Remember all of those difficult decisions during the worst of the COVID-19 pandemic? Which patient gets the ventilator? Who gets the single room? What has to stop to keep on top of the continuous flow of new SARS-CoV-2 results to investigate? Well, one of those difficult decisions was whether or not to continue with screening and contact precautions to prevent the spread of MRSA. A US team made a compelling “natural experiment” out of the discontinuation of screening and contact precautions for MRSA, showing that this was associated with an increased risk of MRSA HCAI.

The study was undertaken in the large group Veteran Health Administration (VA) hospitals in the USA. A monthly survey was completed between July 2020 to June 2022 to see whether any or a combination of MRSA admission screening and contact precautions (for patients with MRSA infection and/or colonisation) were suspended. The rates of MRSA HCAI were compared in the hospitals practicing the various combinations of interventions to prevent the spread of MRSA.

A total 568 MRSA HCAIs were identified over the 2 year period, including BSIs (32%), pneumonia (26%), soft-tissue infections (14%), and urinary tract infections (10%). MRSA infection rates were lowest for hospitals practicing screening and contact precautions for both MRSA infection and colonisation (0.09 MRSA HCAI per 1,000 patient days) and highest for hospitals practicing no interventions to prevent the spread of MRSA (0.22 MRSA HCAI per 1,000 patient days). The rate of MRSA HCAI was between these two points for the other combination of precautions. This effect was similar in ICU and non-ICU settings. Accounting for facility complexity and COVID-19 prevalence did not change the relationship between the MRSA HCAI rate and prevention measures. Also, the rate of CAUTI remained unchanged, reinforcing that the changes in rates of MRSA HCAI were linked to the discontinuation of screening and contact precautions.

Some argue (see this recent commentary) that contact precautions are not an essential intervention to prevent the spread of MRSA in hospitals. Reading the study about the removal of contact precautions and the apparent impact on MRSA HCAI, it’s difficult to see how this position stacks up. Especially when the study only looked at infection as an outcome, and didn’t even look at the impact of screening and contact precautions in preventing the acquisition of MRSA colonisation, which is often a precursor to MRSA infection.