Prevalence studies of vancomycin-resistant enterococci for monitoring a passive surveillance program in a pediatric hospital

The objective of the present study was to check the impact of a program of passive surveillance of stool colonization by vancomycin-resistant enterococci (VRE) by using biannual studies of colonization prevalence in the whole hospital (September 3, 2002, N = 344 patients and June 29, 2004, N = 368 patients). Rectal swabs were obtained and immediately cultured on bile–esculine azide agar plates with 6 μg/ml of vancomycin. A trend in increase in colonization was observed in our hospital between 2002 and 2004. An increasing number of VRE infections have been recorded during 2004 but most of them were acquired outside of the hospital. Moreover, the diversity of clones showed a low trend of spreading of VRE inside the hospital, suggesting the good effect of control procedures. However, as prevalence studies also allowed us to control the spreading of VRE by means of isolation or cohorting patients, and VRE infections are growing in number in Argentina (Red WHONET Argentina, 2003), we propose to do them yearly.