New research from Emory University shows exposures to people with COVID-19 outside the workplace and Black race were the strongest predictors of positive COVID-19 antibody tests, also known as seropositivity, in health care workers. The study was published online in the Annals of Internal MedicineÂ on Jan. 29, 2021.
The researchers also determined living in a zip code with higher COVID-19 incidence increased the risk of seropositivity to SARS-CoV-2, the virus that causes COVID-19, as did reported contact with an infected health care worker.
â€œDemographic and community risk factors, including Black race and exposure to a COVID-19 infected person outside of work, were more strongly associated with SARS-CoV-2 seropositivity among health care workers than exposure in the workplace,â€ explains Steinberg, who is the senior author on theÂ Annals of Internal MedicineÂ paper.
A total of 10,275 health care workers (35 percent of the Emory Healthcare workforce) participated in the testing and survey. Antibody testing, adjusted for false positive and false negative results, showed approximately 3.8 percent of employees/medical staff had antibodies indicating SARS-CoV-2 seropositivity after the first surge of the pandemic.
â€œUnderstanding the factors that put health care workers at risk can guide improvement of infection prevention practices that keep health care workers and patients safe. It’s really difficult to do this without considering risk factors outside the workplace. What we’ve done in this study is account for COVID-19 incidence where health care workers lived, to allow for the possibility that they may have been exposed outside the workplace,â€ says Kristin Nelson, PhD, assistant professor of epidemiology at Rollins School of Public Health, Emory University and co-first author on the paper with postdoctoral fellow Julia Baker, PhD.
Researchers found few risk factors for infection in the workplace. Health care workers who reported caring for patients with COVID-19 and those who worked in procedure areas were not more likely to be seropositive. However, those who worked in certain locations such as the emergency department, non-COVID-19 clinical areas and units set up to care for COVID-19 patients were somewhat more likely to be seropositive.
The researchers were unable to determine if workplace risk was mostly from exposure to patients with known COVID-19, exposure to those without suspected infection or from exposure to other health care workers.
â€œOverall, these data support the effectiveness of our PPE protocols and procedures in reducing the risk of contracting COVID-19 in the workplace,â€ says Steinberg.
The authors state that ongoing efforts to keep the health care workforce safe should emphasize risk mitigation both inside and outside of the workplace.