This was an 18-month multicenter study completed in 2007 that determined if rates of colonization and infection with 2 resistant Gram-positive bacteria - methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) - among patients in adult intensive care units (ICUs) were lower in ICUs that used an intensive infection control strategy plus standard care compared to ICUs that used standard care alone. The intensive control strategy involves: (1) identifying patients who were colonized with MRSA or VRE by the use of prospective surveillance cultures of the anterior nares (for MRSA) and stool or perianal area (for VRE); (2) Universal Gloving until the patients were discharged or their surveillance culture results showed they were not colonized with MRSA or VRE; and (3) Contact Precautions during care of patients who were colonized with MRSA or VRE. Nineteen ICU sites distributed throughout the US were enrolled in the study. Surveillance cultures for the intensive control populations were collected on all patients at the time of admission to the ICU, weekly during their ICU stay, and at the time of discharged. All specimens were processed in the Clinical Center Microbiology Lab. Specimens were screened for MRSA or VRE using an enrichment broth technique and selective agar culture methods, and the resistance genes were detected by PCR. A substantial proportion of patients were colonized during the study: MRSA - 39% in both the standard and intensive control populations; VRE - 56% and 69% in the intensive and standard control populations, respectively. There was no significant difference in the incidence of new MRSA or VRE colonization or infection events between the ICUs using the intensive control or standard control strategies. The results of this multicenter, cluster-randomized controlled trial indicated that a strategy utilizing culture-based active surveilland for MRTSA and VRE was not effective in reducing transmission of MRSA and VRE when compared to standard practice employing standard hand hygiene and use of gowns and gloves by healthcare workers. All isolates of MRSA and VRE have been stored at -80 C for future studies, such as characterization of the resistance genes, assessment of resistance to other antibiotics (e.g., vancomycin resistance in MRSA), and epidemiologic analysis for strain to strain differences. Additional studies were also initiated to compare culture techniques with direct detection of resistant bacteria by nucleic acid amplification techniques.
