Programmatic Use of Molecular Xenomonitoring at the Level of Evaluation Units to Assess Persistence of Lymphatic Filariasis in Sri Lanka.
BACKGROUND:Sri Lanka's Anti Filariasis Campaign distributed 5 rounds of mass drug administration (MDA with DEC plus albendazole) to all endemic regions in the country from 2002-2006. Post-MDA surveillance results have generally been encouraging. However, recent studies have documented low level...
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ftdoajarticles:oai:doaj.org/article:60b27fcb12f440289ec5cbf6dd33a865 2023-05-15T15:14:27+02:00 Programmatic Use of Molecular Xenomonitoring at the Level of Evaluation Units to Assess Persistence of Lymphatic Filariasis in Sri Lanka. Ramakrishna U Rao Sandhya D Samarasekera Kumara C Nagodavithana Manjula W Punchihewa Tharanga D M Dassanayaka Gamini P K D Ethan Ford Udaya S B Ranasinghe Ralph H Henderson Gary J Weil 2016-05-01T00:00:00Z https://doi.org/10.1371/journal.pntd.0004722 https://doaj.org/article/60b27fcb12f440289ec5cbf6dd33a865 EN eng Public Library of Science (PLoS) http://europepmc.org/articles/PMC4873130?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0004722 https://doaj.org/article/60b27fcb12f440289ec5cbf6dd33a865 PLoS Neglected Tropical Diseases, Vol 10, Iss 5, p e0004722 (2016) Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 article 2016 ftdoajarticles https://doi.org/10.1371/journal.pntd.0004722 2022-12-31T10:46:05Z BACKGROUND:Sri Lanka's Anti Filariasis Campaign distributed 5 rounds of mass drug administration (MDA with DEC plus albendazole) to all endemic regions in the country from 2002-2006. Post-MDA surveillance results have generally been encouraging. However, recent studies have documented low level persistence of Wuchereria bancrofti in Galle district based on comprehensive surveys that include molecular xenomonitoring (MX, detection of filarial DNA in mosquitoes) results. The purposes of this study were to demonstrate the use of MX in large evaluation units (EUs) and to field test different mosquito sampling schemes. METHODOLOGY/PRINCIPAL FINDINGS:Galle district (population 1.1 million) was divided into two EUs. These included a coastal EU with known persistent LF and an inland EU with little persistent LF. Mosquitoes were systematically sampled from ~300 trap locations in 30 randomly selected clusters (health administrative units) per EU. Approximately 28,000 Culex quinquefasciatus were collected with gravid traps and tested for filarial DNA by qPCR. 92/625 pools (14.7%) from the coastal EU and 8/583 pools (1.4%) from the inland EU were positive for filarial DNA. Maximum likelihood estimates (MLE) for filarial DNA rates were essentially the same when the same number of mosquito pools were collected and tested from 75, 150, or 300 trap sites (range 0.61-0.78% for the coastal EU and 0.04-0.07% for the inland EU). The ability to use a smaller number of trap sites reduces the cost and time required for mosquito sampling. CONCLUSIONS/SIGNIFICANCE:These results suggest there is widespread persistence of W. bancrofti infection in the coastal Galle EU 8 years after the last round of MDA in 2006, and this is consistent with other data from the district. This study has shown that MX can be used by national programs to assess and map the persistence of W. bancrofti at the level of large EUs in areas with Culex transmission. Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic PLOS Neglected Tropical Diseases 10 5 e0004722 |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
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Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 Ramakrishna U Rao Sandhya D Samarasekera Kumara C Nagodavithana Manjula W Punchihewa Tharanga D M Dassanayaka Gamini P K D Ethan Ford Udaya S B Ranasinghe Ralph H Henderson Gary J Weil Programmatic Use of Molecular Xenomonitoring at the Level of Evaluation Units to Assess Persistence of Lymphatic Filariasis in Sri Lanka. |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
description |
BACKGROUND:Sri Lanka's Anti Filariasis Campaign distributed 5 rounds of mass drug administration (MDA with DEC plus albendazole) to all endemic regions in the country from 2002-2006. Post-MDA surveillance results have generally been encouraging. However, recent studies have documented low level persistence of Wuchereria bancrofti in Galle district based on comprehensive surveys that include molecular xenomonitoring (MX, detection of filarial DNA in mosquitoes) results. The purposes of this study were to demonstrate the use of MX in large evaluation units (EUs) and to field test different mosquito sampling schemes. METHODOLOGY/PRINCIPAL FINDINGS:Galle district (population 1.1 million) was divided into two EUs. These included a coastal EU with known persistent LF and an inland EU with little persistent LF. Mosquitoes were systematically sampled from ~300 trap locations in 30 randomly selected clusters (health administrative units) per EU. Approximately 28,000 Culex quinquefasciatus were collected with gravid traps and tested for filarial DNA by qPCR. 92/625 pools (14.7%) from the coastal EU and 8/583 pools (1.4%) from the inland EU were positive for filarial DNA. Maximum likelihood estimates (MLE) for filarial DNA rates were essentially the same when the same number of mosquito pools were collected and tested from 75, 150, or 300 trap sites (range 0.61-0.78% for the coastal EU and 0.04-0.07% for the inland EU). The ability to use a smaller number of trap sites reduces the cost and time required for mosquito sampling. CONCLUSIONS/SIGNIFICANCE:These results suggest there is widespread persistence of W. bancrofti infection in the coastal Galle EU 8 years after the last round of MDA in 2006, and this is consistent with other data from the district. This study has shown that MX can be used by national programs to assess and map the persistence of W. bancrofti at the level of large EUs in areas with Culex transmission. |
format |
Article in Journal/Newspaper |
author |
Ramakrishna U Rao Sandhya D Samarasekera Kumara C Nagodavithana Manjula W Punchihewa Tharanga D M Dassanayaka Gamini P K D Ethan Ford Udaya S B Ranasinghe Ralph H Henderson Gary J Weil |
author_facet |
Ramakrishna U Rao Sandhya D Samarasekera Kumara C Nagodavithana Manjula W Punchihewa Tharanga D M Dassanayaka Gamini P K D Ethan Ford Udaya S B Ranasinghe Ralph H Henderson Gary J Weil |
author_sort |
Ramakrishna U Rao |
title |
Programmatic Use of Molecular Xenomonitoring at the Level of Evaluation Units to Assess Persistence of Lymphatic Filariasis in Sri Lanka. |
title_short |
Programmatic Use of Molecular Xenomonitoring at the Level of Evaluation Units to Assess Persistence of Lymphatic Filariasis in Sri Lanka. |
title_full |
Programmatic Use of Molecular Xenomonitoring at the Level of Evaluation Units to Assess Persistence of Lymphatic Filariasis in Sri Lanka. |
title_fullStr |
Programmatic Use of Molecular Xenomonitoring at the Level of Evaluation Units to Assess Persistence of Lymphatic Filariasis in Sri Lanka. |
title_full_unstemmed |
Programmatic Use of Molecular Xenomonitoring at the Level of Evaluation Units to Assess Persistence of Lymphatic Filariasis in Sri Lanka. |
title_sort |
programmatic use of molecular xenomonitoring at the level of evaluation units to assess persistence of lymphatic filariasis in sri lanka. |
publisher |
Public Library of Science (PLoS) |
publishDate |
2016 |
url |
https://doi.org/10.1371/journal.pntd.0004722 https://doaj.org/article/60b27fcb12f440289ec5cbf6dd33a865 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
PLoS Neglected Tropical Diseases, Vol 10, Iss 5, p e0004722 (2016) |
op_relation |
http://europepmc.org/articles/PMC4873130?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0004722 https://doaj.org/article/60b27fcb12f440289ec5cbf6dd33a865 |
op_doi |
https://doi.org/10.1371/journal.pntd.0004722 |
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PLOS Neglected Tropical Diseases |
container_volume |
10 |
container_issue |
5 |
container_start_page |
e0004722 |
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1766344909726416896 |