Prevalence of MRSA Colonization among Neonatal and Pediatric ICU Patients in Chicago

Background: Beginning October 2007, the MRSA Screening and Reporting Act (210 ILCS 83/) mandated active surveillance for all ICU patients in Illinois, with isolation of MRSA-colonized patients. We assessed MRSA colonization prevalence among neonatal (NICU) and pediatric (PICU) patients using a series of point prevalence surveys. Methods: Chicago hospitals with NICU or PICU patients were recruited for 6 single-day point prevalence surveys (PPSs) approximately 6 months apart from June 2008 to July 2011. After 2011, yearly surveys were obtained in 2012 and 2013. All ICU patients were cultured for MRSA (nose and umbilicus for neonates; nose and groin for pediatric patients) using a single swab for each body site. Hospital-reported admission screen results (i.e. 210 ILCS 83/-mandated) were also obtained. Point prevalence cultures were screened for MRSA using broth enrichment, chromogenic agar, and standard confirmatory methods. Results: All eligible hospitals (N=10) participated (10 NICUs and 6 PICUs) with 99.6% of NICU and 93% of PICU eligible patients cultured across PPSs. Hospital-reported adherence to admission screens mandated by 210 ILCS 83/ was high (99.6% for NICU and 93.3% for PICU). Overall MRSA prevalence by PPSs in NICUs was 4.2% (89/2101); PICU, 5.7% (36/632). MRSA colonization prevalence declined in NICUs (estimated yearly odds ratio [OR], 0.92, 95% confidence interval [CI] 0.77 to 1.11, P<0.39) but not in PICUs (OR 1.25, 95% CI 1.10 to 1.42, P<0.001). Conclusion: In the time period following implementation of mandatory active surveillance, we found MRSA colonization in a proportion of NICU and PICU patients, with evidence of on-going MRSA transmission.