Mectizan

This study was carried out in Odeda Local Government Area (LGA) of Ogun State, Nigeria, between August and September 2018. Odeda LGA is endemic for onchocerciasis and LF, where community-directed treatment with ivermectin (CDTI) is being implemented annually through mass drug administration (MDA) with single-dose administration of 150–200 μg/kg ivermectin (Mectizan®, Merck & Co Inc.). Treatment coverage was between 66 and 80% in the LGA between 2013 and 2017 according to the ivermectin therapeutic coverage records of the Ogun State Ministry of Health (SMoH). Four communities—Kugba-Ajagbe (7.36102° N, 3.59830° E) and Amini (7.23509° N, 3.74935° E) as intervention communities and Olofin (7.41974° N, 3.64086° E) and Gbagba (7.44530° N, 3.63307° E) as control communities—were selected for the study. The intervention communities have been receiving ivermectin MDA rounds consistently from 2013 to 2017, whereas the control communities have no records of ivermectin treatment (Fig. 1). The four communities are a part of the sparsely dispersed settlements in the border region between Ogun and Oyo States of Nigeria. Each community is located about 3 km from the nearest villages in the surrounding area.Fig. 1

Map of the study area showing the Ogun State communities where the study was conducted

Mosquito sampling was conducted during five collection periods in three West African countries: Senegal, Liberia and Burkina Faso (Table 
1). Senegal: sampling occurred in 2008, 2009 and 2012 in the southeastern villages of Boundacoundi, Damboucoye, Nathia, Ibel, and Ndebou. Bed net coverage ranged from 78.2% in 2009 to 82.0% in 2012. Select villages in this region are treated by MDA with 150 μg/kg of ivermectin alone (Mectizan®, Merck & Co Inc) for onchocerciasis control. Liberia: sampling occurred in 2013 in the village of Ngaisaikoryah (Foya District, Lofa County) where the bed net coverage was 38.3%. MDA was designed to control lymphatic filariasis (LF), onchocerciasis and soil-transmitted helminths with a combination of ivermectin (150 μg/kg) + albendazole (400 mg) (Albenza®, GlaxoSmithKine). Burkina Faso: sampling occurred in 2013 in the villages of Bougouriba (Haut-Bassins region, control) and Diarkadougou East (Sud-Ouest region, treated) where the average bed net coverage was 42.0%. MDA was designed to control LF with a combination of ivermectin (150 μg/kg) + albendazole (400 mg). MDA coverage rates in treatment villages were 82.1-84.0% in Senegal, 76.2% in Liberia and 83.0% in Burkina Faso, and were recorded either directly by investigators or provided by health authorities.