Gaining control of schistosomiasis

Map of Africa with regions indicatedProgram managers need good data on the optimal use of various approaches to mass drug administration (MDA) in areas of high prevalence, where the priority is to quickly reduce rates of schistosomiasis and decrease morbidity from this disease. SCORE is supporting efforts in Kenya, Mozambique, Niger, and Tanzania to understand the benefits and costs of alternative approaches to MDA for schistosomiasis in high-prevalence communities.

Studies of gaining control were implemented in communities with S. haematobium or S. mansoni prevalence among school children of ≥25% (see Box 1 for study arms in Kenya, Mozambique, and Tanzania). Each study arm includes 25 villages. Programs will provide different communities with various combinations of community-wide MDA, school-based MDA, and drug holidays over a period of 4 years, followed by final data collection, analysis, and dissemination of results in the fifth year. In Niger, the study will compare twice a year treatment with treatment once a year. The primary outcome of interest is change in prevalence and intensity of schistosomiasis among children ages 9 – 12. We expect to test 100 children in this age group each year in each village in each study arm that is receiving MDA.

At the beginning and end of the 5-year period, rates of infection and intensity of infection among children 8 years of age and younger and among adults 22 to 55 years of age, will also be determined. Cost data will be collected using protocols consistent with those being used for studies of integration of NTD control funded elsewhere by the Bill & Melinda Gates Foundation.

These gaining control studies were implemented during 2010 in all study areas. Several papers have been written to describe the baseline efforts including the first-year data. See Publications.

Additional evaluations in high prevalence communities are evaluating changes in subtle morbidity indicators in a cohort of children during years 1, 3 and 5.

Data is also being collected to determine which factors may be most important in predicting a community’s response to MDA. These data will include measures related to the environment, snail infections, schistosome population genetics, and other factors that may affect the force of transmission and the likelihood that MDA can lower transmission.

In some study sites, smartphones are being used to collect data and transmit it to servers. Systems in use include EpiCollect (Kenya, Mozambique, and Tanzania) and LINKS (Côte d’Ivoire), with assistance from Imperial College and the Task Force for Global Health, respectively.

Box 1 Study Arms: Studies of Gaining Control of Schistosomiasis