[For a better estimation of the prevalence of intestinal parasitism in the Tunis region]

The prevalence of intestinal parasitism is generally based on the results of 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 (26%). For those specimens that tested positive, 41% of children had infection detected in all three stool specimens; 21%--in two specimens and 38%--in only one. If we assume that the sensitivity of three stool specimen examinations is 100%, then the calculated sensitivity of one examination is equivalent to 68%. This gives an underestimation of the prevalence of 32%. This underestimation 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.