Q fever endocarditis revisited.

A diagnosis of Q fever endocarditis was made in 7 patients, 6 with predisposing factors and 3 with occupational risk factors. Prompt recognition of Coxiella burnettii endocarditis is required when clinical signs of endocarditis such as fever, anaemia, elevated liver transaminases, congestive cardiac failure are accompanied by negative blood cultures. Serological evidence of elevated antibody titres to Phase I and Phase II antigens of Coxiella burnettii are diagnostic. Prolonged antimicrobial therapy combined with surgery has resulted in the marked reduction of mortality from 50 per cent of 17 per cent when Q fever endocarditis is revisited almost 20 yr later.