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What is Tunica reaction is positive in ? and explain in detail?
Ans. is 'b' i.e., R typhi Neill - Mooser (Tunica) reaction When male guinea pigs are inoculated intraperitoneally with blood from a case of endemic typhus or with a culture of R. typhi (R. mooseri) they develop fever and a characteristic scrotal inflammation. This reaction is used to differentiate R. typhi and R. prowazekii.