Objectives
To identify and recruit individuals within selected endemic communities who have been exposed to schistosomiasis; recording their history of exposure, treatment and pathology status.
Three epidemiological groups will be identified:
- Recent infection with S. mansoni and/or S. haematobium, evident in northern Senegal .
- Chronic S. haematobium infection but no history of treatment, evident in the Lambarene region, Gabon.
- Chronic S. haematobium infection and current mass treatment, evident in Volta region Ghana.
Description of work
In each of the 3 African countries, communities/villages will be identified based on information available to the DC partners belonging to the consortium. Before the onset of the study, participants will be informed about the objectives and design of the study and informed consent will be obtained. Each individual will be examined by: intake of questionnaires (personal detail, demographic data), parasitological examination (S. mansoni, S. haematobium, intestinal helminths and malaria co-infection), clinical and ultrasound examination (schistosomiasis and malaria morbidity). Anti-helminth treatment will be provided to all the members of the respective communities. Those with severe pathology will be referred to regional hospitals; those with clinical signs of malaria will be treated preventively. In Gabon, all study participants will be given praziquantel and mebedazole at 3 monthly intervals and after one year. They will be re-analysed for infection, pathology and innate immune responses as before treatment. This will provide information before and after treatment.
Based on sample size calculations, the numbers that will be recruited in Senegal (Richard Toll region and Saint Louis, Louga, Matam) and Ghana (Volta region) will be 300 aged 5-40 years, whereas in Gabon (Lambarene area), 350 individuals of the same age range will be recruited, based on an expected annual drop out rate of 10%. During the surveys, all cases with pathology will be asked to participate; we will aim to include 50 case from each country to allow comparison of 150 pathology cases with 150 without pathology.
Individuals will be located geographically using GPS and environmental data will be collected (see WP6). These patients will form the basis for the immunological assays (WP2).