Achievements and challenges of lymphatic filariasis elimination in Sierra Leone.
<h4>Background</h4>Lymphatic filariasis (LF) is targeted for elimination in Sierra Leone. Epidemiological coverage of mass drug administration (MDA) with ivermectin and albendazole had been reported >65% in all 12 districts annually. Eight districts qualified to implement transmission...
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2020-12-01
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| Series: | PLoS Neglected Tropical Diseases |
| Online Access: | https://doi.org/10.1371/journal.pntd.0008877 |
| _version_ | 1818195224967512064 |
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| author | Yakuba M Bah Jusufu Paye Mohamed S Bah Abdulai Conteh Victoria Redwood-Sawyerr Mustapha Sonnie Amy Veinoglou Joseph B Koroma Mary H Hodges Yaobi Zhang |
| author_facet | Yakuba M Bah Jusufu Paye Mohamed S Bah Abdulai Conteh Victoria Redwood-Sawyerr Mustapha Sonnie Amy Veinoglou Joseph B Koroma Mary H Hodges Yaobi Zhang |
| author_sort | Yakuba M Bah |
| collection | DOAJ |
| description | <h4>Background</h4>Lymphatic filariasis (LF) is targeted for elimination in Sierra Leone. Epidemiological coverage of mass drug administration (MDA) with ivermectin and albendazole had been reported >65% in all 12 districts annually. Eight districts qualified to implement transmission assessment survey (TAS) in 2013 but were deferred until 2017 due to the Ebola outbreak (2014-2016). In 2017, four districts qualified for conducting a repeat pre-TAS after completing three more rounds of MDA and the final two districts were also eligible to implement a pre-TAS.<h4>Methodology/principal findings</h4>For TAS, eight districts were surveyed as four evaluation units (EU). A school-based survey was conducted in children aged 6-7 years from 30 clusters per EU. For pre-TAS, one sentinel and one spot check site per district (with 2 spot check sites in Bombali) were selected and 300-350 persons aged 5 years and above were selected. For both surveys, finger prick blood samples were tested using the Filariasis Test Strips (FTS). For TAS, 7,143 children aged 6-7 years were surveyed across four EUs, and positives were found in three EUs, all below the critical cut-off value for each EU. For the repeat pre-TAS/pre-TAS, 3,994 persons over five years of age were surveyed. The Western Area Urban had FTS prevalence of 0.7% in two sites and qualified for TAS, while other five districts had sites with antigenemia prevalence >2%: 9.1-25.9% in Bombali, 7.5-19.4% in Koinadugu, 6.1-2.9% in Kailahun, 1.3-2.3% in Kenema and 1.7% - 3.7% in Western Area Rural.<h4>Conclusions/significance</h4>Eight districts in Sierra Leone have successfully passed TAS1 and stopped MDA, with one more district qualified for conducting TAS1, a significant progress towards LF elimination. However, great challenges exist in eliminating LF from the whole country with repeated failure of pre-TAS in border districts. Effort needs to be intensified to achieve LF elimination. |
| first_indexed | 2024-12-12T01:14:48Z |
| format | Article |
| id | doaj.art-9457999fb5be43beb698e04d6094f5fc |
| institution | Directory Open Access Journal |
| issn | 1935-2727 1935-2735 |
| language | English |
| last_indexed | 2024-12-12T01:14:48Z |
| publishDate | 2020-12-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Neglected Tropical Diseases |
| spelling | doaj.art-9457999fb5be43beb698e04d6094f5fc2022-12-22T00:43:23ZengPublic Library of Science (PLoS)PLoS Neglected Tropical Diseases1935-27271935-27352020-12-011412e000887710.1371/journal.pntd.0008877Achievements and challenges of lymphatic filariasis elimination in Sierra Leone.Yakuba M BahJusufu PayeMohamed S BahAbdulai ContehVictoria Redwood-SawyerrMustapha SonnieAmy VeinoglouJoseph B KoromaMary H HodgesYaobi Zhang<h4>Background</h4>Lymphatic filariasis (LF) is targeted for elimination in Sierra Leone. Epidemiological coverage of mass drug administration (MDA) with ivermectin and albendazole had been reported >65% in all 12 districts annually. Eight districts qualified to implement transmission assessment survey (TAS) in 2013 but were deferred until 2017 due to the Ebola outbreak (2014-2016). In 2017, four districts qualified for conducting a repeat pre-TAS after completing three more rounds of MDA and the final two districts were also eligible to implement a pre-TAS.<h4>Methodology/principal findings</h4>For TAS, eight districts were surveyed as four evaluation units (EU). A school-based survey was conducted in children aged 6-7 years from 30 clusters per EU. For pre-TAS, one sentinel and one spot check site per district (with 2 spot check sites in Bombali) were selected and 300-350 persons aged 5 years and above were selected. For both surveys, finger prick blood samples were tested using the Filariasis Test Strips (FTS). For TAS, 7,143 children aged 6-7 years were surveyed across four EUs, and positives were found in three EUs, all below the critical cut-off value for each EU. For the repeat pre-TAS/pre-TAS, 3,994 persons over five years of age were surveyed. The Western Area Urban had FTS prevalence of 0.7% in two sites and qualified for TAS, while other five districts had sites with antigenemia prevalence >2%: 9.1-25.9% in Bombali, 7.5-19.4% in Koinadugu, 6.1-2.9% in Kailahun, 1.3-2.3% in Kenema and 1.7% - 3.7% in Western Area Rural.<h4>Conclusions/significance</h4>Eight districts in Sierra Leone have successfully passed TAS1 and stopped MDA, with one more district qualified for conducting TAS1, a significant progress towards LF elimination. However, great challenges exist in eliminating LF from the whole country with repeated failure of pre-TAS in border districts. Effort needs to be intensified to achieve LF elimination.https://doi.org/10.1371/journal.pntd.0008877 |
| spellingShingle | Yakuba M Bah Jusufu Paye Mohamed S Bah Abdulai Conteh Victoria Redwood-Sawyerr Mustapha Sonnie Amy Veinoglou Joseph B Koroma Mary H Hodges Yaobi Zhang Achievements and challenges of lymphatic filariasis elimination in Sierra Leone. PLoS Neglected Tropical Diseases |
| title | Achievements and challenges of lymphatic filariasis elimination in Sierra Leone. |
| title_full | Achievements and challenges of lymphatic filariasis elimination in Sierra Leone. |
| title_fullStr | Achievements and challenges of lymphatic filariasis elimination in Sierra Leone. |
| title_full_unstemmed | Achievements and challenges of lymphatic filariasis elimination in Sierra Leone. |
| title_short | Achievements and challenges of lymphatic filariasis elimination in Sierra Leone. |
| title_sort | achievements and challenges of lymphatic filariasis elimination in sierra leone |
| url | https://doi.org/10.1371/journal.pntd.0008877 |
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