The Lion's gaze: African river blindness from tropical curiosity to international development

Onchocerciasis (river blindness) is a parasitic disease common throughout rural sub-Saharan Africa; the former Belgian, British, and French territories are considered here, 1875--1972. Despite a wide range of serious dermatologic and ocular symptoms, onchocerciasis was the last major vector-borne parasitic disease discovered by Europeans in colonial Africa. Remote geography and perplexing symptomatology rendered the disease comparatively invisible to Westerners. Most endemic areas were beyond the reach of colonial activities and all symptoms had more common alternative causes. Blindness was blamed on cataract, trachoma, and nutritional deficiencies. Skin problems were attributed to scabies, rashes, and bacterial infections. The difficulty of correlating a worm infection with disease is the first of four major themes.; The second theme is the tight connection between the discovery of onchocerciasis and control activities aimed at trypanosomiasis (sleeping sickness). Though most colonial health activities were in urban areas, in the 1920s and afterward large numbers of rural Africans received at least some medical attention in connection with sleeping sickness campaigns. Often co-endemic with onchocerciasis, sleeping sickness brought investigators into contact with both diseases.; The third theme is the regional scope of onchocerciasis, both in the ecology of the disease and in the investigations made to understand it. To a degree perhaps unequaled by any other parasite-vector disease, onchocerciasis was a regional problem, corresponding to the major, interconnected river basins that were fly bionomic zones. The large scale presented difficulties to investigators trying to understand and combat the disease locally.; The fourth theme is the transformation of onchocerciasis from a health problem to a central issue in international development. At the World Bank between about 1965 and 1972, onchocerciasis went from completely unknown to the main socio-economic development obstacle in West Africa. It was the first health matter the Bank ever considered and I attempt to show how staff members discussed this new area of operations and eventually came to support disease control in partnership with the World Health Organization.; This story shows how a set of symptoms was correlated with parasitic infection, defined as a disease, elevated to international prominence, and subject to regional control operations.