The relationship of water sources and other determinants to prevalence of intestinal protozoal infections in a rural community of Saudi Arabia.

A study was carried out in a rural area of Asir region in Southwest of Saudi Arabia where information on the types of domestic water supply and sociodemography in relation to intestinal protozoal infections were obtained from 1417 inhabitants (81.4% of the total) of nine villages. Stool samples were collected from the study population and examined for intestinal parasites. Overall, the prevalence rates of infection with the common water-borne parasites, Giardia lamblia and Entamoeba histolytica were 18.9% and 9.2% respectively, which were high compared to other endemic areas of the Kingdom. The sociodemographic factors including age, sex, degree of education, intrafamilial clustering and crowding index were found to be non significant determinants of both protozoal infections. The source of domestic water was the sole factor significantly associated with the high prevalence rates of infection in the community. This relationship was confirmed by multiple logistic regression analysis. A significantly high risk of contracting the infection with both parasites was observed among individuals who drank jar water (OR = 2.973, 95%CI:1.515-4.402 and OR = 2.831, 95%CI:1.414-3.915, for G. lamblia and E. histolytica respectively) or well water (OR = 2.153, 95%CI:1.211-3.913 and OR = 2.117, 95%CI:1.341-3.715, for G. lamblia and E. histolytica respectively). Those who used desalinated water for drinking seems to have the lowest degree of exposure to the risk of infection (OR = 0.689, 95%CI:0.501-0.849 and OR = 0.793, 95% CI:0.518-0.912, for G. lamblia and E. histolytica respectively). The results indicate that the use of improved water supply, including protection of community wells and domestic storage tanks, together with mandatory inspection measures during transportation and distribution of commercial water should reduce the rate of infection with the two protozoal parasites in this rural community.