Bacterial burden is associated with increased transmission to health care workers from patients colonized with vancomycin-resistant Enterococcus

Background Health care workers (HCWs) are significant vectors for transmission of multidrug-resistant organisms among patients in intensive care units (ICUs). We studied ICU patients on contact precautions, colonized with vancomycin-resistant Enterococcus (VRE), to assess whether bacterial burden is associated with transmission to HCWs’ gloves or gowns, a surrogate outcome for transmission to subsequent patients. Methods From this prospective cohort study, we analyzed 96 VRE-colonized ICU patients and 5 HCWs per patient. We obtained samples from patients’ perianal area, skin, and stool to assess bacterial burden and cultured HCWs’ gloves and gowns for VRE after patient care. Results Seventy-one of 479 (15%) HCW-patient interactions led to contamination of HCWs’ gloves or gowns with VRE. HCW contamination was associated with VRE burden on the perianal swab (odds ratio [OR], 1.37; 95% confidence interval [CI], 1.19, 1.57), skin swabs (OR, 2.14; 95% CI, 1.51, 3.02), and in stool (OR, 1.95; 95% CI, 1.39, 2.72). Compared with colonization with Enterococcus faecalis , colonization with Enterococcus faecium was associated with higher bacterial burden and higher odds of transmission to HCWs. Conclusions We show that ICU patients with higher bacterial burden are more likely to transmit VRE to HCWs. These findings have implications for VRE decolonization and other infection control interventions.