This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chlamypiae, Subject name: Microbiology
Frei's intradermal test is done for: 
Select and explain. 
A. Chlamydiae, B. LGV, C. Herpes simplex, D. Donovanosis
B: LGV
Answer: B: LGV 
Explanation: Ans: b (LGV) Ref: Ananthanarayanan, 7th ed, p. 428Frei's test was an intradermal test commonly used for LGVThe crude chlamydial antigen (from bubo pus)is inoculated intradermally in the forearm. An induration 7mm or more in 2-5 days is taken as positive test. Due to the frequentoccurance or false positive reactions, it is not used now.Other common tests frequently askedMantoux test (I/D)-TBCasoni'stest (I/D)-EcchinococcusIto test-ChancroidNapiers aldehyde test]- Leishmanin test-LeishmaniasisKviem test-SarcoidosisAnton test-ListeriaDick test-Scarlet feverSereny test-Shigella.EIECFairley's test-Schistosoma haematobiumSabin Feldman; Frenkel's test-ToxoplasmaHangar rose test-Cat scratch diseaseEijkman test-E.coliWhey agglutination test-BrucellosisEiken precipitin test-ETEC