Identification of temporal clusters and risk factors of bacteremia by nosocomial vancomycin-resistant enterococci

Background This study aimed to evaluate a different methodology for addressing the evolution of nosocomial bacteremia by vancomycin-resistant enterococci (VRE) in a hospital setting. Methods In this retrospective cohort study, data were collected from the date of first registration up to December 2008 from the electronic medical records of patients with VRE bacteremia in a school hospital. Results Thirty cases of VRE bacteremia and 274 cases of vancomycin-susceptible enterococci (VSE) bacteremia were identified. The average age of the patients was 56 years. The rates of Enterococcus faecium and Enterococcus faecalis in the hospital's intensive care unit (ICU) and wards showed no statistically significant differences. The risk of acquiring VRE bacteremia was at least 3-fold higher in the ICU than in the wards. The risk of death was 2.73-fold higher in patients with VRE bacteremia compared with those with VSE bacteremia. Only one temporal cluster statistically significant of VRE bacteremia was found in the study period. Conclusions The identification of temporal clusters can be an important tool to optimize health actions and thereby reduce the burden of operating costs.