Abstract
Contamination by methicillin-resistant Staphylococcus aureus (MRSA) of the patient care environment in the ICU was investigated at two institutions. The care environments of 33 patients who had undergone mechanical ventilation were surveyed from June until August 2006, from April until September 2007, and from June until October 2009. A total of 395 specimens were obtained from locations such as bed sheets and rails, buttons on mechanical ventilators, stethoscopes, and Jackson Rees. MRSA contamination was detected in 20.0% (28/140) of the specimens from the care environments of 11 inpatients with MRSA–positive body sites. MRSA was detected on bed sheets in 35.3% (6/17) of the specimens and on button sites in 29.4% (5/17) of the specimens in the 48–h period after admission to the ICUs. Contamination of the environment of MRSA–positive patients was detected soon after admission (<24 hours, 7/55), and the percentage of contamination increased with time (≥48 hours, 21/85). On the other hand, MRSA was not detected in the environment at 24 hours after admission of MRSA–negative patients to the ICU, and was detected at only two locations even at ≥48 hours after admission. In addition, in the hospital rooms of MRSA–negative patients, genetic analysis using pulsed-field gel electrophoresis detected only MRSA from the care environment of MRSA–positive patients who were admitted to the ICU earlier. MRSA can survive in the environment for an extended period of time. The present findings suggest that MRSA can be transmitted through contact with a contaminated patient care environment in hospitals.
