Onchocerciasis control by insecticides and chemotherapy stimulates agricultural development in Central West Africa.

The Onchocerciasis Control Programme (OCP) has been successful in controlling transmission of onchocerciasis in large areas of the savanna and rain forest of Central West Africa. Within the center of the OCP, individual infection levels have declined to zero, children born within the last fifteen years are disease free and the progression of ocular disease in older members of the population has been halted. Control has been achieved by the application of insecticides to the aquatic breeding sites of the Simulium intermediate host. Control has been maintained despite development of insecticide resistance in certain areas, migration of infected people into the OCP zone, and temporary recolonization by migratory Simulium. Insecticide mediated control is now beginning to be supplemented by mass chemotherapy using ivermectin. Resettlement into onchocerciasis-free areas, diversification of agricultural practices and enhanced agricultural productivity have been occurring steadily. There now exists a real prospect of significant socioeconomic advancement for the whole of this region of Africa, and by some measures of national agricultural output and gross national product this process is already occurring.