Blog | Wednesday, May 27, 2015

Screening, decolonization and environmental decontamination for MRSA in nursing homes doesn't work

Just in the past couple of weeks, we've written about pneumonia prevention bundles, multidrug-resistant organisms prevention bundles, and spread of Staphylococcus aureus all in nursing homes. It's like no one cares about acute care facilities anymore! (humor) There is now more great data for those charged with managing infection control in nursing homes.

Cristina Bellini and colleagues from Lausanne University Hospital in Switzerland published the results of cluster-randomized trial of a methicillin-resistant S. aureus (MRSA) prevention bundle in 104 nursing homes (53 intervention, 51 control) in the April issue of Infection Control & Hospital Epidemiology. All residents in intervention and control nursing homes, who gave consent, were screened for MRSA carriage at study entry and 12 months thereafter on a single day in each nursing homes. Newly admitted or readmitted residents were screened when admitted to the nursing homes. Screening included nasal, groin and ulcer swabs along with urine cultures if residents had an indwelling catheter. In the intervention nursing homes MRSA colonized residents underwent decolonization along with environmental decontamination.

The primary decolonization bundle included 5 days of nasal mupirocin, 5 days of chlorhexidine gluconate (CHG) oral rinse twice per day, 5 days of CHG showers including CHG shampoo on day 1 and 5. Environmental disinfection included daily clothing changes for 5 days, new linens on day 1 and day 5, and daily bed/table/phone/remote/wheelchair/walker disinfection with 70% alcohol. A lot of steps.

Unfortunately, the MRSA decolonization and decontamination bundle was not successful. The baseline prevalence of MRSA was 8.9% in both groups. The rate declined in intervention units to 5.8% in the intervention unit and 6.6% on the control units after 12 months (P=0.66) No matter how researchers analyzed the intervention, the MRSA bundle intervention did not reduce MRSA prevalence compared to controls. This was despite the fact that the participation rate was 87%.

A limitation of this study was that they only measured prevalence and not individual level acquisition of MRSA. It is possible that by measuring prevalence they missed detecting benefits of the intervention related to reduced patient-to-patient transmission of MRSA. In any case, as I said last week about the study in Clinical Infectious Diseases, congratulations to the authors and journal (this time ICHE) for publishing this important negative study.

Eli N. Perencevich, MD, ACP Member, is an infectious disease physician and epidemiologist in Iowa City, Iowa, who studies methods to halt the spread of resistant bacteria in our hospitals (including novel ways to get everyone to wash their hands). This post originally appeared at the blog Controversies in Hospital Infection Prevention.