Impact Assessment of Repeated Mass Ivermectin Treatment on Onchocerciasis in Abia State, Nigeria

Abstract

The impact assessment of repeated mass ivermectin treatment on onchocerciasis in Abia state, south eastern Nigeria was carried out between June and September 2011, using skin snipping method. Abia state is made up of 17 Local Government Areas, eight of which are endemic for onchocerciasis (2 hyper-endemic and 6 meso-endemic LGAs). The study captured the two LGAs of the state that were rated as hyper-endemic by REMO assessment and had been receiving treatment since 1995. Out of 547 individuals skin snipped, only 3 (0.55%) were infected with microfilariae of Onchocerca volvulus, and this occurred in one community Amiyi-Obilohia. The distribution of infection showed that 0.50% of the infected were males while 0.58% were females. The overall age specific prevalence showed that infection only occurred in individuals 60 years and above, who were low compliers and were not treated during the last treatment period. A CMFL of 0.28 mf/mg obtained is an indication that ivermectin is an effective microfilaricide.

Key words: Impact assessment, Repeated, mass, ivermectin, treatment, Onchocerciasis.