Staphylococcus aureus With Reduced Susceptibility to Vancomycin—United States, 1997

Staphylococcus aureusis one of the most common causes of both hospital- and community-acquired infections worldwide, and the antimicrobial agent vancomycin has been used to treat manyS. aureusinfections, particularly those caused by methicillin-resistantS. aureus(MRSA). In 1996, the first documented case of infection caused by a strain ofS. aureuswith intermediate levels of resistance to vancomycin (VISA; minimum inhibitory concentration [MIC] =8 μg/mL) was reported from Japan.¹This report describes the first isolation of VISA from a patient in the United States, which may be an early warning thatS. aureusstrains with full resistance to vancomycin will emerge. In July 1997, VISA-associated peritonitis was diagnosed in a patient who was being treated with long-term ambulatory peritoneal dialysis. DuringJanuary 1996-June 1997, the patient had been treated with multiple courses of both intraperitoneal and intravenous vancomycin for repeated episodes of MRSA-associated peritonitis. The patient received medical