Maps

World map of soil-transmitted helminth prevalence

Africa map of soil-transmitted helminth prevalence

World map of areas where schistosomiasis is a problem

And for more detailed country maps, please see our rapid appraisal page

The Africa STH prevalence map is based on large-scale, climate-based predictive maps for single STH species and represents the highest prevalence of any single STH species.* These maps help permit the estimation of the scale of the population at risk, and can help inform the design of control approaches. See the 'Step-by-Step Guide for Deworming' for further details.

Note that the maps are only predictions, useful for defining broad-scale patterns of infection. They are not suitable for developing a detailed treatment plan at the district level. Existing data on STH infection based on searches of the published literature and grey literature also exist and will shortly be uploaded as maps, and will inform this planning further.

Schistosome infections are much more geographically concentrated than soil-transmitted helminth infections as prevalence is linked to the distribution of snails and human water contact behaviour.

The global distribution of schistosomiasis was first mapped nearly 20 years ago in the Global Schistosomiasis Atlas. This information was based on a review of historical records, documents and published reports, including hospital-based data. However, changes in transmission have occurred as a consequence of man-made ecological changes such as the construction of large dams and irrigation schemes and the successful implementation of control in some locales.

Existing data on schistosomiasis based on searches of the published literature and grey literature also exist and will also shortly be uploaded as maps.

*Source: Brooker, Clements & Bundy. 2006. Advances in Parasitology 62, 221-261.