Diagnosis of Hydatid disease is by -

Serological tests are the most sensitive and specific tests; includes Immunoblast test, arcs test, ELISA and indirect hemagglutination tests. "The immunoblast test, where available, is the test of choice." - CMDT, 2005, p 1463. Casoni's test - Intradennal injection of 0.2 ml of fresh sterile hydatid fluid produces a wheal of 5 cm in diameter within half an hour in pts with hydatid disease. It has been abandoned because of poor specificity. Ref : CMDT, 2005, p 1462, 1465