Tunica reaction is positive in ?: (A) R prowazekii, (B) R typhi, (C) R tsutsugamushi, (D) R akari
Answer is B. 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.