Blog | Thursday, October 5, 2017

And what about antimicrobial scrubs?

Ascot: a neckband with wide pointed wings, traditionally made of pale grey patterned silk

The role that environmental transmission plays in the spread of important pathogens is increasingly recognized. One of the major mechanisms by which pathogens are thought to spread is via contaminated healthcare worker clothing. A major reason that gowns are included in contact precaution is that they are felt to interrupt the transmission from patient/environment to health care worker attire. An old (2010) study that Dan Morgan completed found that gowns became contaminated 11% of the time when caring for patients with multidrug-resistant-Acinetobacter and 5% of the time when caring for patients with multidrug-resistant-Pseudomonas. A repeat (2012) study found that gowns became contaminated during 4% of health care worker visits caring of Methicillin-resistant Staphylococccus aureus patients, 5% for vancomycin-resistant Enterococcae, 2% for multidrug-resistant Pseudomonas and 13% for multuidrug-resistant Aceintobacter.

With so much contamination and a desire to rid the world of unnecessary gown use, investigators have been exploring the benefits of antimicrobial textiles, such as scrubs. If these novel scrubs could reduce contamination, maybe we could drop the dreaded gown and go with universal gloves for contact precautions?

Which brings us to a ASCOT study by Deverick Anderson and colleagues funded by the Centers for Disease Control and Prevention's Prevention Epicenters Program. ASCOT: Antimicrobial Scrub Contamination and Transmission. The investigators examined the benefits of two different antimicrobial scrubs (Scrub 1: silver-alloy and Scrub 2: organosilane-based quaternary ammonium and a hydrophobic fluoroacrylate copolymer emulsion) vs. standard poly-cotton surgical scrubs in a 3-arm RCT during 3-consecutive 12-hour ICU nursing shifts. The primary outcome was change in total contamination on the nurses scrubs as sum of colony forming units. Of note, all multidrug-resistant organism colonized patients in the study were placed on contact precautions and health care workers placed gowns over their scrubs and wore gloves while caring for those patients.

The study collected many cultures: 2,919 from the environment and 2,185 from the health care worker's clothing. Forty-one nurses were randomized but one was excluded for a total of 40 nurses caring for 102 patients during 167 encounters. Their primary finding was the scrub type had no effect on health care worker's clothing contamination (P=0.70) There is a lot to unpack in this study and it warrants a careful read—a lot of data. Overall, the median colony forming unit increase was 61.5 (interquartile range [IQR], −3.0 to 191.0) in the control arm, 73.0 (IQR, −107.0 to 194.0) in the Scrub 1 arm, and 54.5 (IQR, −60.0 to 215.0) in the Scrub 2 arm.

There were acquisition events during 39 (33%) of the shifts with 20 (17%) environmental acquisitions and 19 (16%) acquisitions on health care worker's attire. Looking at the 19 health care worker's attire acquisition events, 12 (63%) were confirmed: 7 from the patient, 3 from environmental contamination, and 2 from the patient/environment.

Overall, the authors reported that there were no benefits from either antimicrobial scrub. However, there was significant transmission from patient or environment to HCW attire. Back to the drawing board on antimicrobial scrubs? Maybe. I would like to see the study repeated in a hospital where contact precautions are not used to see if benefits might exist in settings where gowns are not worn when caring for MDRO+ patients. With this much acquisition of nurses' clothing, it's going to be hard to ditch gowns, unfortunately.

Oh, and I love the ASCOT name. Brilliant.

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.