Staphylococcus aureus bacteremia and endocarditis: comparison of nosocomial and community-acquired infection

Staphylococcus aureus bacteremia continues to be a frequent clinical problem even in communities where intravenous drug abuse is relatively rare. One-hundred-three evaluable cases of S. aureus bacteremia that occurred in a large tertiary care facility over a four year period (1979-1982) are reviewed. A comparison of nosocomial and community-acquired S. aureus bacteremia reveals several fundamental differences. Community-acquired S. aureus bacteremia frequently develops in the absence of a primary focus of infection and is more likely to result in endocarditis and secondary metastatic foci of clinical infection. In contrast, nosocomial S. aureus bacteremia tends to be diagnosed earlier, a primary site of portal entry is usually identified and endocarditis is less frequent as are secondary foci of infection. Irrespective of the epidemiological origin of S. aureus bacteremia, the mortality remains high particularly in nosocomial infection where the presence of severe underlying disease contributes to the high mortality. Methicillin resistant S. aureus adds a new dimension to the challenge of successful treatment of staphylococcal bacteremia.