Diagnosis of Rhodesian sleeping sickness in the Lambwe Valley (1980–1984)

Abstract

In primary Rhodesian sleeping sickness patients, parasitological diagnosis was best performed by rodent inoculation of blood (98·5% +) followed by Giemsa-stained thick blood smears (93·3% +). Parasitological diagnosis in relapse patients was sometimes impossible and clinical diagnosis based on CSF examination was necessary. Early during a disease outbreak in 1980, 89% of the infections were detected by mobile field teams, but once established in the endemic area a stationary diagnostic facility detected most of the cases. A total number of23 751 examinations for Rhodesian sleeping sickness and malaria were made by mobile field teams during 1980–1984; 102 primary cases (0·43%) and 25 (0·10%) relapse cases were diagnosed. A total of 9339 individuals (39%) had patent malaria infections. The IFAT was positive in 89% of the primary sleeping sickness patients and 77% of the relapse patients. Seventy-nine per cent of the primary patients were positive in a CFT test, and 77% of the relapse patients were considered positive.