Irrigation, farming and schistosomiasis: A case study in the Nile delta

Abstract

Schistosomiasis has long been a serious rural health problem in Egypt. Changing irrigation systems are recognized as affecting the distribution of Schistosoma haematobium and S. Mansoni and its snail vectors. In the Nile delta, although the proportion of full-time farmers is declining, an increasing number of women and men are part-time farmers and may be exposed to schistosomiasis. Epidemiological data from two villages indicate that full-time and part-time farmers, both men and women, have relatively high rates of infection with S. mansoni. Water contact studies identify the exposure patterns associated directly with irrigation, and with washing after farm work and cleaning vegetables in the canals. Farmers are aware of the risk of exposure during farming yet feel that they have no alternative but to come into contact with canal water during irrigation. Data on the distribution of the snail vector, and water quality, show that infection in canals flowing through fields in the study villages is possible. Interventions to protect farmers from schistosomiasis include community supported cleaning of canals, health education targeting farmers and improving treatment strategies. In one study village the modification of the water flow of canals may be feasible. In all settings intersectoral collaboration is essential for effective disease control.