Onchocerciasis (river blindness) is a chronic parasitic infection of humans caused by the nematode Onchocerca volvulus and transmitted by blackflies of the genus Simulium. For infected individuals, the major features of the disease are ocular and dermatological pathology, of which itching is the commonest and blindness the most serious. If many people are infected in a community, onchocerciasis may lead to socioeconomic depression. The disease is endemic in 37 countries in West, East and Central Africa, the Arabian Peninsula and parts of South and Central America (Figure 18b. 1). About 126 million people are at risk of infection in endemic areas, of whom about 18 million are estimated to be infected. The great majority of those infected live in Africa (WHO, 1995). These figures are generally accepted to underestimate the true situation.
Was this article helpful?