The hospital records of 242 patients with hydatid disease operated on at the American University Hospital in Beirut were examined. Results of 492 tests done on these patients were compared, and some observations were made on cyst fertility. The indirect hemagglutination and intradermal tests gave almost equal proportions of positive results (66.4% and 64.5% respectively), but the complement fixation test (51%) was significantly inferior to both. The three tests were more frequently positive when done on patients with hydatid cysts of the liver than when done on patients with hydatid cysts of the lung, while they were often negative in cases of hydatid cyst of the brain.
Similar results were obtained when all three tests done on each of 78 patients were compared. The indirect hemagglutination and the intradermal tests were positive in 69% and 70.5% respectively, while the complement fixation test was again inferior to both (55.1%). Of the 78 patients 37% had all three tests positive and 11.5% had all tests negative. The highest proportion of positive results was obtained with the indirect hemagglutination test in hydatid cyst of the liver, and with the intradermal test in hydatid cyst of the lung. Taken together, the two tests identified 88.5% of cases. No additional cases were identified by the complement fixation test. The intradermal test was exclusively positive in 18% of 78 patients, the indirect hemagglutination test in 4% and the complement fixation test in none.
Hydatid cysts of different organs, excised from 126 patients, were examined histopathologically. Scolices or hooklets were found in 92 specimens (73%). No relation was found between cyst fertility and the positivity of any one of these tests since they were equally positive in the presence of fertile and infertile cysts.