For a better estimation of intestinal parasitism prevalence in the Tunis area

The prevalence of intestinal parasitism is generally based on the results o f a single stool specimen which probably underestimates the real situation. In order to propose a coefficient for correction, we examined three stool specimens taken from 112 asymptomatic children. Intestinal parasites other than Enterobius vermicularis were detected in 29 subjects (25%), For those specimens that tested positive, 41% of children had infection detected in a ll three stool specimens; 21 in two specimens and 38% - in only one. If we assume that the sensitivity of three stool specimen examinations is 1 00%, then the calculated sensitivity of one examination is equivalent to 58 %, This gives an underestimation of the prevalence of 32%. This underestima tion is not homogenous for all species. As regards Giardia intestinalis it is 35%, but for other species it would have to be calculated from a larger sample.