Irrigation Practices and Intestinal Helminth Infections in Southern and Central Zones of Tigray

Background: Irrigation practices have impact on the distribution of schistosomiasis; so, identifying newly established schistosomiasis transmission foci allows for designing prevention and control strategy. Objective: To establish schistosomiasis prevalence and intensity in relation to development of water bodies for irrigation. Methods: A survey of stool specimens of 2000 school children using Kato thick smear method was carried out in Central and Southern Tigray between October 2001 and January 2002. Results: Among the 1012 males and 998 females examined, 29% males and 27.5% females were found positive for one or more parasite. The prevalence of S. mansoni was 27% in longstanding irrigated, 10.8% in recently constructed irrigation schemes and 1.8% in the non-irrigated rural localities. In the urban setting, its prevalence was 15.5% in areas with water body nearby and 0.5% in areas with no water body nearby (P < 0.0001). New S. mansoni infection foci were detected in Tumuga with a prevalence of 87%; Dibdibo (41%), Mariam Shewito (25%), Adiha (23%) and Lekia (9%). Conclusion: The increasing risk of schistosomiasis mansoni in the irrigation sites is high. Hence, designing preventive and control strategies concurrent with the development of the irrigation projects will be required to reduce prevalence of schistosomiasis. [Ethiop.J.Health Dev. 2009; 23(1):48-56]