ONCHOCERCIASIS – A PUBLIC HEALTH PERSPECTIVE

Abstract

Onchocerciasis is a chronic parasitic disease with a wide range of cutaneous and ocular manifestations. It is caused by the tissue nematode, Onchocerca volvulus, and it is transmitted by the bite of a female black fly, Simulium damnosum. Onchocerciasis is a serious public health and socio-economic problem with 95% of all cases being found in Africa south of the Sahara. The WHO Expert Committee has estimated that over 80 million people are at the risk of infection worldwide, some 18 million infected, and 1 million people visually impaired of which some 340,000 are blind. Nigeria is highly endemic for this disease, to the extent that 40% of all cases worldwide are believed to occur in the country. The prevalence of blindness in villages near to fast flowing rivers may reach 15%, often, affecting males (of working age, perhaps 30-40 years old) more frequently than females. In spite of these ravaging consequences of this disease however, remarkable successes have been achieved by the control effort of the Onchocerciasis Control Programme (OCP), which uses chemical and biological larvicides with low environmental impact to kill black fly larvae flies. Other methods of effecting Onchocerciasis control include: (i) Reducing the number of bites by the Simulium fly on man; (ii) Killing the microfilariae with microfilaricides; and (iii) Killing the adult worms. The social and economic consequences of the disease in Nigeria and other African countries are huge, with considerable human suffering. It thus demands unrelenting intensive and concerted effort at the international, national and community levels, making optimal use of the identified modes of control for effective control of this disease which has serious public health and economic consequences.


Key Words: Onchocerciasis, Public Health, Control


Afr. J. Clin. Exper. Microbiol. 2004; 5(2): 165 – 172.