Prevalence of MRSA in ICU Patients After State-Mandated Surveillance

methicillin-resistant S aureus, MRSA
methicillin-resistant S aureus, MRSA
The prevalence of methicillin-resistant Staphylococcus aureus colonization did not decline after implementation of state-legislated active surveillance among critically ill adults.

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) among intensive care unit (ICU) patients in Illinois did not decline after legislatively mandated MRSA surveillance, according to a report published in Clinical Infectious Diseases.

Patients with MRSA colonization can transmit the infection while remaining asymptomatic, which can lead to subsequent invasive disease and outbreaks. In 2007, Illinois was the first state to initiate mandatory active surveillance of MRSA in ICU patients, requiring that staff implement a “search and isolate” protocol.

The prevalence of MRSA infection in Chicago’s ICU patients was analyzed in the 5 years after legislation to determine its effectiveness in reducing the spread of MRSA. 

Since 2008, 8 regionwide point prevalence surveys were conducted, twice yearly between 2008 and 2011, after which they occurred yearly until 2013.

A total of 3909 ICU patients were screened, with 432 (11.1%) found to be colonized with MRSA (95% CI, 10.1%-12.0%). The prevalence of MRSA colonization also remained consistent throughout the study period (year-over-year relative risk, 0.97; 95% CI, 0.89-1.05; P =.48).

Mandatory legislation did not lead to a drop in MRSA prevalence. The investigators did note that MRSA prevalence was assessed in a region where it is widely endemic, so results may not be widely applicable to regions with lower MRSA rates. Nonetheless, the study identified some barriers to prompt use of contact precautions despite mandatory surveillance.

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Evidence exists that “a universal decolonization approach (nasal mupirocin plus chlorhexidine gluconate bathing for all ICU patients, with discontinuation of MRSA active surveillance) is superior,” but according to investigators, the current law does not allow hospitals to cease mandatory screening and adopt the more effective approach, suggesting a reevaluation of the mandatory active MRSA surveillance legislation is needed.


Lin MY, Hayden MK, Lyles RD, et al; CDC Prevention Epicenters Program (R.A.W. – PI). Regional epidemiology of Methicillin-Resistant Staphylococcus aureus among adult intensive care unit patients following state-mandated active surveillance [published online December 7, 2017]. Clin Infect Dis. doi: 10.1093/cid/cix1056