What are the modified Duke criteria for diagnosing S aureus endocarditis?
The modified Duke criteria for diagnosing S aureus endocarditis include the inclusion of S aureus bacteremia as a major criterion, regardless of whether the infection is hospital acquired (with or without a removable source of infection) or community acquired. Specific serological data have also been included in the Duke IE diagnostic schema to establish the pathogenic agents of culture-negative IE more precisely (ie, as a surrogate for positive blood cultures). These serological criteria would be applied in circumstances in which the pathogenic organism is slow growing in routine blood cultures (eg, Brucella species) or requires special blood culture media (eg, Bartonella species, Legionella species, Tropheryma whipplei, fungi, and Mycobacterium species) or in which the organism is not culturable (eg, Coxiella burnetii, the agent of Q fever). Q fever serological results and a single blood culture positive for C burnetii are also considered to be major criteria for diagnosing S aureus endocarditis. 