RAPID ASSESSMENT OF ONCHOCERCIASIS PREVALENCE AND A MODEL FOR SELECTING COMMUNITIES FOR IVERMECTIN DISTRIBUTION IN WEST-AFRICA

Analysis of the prevalence of onchocerciasis in an area of north-east Nigeria indicates that clinical symptoms are generally good predictors of the rate of onchocerciasis infection and of the mean microfilarial density in infected individuals. However, differences between regions and anomalous communities within regions make reliance on a single in dicator dubious. Use of multivariate equations was tested, but offered little improvement over bivariate ones and an algorithmic approach, m aking use of local knowledge of factors which might complicate interpr etation, is proposed instead. The framework is suggested as a basis fo r screening, although a larger database is required to produce definit ive equations.