Schistosomiasis in Africa.

: Schistosomiasis remains endemic in many parts of the tropics and subtropics including Africa. In recent years, there have been two main trends with regard to the size and distribution of the problem posed by this infection. The increasing exploitation of water resources for agro-engineering projects has tended to increase the intensity of the transmission of this infection and to extend it into new foci. At the same time, however, there has been a significant improvement in the tools available for the control of this disease. Furthermore a number of interesting demonstration programmes have shown that control of the disease is feasible by using the appropriate combination of available measures. Why then is the situation mainly static in many endemic areas or even worsening in some others? Three factors will be discussed: a) In some endemic areas, low priority is accorded to the control of schistosomiasis probably because of failure to appreciate its public health significance. b) Insufficient guidance of control programmes from careful epidemiological assessments. c) Technical constraints in terms of efficacy and safety of drugs and other control measures.