% of variability in epidemic magnitude. These findings can aid the targeting of vector-control interventions and the planning for dengue vaccine implementation. PMID:23735713

Cuong, Hoang Quoc; Vu, Nguyen Thanh; Cazelles, Bernard; Boni, Maciej F; Thai, Khoa T D; Rabaa, Maia A; Quang, Luong Chan; Simmons, Cameron P; Huu, Tran Ngoc; Anders, Katherine L

2013-06-01

253

Dengue Virus Type 3, Brazil, 2002  

PubMed Central

During the summer of 2002, Rio de Janeiro had a large epidemic of dengue fever; 288,245 cases were reported. A subset of 1,831 dengue hemorrhagic fever cases occurred. In this study, performed in the first half of 2002, samples from 1,559 patients with suspected cases of dengue infection were analyzed. From this total, 1,497 were obtained from patients with nonfatal cases, and 62 were obtained from patients with fatal cases. By the use of different methods, 831 (53.3%) cases, including 40 fatal cases, were confirmed as dengue infection. When virus identification was successful, dengue virus type 3 (DENV-3) was obtained in 99% of cases. Neurologic involvement was shown in 1 patient with encephalitis, confirmed by the detection of DENV-3 RNA in the cerebrospinal fluid. This explosive epidemic of DENV-3 was the most severe dengue epidemic reported in Brazil since dengue viruses were introduced in 1986. PMID:16229765

Schatzmayr, Hermann Gonçalves; Bispo de Filippis, Ana Maria; Barreto dos Santos, Flávia; Venâncio da Cunha, Rivaldo; Coelho, Janice Oliveira; José de Souza, Luiz; Guimarães, Flávia Ramos; Machado de Araújo, Eliane Saraiva; De Simone, Thatiane Santos; Baran, Meri; Teixeira, Gualberto; Miagostovich, Marize Pereira

2005-01-01

254

Transmission Dynamics of the Four Dengue Serotypes in Southern Vietnam and the Potential Impact of Vaccination  

PubMed Central

Background With approximately 2.5 billion people at risk, dengue is a major international public health concern. Dengue vaccines currently in development should help reduce the burden associated with this disease but the most efficient way of using future dengue vaccines remains to be defined. Mathematical models of transmission can provide insight into the expected impact of different vaccination strategies at a population level and contribute to this definition. Methods and Findings We developed and analyzed an age-structured, host-vector and serotype-specific compartmental model, including seasonality. We first used this transmission model to identify the immunological interactions between serotypes that affect the risks and consequences of secondary infections (cross-protection, increased susceptibility, increased severity, and increased infectiousness) and reproduce the observed epidemiology of dengue. For populating this model, we used routine surveillance data from Southern Vietnam and the results of a prospective cohort study conducted in the same area. The model provided a good fit to the observed data for age, severity of cases, serotype distribution, and dynamics over time, using two scenarios of immunological interaction : short term cross-protection alone (6–17 months) or a combination of short term cross-protection with cross-enhancement (increased susceptibility, severity and infectiousness in the case of secondary infections). Finally, we explored the potential impact of vaccination for these two scenarios. Both highlighted that vaccination can substantially decrease dengue burden by reducing the magnitude and frequency of outbreaks. Conclusion Our model suggests that seasonality and short term cross-protection are key factors for explaining dengue dynamics in Southern Vietnam. Vaccination was predicted to significantly reduce the disease burden, even in the situation where immunological cross-enhancement affects the risks and consequences of secondary infections. PMID:23251466

Coudeville, Laurent; Garnett, Geoff P.

2012-01-01

255

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

256

High-Throughput Quantitative Proteomic Analysis of Dengue Virus Type 2 Infected A549 Cells  

PubMed Central

Disease caused by dengue virus is a global health concern with up to 390 million individuals infected annually worldwide. There are no vaccines or antiviral compounds available to either prevent or treat dengue disease which may be fatal. To increase our understanding of the interaction of dengue virus with the host cell, we analyzed changes in the proteome of human A549 cells in response to dengue virus type 2 infection using stable isotope labelling in cell culture (SILAC) in combination with high-throughput mass spectrometry (MS). Mock and infected A549 cells were fractionated into nuclear and cytoplasmic extracts before analysis to identify proteins that redistribute between cellular compartments during infection and reduce the complexity of the analysis. We identified and quantified 3098 and 2115 proteins in the cytoplasmic and nuclear fractions respectively. Proteins that showed a significant alteration in amount during infection were examined using gene enrichment, pathway and network analysis tools. The analyses revealed that dengue virus infection modulated the amounts of proteins involved in the interferon and unfolded protein responses, lipid metabolism and the cell cycle. The SILAC-MS results were validated for a select number of proteins over a time course of infection by Western blotting and immunofluorescence microscopy. Our study demonstrates for the first time the power of SILAC-MS for identifying and quantifying novel changes in cellular protein amounts in response to dengue virus infection. PMID:24671231

Chiu, Han-Chen; Hannemann, Holger; Heesom, Kate J.; Matthews, David A.; Davidson, Andrew D.

2014-01-01

257

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

258

Dengue fever among U.S. travelers returning from the Dominican Republic - Minnesota and Iowa, 2008.  

PubMed

In February 2008, a group of U.S. residents became ill with symptoms and clinical findings suggestive of dengue fever after returning from the Dominican Republic, where they had traveled to work as missionaries. Dengue is endemic in the Dominican Republic and most tropical and subtropical areas of the world, including the Caribbean, and represents a known health risk for U.S. residents traveling to or working in those areas. Subsequent investigation by the Minnesota Department of Health (MDH), the Iowa Department of Public Health (IDPH), and CDC determined that at least 14 (42%) of 33 missionaries traveling to the Dominican Republic met the case definition for dengue fever, and 12 had cases that were confirmed serologically. Of the 13 patients interviewed, all had weakness and fever, with 12 reporting chills and body or joint pain. Ten patients had noticed mosquitoes inside or outside their house in the Dominican Republic, but only three had used repellent. Before departing on their trip, none of the 13 ill travelers interviewed had been aware of dengue in the Dominican Republic, and only two had sought pre-travel medical advice. The Dominican Republic is a frequent destination for U.S. travelers providing missionary and humanitarian services and also for vacationers. These cases indicate a need to increase awareness of dengue prevention measures among U.S. travelers to areas where they might be at risk for dengue. PMID:20520589

2010-06-01

259

GIS-aided planning of insecticide spraying to control dengue transmission  

PubMed Central

Background The purpose of this paper is to integrate a multi-objective integer programming formulation and geographic information system (GIS) into dynamically planning the insecticide spraying area for preventing the transmission of dengue fever. Methods The optimal spraying area to combat dengue infections is calculated by the multi-objective integer programming model using the dengue epidemic in 2007 in Tainan City of southern Taiwan and is compared with the areas actually sprayed by the local health department. The dynamic epidemic indicators (i.e. frequency, intensity and duration) that identify major temporal characteristics of the dynamic process of an epidemic are all incorporated into the model. Results The results indicate that the model can design the spraying area effectively when the trade-off between the coverage of dengue epidemics risk and area compactness is considered. Conclusions The model provides an alternative way to obtain a cost-effective spraying area in controlling future dengue epidemics. The proposed model in this study will be beneficial for strategically allocating dengue control resources. PMID:24066947

2013-01-01

260

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

261

Controlling Dengue with Vaccines in Thailand  

PubMed Central

Background Dengue is a mosquito-borne infectious disease that constitutes a growing global threat with the habitat expansion of its vectors Aedes aegyti and A. albopictus and increasing urbanization. With no effective treatment and limited success of vector control, dengue vaccines constitute the best control measure for the foreseeable future. With four interacting dengue serotypes, the development of an effective vaccine has been a challenge. Several dengue vaccine candidates are currently being tested in clinical trials. Before the widespread introduction of a new dengue vaccine, one needs to consider how best to use limited supplies of vaccine given the complex dengue transmission dynamics and the immunological interaction among the four dengue serotypes. Methodology/Principal Findings We developed an individual-level (including both humans and mosquitoes), stochastic simulation model for dengue transmission and control in a semi-rural area in Thailand. We calibrated the model to dengue serotype-specific infection, illness and hospitalization data from Thailand. Our simulations show that a realistic roll-out plan, starting with young children then covering progressively older individuals in following seasons, could reduce local transmission of dengue to low levels. Simulations indicate that this strategy could avert about 7,700 uncomplicated dengue fever cases and 220 dengue hospitalizations per 100,000 people at risk over a ten-year period. Conclusions/Significance Vaccination will have an important role in controlling dengue. According to our modeling results, children should be prioritized to receive vaccine, but adults will also need to be vaccinated if one wants to reduce community-wide dengue transmission to low levels. PMID:23145197

Chao, Dennis L.; Halstead, Scott B.; Halloran, M. Elizabeth; Longini, Ira M.

2012-01-01

262

Community Knowledge, Health Beliefs, Practices and Experiences Related to Dengue Fever and Its Association with IgG Seropositivity  

PubMed Central

Background Demographic, economic and behavioural factors are central features underpinning the successful management and biological control of dengue. This study aimed to examine these factors and their association with the seroprevalence of this disease. Methodology We conducted a cross-sectional telephone survey of households in a 3 km radius of the schools where we had conducted serological tests on the student population in a previous study. Households were surveyed about their socio-demographics, knowledge, practices, and Health Belief Model (HBM) constructs. The results were then associated with the prevalence rate of dengue in the community, as marked by IgG seropositivity of the students who attended school there. Results A total of 1,400 complete responses were obtained. The community's IgG seropositivity was significantly positively associated with high household monthly income, high-rise residential building type, high surrounding vegetation density, rural locality, high perceived severity and susceptibility, perceived barriers to prevention, knowing that a neighbour has dengue, frequent fogging and a higher level of knowledge about dengue. In the multivariate analyses, three major correlates of the presence of IgG seropositivity in the community: (1) high-rise residential apartment house type or condominium buildings; (2) the main construct of the HBM, perceived severity and susceptibility; and (3) the additional constructs of the HBM, lack of preventive measures from the community level and having a neighbour with dengue as a cue to action. Weak correlations were found between self-practices to prevent dengue and the level of dengue seropositivity in the community, and between HBM constructs and knowledge (r?=?0.09). Conclusions The residential environment factor and the constructs of the HBM are useful and important elements in developing interventions to prevent and control dengue. The study also sheds light on the importance of the need for approaches that ensure the translation of knowledge into practice. PMID:24853259

Wong, Li Ping; AbuBakar, Sazaly; Chinna, Karuthan

2014-01-01

263

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

Lourenço, José; Recker, Mario

2013-01-01

264

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

265

Modeling the Transmission Dynamics of the Dengue Virus.  

E-print Network

??Dengue (pronounced den'guee) Fever (DF) and Dengue Hemorrhagic Fever (DHF), collectively known as "dengue," are mosquito-borne, potentially mortal, flu-like viral diseases that affect humans worldwide.… (more)

Katri, Patricia

2010-01-01

266

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

267

Larval occurrence, oviposition behavior and biting activity of potential mosquito vectors of dengue on Samui Island, Thailand  

Microsoft Academic Search

A 1995 outbreak of dengue haemorrhagic fever (DHF) occurred on Samui Island in Thailand with an incidence of almost 500 cases\\/100,000 population. To find and develop effective strategies to control this disease through cost-effective vector control programs, entomological studies were carried out on the island between 1996 and 1998. There were two species of DHF vectors, Aedes aegypti and Ae.

Usavadee Thavara; Apiwat Tawatsin; Chitti Chansang; Wichai Kong-ngamsuk; Supol Paosriwong; Jotika Boon-Long; Yupa Rongsriyam; Narumon Komalamisra

268

Co-circulation of two genotypes of dengue virus serotype 3 in Guangzhou, China, 2009  

PubMed Central

Dengue is emerging as the most important mosquito borne viral disease in the world. In mainland China, sporadic and large outbreaks of dengue illness caused by the four serotypes of dengue virus (DENV-1 to DENV-4) have been well documented. Guangdong province is the major affected area in China, and DENV-1 has dominantly circulated in Guangdong for a long time. In this study, a family cluster of DENV-3 infection in Guangzhou was described. Three cases were diagnosed as dengue fever based on clinical manifestation, serological and RT-PCR assays. Two DENV-3 strains were isolated in C6/36 cells and the complete genome sequences were determined. Phylogenetic analysis revealed that the new DENV-3 isolates from the family cluster were grouped within genotype III. Considering the fact that several DENV-3 strains within genotype V were also identified in Guangzhou in 2009, at least two genotypes of DENV-3 co-circulated in Guangzhou. Careful investigation and virological analysis should be warranted in the future. PMID:22721418

2012-01-01

269

Hepatitis A outbreaks in the vaccination era in Catalonia, Spain.  

PubMed

Hepatitis A outbreaks have a major impact on public health services and involve case investigation and intervention measures to susceptible contacts. At the end of 1998 a universal vaccination program with a combined hepatitis A+B vaccine was started in Catalonia (Spain) in 12-years-old preadolescents. The objective of this study was to compare the characteristics of hepatitis A outbreaks in the periods before and after the introduction of the preadolescent vaccination program and to estimate the preventable fraction of cases associated to outbreaks. The incidence rates of outbreaks, cases and hospitalization associated with each outbreak were calculated. Two periods were considered: before (1991-1998) and after (2000-2007) the introduction of mass vaccination. The preventable fraction and 95% confidence intervals (CI) of cases associated with outbreaks was calculated. The rate of associated cases with outbreaks was higher in the period before the vaccination program than in the post vaccination period (1.53 per 100,000 person-year vs 1.12 ; p< 0.001), but the rate of hospitalization was greater in the period after the introduction of vaccination program than in the period previous to vaccination (0.70 per million persons-year vs 0.08; p< 0.001). The preventable fraction of cases associated to outbreaks was 19.6%(95%CI 6.7-32.5) in the 0-4 years group and 16.7% (95% CI 6.0-27.5) in the 5-14 years group, but the highest figure (38.6%; 95%CI 21.3-55.9) was observed in the 15-24 years age group. The estimated proportion of cases associated with outbreaks that would theoretically have been prevented with the vaccination program suggests that substantial benefits have been obtained in Catalonia in people aged less than 25 years. PMID:21285534

Martínez, Ana; Broner, Sonia; Torner, Nuria; Godoy, Pere; Batalla, Joan; Alvarez, Josep; Barrabeig, Irene; Camps, Neus; Carmona, Gloria; Minguell, Sofía; Sala, Rosa; Caylà, Joan; Domínguez, Angela

2011-01-01

270

Fungal Diseases Outbreaks  

MedlinePLUS

... 1 page] Blastomycosis in Wisconsin Outbreak of blastomycosis, Marathon County, Wisconsin, 2010-2011 Number of cases: 55 ... Blastomyces dermatitidis Type of infection: Mostly pulmonary Setting: Marathon County, Wisconsin Source: Likely multiple foci in the ...

271

Foodborne Outbreaks Surveillance Data  

MedlinePLUS

... used for CDC’s latest Vital Signs publication on Listeria . Learn More about Foodborne Outbreak Tracking and Reporting ... Shiga toxin-producing E. coli O157, or Campylobacter, Listeria, or Salmonella species associated with food commodity groups ...

272

The importance of hematopoietic progenitor cells in dengue  

PubMed Central

Scientific investigations designed to better understand and assess the distinguishing clinical characteristics pave the way to a successful treatment for a disease. Since the peripheral blood is obtained easily, the most frequent type of investigation performed on infectious agents focuses on the hematological components of blood drawn from patients. Bone marrow aspirates, although somewhat more difficult to obtain, should be evaluated more frequently because they provide additional information, giving us a glimpse into the development of the disease. Understanding the distinct and unique changes in hematological components of the bone marrow induced by a particular pathogen or corresponding to a specific illness may be a valuable asset for the diagnosis and prognosis of disease. A good example of a pathogen that could be better evaluated with greater knowledge of the bone marrow is dengue, one of the most important public vector-borne human diseases. Owing to the multitude of clinical manifestations and the dynamic alterations of various blood components over time, this disease is one of the most difficult to prevent and treat in humans. Although large amounts of data have been generated in the literature, there remains a large gap between this information and its relevance for the purpose of patient care. While evaluating the cellular components in the circulated blood from ill patients provides us with valuable information about the pathogenesis of various pathogens, there are other players participating in the progression to disease. The goal of this review is to emphasize the importance of bone marrow hematopoietic progenitor cells in disease and to inspire other researchers to incorporate them into their investigations on dengue pathogenesis. It is anticipated that the knowledge derived from these investigations not only elicit original concepts on the pathogenesis of dengue but also foster a new way of thinking in terms of vaccine or therapeutic development to prevent and treat dengue. PMID:23556112

Tsai, Jih-Jin; Liu, Li-Teh; Chang, Ko; Wang, Shu-Hui; Hsiao, Hui-Mien; Clark, Kristina B.

2012-01-01

273

Generation and characterization of potential dengue vaccine candidates based on domain III of the envelope protein and the capsid protein of the four serotypes of dengue virus.  

PubMed

Dengue is currently one of the most important arthropod-borne diseases, causing up to 25,000 deaths annually. There is currently no vaccine to prevent dengue virus infection, which needs a tetravalent vaccine approach. In this work, we describe the cloning and expression in Escherichia coli of envelope domain III-capsid chimeric proteins (DIIIC) of the four dengue serotypes as a tetravalent dengue vaccine candidate that is potentially able to generate humoral and cellular immunity. The recombinant proteins were purified to more than 85 % purity and were recognized by anti-dengue mouse and human sera. Mass spectrometry analysis verified the identity of the proteins and the correct formation of the intracatenary disulfide bond in the domain III region. The chimeric DIIIC proteins were also serotype-specific, and in the presence of oligonucleotides, they formed aggregates that were visible by electron microscopy. These results support the future use of DIIIC recombinant chimeric proteins in preclinical studies in mice for assessing their immunogenicity and efficacy. PMID:24420159

Suzarte, Edith; Marcos, Ernesto; Gil, Lázaro; Valdés, Iris; Lazo, Laura; Ramos, Yassel; Pérez, Yusleidi; Falcón, Viviana; Romero, Yaremis; Guzmán, María G; González, Sirenia; Kourí, Juan; Guillén, Gerardo; Hermida, Lisset

2014-07-01

274

Immature dengue virus : functional properties and potential contribution to disease.  

E-print Network

??Beter inzicht in mechanismen achter infectieziekte dengue Dengue (‘knokkelkoorts’) is een veelvoorkomende, tropische infectieziekte die wordt overgebracht door muggen. Naar schatting raken jaarlijks zo’n vijftig… (more)

Voorham, Júlia Maria da Silva

2013-01-01

275

Nation-Wide, Web-Based, Geographic Information System for the Integrated Surveillance and Control of Dengue Fever in Mexico  

PubMed Central

Dengue fever incidence and its geographical distribution are increasing throughout the world. Quality and timely information is essential for its prevention and control. A web based, geographically enabled, dengue integral surveillance system (Dengue-GIS) was developed for the nation-wide collection, integration, analysis and reporting of geo-referenced epidemiologic, entomologic, and control interventions data. Consensus in the design and practical operation of the system was a key factor for its acceptance. Working with information systems already implemented as a starting point facilitated its acceptance by officials and operative personnel. Dengue-GIS provides the geographical detail needed to plan, asses and evaluate the impact of control activities. The system is beginning to be adopted as a knowledge base by vector control programs. It is used to generate evidence on impact and cost-effectiveness of control activities, promoting the use of information for decision making at all levels of the vector control program. Dengue-GIS has also been used as a hypothesis generator for the academic community. This GIS-based model system for dengue surveillance and the experience gathered during its development and implementation could be useful in other dengue endemic countries and extended to other infectious or chronic diseases. PMID:23936394

Hernández-Ávila, Juan Eugenio; Rodríguez, Mario-Henry; Santos-Luna, René; Sánchez-Castañeda, Veronica; Román-Pérez, Susana; Ríos-Salgado, Víctor Hugo; Salas-Sarmiento, Jesús Alberto

2013-01-01

276

Nation-wide, web-based, geographic information system for the integrated surveillance and control of dengue fever in Mexico.  

PubMed

Dengue fever incidence and its geographical distribution are increasing throughout the world. Quality and timely information is essential for its prevention and control. A web based, geographically enabled, dengue integral surveillance system (Dengue-GIS) was developed for the nation-wide collection, integration, analysis and reporting of geo-referenced epidemiologic, entomologic, and control interventions data. Consensus in the design and practical operation of the system was a key factor for its acceptance. Working with information systems already implemented as a starting point facilitated its acceptance by officials and operative personnel. Dengue-GIS provides the geographical detail needed to plan, asses and evaluate the impact of control activities. The system is beginning to be adopted as a knowledge base by vector control programs. It is used to generate evidence on impact and cost-effectiveness of control activities, promoting the use of information for decision making at all levels of the vector control program. Dengue-GIS has also been used as a hypothesis generator for the academic community. This GIS-based model system for dengue surveillance and the experience gathered during its development and implementation could be useful in other dengue endemic countries and extended to other infectious or chronic diseases. PMID:23936394

Hernández-Ávila, Juan Eugenio; Rodríguez, Mario-Henry; Santos-Luna, René; Sánchez-Castañeda, Veronica; Román-Pérez, Susana; Ríos-Salgado, Víctor Hugo; Salas-Sarmiento, Jesús Alberto

2013-01-01

277

[Waterborne diseases outbreaks in the Czech Republic, 1995-2005].  

PubMed

Despite considerable advances in drinking water safety assurance and adherence to the public health standards, waterborne diaseases outbreaks have still been observed even in industrialized countries. The study objective was to map such outbreaks in the Czech Republic in 1995-2005. In this study, an outbreak is the occurrence of more cases of disease than normally expected within a specific place over a given period of time and a waterborne disease is a disease where water is the vehicle or source of infection. The data on waterborne outbreaks was obtained from the EPIDAT database (national infectious diseases reporting system) information provided by epidemiologists of all regional public health authorities and the National Reference Laboratory for Legionella. In 1995 - 2005, 33 outbreaks with water indicated as the route of transmission were recorded in the Czech Republic. The leading cause was unsafe drinking water (27 outbreaks), mainly from wells (19 outbreaks); nevertheless, the most serious consequences were observed in two outbreaks caused by microbiologically contaminated hot water. Other sources of waterborne infection were mineral water springs, a swimming pool and a brook. The total of reported cases of waterborne diseases was 1655, 356 hospitalisations and ten deaths due to legionellosis were recorded. The highest number of outbreaks (7) as well as the highest number of cases (841) were reported in 1997. Comparison of two five-year periods, i.e. 1996-2000 and 2001-2005, showed a nearly one third decrease in the total of outbreaks and a half reduction in the total of cases in the latter. In view of the limited length of monitoring, it is not possible to say with certainty whether it is a random distribution or an actual trend. Almost two thirds of cases were diagnosed as acute gastroenteritis of probable infectious origin and other frequent waterborne diseases were viral hepatitis A and bacillary dysentery. When analyzing the described outbreaks, it should be taken into account that only the diagnosed and reported outbreak cases are covered, while the actual number of cases is likely to be underreported. Although no evidence is available that any vast and serious waterborne diseases outbreaks escaped reporting, some small and less serious outbreaks may have occurred unnoticed. In the future, the diagnosis, investigation and evaluation of waterborne diseases outbreaks should be improved, among others by implementing an evidence-based classification system and issuing regular surveys of outbreaks and their causes which would be helpful in preventing failures in other similar water sources. PMID:19750823

Kozísek, F; Jeligová, H; Dvoráková, A

2009-08-01

278

Scientific consultation on cell mediated immunity (CMI) in dengue and dengue vaccine development  

Microsoft Academic Search

Dengue is a re-emerging arboviral disease of great public health importance. Limited understanding of protective immune responses against dengue has hampered advancement of dengue vaccine candidates. Demonstrating an immunological correlate of protection has been limited to associating quantitative neutralizing antibody titers with clinical outcomes following infection. There have been a number of studies investigating the role of cell mediated immunity

Stephen J. Thomas; Joachim Hombach; Alan Barrett

2009-01-01

279

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

280

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

281

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

282

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

283

Characterization of Dengue Virus Type 2: New Insights on the 2010 Brazilian Epidemic  

PubMed Central

Dengue viruses (DENV) serotypes 1, 2, and 3 have been causing yearly outbreaks in Brazil. In this study, we report the re-introduction of DENV2 in the coast of São Paulo State. Partial envelope viral genes were sequenced from eighteen patients with dengue fever during the 2010 epidemic. Phylogenetic analysis showed this strain belongs to the American/Asian genotype and was closely related to the virus that circulated in Rio de Janeiro in 2007 and 2008. The phylogeny also showed no clustering by clinical presentation, suggesting that the disease severity could not be explained by distinct variants or genotypes. The time of the most recent common ancestor of American/Asian genotype and the São Paulo and Rio de Janeiro (SP/RJ) monophyletic cluster was estimated to be around 40 and 10 years, respectively. Since this virus was first identified in Brazil in 2007, we suggest that it was already circulating in the country before causing the first documented outbreak. This is the first description of the 2010 outbreak in the State of São Paulo, Brazil, and should contribute to efforts to control and monitor the spread of DENVs in endemic areas. PMID:20676363

Romano, Camila Malta; de Matos, Andréia Manso; Araújo, Evaldo Stanislau A.; Villas-Boas, Lucy Santos; da Silva, Wanessa Cardoso; Oliveira, Olímpia M. N. P. F.; Carvalho, Karina I.; de Souza, Ana Carolina Mamana; Rodrigues, Celia L.; Levi, José Eduardo; Kallas, Esper G.; Pannuti, Claudio Sergio

2010-01-01

284

The global distribution and burden of dengue  

PubMed Central

Dengue is a systemic viral infection transmitted between humans by Aedes mosquitoes1. For some patients dengue is a life-threatening illness2. There are currently no licensed vaccines or specific therapeutics, and substantial vector control efforts have not stopped its rapid emergence and global spread3. The contemporary worldwide distribution of the risk of dengue virus infection4 and its public health burden are poorly known2,5. Here we undertake an exhaustive assembly of known records of dengue occurrence worldwide, and use a formal modelling framework to map the global distribution of dengue risk. We then pair the resulting risk map with detailed longitudinal information from dengue cohort studies and population surfaces to infer the public health burden of dengue in 2010. We predict dengue to be ubiquitous throughout the tropics, with local spatial variations in risk influenced strongly by rainfall, temperature and the degree of urbanisation. Using cartographic approaches, we estimate there to be 390 million (95 percent credible interval 284-528) dengue infections per year, of which 96 million (67-136) manifest apparently (any level of clinical or sub-clinical severity). This infection total is more than three times the dengue burden estimate of the World Health Organization2. Stratification of our estimates by country allows comparison with national dengue reporting, after taking into account the probability of an apparent infection being formally reported. The most notable differences are discussed. These new risk maps and infection estimates provide novel insights into the global, regional and national public health burden imposed by dengue. We anticipate that they will provide a starting point for a wider discussion about the global impact of this disease and will help guide improvements in disease control strategies using vaccine, drug and vector control methods and in their economic evaluation. [285] PMID:23563266

Bhatt, Samir; Gething, Peter W.; Brady, Oliver J.; Messina, Jane P.; Farlow, Andrew W.; Moyes, Catherine L.; Drake, John M.; Brownstein, John S.; Hoen, Anne G.; Sankoh, Osman; Myers, Monica F.; George, Dylan B.; Jaenisch, Thomas; Wint, G.R. William; Simmons, Cameron P.; Scott, Thomas W.; Farrar, Jeremy J.; Hay, Simon I.

2013-01-01

285

Juillet 2012 Prvoir les flambes de dengue  

E-print Network

vaccin ni traitement spécifique. La région Pacifique Sud est régulièrement le siège d'épidémies de dengueN° 410 Juillet 2012 Prévoir les flambées de dengue en fonction du climat Scientific news Actualidad cientifica Actualité scientifique Véhiculée principalement par le moustique Aedes aegypti, la dengue est

286

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

287

Safety and immunogenicity of attenuated dengue virus vaccines (Aventis Pasteur) in human volunteers  

Microsoft Academic Search

A randomized, controlled, double-blinded study was conducted to determine safety and immunogenicity of five live attenuated dengue vaccines produced by Aventis Pasteur (AvP). The study was completed with 40 flavivirus non-immune volunteers: five recipients of each monovalent (dengue-1, dengue-2, dengue-3, or dengue-4) vaccine, ten recipients of tetravalent (dengue-1, dengue-2, dengue-3, and dengue-4) vaccine, and ten recipients of vaccine vehicle alone.

N. Kanesa-thasan; W. Sun; G. Kim-Ahn; S. Van Albert; J. R. Putnak; A. King; B. Raengsakulsrach; H. Christ-Schmidt; K. Gilson; J. M. Zahradnik; D. W. Vaughn; B. L. Innis; J.-F. Saluzzo; C. H. Hoke Jr

2001-01-01

288

Spatial and Temporal Clustering of Dengue Virus Transmission in Thai Villages  

Microsoft Academic Search

BackgroundTransmission of dengue viruses (DENV), the leading cause of arboviral disease worldwide, is known to vary through time and space, likely owing to a combination of factors related to the human host, virus, mosquito vector, and environment. An improved understanding of variation in transmission patterns is fundamental to conducting surveillance and implementing disease prevention strategies. To test the hypothesis that

Mammen P Mammen; Chusak Pimgate; Constantianus J. M Koenraadt; Alan L Rothman; Jared Aldstadt; Ananda Nisalak; Richard G Jarman; James W Jones; Anon Srikiatkhachorn; Charity Ann Ypil-Butac; Arthur Getis; Suwich Thammapalo; Amy C Morrison; Daniel H Libraty; Sharone Green; Thomas W Scott

2008-01-01

289

Surveillance of Dengue Fever Virus: A Review of Epidemiological Models and Early Warning Systems  

Microsoft Academic Search

Dengue fever affects over a 100 million people annually hence is one of the world's most important vector-borne diseases. The transmission area of this disease continues to expand due to many direct and indirect factors linked to urban sprawl, increased travel and global warming. Current preventative measures include mosquito control programs, yet due to the complex nature of the disease

Vanessa Racloz; Rebecca Ramsey; Shilu Tong; Wenbiao Hu

2012-01-01

290

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

291

STAT2 signaling and dengue virus infection  

PubMed Central

Dengue virus (DENV) is an important human pathogen whose byzantine relationship with the immune response is poorly understood. DENV causes dengue fever and dengue hemorrhagic fever/dengue shock syndrome, diseases for which palliative care is the only treatment. DENV immunopathogenesis studies are complicated by the lack of an immunocompetent small-animal model, and this has hindered anti-DENV drug and vaccine development. This review describes strategies that DENV uses to evade the type I interferon response and focuses on how data gained from the study of DENV NS5-mediated STAT2 degradation may be used to create immunocompetent DENV mouse models and design anti-DENV therapeutics. PMID:24778924

Morrison, Juliet; García-Sastre, Adolfo

2014-01-01

292

Dengue blood analysis by Raman spectroscopy  

NASA Astrophysics Data System (ADS)

In this work Raman spectra of normal and dengue infected serum and whole blood were analyzed. In normal whole blood and serum characteristic peaks were observed when excited at 442 and 532 nm. In dengue whole blood and serum all peaks found to be blue shifted with reduced Raman intensity. Dengue whole blood and serum shows two peaks at 1614 and 1750 cm-1 which are due to presence of Immunoglobulin antibodies IgG and IgM. Whole study provides a route of information for diagnosis of dengue viral infection.

Rehman, A.; Anwar, S.; Firdous, S.; Ahmed, M.; Rasheed, R.; Nawaz, M.

2012-06-01

293

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

294

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

295

Evolution and heterogeneity of multiple serotypes of Dengue virus in Pakistan, 2006–2011  

PubMed Central

Background Even though dengue has been recognized as one of the major public health threats in Pakistan, the understanding of its molecular epidemiology is still limited. The genotypic diversity of Dengue virus (DENV) serotypes involved in dengue outbreaks since 2005 in Pakistan is not well studied. Here, we investigated the origin, diversity, genetic relationships and geographic distribution of DENV to understand virus evolution during the recent expansion of dengue in Pakistan. Methods The study included 200 sera obtained from dengue-suspected patients from 2006 to 2011. DENV infection was confirmed in 94 (47%) sera by a polymerase chain reaction assay. These included 36 (38.3%) DENV-2, 57 DENV-3 (60.6%) and 1 DENV-4 (1.1%) cases. Sequences of 13 whole genomes (6 DENV-2, 6 DENV-3 and 1 DENV-4) and 49 envelope genes (26 DENV-2, 22 DENV-3 and 1 DENV-4) were analysed to determine the origin, phylogeny, diversity and selection pressure during virus evolution. Results DENV-2, DENV-3 and DENV-4 in Pakistan from 2006 to 2011 shared 98.5-99.6% nucleotide and 99.3-99.9% amino acid similarity with those circulated in the Indian subcontinent during the last decade. Nevertheless, Pakistan DENV-2 and DENV-3 strains formed distinct clades characterized by amino acid signatures of NS2A-I116T + NS5-K861R and NS3-K590R + NS5-S895L respectively. Each clade consisted of a heterogenous virus population that circulated in Southern (2006–2009) and Northern Pakistan (2011). Conclusions DENV-2, DENV-3 and DENV-4 that circulated during 2006–2011 are likely to have first introduced via the southern route of Pakistan. Both DENV-2 and DENV-3 have undergone in-situ evolution to generate heterogenous populations, possibly driven by sustained local DENV transmission during 2006–2011 periods. While both DENV-2 and DENV-3 continued to circulate in Southern Pakistan until 2009, DENV-2 has spread in a Northern direction to establish in Punjab Province, which experienced a massive dengue outbreak in 2011. PMID:24007412

2013-01-01

296

Outbreaks associated with cantaloupe, watermelon, and honeydew in the United States, 1973-2011.  

PubMed

Abstract Fresh fruits and vegetables are an important part of a healthy diet. Melons have been associated with enteric infections. We reviewed outbreaks reported to the Centers for Disease Control and Prevention's Foodborne Disease Outbreak Surveillance System during 1973-2011 in which the implicated food was a single melon type. We also reviewed published literature and records obtained from investigating agencies. During 1973-2011, 34 outbreaks caused by a single melon type were reported, resulting in 3602 illnesses, 322 hospitalizations, 46 deaths, and 3 fetal losses. Cantaloupes accounted for 19 outbreaks (56%), followed by watermelons (13, 38%) and honeydew (2, 6%). Melon-associated outbreaks increased from 0.5 outbreaks per year during 1973-1991 to 1.3 during 1992-2011. Salmonella was the most common etiology reported (19, 56%), followed by norovirus (5, 15%). Among 13 outbreaks with information available, melons imported from Mexico and Central America were implicated in 9 outbreaks (69%) and domestically grown melons were implicated in 4 outbreaks (31%). The point of contamination was known for 20 outbreaks; contamination occurred most commonly during growth, harvesting, processing, or packaging (13, 65%). Preventive measures focused on reducing bacterial contamination of melons both domestically and internationally could decrease the number and severity of melon-associated outbreaks. PMID:25407556

Walsh, Kelly A; Bennett, Sarah D; Mahovic, Michael; Gould, L Hannah

2014-12-01

297

Characteristics and outcome of dengue infection; clinical perspective from a secondary care hospital of Karachi  

PubMed Central

Objective: To determine the frequency and characteristics of dengue fever (DF) in patients of acute febrile illness presenting at a secondary care hospital. Methodology: The observational cross sectional study was carried out from May to October 2010 in Remedial Centre Karachi and included patients above the age of 12 years who presented with acute febrile illness. The WHO classification and case definitions were used to classify the disease as Dengue Fever (DF), dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Clinical, hematological and biochemical findings were recorded serially until discharge. Results: During the study period, 90 (34.75%) presented with typical features of DF, 28 (31.11%) were dengue proven, seven (7.7%) proved to be of malaria in which malarial parasites were found positive in the peripheral blood, while the remaining 55 (61.11%) patients were dengue probable. Age of the patients ranged from 13 to 76 years. Fever was the most common clinical presentation (100%) followed by vomiting 50 (55.56%), body ache 31 (34.44%) abdominal pain 17 (18.89%) and headache 9 (10%). Maculopapular rash was seen in 4(4.44%) patients. Laboratory findings included thrombocytopenia, leucopenia and raised alanine aminotransferase levels. Eighty one patients (90%) improved clinically and hematologically and were discharged in stable condition. Conclusion: Fever and thrombocytopenia were the most common presentation of dengue fever (DF). The overall mortality of DF is low, if treated appropriately. Awareness of health care professionals and public regarding preventive strategies is essential to fight against this disease. PMID:24353520

Hasan, Syed Riazul; Riaz, Musarrat; Jafri, Farhat Ali

2013-01-01

298

Dengue infection in patients presenting with neurological manifestations in a dengue endemic population.  

PubMed

The evaluation of the contribution of neurological dengue in suspected central nervous system (CNS) viral infections is essential to better understand the impact of neurological dengue on morbidity and mortality in dengue endemic regions such as Jamaica. For this study 401 cases of suspected viral CNS infections were investigated for evidence of dengue infection. The frequency of neurological dengue among these CNS cases was found to be 13.5% (54/401). Fifty-three cases were confirmed serologically by haemagglutination inhibition assay (HI) and IgM antibody (ELISA) and the virus was isolated in one case only. Clinical manifestations among dengue positive CNS cases included encephalitis in 51.8% (28/54), meningitis in 33.3% (18/54), seizures in 11.1% (6/54) and acute flaccid paralysis/Guillain-Barré syndrome in 3.7% (2/54). The clinical diagnosis of dengue neurological infection corresponded with laboratory confirmation in 22.2% (12/54) of cases only. Deaths occurred in 3.7% (2/54) of cases and were associated with patients with dengue neurological infection. The high risk of dengue among patients with suspected viral CNS infections in this study supports the need for an increased index of suspicion of dengue in patients presenting with neurological manifestations in dengue endemic countries. PMID:19566019

Jackson, S T; Mullings, A; Bennett, F; Khan, C; Gordon-Strachan, G; Rhoden, T

2008-09-01

299

A case presentation of a fatal dengue myocarditis showing evidence for dengue virus-induced lesion  

PubMed Central

Dengue is a prevalent arthropod-borne viral disease in tropical and subtropical areas of the globe. Dengue clinical manifestations include asymptomatic infections; undifferentiated fever; dengue fever, which is characterized by fever, headache, retroorbital pain, myalgia, and arthralgia; and a severe form of the disease denominated dengue haemorrhagic fever/dengue shock syndrome, characterized by haemoconcentration, thrombocytopenia, and bleeding tendency. However, atypical manifestations, such as liver, central nervous system, and cardiac involvement, have been increasingly reported. We report an atypical and rare presentation of dengue disease marked by a dramatic and fatal cardiogenic shock due to acute myocarditis. Histopathological analysis of heart tissue showed several multifocal areas of muscle necrosis and intense interstitial oedema associated with clusters of virus particles inside the cardiomyocytes and in the interstitial space, providing evidence of a possible direct action of dengue virus on myocardium. PMID:24222821

Miranda, Carlos Henrique; Borges, Marcos de Carvalho; Schmidt, André; Pazin-Filho, Antônio; Rossi, Marcos Antônio; Ramos, Simone Gusmão

2013-01-01

300

77 FR 25180 - Disease, Disability, and Injury Prevention and Control Special Emphasis Panel (SEP): Initial Review  

Federal Register 2010, 2011, 2012, 2013, 2014

...Injury Prevention and Control Special Emphasis Panel (SEP): Initial Review The meeting announced below concerns Evaluation of Dengue Epidemiology, Outcomes, and Prevention in Sentinel Surveillance and Research Sites in Puerto Rico, Funding Opportunity...

2012-04-27

301

Comparison of Vector Competence of Aedes mediovittatus and Aedes aegypti for Dengue Virus: Implications for Dengue Control in the Caribbean  

PubMed Central

Background Aedes mediovittatus mosquitoes are found throughout the Greater Antilles in the Caribbean and often share the same larval habitats with Ae. Aegypti, the primary vector for dengue virus (DENV). Implementation of vector control measures to control dengue that specifically target Ae. Aegypti may not control DENV transmission in Puerto Rico (PR). Even if Ae. Aegypti is eliminated or DENV refractory mosquitoes are released, DENV transmission may not cease when other competent mosquito species like Ae. Mediovittatus are present. To compare vector competence of Ae. Mediovittatus and Ae. Aegypti mosquitoes, we studied relative infection and transmission rates for all four DENV serotypes. Methods To compare the vector competence of Ae. Mediovittatus and Ae. Aegypti, mosquitoes were exposed to DENV 1–4 per os at viral titers of 5–6 logs plaque-forming unit (pfu) equivalents. At 14 days post infectious bloodmeal, viral RNA was extracted and tested by qRT-PCR to determine infection and transmission rates. Infection and transmission rates were analyzed with a generalized linear model assuming a binomial distribution. Results Ae. Aegypti had significantly higher DENV-4 infection and transmission rates than Ae. mediovittatus. Conclusions This study determined that Ae. Mediovittatus is a competent DENV vector. Therefore dengue prevention programs in PR and the Caribbean should consider both Ae. Mediovittatus and Ae. Aegypti mosquitoes in their vector control programs. PMID:25658951

Poole-Smith, B. Katherine; Hemme, Ryan R.; Delorey, Mark; Felix, Gilberto; Gonzalez, Andrea L.; Amador, Manuel; Hunsperger, Elizabeth A.; Barrera, Roberto

2015-01-01

302

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

303

Policymakers’ views on dengue fever\\/dengue haemorrhagic fever and the need for dengue vaccines in four southeast Asian countries  

Microsoft Academic Search

A survey of policymakers and other influential professionals in four southeast Asian countries (Cambodia, Indonesia, Philippines and Vietnam) was conducted to determine policymakers’ views on the public health importance of dengue fever and dengue haemorrhagic fever (DHF), the need for a vaccine and the determinants influencing its potential introduction. The survey, which involved face-to-face interviews with policymakers, health programme managers,

Denise DeRoeck; Jacqueline Deen; John D. Clemens

2003-01-01

304

Evaluation of molecular strategies to develop a live dengue vaccine  

Microsoft Academic Search

Background: Millions of individuals are estimated to become infected with dengue virus each year, particularly in tropical and subtropical regions. Mortality is low but infection can lead to a severe form of dengue, characterised by haemorrhage and shock. A safe and effective vaccine against dengue is still not available.Objective: To use the successful construction of dengue type 4 virus (DEN4)

C. J Lai; M Bray; R Men; A Cahour; W Chen; H Kawano; M Tadano; K Hiramatsu; I Tokimatsu; A Pletnev; S Arakai; G Shameem; M Rinaudo

1998-01-01

305

Policy Platform Assessing the Potential of a Candidate Dengue Vaccine  

E-print Network

-attenuated, tetravalent, chimeric yellow fever dengue vaccine-- commenced Phase II and Phase IIB clinical trials in 2009-sense RNA viruses (genus Flavivirus, family Flaviviridae) that are the etiological agents of dengue fever ranges from asymptomatic infection to life threatening dengue hemorrhagic fever (DHF) and dengue shock

Rohani, Pej

306

Urban Epidemic of Dengue Virus Serotype 3 Infection, Senegal, 2009  

PubMed Central

An urban epidemic of dengue in Senegal during 2009 affected 196 persons and included 5 cases of dengue hemorrhagic fever and 1 fatal case of dengue shock syndrome. Dengue virus serotype 3 was identified from all patients, and Aedes aegypti mosquitoes were identified as the primary vector of the virus. PMID:24572297

Faye, Ousmane; Ba, Yamar; Faye, Oumar; Talla, Cheikh; Diallo, Diawo; Chen, Rubing; Mondo, Mireille; Ba, Rouguiétou; Macondo, Edgard; Siby, Tidiane; Weaver, Scott C.; Diallo, Mawlouth

2014-01-01

307

Urban epidemic of dengue virus serotype 3 infection, Senegal, 2009.  

PubMed

An urban epidemic of dengue in Senegal during 2009 affected 196 persons and included 5 cases of dengue hemorrhagic fever and 1 fatal case of dengue shock syndrome. Dengue virus serotype 3 was identified from all patients, and Aedes aegypti mosquitoes were identified as the primary vector of the virus. PMID:24572297

Faye, Ousmane; Ba, Yamar; Faye, Oumar; Talla, Cheikh; Diallo, Diawo; Chen, Rubing; Mondo, Mireille; Ba, Rouguiétou; Macondo, Edgard; Siby, Tidiane; Weaver, Scott C; Diallo, Mawlouth; Sall, Amadou Alpha

2014-03-01

308

Multilevel analyses of spatial and temporal determinants for dengue infection  

Microsoft Academic Search

BACKGROUND: Dengue is a mosquito-borne viral infection that is now endemic in most tropical countries. In Thailand, dengue fever\\/dengue hemorrhagic fever is a leading cause of hospitalization and death among children. A longitudinal study among 1750 people in two rural and one urban sites in northern Thailand from 2001 to 2003 studied spatial and temporal determinants for recent dengue infection

Sophie O Vanwambeke; Birgit HB van Benthem; Nardlada Khantikul; Chantal Burghoorn-Maas; Kamolwan Panart; Linda Oskam; Eric F Lambin; Pradya Somboon

2006-01-01

309

Restriction enzyme analysis of American region dengue viruses  

Microsoft Academic Search

Summary Restriction fragment heterogeneity of Hae III digestion products of cDNA to virion RNA was used to map the distribution of dengue virus topotypes found in the American region. By comparing the electrophoretic patterns of fragments produced, dengue virus isolates were placed in groups that agreed with those previously determined by oligonucleotide fingerprinting. Dengue-1 and dengue-4 viruses occur throughout the

V. Vorndam; R. M. R. Nogueira; D. W. Trent

1994-01-01

310

Dengue Vaccine Candidates in Development  

Microsoft Academic Search

\\u000a Each of the DENV serotypes can cause the full spectrum of dengue illness. Epidemiological studies have implicated preexisting\\u000a heterotypic DENV antibody as a risk factor for more severe disease upon secondary DENV infection. For these reasons, a successful\\u000a DENV vaccine must protect against all four DENV serotypes. Live attenuated DENV vaccine candidates are the furthest along\\u000a in development and clinical

Anna P. Durbin; Stephen S. Whitehead

311

Total Economic Cost and Burden of Dengue in Nicaragua: 1996–2010  

PubMed Central

The burden of dengue in Nicaragua has been steadily rising during the last three decades; however, there have been few efforts to quantify the burden (measured in disability-adjusted life years [DALYs]) and cost to society. Using primary data from the Nicaraguan Ministry of Health (MINSA), the total cost and burden of dengue were calculated from 1996 to 2010. Total costs included both direct costs from medical expenditures and prevention activities and indirect costs from lost productivity. The annual disease burden ranged from 99 to 805 DALYs per million, with a majority associated with classic dengue fever. The total cost was estimated to be US$13.5 million/year (range: US$5.1–27.6 million). This analysis can help improve allocation of dengue control resources in Nicaragua and the region. As one of the most comprehensive analyses of its type to date in Nicaragua and Latin America, this study can serve as a model to determine the burden and cost of dengue. PMID:22890033

Wettstein, Zachary S.; Fleming, Michael; Chang, Aileen Y.; Copenhaver, David J.; Wateska, Angela R.; Bartsch, Sarah M.; Lee, Bruce Y.; Kulkarni, Rajan P.

2012-01-01

312

Total economic cost and burden of dengue in Nicaragua: 1996-2010.  

PubMed

The burden of dengue in Nicaragua has been steadily rising during the last three decades; however, there have been few efforts to quantify the burden (measured in disability-adjusted life years [DALYs]) and cost to society. Using primary data from the Nicaraguan Ministry of Health (MINSA), the total cost and burden of dengue were calculated from 1996 to 2010. Total costs included both direct costs from medical expenditures and prevention activities and indirect costs from lost productivity. The annual disease burden ranged from 99 to 805 DALYs per million, with a majority associated with classic dengue fever. The total cost was estimated to be US$13.5 million/year (range: US$5.1-27.6 million). This analysis can help improve allocation of dengue control resources in Nicaragua and the region. As one of the most comprehensive analyses of its type to date in Nicaragua and Latin America, this study can serve as a model to determine the burden and cost of dengue. PMID:22890033

Wettstein, Zachary S; Fleming, Michael; Chang, Aileen Y; Copenhaver, David J; Wateska, Angela R; Bartsch, Sarah M; Lee, Bruce Y; Kulkarni, Rajan P

2012-10-01

313

[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

314

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

315

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

316

Prospects for a dengue virus vaccine  

Microsoft Academic Search

The number of cases of severe dengue disease continues to grow in endemic areas of southeast Asia, Central and South America, and other subtropical regions. Children bear the greatest burden of disease, and the development of an effective vaccine remains a global public health priority. A tetravalent vaccine is urgently needed and must be effective against all four dengue virus

Joseph E. Blaney; Anna P. Durbin; Brian R. Murphy; Stephen S. Whitehead

2007-01-01

317

Dengue and Chikungunya Vector Control Pocket Guide  

Technology Transfer Automated Retrieval System (TEKTRAN)

This technical guide consolidates information and procedures for surveillance and control of mosquitoes that transmit dengue and chikungunya viruses. The guide focuses on mosquitoes that transmit dengue but also makes reference to chikungunya and yellow fever because the pathogens that cause these ...

318

Typhoid and dengue coinfection: Case reports.  

PubMed

Both dengue and typhoid fever have emerged as major public health problems in India. Coinfection with both these diseases is rarely reported. Here we report two confirmed cases of concurrent illness of dengue with typhoid fever; both patients were managed as outpatients and recovered completely. PMID:25315238

Bansal, Rohit; Bansal, Priya; Tomar, Laxmikant Ramkumarsingh

2015-01-01

319

Density-Dependent Competitive Suppression of Sylvatic Dengue Virus by Endemic Dengue Virus in Cultured Mosquito Cells  

E-print Network

Density-Dependent Competitive Suppression of Sylvatic Dengue Virus by Endemic Dengue Virus University, Las Cruces, New Mexico Abstract Mosquito-borne dengue viruses are maintained in two discrete Dengue virus; Competition; Density-dependent; Superinfection; Sylvatic; Aedes Introduction THE FOUR

Hanley, Kathryn A.

320

2nd International External Quality Control Assessment for the Molecular Diagnosis of Dengue Infections  

PubMed Central

Background Currently dengue viruses (DENV) pose an increasing threat to over 2.5 billion people in over 100 tropical and sub-tropical countries worldwide. International air travel is facilitating rapid global movement of DENV, increasing the risk of severe dengue epidemics by introducing different serotypes. Accurate diagnosis is critical for early initiation of preventive measures. Different reverse transcriptase PCR (RT-PCR) methods are available, which should be evaluated and standardized. Epidemiological and laboratory-based surveillance is required to monitor and guide dengue prevention and control programmes, i.e., by mosquito control or possible vaccination (as soon as an effective and safe vaccine becomes available). Objective The purpose of the external quality assurance (EQA) study described is to assess the efficiency and accuracy of dengue molecular diagnosis methods applied by expert laboratories. Study Design A panel of 12 human plasma samples was distributed and tested for DENV-specific RNA. The panel comprised 9 samples spiked with different DENV serotypes (DENV-1 to DENV-4), including 10-fold dilution series of DENV-1 and DENV-3. Two specificity controls consisted of a sample with a pool of 4 other flaviviruses and a sample with chikungunya virus. A negative control sample was also included. Results Thirty-seven laboratories (from Europe, Middle East Asia, Asia, the Americas/Caribbean, and Africa) participated in this EQA study, and reports including 46 sets of results were returned. Performance among laboratories varied according to methodologies used. Only 5 (10.9%) data sets met all criteria with optimal performance, and 4 (8.7%) with acceptable performance, while 37 (80.4%) reported results showed the need for improvement regarding accomplishment of dengue molecular diagnosis. Failures were mainly due to lack of sensitivity and the presence of false positives. Conclusions The EQA provides information on each laboratory's efficacy of RT-PCR techniques for dengue diagnosis and indicates for most laboratories an urgent need to improve sensitivity and specificity. PMID:20957194

Domingo, Cristina; Niedrig, Matthias; Teichmann, Anette; Kaiser, Marco; Rumer, Leonid; Jarman, Richard G.; Donoso-Mantke, Oliver

2010-01-01

321

Dengue fever: a Wikipedia clinical review.  

PubMed

Dengue fever, also known as breakbone fever, is a mosquito-borne infectious tropical disease caused by the dengue virus. Symptoms include fever, headache, muscle and joint pains, and a characteristic skin rash that is similar to measles. In a small proportion of cases, the disease develops into life-threatening dengue hemorrhagic fever, which results in bleeding, thrombocytopenia, and leakage of blood plasma, or into dengue shock syndrome, in which dangerously low blood pressure occurs. Treatment of acute dengue fever is supportive, with either oral or intravenous rehydration for mild or moderate disease and use of intravenous fluids and blood transfusion for more severe cases. Along with attempts to eliminate the mosquito vector, work is ongoing to develop a vaccine and medications targeted directly at the virus. PMID:25426178

Heilman, James M; De Wolff, Jacob; Beards, Graham M; Basden, Brian J

2014-01-01

322

Tuberculosis Outbreak Investigations in the United States, 2002–2008  

PubMed Central

To understand circumstances of tuberculosis transmission that strain public health resources, we systematically reviewed Centers for Disease Control and Prevention (CDC) staff reports of US outbreaks in which CDC participated during 2002–2008 that involved >3 culture-confirmed tuberculosis cases linked by genotype and epidemiology. Twenty-seven outbreaks, representing 398 patients, were reviewed. Twenty-four of the 27 outbreaks involved primarily US-born patients; substance abuse was another predominant feature of outbreaks. Prolonged infectiousness because of provider- and patient-related factors was common. In 17 outbreaks, a drug house was a notable contributing factor. The most frequently documented intervention to control the outbreak was prioritizing contacts according to risk for infection and disease progression to ensure that the highest risk contacts were completely evaluated. US-born persons with reported substance abuse most strongly characterized the tuberculosis outbreaks in this review. Substance abuse remains one of the greatest challenges to controlling tuberculosis transmission in the United States. PMID:21392433

Oeltmann, John E.; Ijaz, Kashef; Haddad, Maryam B.

2011-01-01

323

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

324

Quantifying Reporting Timeliness to Improve Outbreak Control  

PubMed Central

The extent to which reporting delays should be reduced to gain substantial improvement in outbreak control is unclear. We developed a model to quantitatively assess reporting timeliness. Using reporting speed data for 6 infectious diseases in the notification system in the Netherlands, we calculated the proportion of infections produced by index and secondary cases until the index case is reported. We assumed interventions that immediately stop transmission. Reporting delays render useful only those interventions that stop transmission from index and secondary cases. We found that current reporting delays are adequate for hepatitis A and B control. However, reporting delays should be reduced by a few days to improve measles and mumps control, by at least 10 days to improve shigellosis control, and by at least 5 weeks to substantially improve pertussis control. Our method provides quantitative insight into the required reporting delay reductions needed to achieve outbreak control and other transmission prevention goals. PMID:25625374

Swaan, Corien; van Steenbergen, Jim; Kretzschmar, Mirjam

2015-01-01

325

Quantifying reporting timeliness to improve outbreak control.  

PubMed

The extent to which reporting delays should be reduced to gain substantial improvement in outbreak control is unclear. We developed a model to quantitatively assess reporting timeliness. Using reporting speed data for 6 infectious diseases in the notification system in the Netherlands, we calculated the proportion of infections produced by index and secondary cases until the index case is reported. We assumed interventions that immediately stop transmission. Reporting delays render useful only those interventions that stop transmission from index and secondary cases. We found that current reporting delays are adequate for hepatitis A and B control. However, reporting delays should be reduced by a few days to improve measles and mumps control, by at least 10 days to improve shigellosis control, and by at least 5 weeks to substantially improve pertussis control. Our method provides quantitative insight into the required reporting delay reductions needed to achieve outbreak control and other transmission prevention goals. PMID:25625374

Marinovi?, Axel Bona?i?; Swaan, Corien; van Steenbergen, Jim; Kretzschmar, Mirjam

2015-02-01

326

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

327

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

328

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

2014-01-01

329

Diagnosis of dengue in Sri Lanka: improvements to the existing state of the art in the island.  

PubMed

Dengue fever (DF) is a mosquito borne virus infection which is endemic to the tropical regions of the world. In Sri Lanka, the first sero-positive case was reported in the 1960s; since then the island has experienced several outbreaks of DF/dengue haemorrhagic fever (DHF). The disease is more prevalent in some parts of the country where rapid urbanisation has taken place. Diagnosis of DF/DHF is mainly done using the clinical features only due to the unavailability of laboratory diagnosis in many parts of the country and this might lead to over or under diagnosis of the disease. A rational diagnostic approach which combines the history and clinical profiles together with specific virological laboratory data would help in the correct identification of the disease. Furthermore, a feasible algorithm for the laboratory diagnosis of dengue will help to confirm the cases with a high level of clinical suspicion. This would then facilitate the notification of correctly identified cases to the public health authorities to assess the dengue burden. The scope of this review is to improve the existing laboratory diagnosis of DF/DHF by proposing a feasible algorithm to implement in Sri Lanka that would enable better detection of cases. PMID:25233937

Senaratne, Thamarasi N; Noordeen, Faseeha

2014-11-01

330

Acute Gastroenteritis Surveillance through the National Outbreak Reporting System, United States  

PubMed Central

Implemented in 2009, the National Outbreak Reporting System provides surveillance for acute gastroenteritis outbreaks in the United States resulting from any transmission mode. Data from the first 2 years of surveillance highlight the predominant role of norovirus. The pathogen-specific transmission pathways and exposure settings identified can help inform prevention efforts. PMID:23876187

Wikswo, Mary E.; Manikonda, Karunya; Roberts, Virginia A.; Yoder, Jonathan S.; Gould, L. Hannah

2013-01-01

331

Increased Outbreaks Associated with Nonpasteurized Milk, United States, 2007–2012  

PubMed Central

The number of US outbreaks caused by nonpasteurized milk increased from 30 during 2007–2009 to 51 during 2010–2012. Most outbreaks were caused by Campylobacter spp. (77%) and by nonpasteurized milk purchased from states in which nonpasteurized milk sale was legal (81%). Regulations to prevent distribution of nonpasteurized milk should be enforced. PMID:25531403

Behravesh, Casey Barton

2015-01-01

332

Dengue epidemics and human mobility  

NASA Astrophysics Data System (ADS)

In this work we explore the effects of human mobility on the dispersion of a vector borne disease. We combine an already presented stochastic model for dengue with a simple representation of the daily motion of humans on a schematic city of 20×20 blocks with 100 inhabitants in each block. The pattern of motion of the individuals is described in terms of complex networks in which links connect different blocks and the link length distribution is in accordance with recent findings on human mobility. It is shown that human mobility can turn out to be the main driving force of the disease dispersal.

Barmak, D. H.; Dorso, C. O.; Otero, M.; Solari, H. G.

2011-07-01

333

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

334

[Imported dengue: An emerging arbovirosis in Spain].  

PubMed

Dengue is caused by one of 4 serotypes of dengue virus. Only imported cases have been reported in Spain. The main clinical findings are fever and exanthema, although there may be severe forms, particularly in secondary infections. Five children with a primary, non severe dengue infection are presented. The diagnosis was based on clinical suspicion and epidemiological history, and confirmed by immunochromatography and ELISA tests. The outcome was favourable in all cases. It is important to consider this diagnosis in international travellers that present with fever within the 14 days of returning from an endemic area, in order to get an early diagnosis, adequate treatment and a good prognosis. PMID:24880817

Ramos Geldres, T T; García López-Hortelano, M; Baquero-Artigao, F; Montero Vega, D; López Quintana, B; Mellado Peña, M J

2015-01-01

335

Bromeliad-inhabiting mosquitoes in an urban botanical garden of dengue endemic Rio de Janeiro. Are bromeliads productive habitats for the invasive vectors Aedes aegypti and Aedes albopictus?  

PubMed Central

Immatures of both Aedes aegypti and Aedes albopictus have been found in water-holding bromeliad axils in Brazil. Removal of these plants or their treatment with insecticides in public and private gardens have been undertaken during dengue outbreaks in Brazil despite uncertainty as to their importance as productive habitats for dengue vectors. From March 2005-February 2006, we sampled 120 randomly selected bromeliads belonging to 10 species in a public garden less than 200 m from houses in a dengue-endemic neighborhood in Rio de Janeiro. A total of 2,816 mosquito larvae and pupae was collected, with an average of 5.87 immatures per plant per collection. Culex (Microculex) pleuristriatus and Culex spp of the Ocellatus Group were the most abundant culicid species, found in all species of bromeliads; next in relative abundance were species of the genus Wyeomyia. Only two individuals of Ae. aegypti (0.07%) and five of Ae. albopictus (0.18%) were collected from bromeliads. By contrast, immatures of Ae. aegypti were found in manmade containers in nearly 5% of nearby houses. These results demonstrate that bromeliads are not important producers of Ae. aegypti and Ae. albopictus and, hence, should not be a focus for dengue control. However, the results of this study of only one year in a single area may not represent outcomes in other urban localities where bromeliads, Ae. aegypti and dengue coincide in more disturbed habitats. PMID:20140379

Mocellin, Márcio Goulart; Simões, Taynãna César; do Nascimento, Teresa Fernandes Silva; Teixeira, Maria Lucia França; Lounibos, Leon Philip; de Oliveira, Ricardo Lourenço

2012-01-01

336

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

337

Dengue and its effects on liver  

PubMed Central

Dengue has emerged as an important arboviral disease with significant impact on the disease burden in population residing in tropical countries. Dengue is spread by the bite of Aedes mosquito. The virus seems to have some hepatotoxic effects. Affliction of liver in form of derangements in the liver function tests is common and may include mild elevations in serum bilirubin, elevated transaminases and derangements in serum albumin. Although asymptomatic in most cases, clinical manifestations like jaundice, and acute liver failure (ALF) may occasionally complicate the clinical picture. Indeed, dengue has been implicated as an important cause of ALF in endemic countries. The present review focuses on the hepatic manifestations and the pathogenesis of the liver injury in dengue.

Samanta, Jayanta; Sharma, Vishal

2015-01-01

338

Dengue and its effects on liver.  

PubMed

Dengue has emerged as an important arboviral disease with significant impact on the disease burden in population residing in tropical countries. Dengue is spread by the bite of Aedes mosquito. The virus seems to have some hepatotoxic effects. Affliction of liver in form of derangements in the liver function tests is common and may include mild elevations in serum bilirubin, elevated transaminases and derangements in serum albumin. Although asymptomatic in most cases, clinical manifestations like jaundice, and acute liver failure (ALF) may occasionally complicate the clinical picture. Indeed, dengue has been implicated as an important cause of ALF in endemic countries. The present review focuses on the hepatic manifestations and the pathogenesis of the liver injury in dengue. PMID:25685758

Samanta, Jayanta; Sharma, Vishal

2015-02-16

339

Immunogenicity of sanofi pasteur tetravalent dengue vaccine  

Microsoft Academic Search

A candidate tetravalent (TV) dengue vaccine based on the yellow fever (YF) 17D vaccine has been developed by sanofi pasteur. This dengue TV vaccine induced a controlled dendritic cell stimulation in vitro. In clinical trials, Th1 and CD8 responses were induced with an IFN-?\\/TNF-? ratio favouring IFN-? in both cases, regardless of whether the vaccine recipients were flavivirus naive or

Bruno Guy

2009-01-01

340

Dengue Shock Syndrome with Two Atypical Complications  

Microsoft Academic Search

The authors present 2 cases of dengue shock syndrome with unusual complications. In the first case, a 14-y-old boy with dengue\\u000a shock syndrome who required aggressive fluid resuscitation, developed abdominal compartment syndrome (ACS). Patient developed\\u000a severe shock, increased ventilator requirement and oliguria as a consequence of ACS. Patient responded well to abdominal paracentesis\\u000a draining 2.7 l of fluid and made rapid

Hasmukh Chapsi Gala; Bhupendra S. Avasthi; Madhukar R. Lokeshwar

341

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...

342

Probing functional polymorphisms in the dengue vector, Aedes aegypti  

PubMed Central

Background Dengue is the most prevalent arboviral disease world-wide and its primary vector is the mosquito Aedes aegypti. The current lack of commercially-available vaccines makes control of vector populations the only effective strategy to prevent dengue transmission. Aedes aegypti geographic populations exhibit great variability in insecticide resistance and susceptibility to dengue infection. The characterization of single nucleotide polymorphisms (SNPs) as molecular markers to study quantitatively this variation is needed greatly because this species has a low abundance of microsatellite markers and limited known restriction fragments length polymorphisms (RFLPs) and single-strand conformation polymorphism (SSCP) markers. Results We used RNA-seq to characterize SNPs in three Ae. aegypti strains, including the Liverpool (LVP) strain, from which the current genome annotation is derived. We identified 131,764 unique genome locations with at least one alternative nucleotide to what is reported in the reference annotation. These comprised changes in both open-reading frames (ORFs) and untranslated regions (UTRs) of transcripts. An in depth-look at sequence variation in immunity genes revealed that those associated with autophagy, MD2-like receptors and Peptidoglycan Recognition Proteins had more sequence variation in their 3’UTRs than mutations associated with non-synonymous changes. This supports the conclusion that these genes had maintained their functional specificity while being adapted to different regulatory domains. In contrast, a number of peroxidases, serpins and Clip-domain serine proteases exhibited conservation of putative UTR regulatory sequences while displaying diversification of the ORFs. Transcriptome evidence also was found for ~2500 novel transcriptional units (NTUs) not annotated in the reference genome. Conclusions The transcriptome-wide assessment of within and inter-strain polymorphisms in Ae. aegypti adds considerably to the number of molecular markers available for genetic studies in this mosquito. Additionally, data supporting NTU discovery emphasizes the need for continuous amendments of the reference genome annotation. PMID:24168143

2013-01-01

343

Dengue fever: new paradigms for a changing epidemiology  

PubMed Central

Dengue is the most important arthropod-borne viral disease of public health significance. Compared with nine reporting countries in the 1950s, today the geographic distribution includes more than 100 countries worldwide. Many of these had not reported dengue for 20 or more years and several have no known history of the disease. The World Health Organization estimates that more than 2.5 billion people are at risk of dengue infection. First recognised in the 1950s, it has become a leading cause of child mortality in several Asian and South American countries. This paper reviews the changing epidemiology of the disease, focusing on host and societal factors and drawing on national and regional journals as well as international publications. It does not include vaccine and vector issues. We have selected areas where the literature raises challenges to prevailing views and those that are key for improved service delivery in poor countries. Shifts in modal age, rural spread, and social and biological determinants of race- and sex-related susceptibility have major implications for health services. Behavioural risk factors, individual determinants of outcome and leading indicators of severe illness are poorly understood, compromising effectiveness of control programmes. Early detection and case management practices were noted as a critical factor for survival. Inadequacy of sound statistical methods compromised conclusions on case fatality or disease-specific mortality rates, especially since the data were often based on hospitalised patients who actively sought care in tertiary centres. Well-targeted operational research, such as population-based epidemiological studies with clear operational objectives, is urgently needed to make progress in control and prevention. PMID:15743532

Guha-Sapir, Debarati; Schimmer, Barbara

2005-01-01

344

Gastroenteritis Outbreak Associated with Unpasteurized Tempeh, North Carolina, USA  

PubMed Central

During an investigation of an outbreak of gastroenteritis caused by Salmonella enterica serovar Paratyphi B variant L(+) tartrate(+), we identified unpasteurized tempeh as a novel food vehicle and Rhizopus spp. starter culture as the source of the contamination. Safe handling of uncooked, unpasteurized tempeh should be emphasized for prevention of foodborne illnesses. PMID:23965530

Fleischauer, Aaron T.; MacFarquhar, Jennifer K.; Moore, Zackary; Harrelson, Cris; Valiani, Anita; Morrison, Sue Ellen; Sweat, David; Maillard, Jean-Marie; Griffin, Denise; Springer, Debra; Mikoleit, Matthew; Newton, Anna E.; Jackson, Brendan; Nguyen, Thai-An; Bosch, Stacey; Davies, Megan

2013-01-01

345

Dengue Vaccine Development: Strategies and Challenges.  

PubMed

Abstract Infection with dengue virus may result in dengue fever or a more severe outcome, such as dengue hemorrhagic syndrome/shock. Dengue virus infection poses a threat to endemic regions for four reasons: the presence of four serotypes, each with the ability to cause a similar disease outcome, including fatality; difficulties related to vector control; the lack of specific treatment; and the nonavailability of a suitable vaccine. Vaccine development is considered challenging due to the severity of the disease observed in individuals who have acquired dengue-specific immunity, either passively or actively. Therefore, the presence of vaccine-induced immunity against a particular serotype may prime an individual to severe disease on exposure to dengue virus. Vaccine development strategies include live attenuated vaccines, chimeric, DNA-based, subunit, and inactivated vaccines. Each of the candidates is in various stages of preclinical and clinical development. Issues pertaining to selection pressures, viral interaction, and safety still need to be evaluated in order to induce a complete protective immune response against all four serotypes. This review highlights the various strategies that have been employed in vaccine development, and identifies the obstacles to producing a safe and effective vaccine. PMID:25494228

Ramakrishnan, Lakshmy; Radhakrishna Pillai, Madhavan; Nair, Radhakrishnan R

2014-12-10

346

Inhibition of interferon signaling by dengue virus  

PubMed Central

Dengue virus is a worldwide-distributed mosquito-borne flavivirus with a positive strand RNA genome. Its transcribed polyprotein is cleaved by host- and virus-encoded peptidases into 10 proteins, some of which are of unknown function. Although dengue virus-infected cells seem to be resistant to the antiviral action of IFN, the viral products that mediate this resistance are unknown. Therefore, we have analyzed the ability of the 10 dengue virus-encoded proteins to antagonize the IFN response. We found that expression in human A549 cells of the dengue virus nonstructural proteins NS2A, NS4A, or NS4B enhances replication of an IFN-sensitive virus. Moreover, expression of NS4B and, to a lesser extent, of NS2A and NS4A proteins results in down-regulation of IFN-?-stimulated gene expression. Cells expressing NS4B or infected with dengue virus do not exhibit nuclear signal transducer and activator of transcription (STAT) 1 on treatment with IFN-? or IFN-?, indicating that NS4B might be involved in blocking IFN signaling during dengue virus infections. This protein, encoded by a positive strand RNA virus, is implicated as an IFN-signaling inhibitor. PMID:14612562

Muñoz-Jordán, Jorge L.; Sánchez-Burgos, Gilma G.; Laurent-Rolle, Maudry; García-Sastre, Adolfo

2003-01-01

347

Seropositivity of Dengue Antibodies during Pregnancy  

PubMed Central

Purpose. Malaysia a dengue endemic country with dengue infections in pregnancy on the rise. The present study was aimed at determining dengue seroprevalence (IgG or IgM) during pregnancy and its neonatal transmission in dengue seropositive women. Methods. Maternal with paired cord blood samples were tested for dengue antibodies (IgG and IgM) using an enzyme-linked immunosorbent assay (ELISA). Maternal age, parity, occupation, ethnic group, and gestational age were recorded. Data on neonatal Apgar score and admissions to the Neonatal Intensive Care Unit (NICU) were analyzed. Results. Out of 358 women recruited, about 128 (35.8%) patients were seropositive. Twelve patients (3.4%) had recent infections (IgM positive) and another 116 women (32.4%) were with past infections (IgG positive). All babies born to seropositive mothers had positive IgG paired cord blood; however, no IgM seropositivity was observed. All neonates had good Apgar scores and did not require NICU admission. Conclusion. In this study, 35.8% pregnant women were found to be dengue seropositive. However, transplacental transfer of IgG antibodies had no detrimental effect on the neonatal outcomes. PMID:25587564

Mohamed Ismail, Nor Azlin; Wan Abd Rahim, Wan Elly Rushima; Salleh, Sharifah Azura; Neoh, Hui-Min; Jamal, Rahman; Jamil, Muhammad Abdul

2014-01-01

348

Backward bifurcations in dengue transmission dynamics.  

PubMed

A deterministic model for the transmission dynamics of a strain of dengue disease, which allows transmission by exposed humans and mosquitoes, is developed and rigorously analysed. The model, consisting of seven mutually-exclusive compartments representing the human and vector dynamics, has a locally-asymptotically stable disease-free equilibrium (DFE) whenever a certain epidemiological threshold, known as the basic reproduction number(R(0)) is less than unity. Further, the model exhibits the phenomenon of backward bifurcation, where the stable DFE coexists with a stable endemic equilibrium. The epidemiological consequence of this phenomenon is that the classical epidemiological requirement of making R(0) less than unity is no longer sufficient, although necessary, for effectively controlling the spread of dengue in a community. The model is extended to incorporate an imperfect vaccine against the strain of dengue. Using the theory of centre manifold, the extended model is also shown to undergo backward bifurcation. In both the original and the extended models, it is shown, using Lyapunov function theory and LaSalle Invariance Principle, that the backward bifurcation phenomenon can be removed by substituting the associated standard incidence function with a mass action incidence. In other words, in addition to establishing the presence of backward bifurcation in models of dengue transmission, this study shows that the use of standard incidence in modelling dengue disease causes the backward bifurcation phenomenon of dengue disease. PMID:18573507

Garba, S M; Gumel, A B; Abu Bakar, M R

2008-09-01

349

[Lessons learned from tuberculosis outbreak cases].  

PubMed

Most TB outbreaks were caused by exposure of many people to tuberculosis bacilli due to delayed detection of initial cases who had long-lasting severe coughs and excretion of massive tuberculosis bacilli. They were also affected by several other factors, such as socio-environmental factors of the initial case; time and place of infection; and host factors of the infected persons such as immune status, infectivity, and/or pathogenicity of the bacilli. In this symposium, we learned the seriousness of infection and disease among immune-suppressed groups, special environmental factors with regard to the spread of infection, disease after treatment of latent tuberculosis infection, diagnostic specification of IGRA, and bacteriological features including genotyping of the bacilli. We reaffirmed that countermeasures for the case are important, but outbreaks can provide excellent opportunities to learn important information about infection, disease progression, etc. 1. Tuberculosis outbreak in a cancer ward: Katsuhiro KUWABARA (Division of Respiratory Diseases, National Hospital Organization Nishi-Niigata Chuo National Hospital) There was an outbreak of tuberculosis in a cancer ward of a highly specialized medical center. Outbreak cases included eight hospitalized patients and two medical staff members over a 1.5-year observation period after initial contact. Three immune-compromised patients including the index patent died of cancer and tuberculosis. Community hospitals and highly specialized medical centers, such as cancer centers, should carefully prepare a proper system to prevent nosocomial transmission of tuberculosis. 2. Sixty-one cases of TB exposures in hospital settings and contact investigations of the hospital staff, with special reference to the application of QFT: Hiroko Yoshikawa NIGORIKAWA (The Division of Infectious Diseases, Tokyo Metropolitan Health and Medical Treatment Corporation, Toshima Hospital; present: Division of Infectious Diseases, Tokyo Teishin Hospital), Toru MORI (Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association) The index case was a patient who was admitted to a general hospital where she was treated with pulsed corticosteroid therapy and then put on a respirator. Soon after, she developed tuberculosis (TB) and died. Immediately after her death, the healthcare workers who had close contact with the index case were given the QuantiFERON TB Gold (QFT) test, which indicated that all staff except one were negative. However, a QFT test administered eight weeks later had a positive rate of 18.6%. Subsequently, a total of five workers, including a doctor, nurses, and radiology technicians, developed TB. The bacterial isolates from five of them exhibited an RFLP pattern identical to that of the index case. These secondary cases of TB included a case who had contact of less than 5 minutes, a case whose QFT was negative ("doubtful" in the Japanese criterion of the QFT), and a case who was QFT-positive but declined to be treated for latent TB infection (LTBI). No other workers nor hospitalized patients developed TB. The healthcare worker contacts were further examined with the QFT 6, 9 and 12 months after the contact. The QFT results revealed four additional positive reactors and four "doubtful" reactors who were indicated for LTBI treatment. Among them were seven subjects who turned positive six months after the contact. TB prevention in hospital settings and contact investigations were discussed with the hospital staff, with special reference to the application of QFT. 3. Summary and issues of concern relating to a tuberculosis outbreak in a prison: Mitsunobu HOMMA, Takefumi ITOH (Department of Respiratory Medicine, Akita City Hospital) We report a tuberculosis outbreak that occurred in a prison in the spring of 2011, resulting in 11 cases of active disease and 40 cases of infection. The primary cause of the outbreak is thought to be the delay in identifying the index case, where the screening result interpretation might have contributed to the delay. However, w

Kato, Seiya; Kuwabara, Katsuhiro

2014-02-01

350

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

351

Evasion of the human innate immune system by dengue virus  

PubMed Central

Dengue virus is a worldwide health problem, with billions of people at risk annually. Dengue virus causes a spectrum of diseases, namely dengue fever, dengue hemorrhagic fever and dengue shock syndrome with the latter two being linked to death. Understanding how dengue is able to evade the immune system and cause enhanced severity of disease is the main topics of interest in the Fernandez-Sesma laboratory at Mount Sinai School of Medicine. Using primary human immune cells, our group investigates the contribution of dengue virus-specific proteins to the evasion of innate immunity by this virus and the host factors that the virus interacts with in order to evade immune recognition and to establish infection in humans. Here, we review recent findings from our group as well as published data from other groups regarding immune modulation by dengue virus. PMID:22569913

Pagni, Sarah; Fernandez-Sesma, Ana

2014-01-01

352

Transmission spectroscopy of dengue viral infection Transmission spectroscopy of dengue viral infection  

NASA Astrophysics Data System (ADS)

We presented the rapid diagnostic test for dengue infection based on light spectrum of human blood. The transmission spectra of dengue infected whole blood samples have been recorded in ultra violet to near infrared range (400 – 800 nm) of about 30 conformed infected patients and compared to normal blood samples. Transmission spectra of dengue infected blood illustrate a strong band from 400 – 600 nm with prominant peaks at 540 and 580 nm, where is in case of normal blood below 600 nm, total absorption has been observed. These prominent peaks from 400 – 600 nm are characteristics of cells damage and dangue virus antibodies immunoglobulin G (IgG) and immunoglobulin M (IgM) produced against dengue antigen. The presented diagnostic method is non invasive, cost effective, easy and fast screening technique for dengue infected patients.

Firdous, S.; Ahmed, M.; Rehman, A.; Nawaz, M.; Anwar, S.; Murtaza, S.

2012-04-01

353

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...

354

A Systematic Review and Meta-Analysis of Dengue Risk with Temperature Change  

PubMed Central

Dengue fever (DF) is the most serious mosquito-borne viral disease in the world and is significantly affected by temperature. Although associations between DF and temperatures have been reported repeatedly, conclusions have been inconsistent. Six databases were searched up to 23 March 2014, without language and geographical restrictions. The articles that studied the correlations between temperatures and dengue were selected, and a random-effects model was used to calculate the pooled odds ratio and 95% confidence intervals. Of 1589 identified articles, 137 were reviewed further, with 33 satisfying inclusion criteria. The closest associations were observed between mean temperature from the included studies (23.2–27.7 °C) and DF (OR 35.0% per 1 °C; 95% CI 18.3%–51.6%) positively. Additionally, minimum (18.1–24.2 °C) (29.5% per 1 °C; 20.9%–38.1%) and maximum temperature (28.0–34.5 °C) (28.9%; 10.3%–47.5%) were also associated with increased dengue transmission. The OR of DF incidence increased steeply from 22 °C to 29 °C, suggesting an inflexion of DF risk between these lower and upper limits of DF risk. This discovery is helpful for government decision-makers focused on preventing and controlling dengue in areas with temperatures within this range. PMID:25546270

Fan, Jingchun; Wei, Wanxia; Bai, Zhenggang; Fan, Chunling; Li, Shulan; Liu, Qiyong; Yang, Kehu

2014-01-01

355

Disease mapping based on stochastic SIR-SI model for Dengue and Chikungunya in Malaysia  

NASA Astrophysics Data System (ADS)

This paper describes and demonstrates a method for relative risk estimation which is based on the stochastic SIR-SI vector-borne infectious disease transmission model specifically for Dengue and Chikungunya diseases in Malaysia. Firstly, the common compartmental model for vector-borne infectious disease transmission called the SIR-SI model (susceptible-infective-recovered for human populations; susceptible-infective for vector populations) is presented. This is followed by the explanations on the stochastic SIR-SI model which involve the Bayesian description. This stochastic model then is used in the relative risk formulation in order to obtain the posterior relative risk estimation. Then, this relative estimation model is demonstrated using Dengue and Chikungunya data of Malaysia. The viruses of these diseases are transmitted by the same type of female vector mosquito named Aedes Aegypti and Aedes Albopictus. Finally, the findings of the analysis of relative risk estimation for both Dengue and Chikungunya diseases are presented, compared and displayed in graphs and maps. The distribution from risk maps show the high and low risk area of Dengue and Chikungunya diseases occurrence. This map can be used as a tool for the prevention and control strategies for both diseases.

Samat, N. A.; Ma'arof, S. H. Mohd Imam

2014-12-01

356

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

357

Guidelines for clinical trials of dengue vaccine in endemic areas  

Microsoft Academic Search

Guidelines for the clinical evaluation of dengue vaccines in endemic areas have recently been developed, building upon earlier recommendations published in 2002 (WHO. 2002. Guidelines for the evaluation of dengue vaccines in populations exposed to natural infection. Geneva, Switzerland. Report no. TDR\\/IVR\\/DEN\\/02.1). This new document discusses the rationale and background of dengue vaccine trials and outlines dengue case definitions, proposed

Joachim Hombach

2009-01-01

358

[Endemic dengue: surveillance strategy challenges].  

PubMed

Interaction between clinical infection, vector, and population serotype immunity defines dengue epidemic risk. An endemic-sporadic epidemiological situation is an acceptable control target in metropolitan regions deficient in urban upgrading, sanitation, and health agents' access to residences, besides low residual power of biological insecticides and social mobilization problems. Surveillance requires continued action by government and society (particularly when incidence decreases) and adequate proposals. To establish a sensitive and specific surveillance system for endemic periods, the authors propose the sentinel clinical component as part of emergency care (detecting serious tip-of-the-iceberg cases) and reference services for acute febrile diseases, defining clinical forms and providing diagnostic confirmation. Although complex, sample serotype surveys should be conducted in strategic areas, evaluating: immunity and susceptibility of age groups to circulating serotypes; estimation of sub-clinical cases; and Surveillance and Control System reach. PMID:15361960

Marzochi, Keyla Belizia Feldman

2004-01-01

359

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

360

RESEARCH Open Access Detection of dengue group viruses by  

E-print Network

virus or yellow fever virus. The same protocol was used on salivary glands of Ae. albopictus fed and Patrick Mavingui1* Abstract Background: Dengue fever (DF) and dengue hemorrhagic fever (DHF) represent://www.parasitesandvectors.com/content/5/1/243 #12;Background Dengue fever (DF) is the most common arthropod-borne human viral disease

Boyer, Edmond

361

RESEARCH Open Access Phenotypic characterization of patient dengue  

E-print Network

RESEARCH Open Access Phenotypic characterization of patient dengue virus isolates in BALB/c mice Background: Dengue virus (DENV) infection is the most common arthropod-borne viral disease in man the original work is properly cited. #12;Keywords: dengue virus, mouse model, tropism, clinical isolate

Boyer, Edmond

362

Communication Secondary structure of dengue virus type 4  

E-print Network

Short Communication Secondary structure of dengue virus type 4 39 untranslated region: impact of the 39 untranslated region (UTR) of Dengue virus (DEN); however, experimental verification structure, yet viruses carrying these mutations were viable. The four serotypes of mosquito-borne Dengue

Hanley, Kathryn A.

363

Julio de 2012 Predecir los brotes de dengue  

E-print Network

veranos cálidos o húmedos. Transmitido por mosquitos del tipo Aedes, el virus del dengue afecta a unosN° 410 Julio de 2012 Predecir los brotes de dengue en función del clima Scientific news Actualidad cientifica Actualité scientifique Transmitido principalmente por el mosquito Aedes aegypti, el dengue está

364

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

365

Outbreak of Hepatitis A on an Offshore Petroleum Platform, Alaska  

PubMed Central

An outbreak of 8 cases of hepatitis A among the 36-member crew of an offshore Alaska petroleum production platform was linked to a previous outbreak in an urban day-care center. Transmission of hepatitis A on the platform related most plausibly to refrigerated food items contaminated by a cook with mild disease. Control efforts included identifying and treating contacts of case patients who had traveled far from the platform before becoming ill. Early serologic confirmation of diagnosed cases and rapid reporting to public health authorities are essential to prevent disease transmission. Timely investigation can limit the administration of immune globulin to persons at high risk of contracting the disease. PMID:3348024

Kosatsky, Tom; Middaugh, John P.; Hall, David

1988-01-01

366

Carnival or football, is there a real risk for acquiring dengue fever in Brazil during holidays seasons?  

PubMed

More than 600,000 football fans, coming from all over the world, were expected to visit Brazil during the FIFA World Cup 2014. International travel can become a public health problem when the visitors start to become sick, needing medical intervention and eventually hospitalization. The occurrence of dengue fever infections in Brazil is persistent and has been increasing since the 1980s, and the health authorities were expected to take preventive measures and to warn the visitors about the risks during the tournament period. Before the World Cup started, studies have been published stating that dengue could be a significant problem in some of the Brazilian cities hosting the games. These conclusions were taken after a brief observation of the available data, analyzing its mean and standard deviation only, or based on seasonal climate forecasts, causing alarm for the world cup in Brazil. Here, with a more careful data analysis, we show that the seasonality of the disease plays a major role in dengue transmission. The density of dengue cases in Brazil is residual during winter in the Southern hemisphere (mid June to mid September) and the fans of football were not likely to get dengue during the tournament period. PMID:25684648

Aguiar, Maíra; Rocha, Filipe; Pessanha, José Eduardo Marques; Mateus, Luis; Stollenwerk, Nico

2015-01-01

367

Host and viral features of human dengue cases shape the population of infected and infectious Aedes aegypti mosquitoes  

PubMed Central

Dengue is the most prevalent arboviral disease of humans. The host and virus variables associated with dengue virus (DENV) transmission from symptomatic dengue cases (n = 208) to Aedes aegypti mosquitoes during 407 independent exposure events was defined. The 50% mosquito infectious dose for each of DENV-1–4 ranged from 6.29 to 7.52 log10 RNA copies/mL of plasma. Increasing day of illness, declining viremia, and rising antibody titers were independently associated with reduced risk of DENV transmission. High early DENV plasma viremia levels in patients were a marker of the duration of human infectiousness, and blood meals containing high concentrations of DENV were positively associated with the prevalence of infectious mosquitoes 14 d after blood feeding. Ambulatory dengue cases had lower viremia levels compared with hospitalized dengue cases but nonetheless at levels predicted to be infectious to mosquitoes. These data define serotype-specific viremia levels that vaccines or drugs must inhibit to prevent DENV transmission. PMID:23674683

Nguyen, Nguyet Minh; Thi Hue Kien, Duong; Tuan, Trung Vu; Quyen, Nguyen Than Ha; Tran, Chau N. B.; Vo Thi, Long; Thi, Dui Le; Nguyen, Hoa Lan; Farrar, Jeremy J.; Holmes, Edward C.; Rabaa, Maia A.; Bryant, Juliet E.; Nguyen, Truong Thanh; Nguyen, Huong Thi Cam; Nguyen, Lan Thi Hong; Pham, Mai Phuong; Nguyen, Hung The; Luong, Tai Thi Hue; Wills, Bridget; Nguyen, Chau Van Vinh; Wolbers, Marcel; Simmons, Cameron P.

2013-01-01

368

Preparing for introduction of a dengue vaccine: Recommendations from the 1st Dengue v2V Asia-Pacific Meeting  

Microsoft Academic Search

Infection with dengue virus is a major public health problem in the Asia-Pacific region and throughout tropical and sub-tropical regions of the world. Vaccination represents a major opportunity to control dengue and several candidate vaccines are in development. Experts in dengue and in vaccine introduction gathered for a two day meeting during which they examined the challenges inherent to the

Sai Kit Lam; Donald Burke; Maria Rosario Capeding; Chee Keong Chong; Laurent Coudeville; Jeremy Farrar; Duane Gubler; Sri Rezeki Hadinegoro; Jeffrey Hanna; Jean Lang; Han Lim Lee; Yee Sin Leo; Chan Quang Luong; Richard Mahoney; John Mcbride; Jorge Mendez-Galvan; Lee Ching Ng; Suchitra Nimmannitya; Eng Eong Ooi; Donald Shepard; Jaco Smit; Rémy Teyssou; Laurent Thomas; Joseph Torresi; Pedro Vasconcelos; Dewa Nyoman Wirawan; Sutee Yoksan

369

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

370

Of cascades and perfect storms: the immunopathogenesis of dengue haemorrhagic fever-dengue shock syndrome (DHF\\/DSS)  

Microsoft Academic Search

The past four decades has witnessed a consolidation of the original observations made in the 1970s that dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS) have an immunological basis. Following reinfection with a dengue virus of different serotype, severe disease is linked to high levels of antibody-enhanced viral replication early in illness which is followed by a cascade of

Tikki Pang; Mary Jane Cardosa; Maria G Guzman

2007-01-01

371

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

372

Cholera outbreaks in India.  

PubMed

Cholera is a global health problem as several thousands of cases and deaths occur each year. The unique epidemiologic attribute of the disease is its propensity to occur as outbreaks that may flare-up into epidemics, if not controlled. The causative bacterial pathogen Vibrio cholerae prevails in the environment and infects humans whenever there is a breakdown in the public health component. The Indian subcontinent is vulnerable to this disease due its vast coastlines with areas of poor sanitation, unsafe drinking water, and overcrowding. Recently, it was shown that climatic conditions also play a major role in the persistence and spread of cholera. Constant change in the biotypes and serotypes of V. cholerae are also important aspects that changes virulence and survival of the pathogen. Such continuous changes increase the infection ability of the pathogen affecting the susceptible population including the children. The short-term carrier status of V. cholerae has been studied well at community level and this facet significantly contributes to the recurrence of cholera. Several molecular tools recognized altering clonality of V. cholerae in relation with the advent of a serogroup or serotype. Rapid identification systems were formulated for the timely detection of the pathogen so as to identify and control the outbreak and institute proper treatment of the patients. The antimicrobials used in the past are no longer useful in the treatment of cholera as V. cholerae has acquired several mechanisms for multiple antimicrobial resistance. This upsurge in antimicrobial resistance directly influences the management of the disease. This chapter provides an overview of cholera prevalence in India, possible sources of infection, and molecular epidemiology along with antimicrobial resistance of V. cholerae. PMID:24831345

Ramamurthy, Thandavarayan; Sharma, Naresh C

2014-01-01

373

Clinical and Virological Study of Dengue Cases and the Members of Their Households: The Multinational  

E-print Network

dengue infection and a specific dengue virus serotype were not associated with symptomatic dengueClinical and Virological Study of Dengue Cases and the Members of Their Households´ de Pathoge´nie Virale, Paris, France Abstract Background: Dengue has emerged as the most important

Paris-Sud XI, Université de

374

Dengue virus nonstructural protein 3 redistributes fatty acid synthase to sites of viral replication and  

E-print Network

Dengue virus nonstructural protein 3 redistributes fatty acid synthase to sites of viral August 27, 2010 (received for review July 23, 2010) Dengue virus (DENV) modifies cellular membranes | replication complex Dengue virus (DENV) is the causative agent of dengue fever, dengue hemorrhagic fever

375

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

376

Dengue Vectors and their Spatial Distribution.  

PubMed

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

2011-12-01

377

Developing a Vulnerability Mapping Methodology: Applying the Water-Associated Disease Index to Dengue in Malaysia  

PubMed Central

The Water-associated Disease Index (WADI) was developed to identify and visualize vulnerability to different water-associated diseases by integrating a range of social and biophysical determinants in map format. In this study vulnerability is used to encompass conditions of exposure, susceptibility, and differential coping capacity to a water-associated health hazard. By assessing these conditions, the tool is designed to provide stakeholders with an integrated and long-term understanding of subnational vulnerabilities to water-associated disease and contribute to intervention strategies to reduce the burden of illness. The objective of this paper is to describe and validate the WADI tool by applying it to dengue. A systemic ecohealth framework that considers links between people, the environment and health was applied to identify secondary datasets, populating the index with components including climate conditions, land cover, education status and water use practices. Data were aggregated to create composite indicators of exposure and of susceptibility in a Geographic Information System (GIS). These indicators were weighted by their contribution to dengue vulnerability, and the output consisted of an overall index visualized in map format. The WADI was validated in this Malaysia case study, demonstrating a significant association with dengue rates at a sub-national level, and illustrating a range of factors that drive vulnerability to the disease within the country. The index output indicated high vulnerability to dengue in urban areas, especially in the capital Kuala Lumpur and surrounding region. However, in other regions, vulnerability to dengue varied throughout the year due to the influence of seasonal climate conditions, such as monsoon patterns. The WADI tool complements early warning models for water-associated disease by providing upstream information for planning prevention and control approaches, which increasingly require a comprehensive and geographically broad understanding of vulnerability for implementation. PMID:23667642

Dickin, Sarah K.; Schuster-Wallace, Corinne J.; Elliott, Susan J.

2013-01-01

378

Developing a vulnerability mapping methodology: applying the water-associated disease index to dengue in Malaysia.  

PubMed

The Water-associated Disease Index (WADI) was developed to identify and visualize vulnerability to different water-associated diseases by integrating a range of social and biophysical determinants in map format. In this study vulnerability is used to encompass conditions of exposure, susceptibility, and differential coping capacity to a water-associated health hazard. By assessing these conditions, the tool is designed to provide stakeholders with an integrated and long-term understanding of subnational vulnerabilities to water-associated disease and contribute to intervention strategies to reduce the burden of illness. The objective of this paper is to describe and validate the WADI tool by applying it to dengue. A systemic ecohealth framework that considers links between people, the environment and health was applied to identify secondary datasets, populating the index with components including climate conditions, land cover, education status and water use practices. Data were aggregated to create composite indicators of exposure and of susceptibility in a Geographic Information System (GIS). These indicators were weighted by their contribution to dengue vulnerability, and the output consisted of an overall index visualized in map format. The WADI was validated in this Malaysia case study, demonstrating a significant association with dengue rates at a sub-national level, and illustrating a range of factors that drive vulnerability to the disease within the country. The index output indicated high vulnerability to dengue in urban areas, especially in the capital Kuala Lumpur and surrounding region. However, in other regions, vulnerability to dengue varied throughout the year due to the influence of seasonal climate conditions, such as monsoon patterns. The WADI tool complements early warning models for water-associated disease by providing upstream information for planning prevention and control approaches, which increasingly require a comprehensive and geographically broad understanding of vulnerability for implementation. PMID:23667642

Dickin, Sarah K; Schuster-Wallace, Corinne J; Elliott, Susan J

2013-01-01

379

[Interdisciplinary management of a large Legionella outbreak in Germany].  

PubMed

Between December 2009 and the end of January 2010, the largest hitherto known outbreak of Legionella in Germany took place in the cities of Ulm and Neu-Ulm. Of a total of 64 patients involved, 60 patients had to be hospitalized, and 5 patients died from the infection. This event was caused by a wet cooling tower of a large air conditioning system in the city center of Ulm. The search for the source of the Legionella emission was extremely difficult, since these plants are neither notifiable nor subject to authorization in Germany. We report about the search for the source and the measures to control the outbreak. We also discuss communication and coordination during these investigations. Regulatory measures as proposed by the World Health Organization (WHO) and the European Network for Legionellosis (EWGLI) and already implemented in numerous other European countries would be desirable to prevent such outbreaks in the future. PMID:22015788

Freudenmann, M; Kurz, S; von Baum, H; Reick, D; Schreff, A M; Essig, A; Lück, C; Gonser, T; Brockmann, S O; Härter, G; Eberhardt, B; Embacher, A; Höller, C

2011-11-01

380

Universal Single-Probe RT-PCR Assay for Diagnosis of Dengue Virus Infections  

PubMed Central

Background Dengue is a mosquito-borne viral disease that has become more prevalent in the last few decades. Most patients are viremic when they present with symptoms, and early diagnosis of dengue is important in preventing severe clinical complications associated with this disease and also represents a key factor in differential diagnosis. Here, we designed and validated a hydrolysis-probe-based one-step real-time RT-PCR assay that targets the genomes of dengue virus serotypes 1–4. Methodology/Principal Findings The primers and probe used in our RT-PCR assay were designed to target the 3? untranslated region of all complete genome sequences of dengue virus available in GenBank (n?=?3,305). Performance of the assay was evaluated using in vitro transcribed RNA, laboratory-adapted virus strains, external control panels, and clinical specimens. The linear dynamic range was found to be 104–1011 GCE/mL, and the detection limit was between 6.0×102 and 1.1×103 GCE/mL depending on target sequence. The assay did not cross-react with human RNA, nor did it produce false-positive results for other human pathogenic flaviviruses or clinically important etiological agents of febrile illnesses. We used clinical serum samples obtained from returning travelers with dengue-compatible symptomatology (n?=?163) to evaluate the diagnostic relevance of our assay, and laboratory diagnosis performed by the RT-PCR assay had 100% positive agreement with diagnosis performed by NS1 antigen detection. In a retrospective evaluation including 60 archived serum samples collected from confirmed dengue cases 1–9 days after disease onset, the RT-PCR assay detected viral RNA up to 9 days after appearance of symptoms. Conclusions/Significance The validation of the RT-PCR assay presented here indicates that this technique can be a reliable diagnostic tool, and hence we suggest that it be introduced as the method of choice during the first 5 days of dengue symptoms. PMID:25522325

Alm, Erik; Lesko, Birgitta; Lindegren, Gunnel; Ahlm, Clas; Söderholm, Sandra; Falk, Kerstin I.; Lagerqvist, Nina

2014-01-01

381

The Association of Cytokines with Severe Dengue in Children  

PubMed Central

Background: Dengue virus infection is a major public health problem. A hypothesis put forward for severe dengue is the cytokine storm, a sudden increase in cytokines that induces vascular permeability. Previous studies and our recent meta-analysis showed that IL-6, IL-8, IFN?, TNF?, VEGF-A and VCAM-1 are associated with dengue shock syndrome. Therefore, in this study we aim to validate the association of these cytokines with severe dengue. Methods & Findings: In a hospital based-case control study in Vietnam, children with dengue fever, other febrile illness and healthy controls were recruited. Dengue virus infection was confirmed by several diagnostic tests. Multiplex immunoassay using Luminex technology was used to measure cytokines simultaneously. A positive association with dengue shock syndrome was found for VCAM-1, whereas a negative association was found for IFN?. Furthermore, multivariate logistic analysis also showed that VCAM-1 and IFN? were independently correlated with dengue shock syndrome. Conclusion: IFN? and VCAM-1 were associated with dengue shock syndrome, although their role in the severe dengue pathogenesis remains unclear. Additional studies are required to shed further light on the function of these cytokines in severe dengue.

Mangione, Julia N.A.; Huy, Nguyen Tien; Lan, Nguyen Thi Phuong; Mbanefo, Evaristus Chibunna; Ha, Tran Thi Ngoc; Bao, Lam Quoc; Nga, Cao Thi Phi; Tuong, Vo Van; Dat, Tran Van; Thuy, Tran Thi; Tuan, Ha Manh; Huong, Vu Thi Que; Hirayama, Kenji

2014-01-01

382

Are Aedes albopictus or other mosquito species from northern Italy competent to sustain new arboviral outbreaks?  

PubMed

The Asian tiger mosquito Aedes albopictus (Skuse) (Diptera: Culicidae), native to Southeast Asia, has extended its geographical distribution to invade new temperate and tropical regions. This species was introduced in 1990 to Italy and has since become the main pest in urban settings. It was incriminated as a principal vector in the first European outbreak of chikungunya virus (CHIKV) in the province of Ravenna (Italy) in 2007. This outbreak was associated with CHIKV E1-226V, efficiently transmitted by Ae. albopictus. The occurrence of this outbreak in a temperate country led us to estimate the potential of Ae. albopictus to transmit CHIKV and dengue virus (DENV), and to determine the susceptibility to CHIKV of other mosquito species collected in northern Italy. Experimental infections showed that Ae. albopictus exhibited high disseminated infection rates for CHIKV (75.0% in Alessandria; 90.3% in San Lazzaro) and low disseminated infection rates for DENV-2 (14.3% in San Lazzaro; 38.5% in Alessandria). Moreover, Ae. albopictus was able to attain a high level of viral replication, with CHIKV detectable in the salivary glands at day 2 after infection. In addition, the other three mosquito species, Anopheles maculipennis Meigen, Aedes vexans vexans (Meigen) and Culex pipiens L., showed variable susceptibilities to infection with CHIKV, of 0%, 7.7% and 0-33%, respectively. This information on vector competence is crucial in assessing the risk for an outbreak of CHIKV or DENV in Italy. PMID:20377735

Talbalaghi, A; Moutailler, S; Vazeille, M; Failloux, A-B

2010-03-01

383

Dengue: the risk to developed and developing countries.  

PubMed Central

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. The risk of sequential infections, and consequently the incidence of DHF, has risen dramatically, first in Asia and now in the Americas. At the root of the emergence of dengue as a major health problem are changes in human demography and behavior, leading to unchecked populations of and increased exposure to the principal domestic mosquito vector, Aedes aegypti. Virus-specified factors also influence the epidemiology of dengue. Speculations on future events in the epidemiology, evolution, and biological expression of dengue are presented. Images PMID:8146129

Monath, T P

1994-01-01

384

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

385

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

386

Multi-Country Evaluation of the Sensitivity and Specificity of Two Commercially-Available NS1 ELISA Assays for Dengue Diagnosis  

PubMed Central

Background Early diagnosis of dengue can assist patient triage and management and prevent unnecessary treatments and interventions. Commercially available assays that detect the dengue virus protein NS1 in the plasma/serum of patients offers the possibility of early and rapid diagnosis. Methodology/Principal Findings The sensitivity and specificity of the Pan-E Dengue Early ELISA and the Platelia™ Dengue NS1 Ag assays were compared against a reference diagnosis in 1385 patients in 6 countries in Asia and the Americas. Platelia was more sensitive (66%) than Pan-E (52%) in confirmed dengue cases. Sensitivity varied by geographic region, with both assays generally being more sensitive in patients from SE Asia than the Americas. Both kits were more sensitive for specimens collected within the first few days of illness onset relative to later time points. Pan-E and Platelia were both 100% specific in febrile patients without evidence of acute dengue. In patients with other confirmed diagnoses and healthy blood donors, Platelia was more specific (100%) than Pan-E (90%). For Platelia, when either the NS1 test or the IgM test on the acute sample was positive, the sensitivity versus the reference result was 82% in samples collected in the first four days of fever. NS1 sensitivity was not associated to disease severity (DF or DHF) in the Platelia test, whereas a trend for higher sensitivity in DHF cases was seen in the Pan-E test (however combined with lower overall sensitivity). Conclusions/Significance Collectively, this multi-country study suggests that the best performing NS1 assay (Platelia) had moderate sensitivity (median 64%, range 34–76%) and high specificity (100%) for the diagnosis of dengue. The poor sensitivity of the evaluated assays in some geographical regions suggests further assessments are needed. The combination of NS1 and IgM detection in samples collected in the first few days of fever increased the overall dengue diagnostic sensitivity. PMID:20824173

Guzman, Maria G.; Jaenisch, Thomas; Gaczkowski, Roger; Ty Hang, Vo Thi; Sekaran, Shamala Devi; Kroeger, Axel; Vazquez, Susana; Ruiz, Didye; Martinez, Eric; Mercado, Juan C.; Balmaseda, Angel; Harris, Eva; Dimano, Efren; Leano, Prisca Susan A.; Yoksan, Sutee; Villegas, Elci; Benduzu, Herminia; Villalobos, Iris; Farrar, Jeremy; Simmons, Cameron P.

2010-01-01

387

Waterborne gastroenteritis outbreak in Albania  

Microsoft Academic Search

Three different studies are reported concerning the environmental pollution caused by viruses in Albania. The first study describes an outbreak of gastroenteritis in the capital city, involving 2,722 children attending the Paediatric Unit of Tirana Hospital. The age group with the highest morbidity was 0-5 years, with 89.5%; no fatalities were recorded during the outbreak. Rotavirus was detected in 26\\/28

M. Divizia; R. Gabrieli; D. Donia; A. Macaluso; A. Bosch; S. Guix; G. Sánchez; C. Villena; R. M. Pintó; L. Palombi; E. Buonuomo; F. Cenko; L. Leno; D. Bebeci; S. Bino

388

Understanding dengue pathogenesis: implications for vaccine design.  

PubMed Central

In the second half of the twentieth century dengue spread throughout the tropics, threatening the health of a third of the world's population. Dengue viruses cause 50-100 million cases of acute febrile disease every year, including more than 500,000 reported cases of the severe forms of the disease--dengue haemorrhagic fever and dengue shock syndrome. Attempts to create conventional vaccines have been hampered by the lack of suitable experimental models, the need to provide protection against all four serotypes simultaneously and the possible involvement of virus-specific immune responses in severe disease. The current understanding of dengue pathogenesis is outlined in this review, with special emphasis on the role of the immune response. The suspected involvement of the immune system in increased disease severity and vascular damage has raised concerns about every vaccine design strategy proposed so far. Clearly more research is needed on understanding the correlates of protection and mechanisms of pathogenesis. There is, however, an urgent need to provide a solution to the escalating global public health problems caused by dengue infections. Better disease management, vector control and improved public health measures will help reduce the current disease burden, but a safe and effective vaccine is probably the only long-term solution. Although concerns have been raised about the possible safety and efficacy of both conventional and novel vaccine technologies, the situation is now so acute that it is not possible to wait for the perfect vaccine. Consequently the careful and thorough evaluation of several of the current candidate vaccines may be the best approach to halting the spread of disease. PMID:15868023

Stephenson, John R.

2005-01-01

389

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

390

Dengue Fever Presenting as Acute Pancreatitis  

PubMed Central

A 56-year-old non-alcoholic male was admitted with complaints of severe abdominal pain and was diagnosed with acute pancreatitis after blood investigations and a computed tomography scan of the abdomen. He developed a high-grade fever on the third day of admission, and serology tested positive for dengue. Treatment for dengue was instituted, leading to a good response and complete resolution of pancreatitis. The patient has been doing well and has had no recurrence of pancreatitis at the end of one year of follow-up.

Seetharam, Prasad; Rodrigues, Gabriel

2010-01-01

391

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

392

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...