Predictors of hVISA among patients with MRSA bacteraemia

Abstract number: P1462

Patel N., Graffunder E., Evans A., Helmecke M., Stellrecht K., Lodise T.P.

Objectives: The objectives were (1) to determine the proportion of MRSA bloodstream infections at our institution that express heterogenous resistance to vancomycin (hVISA) and (2) to identify clinical predictors of hVISA among the patient population.

Methods: A cross-sectional study was conducted at Albany Medical Center (Albany, NY). All patients with a positive MRSA bloodstream culture between 01/2005 and 5/2007 were eligible. Inclusion criteria: age leqslant R: less-than-or-eq, slant18 years, non-neutropenic, and MRSA blood culture met CDC criteria for infection. Demographics, co-morbid conditions, microbiology, and antibiotic exposure data were collected. MRSA strains with an MIC value leqslant R: less-than-or-eq, slant6 mg/L on high inoculum brain heart infusion agar plates were considered hVISA (method of Walsh et al). Parameters associated with hVISA by bivariate analysis (P < 0.2) were included a multivariate analysis and a stepwise approach was used to identify independent predictors. The CART technique was used to identify significant breakpoints in continuous clinical features that were associated with an increased proportion of hVISA.

Results: During the study period, 103 patients the inclusion criteria. Of the 103 patients, 20 (19.4%) were hVISA positive. Bivariate comparison of clinical paramaters between patients with hVISA and non-hVISA are provided in the table. Source of infection did not differ between groups (P = 0.5). In the logistic regression, recent history of healthcare institution exposure (AOR= 5.7, 95% CI: 1.2–27.8, p = 0.03) and creatinine clearance (Crcl) leqslant R: less-than-or-eq, slant27.6 ml/min (AOR=5.3, 95% CI: 1.8–15.6, P = 0.002) were the only independent predictors of hVISA.

Bivariate analysis of clinical features between hVISA patient groups

Conclusions: Recent healthcare institution exposure and CrCl leqslant R: less-than-or-eq, slant27 mL/min were highly predictive of hVISA. This knowledge can be used to direct therapy decisions by targeting aggressive therapy in pts at highest risk for hVISA.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
Back to top