Evaluation of the indirect haemagglutination and intradermal tests on hydatid and nonhydatid cases.

Evaluation of the immediate intradermal (ID) test showed a direct relationship between nitrogen concentration and sensitivity. Antigens of low nitrogen concentration were less reactive but more specific. Intradermal antigens prepared from Echinococcus multilocularis can be used in Isfahan, Iran, for the diagnosis of E. granulosus in man. The ID delayed reaction was observed in a few patients who had positive immediate skin tests. Because of its high sensitivity, the indirect haemagglutination (IHA) test was preferred for the serologic diagnosis of echinococcosis. Based on the results outlined in their study the IHA test appears to offer good sensitivity, and the ID, with an antigen of low nitrogen concentration, good specificity.