Key Point

Rapid MRSA screening provides better control of MRSA cross-infection in critically ill patients.

GENEVA—A new screening technique for methicillin-resistant Staphylococcus aureus (MRSA) may help control transmission of the bacteria among critically ill patients.¹ The new screening method resulted in reductions in both time to notification of test results and number of preemptive isolation days.

Stephan Harbarth, MD, an Associate Hospital Epidemiologist in the Infection Control Program at Geneva University Hospitals, and colleagues hypothesized that a new molecular technique that enables early detection of MRSA could substantially decrease the time between ICU admission and notification of screening results. They also evaluated the effect of a strategy combining early MRSA detection and preemptive contact isolation on the rate of ICU-acquired MRSA infections.

Patients admitted to two adult ICUs for longer than 24 hours were screened for MRSA upon admission using quick, multiplex immunocapture-coupled polymerase chain reaction (qMRSA). Outcomes in these patients were compared with those of historical controls. The researchers found that MRSA was prevalent in 71 of 1,053 patients (6.7%). Median time from admission to notification of test results decreased from 87 to 21 hours in the surgical ICU and from 106 to 23 hours in the medical ICU. Among 245 MRSA-negative patients in the surgical ICU, a total of 1,227 preemptive isolation days were saved using qMRSA.

These findings have important implications for clinical practice because delays in notification of screening results mean either that patients without MRSA remain isolated or that patients with MRSA remain a hidden reservoir for cross-infection, said the researchers.

"Current limitations to routine implementation of [polymerase chain reaction]-based MRSA screening tests are their high costs, the workload of specimen processing, and the lack of trained laboratory technicians," said the research team.

"Nevertheless, the rapid qMRSA test saved a large number of unnecessary isolation days in the surgical ICU and helped to decrease substantially MRSA infections in the medical ICU," they concluded.

—Karen L. Spittler

Reference
1. Harbarth S, Masuet-Aumatell C, Schrenzel J, et al. Evaluation of rapid screening and pre-emptive contact isolation for detecting and controlling methicillin-resistant Staphylococcus aureus in critical care: an interventional cohort study. Crit Care. 2006;10:R25.

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