Epidemiology of Wuchereria bancrofti in Leogane, Haiti.
ABSTRACT A survey for Wuchereria bancrofti in Leogane, Haiti, revealed that 140 of 421 individuals (33%) had a patent infection, of which 40% lived in the suburban outskirts of the city. The median microfilaria density was 19.1 per 20 mm3 of blood for suburban dwellers compared with only 8.8 for those living in the city. The vector, Culex quinquefasciatus (Say), breeds mostly in and around numerous rum distilleries, located exclusively around the periphery of the city, and this undoubtedly accounts for the higher prevalence and intensity of infection among suburban dwellers.
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ABSTRACT: Antifilarial antibody testing has been established as a sensitive and specific method of diagnosing lymphatic filariasis. However, the development of serological responses to specific filarial antigens and their relationship to acquisition of infection is poorly understood. In order to evaluate whether the development of antigen specific antifilarial antibodies precedes microfilaremia and antigenemia, we compared the antibody responses of serum samples collected between 1990 and 1999 from a cohort of 142 Haitian children followed longitudinally. Antigen status was determined using the Og4C3 ELISA and the presence of microfilaremia was detected using microscopy. Antibody responses to Wb123, a Wuchereria bancrofti L3 antigen, were measured using a Luciferase Immunoprecipitation System (LIPS) assay. Antibody responses to Bm14 and Bm33, Brugia malayi antigens and to a major surface protein (WSP) from Wolbachia were analyzed using a multiplex bead assay. Over follow-up, 80 (56%) of the children became antigen-positive and 30 (21%) developed microfilaremia. Detectable antibody responses to Bm14, Bm33, Wb123, and WSP developed in 95%, 100%, 92%, and 29% of children, respectively. With the exception of WSP, the development of antibody responses generally preceded detection of filarial antigen. Our results show that antifilarial antibody responses can serve as an important epidemiological indicator in a sentinel population of young children and thus, may be valuable as tool for surveillance in the context of lymphatic filariasis elimination programs.PLoS Neglected Tropical Diseases 12/2012; 6(12):e1941. · 4.49 Impact Factor
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ABSTRACT: This paper describes the construction and application of a social deprivation index that was created to explore the relationship between lymphatic filariasis and socioenvironmental variables in the municipality of Jaboatão dos Guararapes, Pernambuco, Brazil, thereby contributing towards identifying priority areas for interventions. This indicator was obtained from principal-component factor analysis. Variables available from the national census representing socioenvironmental conditions, household characteristics and urban services were used. Epidemiological data came from a parasitological survey on lymphatic filariasis. 23 673 individuals were examined and 323 were positive (1.4%). Two factors that together explained 80.61% of the total variance were selected. The social deprivation strata were capable of indicating a risk gradient, with 74.9% of the microfilaremia cases situated in the high-risk stratum. Principal-component factor analysis was shown to be sensitive for selecting indicators associated with the risk of lymphatic filariasis transmission and for detecting areas potentially at risk. The capacity of the social deprivation index for picking up social inequalities qualifies it as a new tool for use in planning interventions aimed at controlling lymphatic filariasis in urban spaces.International Health 09/2009; 1(1):78-84. · 1.13 Impact Factor
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ABSTRACT: Background: Lymphatic filariasis (LF) is one of the neglected tropical diseases targeted for global elimination by 2020 and to guide elimination efforts countries have, in recent years, conducted extensive mapping surveys. Documenting the past and present distribution of LF and its environmental limits is important for a number of reasons. Here, we present an initiative to develop a global atlas of LF and present a new global map of the limits of LF transmission. Methods: We undertook a systematic search and assembly of prevalence data worldwide and used a suite of environmental and climatic data and boosted regression trees (BRT) modelling to map the transmission limits of LF. Results: Data were identified for 66 of the 72 countries currently endemic and for a further 17 countries where LF is no longer endemic. Our map highlights a restricted and highly heterogeneous distribution in sub-Saharan Africa, with transmission more widespread in West Africa compared to east, central and southern Africa where pockets of transmission occur. Contemporary transmission occurs across much of south and South-east Asia and the Pacific. Interestingly, the risk map reflects environmental conditions suitable for LF transmission across Central and South America, including the southern States of America, although active transmission is only known in a few isolated foci. In countries that have eliminated LF, our predictions of environmental suitability are consistent with historical distribution. Conclusions: The global distribution of LF is highly heterogeneous and geographically targeted and sustained control will be required to achieve elimination. This first global map can help evaluate the progress of interventions and guide surveillance activities.Parasites & Vectors 10/2014; 7(1):466. · 3.25 Impact Factor