Screening for Intestinal Colonization with Vancomycin Resistant Enterococci and Associated Risk Factors among Patients Admitted to an Adult Intensive Care Unit of a Large Teaching Hospital

Introduction: Gut colonization with Vancomycin Resistant Enterococci (VRE) increases the risk of acquiring infection during hospital stay. Patients admitted in the ICU's are the major reservoirs for VRE colonization due to higher antibiotic pressure. Aim: To determine the rate of VRE colonization among patients admitted in the Medical Intensive Care Unit (MICU) and to assess the various risk factors which are associated with VRE colonization. Materials and Methods: This was a prospective study carried out over a period of 18 months from September 2013 to February 2015 in the Jawaharlal Institute of Post graduate Medical Education and Research (JIPMER), Pondicherry, South India. After 48 hours of ICU admission rectal swabs were collected from a total of 302 patients, admitted in MICU. The samples were inoculated on to Bile Esculin Sodium Azide agar with 6mg/L of vancomycin. Vancomycin resistance was confirmed by determination of Minimum Inhibitory Concentration (MIC) by agar dilution method. Isolates were identified up to species level by standard biochemical tests. Vancomycin resistance genes such as van A, van B and van C, were detected by Polymerase Chain Reaction (PCR). Risk factors were assessed by multivariate logistic regression analysis. Results: The rates of VRE colonization in patients admitted to MICU was 29%. Majority of the isolates were Enterococcus faecium (77.2 %) followed by Enterococcus faecalis (23.8%). All the VRE isolates were positive for van A gene. Increased duration of hospital stay, younger age, consumption of ceftriaxone and vancomycin were found to be significantly associated with VRE colonization in MICU. Among VRE colonized patients, six (4.5%) acquired VRE infection. Conclusion: The rates of VRE colonization in our ICU were similar to other hospitals worldwide. Educating health care workers on the importance of adherence to hand hygiene is essential to bring down VRE colonization rates.