Demonstrating the Ability to Protect Healthcare Personnel from COVID-19 in High-Risk Settings

This content can also be found on the NIOSH Science Blog.

The COVID-19 pandemic brought about stresses to the U.S. healthcare workforce never seen before. Since early in the pandemic, reports have abounded of healthcare personnel (HCP) being infected, sometimes resulting in severe outcomes and death. As of July 20, 2022, there have been nearly 1 million COVID-19 cases and over 2,000 deaths reported to CDC among U.S. HCP. Meanwhile, the increased workload and the emotional toll of caring for millions of severely ill patients has led to stress-related conditions including burnout among many HCP. Emergency departments (EDs) are one care location where these pressures have been felt most acutely, as HCP frequently treat patients with unknown infection status and perform procedures that may generate higher concentrations of infectious respiratory aerosols.

It is therefore encouraging to be able to highlight the results of a recently published prospective study assessing the incidence of infection in a cohort of ED HCP. The study by Mohr et al. was funded through an existing CDC cooperative agreement and conducted in over 1600 HCP working in 20 U.S. centers over 20 weeks from May to December 2020, before the availability of COVID-19 vaccines. The cohort was divided evenly between physicians or advanced practice providers (APPs; e.g. physician assistants and nurse practitioners), nurses, and non-clinical staff. Participants provided monthly viral test (nasal) and serology specimens and weekly exposure and procedure information.  Time intervals of potential exposure, based on the intervals between serologic and viral testing, were further analyzed for physicians/APPs and nurses by whether the individual participated in intubations or cardiac arrest care (i.e., potential aerosol-generating procedures) of patients, inclusive of those with confirmed or suspected COVID-19.

Over the 20 weeks, 75 participants (4.5%) acquired SARS-CoV-2 infection.  Physicians/APPs did not have a higher risk of becoming infected than non-clinical staff. Nurses had the highest absolute SARS-CoV-2 infection risk, but the relative risk did not reach statistical significance. Although there was overall high compliance with using CDC-recommended personal protective equipment (PPE), lapses in use still occurred and there was widespread reuse of PPE. However, neither these lapses nor participation in patient intubations/cardiac arrest care were associated with SARS-CoV-2 infection on multivariate analysis.  What was associated with the acquisition of infection among HCP was household SARS-CoV-2 exposure; hospital and community SARS-CoV-2 burden; community exposure; and mask non-use in public.

Similar to another larger study by Jacob et al., which was not limited to EDs but also conducted in academic medical centers in 2020 prior to the availability of vaccination, the study by Mohr et al. found that the occupational risk of COVID-19 to HCP can be largely eliminated using recommended prevention practices. While Jacob et al. already found that working in an ED was not associated with an increased risk of infection vs. other clinical and non-clinical staff, the study by Mohr et al. was able to further delineate exposure risks by prospectively tracking self-reported factors previously associated with coronavirus transmission. These included participating in patient intubations and cardiac arrest care, as well as non-compliance with PPE recommendations during those individual procedures or other clinical care activities.

While findings of Mohr et al. and Jacob et al. are encouraging in suggesting that risks of SARS-CoV-2 transmission due to direct patient care are effectively controlled by recommended interventions, both studies were conducted in academic medical centers, where infection prevention and occupational health expertise and capacity, as well as PPE availability and training, were likely greater than that found across all U.S. healthcare settings. However, while the study by Mohr et al. was focused only on EDs, Jacob et al. did include HCP from 100 affiliated regional ambulatory locations, administrative locations, rehabilitation facilities, and skilled nursing facilities. Both the studies involved HCP who volunteered to participate and thus may have been more advanced in their understanding and practice of infection prevention and safe healthcare work practices than the general healthcare workforce.

The findings of Mohr et al. and Jacob et al. demonstrate that exposure in family and community settings plays an extremely important role in acquisition of COVID-19 by HCP. Thus, interventions such as vaccination that provide protection in both work and non-work settings are critical for preventing COVID-19 in HCP. Nonetheless, the conclusions of Mohr et al. are encouraging from the standpoint of demonstrating how existing recommended practices are effective and protect HCP from the occupational risks of emerging respiratory viruses, even before vaccines become available. These findings should redouble public health and healthcare infection prevention and occupational health efforts to work together to ensure that the practices prevalent across the academic settings studied by both Mohr et al. and Jacob et al. are the minimal standard in all U.S. healthcare settings. Despite the rise of telemedicine, in-person care remains an essential component of healthcare delivery, and, although the studies by Mohr et al. and Jacob et al. did not specifically examine it, simply needing to travel out of the home to an onsite workplace carries with it increased risk during periods of high SARS-CoV-2 community burden.  Thus, as HCP remain largely frontline workers, these findings remind us how promoting the acceptance of community mitigation and vaccination measures is integral to protecting both the healthcare and non-healthcare workforce.

L. Clifford McDonald, MD, Associate Director for Science, Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention.

David Weissman, MD, Director, Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention.

Mohr NM, Krishnadasan A, Harland KK, Eyck PT, Mower W, Schrading WA, Montoy JC, McDonald LC, Kutty PK, Hesse E, Santibanez S, Weissman DN, Slev P, Talan DA for the Project COVERED Emergency Department Network. Emergency department personnel patient care-related COVID-19 risk. PLOS One. 2022.