Clinical features associated with bacteremia due to heterogeneous vancomycin-intermediate Staphylococcus aureus. Clin. Infect. Dis

We assessed all episodes of methicillin-resistant Staphy-lococcus aureus (MRSA) bacteremia at our hospital during a 12-month period ( ) and compared those due tonp 53 heterogeneous vancomycin-intermediate S. aureus (hVISA; np5, 9.4%) with those due to vancomycin-susceptible MRSA (). Patients with hVISA bacteremia were more likelynp 48 to have high bacterial load infections (), vancomycinPp.001 treatment failure (persistent fever and bacteremia for 17 days after the start of therapy; 1), and initially low serumP!.00 vancomycin levels (). These clinical markers of hVISAPp.006 bacteremia may help focus diagnostic efforts and treatment. Infections due to methicillin-resistant Staphylococcus aureus (MRSA) constitute approximately one-half of all S. aureus in-fections in Australian hospitals, with treatment predominantly reliant upon the use of glycopeptides [1]. Strains of MRSA with reduced vancomycin susceptibility were first reported in 1997 [2], and in Australia in 2001 [3], but their clinical significance has been debated [4–12]. S. aureus strains with reduced van-comycin susceptibility include vancomycin-intermediate strains (VISA; MIC, 8–16 mg/mL); vancomycin-resistant strains (VRSA; MIC, 32 mg/mL); and heterogeneous VISA (hVISA) strains, which are defined by the presence of subpopulations of MRSA, typically at a rate of 1 organism per 105–106 organisms, with intermediate vancomycin resistance [3, 4]. The accurate laboratory detection of hVISA is time-consum-ing. Although susceptibility testing with the Etest (AB Biodisk