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What is Casoni's test is used in the diagnosis of: and explain in detail?
Ans. B. Hydatid diseasea. Immunological methods, employed include the Casoni's intradermal test & serological tests.b. The Casoni's test is an immediate hypersensitivity test originally introduced by Casoni in 1911.c. The antigen is hydatid fluid collected from animal or human cysts and sterilized by Seitz or membrane filtration and injected (0.2 ml) intradermally on one arm and an equal volume of saline as control on the other arm.d. In positive case a large wheal, about 5 cm in diameter with multiple pseudopodal projections appears within 20 to 30 minutes at the test site and fades in an houre. A secondary reaction consisting of oedema and induration appears after 8 hours.f. The test is very sensitive, but not specific and false-positive reactions may not cause a similar antibody response.