Scrub Typhus in South Vietnam

With the use of indirect fluorescent antibody or mouse inoculation methods, scrub typhus was diagnosed in 109 of 1650 febrile American servicemen in Vietnam. The fluorescent antibody test was positive in all 32 patients from whom rickettsia were recovered, but a rising antibody titer to Proteus OXK occurred in only 47%, which included only 5 of 27 patients infected with Gilliam strain. The diagnosis was clinically suspected in only 51 patients. Generalized lymphadenopathy and lymphocytosis were commoner than either eschar or rash, and, in the absence of the latter findings, the illness was frequently mistaken for infectious mononucleosis. Early treatment with tetracycline shortened the duration of illness and suppressed the convalescence indirect fluorescent antibody titer. No relapses occurred in those patients who received tetracycline for at least 7 days.