678 Glass half empty or half full? The effectiveness of mandated active surveillance in placing methicillin-resistant Staphylococcus aureus (MRSA)-colonized intensive care unit (ICU) patients in Contact Precautions

Saturday, March 20, 2010: 3:00 PM
Centennial III-IV (Hyatt Regency Atlanta)
Michael Lin, MD, MPH , Rush University Medical Center, Chicago, IL
Rosie Lyles, MD, MS , John H. Stroger, Jr. Hospital of Cook County, Chicago, IL
Karen Lolans, B.S. , Rush University Medical Center, Chicago, IL
Mary Hayden, MD , Rush University Medical Center, Chicago, IL
Alexander Kallen, MD, MPH , Centers for Disease Control and Prevention, Atlanta, GA
Stephen Weber, MD, MSc , University of Chicago Medical Center, Chicago, IL
Robert Weinstein, MD , John H. Stroger, Jr. Hospital of Cook County and Rush University Medical Center, Chicago, IL
William Trick, MD , John H. Stroger, Jr. Hospital of Cook County, Chicago, IL


In 2007, Illinois mandated MRSA active surveillance of all patients admitted to ICUs. As a program evaluation, we initiated semi-yearly point prevalence surveys (PPS) of Chicago ICU patients for MRSA colonization and collected information on their Contact Precaution status.


To assess the effectiveness of MRSA active surveillance in identifying MRSA-colonized ICU patients and implementing Contact Precautions.


Hospitals in Chicago with ≥10 ICU beds were recruited for 1-day PPSs during two survey periods (1st PPS, 7/08 1/09; 2nd PPS, 1/09 7/09). All patients in adult and neonatal ICUs were cultured for MRSA (nose and groin for adults; nose and umbilicus for neonates). All PPS cultures and data (including bedside assessment of Contact Precaution status) were collected by local infection preventionists or nurses. All PPS cultures were processed centrally. By end of PPS day, hospitals also reported known results of mandated admission surveillance cultures; if pending, results were reported when final. 95% confidence intervals (CI) were calculated using exact binomial methods.


All 26 eligible hospitals participated in both PPSs; combined results are reported. 1011 adults and 533 neonatal patients participated (Table). Hospital compliance with admission surveillance was 95% for adults, 98% for neonates. Hospital-reported MRSA admission prevalence was 9.3% for adults, 1.3% for neonates. MRSA prevalence on day of PPS was 12.4% for adults, 5.3% for neonates. On day of PPS, 26% of adults and 5% of neonates were on contact isolation for any reason. Of patients with hospital-reported admission cultures known to be MRSA positive, 87% of adults and 86% of neonates were in Contact Precautions. Of patients with PPS cultures positive for MRSA, 52% (95% CI 43 61%) of adults and 39% (95% CI 22 59%) of neonates were in Contact Precautions. Of 77 PPS-identified MRSA-colonized patients not in Contact Precautions, 20 had pending admission cultures on day of PPS (later finalized as 8 MRSA+, 12 MRSA-), 51 had known admission culture results (6 MRSA+, 45 MRSA-), and 6 had no admission cultures performed.


In a region with high compliance with mandated MRSA active surveillance and initiation of Contact Precautions for known MRSA-positive patients, PPSs demonstrated that at a given point in time, approximately half of MRSA-colonized ICU patients were not in Contact Precautions. Whether this rate of Contact Precautions is sufficient to reduce MRSA transmission and infection is unclear. Inadequate MRSA active surveillance test sensitivity (e.g., failure to detect colonization at non-cultured body sites), lag time for results, lack of post-admission periodic surveillance and on-going nosocomial MRSA acquisition may explain the Contact Precautions deficit.