Abstract | BACKGROUND: METHODOLOGY AND PRINCIPAL FINDINGS: Transmission assessment surveys (TAS) were performed per WHO guidelines in primary school children in 11 evaluation units (EUs) in all 8 formerly endemic districts. All EUs easily satisfied WHO criteria for stopping MDA. Comprehensive surveillance was performed in 19 Public Health Inspector (PHI) areas (subdistrict health administrative units). The surveillance package included cross-sectional community surveys for microfilaremia (Mf) and circulating filarial antigenemia (CFA), school surveys for CFA and anti-filarial antibodies, and collection of Culex mosquitoes with gravid traps for detection of filarial DNA (molecular xenomonitoring, MX). Provisional target rates for interruption of LF transmission were community CFA <2%, antibody in school children <2%, and filarial DNA in mosquitoes <0.25%. Community Mf and CFA prevalence rates ranged from 0-0.9% and 0-3.4%, respectively. Infection rates were significantly higher in males and lower in people who denied prior treatment. Antibody rates in school children exceeded 2% in 10 study sites; the area that had the highest community and school CFA rates also had the highest school antibody rate (6.9%). Filarial DNA rates in mosquitoes exceeded 0.25% in 10 PHI areas. CONCLUSIONS: Comprehensive surveillance is feasible for some national filariasis elimination programs. Low-level persistence of LF was present in all study sites; several sites failed to meet provisional endpoint criteria for LF elimination, and follow-up testing will be needed in these areas. TAS was not sensitive for detecting low-level persistence of filariasis in Sri Lanka. We recommend use of antibody and MX testing as tools to complement TAS for post-MDA surveillance.
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Authors | Ramakrishna U Rao, Kumara C Nagodavithana, Sandhya D Samarasekera, Asha D Wijegunawardana, Welmillage D Y Premakumara, Samudrika N Perera, Sunil Settinayake, J Phillip Miller, Gary J Weil |
Journal | PLoS neglected tropical diseases
(PLoS Negl Trop Dis)
Vol. 8
Issue 11
Pg. e3281
( 2014)
ISSN: 1935-2735 [Electronic] United States |
PMID | 25393404
(Publication Type: Journal Article, Research Support, N.I.H., Extramural)
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Chemical References |
- Anthelmintics
- Antibodies, Helminth
- Antigens, Helminth
- DNA, Helminth
- Filaricides
- Albendazole
- Diethylcarbamazine
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Topics |
- Adolescent
- Adult
- Albendazole
(therapeutic use)
- Animals
- Anthelmintics
(administration & dosage)
- Antibodies, Helminth
(blood)
- Antigens, Helminth
(blood)
- Child
- Cross-Sectional Studies
- Culex
(parasitology)
- DNA, Helminth
(isolation & purification)
- Diethylcarbamazine
(therapeutic use)
- Disease Eradication
- Elephantiasis, Filarial
(drug therapy, epidemiology)
- Female
- Filaricides
(therapeutic use)
- Humans
- Insect Vectors
(parasitology)
- Longitudinal Studies
- Male
- Microfilariae
(immunology, isolation & purification)
- Middle Aged
- Prevalence
- Sri Lanka
(epidemiology)
- Young Adult
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