Staphylococcus aureus with reduced susceptibility to vancomycin--Illinois, 1999.

Staphylococcus aureus is one of the most common causes of hospital- and community-acquired infections. Nosocomial methicillin-resistant S. aureus (MRSA) infections have become common, and cases of community-acquired MRSA infections also have occurred. Since 1996, vancomycin-intermediate S. aureus (VISA; vancomycin minimum inhibitory concentration [MIC = 8-16 microg/mL) has been identified in Europe, Asia, and the United States. The emergence of reduced vancomycin susceptibility in S. aureus increases the possibility that some strains will become fully resistant and that available antimicrobial agents will become ineffective for treating infections caused by such strains. This report describes the fourth case of confirmed VISA from a patient in the United States.