VANCOMYCIN INTERMEDIATE-RESISTANT STAPHYLOCOCCUS-AUREUS

OBJECTIVE: To describe further details about the third reported case o f vancomycin intermediate-resistant Staphylococcus aureus (VISA). CASE SUMMARY: A patient with a history of recurrent methicillin-resistant S. aureus Ch (MRSA) bacteremia was treated with several courses of van comycin for 18 of 23 possible weeks on an inpatient/outpatient basis. After 6 months of repeated courses, an isolate of MRSA showed a minimu m inhibitory concentration of 8 mu g/mL, indicating intermediate resis tance to vancomycin. The patient continued to receive a vancomycin/ami noglycoside/rifampin regimen and, when he was hospitalized several wee ks later, no further MRSA or VISA was detected. DISCUSSION: Prolonged, intermittent vancomycin use (18 of 23 possible weeks) for MRSA bacter emia on an inpatient/outpatient basis most likely contributed to the d evelopment of VISA. Infection control measures prevented the spread of VISA among patients and healthcare workers. CONCLUSIONS: Infection co ntrol measures and evaluation of antimicrobial prescribing need to be strongly enforced to further prevent the spread and development of res istant organisms.