The control of sleeping sickness in Nigeria

Abstract

Summary 1. Conditions conducive to a high degree of contact between man and riverine tsetse are common in Nigeria, especially in the Northern Provinces. 2. The occurrence of strains of T. gambiense naturally resistant to arsenicals demands the administration to all infective cases of antrypol or a similar drug. This has been the rule in Nigeria since 1934. 3. Since 1931, 3,202,295 people have been examined at primary surveys, and the average infection rate was 9·6 per cent. Incidence was high (10 to 20 per cent.) in central provinces, lower (1 to 5 per cent.) at the edges of the endemic area. In peripheral provinces, despite similar contact with fly, infection was sporadic or focal. 4. “Mild” trypanosomiasis may be associated with depopulation. If not so associated, such a condition is not necessarily stable. A toxaemic exacerbation of previously mild symptoms is a common cause of death. 5. Standard treatment is a combination of tryparsamide following, or simultaneously with, either antrypol or pentamidine, the latter combination being less toxic. Results of treatment, especially in survey cases, are good. Administrative arrangements to ensure early diagnosis and regularity of treatment are essential. 6. As a prophylactic pentamidine appears safer than, and superior to, antrypol, and is being used in mining camps. 7. Mass treatment and dispensaries have reduced infection rates to about 1 per cent. in the highly infected central endemic areas. This incidence does not seriously affect the public health but there must be positive evidence that infection rates are not increasing, and proper use must be made of the treatment facilities provided. 8. Permanent control means vector control: 500,000 people have been protected by defensive clearings, and another 50,000 live in the Anchau corridor which has been made tsetse-free by a combination of partial and barrier clearings. Movement or concentration of population is a last resort. At Anchau experimental concentration was associated with measures of rural development.