A perspective published in JAMA today (free full text here) takes another whack at contact precautions. In this piece, Dan Morgan, Dick Wenzel, and Gonzalo Bearman nicely lay out the arguments against the use of contact precautions for endemic MRSA and VRE.
One thing this paper did was to stimulate me to think about using the gloved/gowned encounter as the unit of analysis rather than the number of days of isolation, or the number of patients impacted. Doing so highlights the burden for healthcare workers. To that end, I looked at the data cited in the perspective and did some calculations.
In the paper, they note that universal gowns and gloves in the BUGG Study resulted in a decrease of 1 acquisition of MRSA for every 336 patient-days of the intervention. There were 4 room entries per hour (96/day) in the BUGG Study in the intervention arm. They also note that 19% of S. aureus acquisitions represent transmission events when analyzed by whole genome sequencing. And 1 in 3 patients who acquire MRSA will become infected.
Doing the math, we find that in order to prevent 1 MRSA infection in the ICU setting using universal gowns and gloves requires 514,449 “protected” (gowned/gloved) encounters. Now using contact precautions for patients with targeted pathogens only (as opposed to universally) would greatly reduce the burden of the intervention, but even if it were reduced by a factor of 10, or even 20, the burden would remain extraordinarily high.
When you combine high burden with questionable effectiveness and the current focus on alternative interventions (like hand hygiene and chlorhexidine bathing), it’s not surprising that contact precautions is increasingly viewed as a decrepit concept.