BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSIONS/SIGNIFICANCE: 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.
BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSIONS/SIGNIFICANCE: 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.
Authors: Nana-Kwadwo Biritwum; Paul Yikpotey; Benjamin K Marfo; Samuel Odoom; Ernest O Mensah; Odame Asiedu; Bright Alomatu; Edward T Hervie; Abednego Yeboah; Serge Ade; Sven G Hinderaker; Anthony Reid; Kudakwashe C Takarinda; Benjamin Koudou; Joseph B Koroma Journal: Trans R Soc Trop Med Hyg Date: 2016-12-01 Impact factor: 2.184
Authors: Mary E Hodges; Joseph B Koroma; Mustapha Sonnie; Ngozi Kennedy; Emily Cotter; Chad Macarthur Journal: Int Health Date: 2011-06 Impact factor: 2.473
Authors: Joseph B Koroma; Momodu M Bangura; Mary H Hodges; Mohamed S Bah; Yaobi Zhang; Moses J Bockarie Journal: Parasit Vectors Date: 2012-01-11 Impact factor: 3.876
Authors: Sellase Pi-Bansa; Joseph Harold Nyarko Osei; Kwadwo Kyeremeh Frempong; Elizabeth Elhassan; Osei Kweku Akuoko; David Agyemang; Collins Ahorlu; Maxwell Alexander Appawu; Benjamin Guibehi Koudou; Michael David Wilson; Dziedzom Komi de Souza; Samuel Kweku Dadzie; Jürg Utzinger; Daniel Adjei Boakye Journal: Infect Dis Poverty Date: 2019-02-05 Impact factor: 4.520
Authors: Samuel Wanji; Nathalie Amvongo-Adjia; Benjamin Koudou; Abdel Jelil Njouendou; Patrick W Chounna Ndongmo; Jonas A Kengne-Ouafo; Fabrice R Datchoua-Poutcheu; Bridget Adzemye Fovennso; Dizzle Bita Tayong; Fanny Fri Fombad; Peter U Fischer; Peter I Enyong; Moses Bockarie Journal: PLoS Negl Trop Dis Date: 2015-11-06