The efficiency of the examination of compressed fecal samples for Schistosoma mansoni eggs

Abstract

The control of schistosomiasis depends mostly upon the sensitivity of stool examinations. We used both the Kato-Katz technique and the compression of samples between the slide and a polypropylene cover glass, according to Ferreira. Out of 1,282 samples collected between 1998 and 2000 in the Palha District, Municipality of Bananal, São Paulo State, Brazil, 105 (8.2 %) were positive. The first and second methods revealed 90 (7%) and 88 (6.9 %) positive cases, respectively. According to the kappa statistic, both methods were in agreement. In Bananal, the proportion of positive cases and egg per gram (epg) values are low, which calls for the examination of larger than usual volumes of feces. The viability of Schistosoma mansoni eggs can also be checked when using the second method, which dispenses with glycerin solution, measuring plates and sieves. The latter cause a further loss of precision in epg determinations.

Schistosoma mansoni; Fecal examination; Sensitivity; Schistosomiasis; Morbidity