Diagnostic value of rectal biopsy and concentration methods in Schistosomiasis intercalatum: quantitative comparison of three techniques.

The diagnostic value of the rectal biopsy was compared to a quantitative stool filtration and the MIF concentration technique in schistosomiasis intercalatum in the Gabon. The rectal biopsy was significantly more sensitive in proving the presence of ova of Schistosoma intercalatum than the stool filtration (p less than 0.001). However, if the two techniques were compared on the basis of the capability to detect viable eggs in rectal mucosa or stool, no difference in sensitivity could be found. The MIF concentration technique was significantly less sensitive than the stool filtration (p less than 0.01) and seems only of minor diagnostic value in schistosomiasis intercalatum. It could be shown that the relative sensitivities of the three techniques in detecting S. intercalatum eggs depended on the age of the examined population, as presence of viable eggs in rectal mucosa and excretion of eggs in stool was inversely correlated to the age of the patients.