Evaluation of some laboratory procedures in diagnosing infections with Schistosoma mansoni.

Abstract

THIS PAPER REPORTS ON A COMPARATIVE EVALUATION CARRIED OUT IN PUERTO RICO ON THE FOLLOWING PROCEDURES USED IN DIAGNOSING BILHARZIASIS: recovery of S. mansoni ova from stools; serological tests (complement-fixation tests with adult worm and cercarial antigens, slide flocculation test with cercarial antigens, cercarial agglutination test, and circumoval precipitin test) and intradermal tests with adult worm, cercarial and egg antigens.Stool examinations revealed infections in only 74% of 485 patients hospitalized for bilharziasis, but most of the serological and intradermal tests gave results which, when corrected for false negative reactions, suggested infections in 89%-94% of patients. Cercarial agglutination results were discounted because of weak reactions and low specificity; the intradermal test with egg antigen lacked specificity.From the results of their comparative studies, the authors suggest particular uses for the various serological and stool tests, but consider that the intradermal tests do not appear to have a definable role in the diagnosis or detection of bilharziasis.