Contact Precautions in Long-Term VA Facilities Don't Cut MRSA Infections, Study Shows

Contact precaution procedures, such as requiring gowns or gloves in certain settings, have been established to prevent the spread of health care-associated infections (HAIs) within health systems. However, a new study evaluating 75,414 patient admissions from 74 long-term care facilities (LTCF) in the US Department of Veterans Affairs (VA) system found that policies requiring active surveillance and contact precautions for methicillin-resistant Staphylococcus aureus (MRSA) had no impact on MRSA acquisition or infection.

MRSA is a common cause of HAIs in LTCFs, and the VA recently implemented United States Centers for Disease Control and Prevention (CDC) recommended contact precautions in a modified fashion.

To evaluate whether the precautions impacted MRSA acquisition, investigators conducted an effectiveness study, which was published recently in Clinical Infectious Diseases. The study team compared data collected in the VA health care system from January 1, 2011, through December 31, 2015. This duration spanned 2-year periods both before and after the new contact precautions were implemented in 2013.

LTCFs in the VA were selected for this effectiveness study in part because national VA policy required obtaining a MRSA surveillance test for all residents at admission and discharge. This allowed an assessment of MRSA acquisition, which is typically only attainable through research studies. MRSA HAIs are entered into a national database each month by infection control nurses at each facility as part of the VA Multidrug-Resistant Organism (MDRO) prevention initiative.

All VA LTCFs were eligible for inclusion in the study. Out of 136 LTCFs, 88 provided their MRSA prevention policies. Laboratory data on MRSA infection rates were not available for 14 facilities, making the final primary cohort composed of 74 LTCFs across 39 states and including the District of Columbia and Puerto Rico. Some of the facilities that were included in the analysis used standard precautions during some or all of the study, while others used contact precautions throughout.

Investigators calculated their results using generalized estimating equations with Poisson distribution and a logarithm link function to examine associations of facility level MRSA prevention policy with facility level rate of MRSA acquisitions. The outcome variable was the number of acquisitions per facility, with an offset variable to account for varied person-time.

MRSA HAIs did decline during the study period by 30% but, according to investigators, this was not related to the contact precautions policy. Declining MRSA colonization at admission was observed for the period both before and after widespread use of contact precautions. Study authors speculated the MRSA HAI reduction observed during the study period “could relate to other aspects of the MRSA prevention initiative, including increased resources for infection control, improved hand hygiene, standardized HAI reporting, and bundled approaches to device insertion and care or may relate to secular trends.”

Investigators hypothesize that contact precautions may not have been effective in this setting for reasons including that in long-term care compliance was low and that there tends to be significant patient contact in common areas where contact precautions are not practiced and could not be implemented easily.

Furthermore, the investigators noted that their results do not necessarily imply that more targeted approaches to the use of gowns and gloves do not impact HAI acquisition, citing earlier studies that support targeted use of contact precautions when focused on high risk activities and patients. Study authors also noted that “colonization pressure may be able to be decreased by interventions such as chlorhexidine and mupirocin to reduce the burden of MRSA colonization.”

In interpreting their results, investigators noted that the study could only assess in pragmatic terms whether VA policies around requiring contact precautions for MRSA in LTCF were effective, not whether a hypothetical complete compliance with contact precautions would be effective.

Previous research has yielded similar results, such as when 12 hospitals stopped employing contact precautions in February of 2018 with no statistically significant increase in MRSA HAI rates compared to controls which maintained contact precautions.