Investigators Show That Exposure to Antibiotics is Responsible for High VRE Colonization

Vancomycin-resistant Enterococcus (VRE) has been established as a significant healthcare-associated problem. Karki, et al. (2012) measured the point prevalence and identified risk factors associated with vanB VRE colonization in a tertiary-care hospital in Melbourne, Australia where VRE has been endemic for 15 years.
A hospital-wide point prevalence survey was conducted on Oct. 13, 2008 with colonization detected using rectal swab culture. Patients' demographic and medical information was collected through a review of medical records. Factors associated with VRE colonization in univariate analysis were included in multivariate logistic regression model to adjust for confounding.
The prevalence of VRE colonization on the day of screening was 17.5 percent. VRE was detected from patients in each ward with the prevalence ranging from 3 percent to 29 percent. Univariate analysis showed the use of any antibiotic, meropenem, ciprofloxacin, diarrhea and longer length of hospital stay were associated with increased risk of VRE colonization (p<0.05).  However, age, sex, proximity to VRE positive cases, use of other antibiotics including cephalosporins, vancomycin were not  associated with increased risk (P>0.05). Multivariate analysis showed the exposure to meropenem (p=0.004), age (>=65 years) (p=0.036) and length of stay >=7 days (p<0.001) as independent predictors of VRE colonization.

The researchers say their study suggests that exposure to antibiotics may have been more important than recent cross transmission for a high prevalence of vanB VRE colonisation at their hospital. Their research was published in Antimicrobial Resistance and Infection Control.

Reference: Karki S, et al. Prevalence and risk factors for VRE colonisation in a tertiary hospital in Melbourne, Australia: a cross sectional study. Antimicrobial Resistance and Infection Control 2012, 1:31 doi:10.1186/2047-2994-1-31