Chemotherapy-based control of schistosomiasis haematobia. 3. Snail studies monitoring the effect of chemotherapy on transmission in the Msambweni area, Kenya.

Regular snail sampling was performed at 40 sites, representing the principal snail habitats, during a 4 year chemotherapy programme targetted at school-children in the Msambweni area of the coastal plain of Kenya. Populations of Bulinus africanus group snails, primarily from pools, showed seasonal variations, dropping when sites dried out and rising when they were refilled by the rains. Transmission, judged by the recovery of snails shedding typical fucocercous cercariae, continued throughout the treatment period at very low levels (less than 1% of the snails collected were infected) with peaks in October/November and in January/February after seasonal rains.

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

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%+).

Treatment of Rhodesian sleeping sickness in Kenya.

In a study of 269 sleeping sickness patients treated with Mel-B, 14 (5.2%) died during treatment. With total dosages of at least 30 ml (1.

Epidemiology of Rhodesian sleeping sickness in the Lambwe Valley, Kenya.

A total of 912 cases of sleeping sickness have been recorded from the Lambwe Valley from 1959 to 1984. After a period of decreasing prevalence in the 1970s an outbreak of disease occurred between 1980 and 1984. The incidence of disease for this five-year period was highest in areas adjoining the Ruma National Park, reaching 54% in Area I.

Demographic characteristics of the Lambwe Valley population.

Thirty-four per cent of the population (11,079) in the Lambwe Valley study site was under the age of 10, and 59% were under the age of 20. The population was equally divided among males and females (M/F 0.99).