AITHM Seminar - Onchocerciasis elimination in West Africa: a population geneticist’s perspective
Presented by Dr Warwick Grant
Genome resequencing of small pools of adult female Onchocerca volvulus that had been phenotyped as either good responders or poor (sub-optimal responders) for variation in response to ivermectin showed that there is a strong genetic association between several regions of the genome and ivermectin response. The parasites composing those pools were from several locations in Ghana and Cameroon, and analysis of the same data from a population genetics perspective showed that there is strong population structure (low transmission) between Ghana and Cameroon, but that population structure was absent within Ghana. Subsequent work on a much larger sample of individual parasites across 3 river basins in Ghana using whole mitochondrial genome sequences showed that the whole of central Ghana appears as a single transmission zone despite the focal nature of vector breeding sites. Warwick will describe these data, and follow up studies elsewhere in Africa and discuss how these approaches could be applied to inform decisions concerning onchocerciasis elimination.