December 3, 2019

CDC investigators find poor doffing practices.

The clothing, skin, and personal protective equipment (PPE) of healthcare workers (HCW) are often contaminated with respiratory viruses after they care for patients, according to US Centers for Disease Control and Prevention investigators. Their conclusion, published in the December issue of Infection Control & Hospital Epidemiology, reinforces the need for “complete hand hygiene” and frequent changing of PPE to prevent virus transmission. 

Investigators found viruses on 31% of glove samples, 21% of gown samples, and 12% of face mask samples. In addition, 21% of bare hand samples, 11% of scrub samples, and 7% of face samples tested positive for respiratory viruses.  

The data were collected from 59 healthcare workers at a 465-bed acute care academic hospital in the Chicago area who volunteered to have their skin, cloths and PPE swabbed for virus measurement. The swabbing took place from March to June 2017 and again from September 2017 to April 2018. 

Investigators wanted primarily to characterize the presence and magnitude of viruses on healthcare workers after they provided routine care for patients suffering from respiratory infection and who had been placed under droplet and/or contact isolation. But they also wanted to measure the connection between how healthcare workers can contaminate themselves through faulty doffing practices. 

“Our findings of viral contamination on PPE, clothes, and skin of HCWs emphasize the significance of appropriate PPE use, PPE doffing practices, and hand hygiene in infectious transmission prevention via the contact route,” the study states. 

The 52 patient participants provided written informed consent and authorized access to use and disclose health information for the study. Investigators observed the care given to patients during a 3-hour period, typically between 8 a.m. and noon. 

“To our knowledge, our study is the first to evaluate the association of self-contacts by HCWs and virus contamination on their PPE and bodies,” the study states. 

They found an association between the number of self-contacts by HCWs with their gloves, gowns, or masks and the concentration of virus on those pieces: the more self-contacts, the more virus. 

“The strongest correlation identified was between self-contact with the gown (torso) and virus concentrations on a personal stethoscope, which is often draped around the neck,” the study states. Investigators were unable to discern the direction of virus transfer upon contact between the healthcare workers’ hands or gloves and a surface, but results suggest that those contacts contributed to virus dissemination. 

Investigators also said that they observed doffing practices that deviated from CDC guidelines

 

“Exposure modeling and quantitative microbial risk assessment should be used to evaluate the importance of the presence and magnitude of different viruses at different locations in the environment and on HCWs for occupational and patient health impact,” the study states. 

x