Healthcare personnel who were infected with COVID-19 had stronger risk factors outside the workplace than in their hospital or healthcare setting. That is the finding of a new study published today in JAMA Network Open conducted by University of Maryland School of Medicine (UMSOM) researchers, colleagues at the Centers for Disease Control and Prevention (CDC) and three other universities.
The study examined survey data from nearly 25,000 healthcare providers in Baltimore, Atlanta, and Chicago including at University of Maryland Medical System (UMMS) hospitals. They found that having a known exposure to someone who tested positive for COVID-19 in the community was the strongest risk factor for testing positive for COVID-19. Living in a zip code with a high COVID-19 cumulative incidence was also a strong risk factor.
"The news is reassuring in that it shows the measures taken are working to prevent infections from spreading in healthcare facilities," said study co-author Anthony Harris, MD, MPH, Professor of Epidemiology & Public Health at UMSOM. "Vaccination for healthcare workers, however, should remain a priority because of continual exposures in the workplace. There is also an urgent need to keep healthcare providers healthy so they can care for sick patients and reduce the risk of transmitting the virus to vulnerable patients."
Researchers from Emory University School of Medicine and Rollins School of Public Health in Atlanta, Rush University Medical Center in Chicago, and Johns Hopkins University School of Medicine also participated in this study. UMSOM faculty Robert Christenson, PhD, Brent King, MD, Surbhi Leekha, MBBS, Lyndsay O'Hara, PhD, Peter Rock, MD, MBA, and Gregory Schrank, MD, were co-authors on this study. The study was funded by CDC's Prevention Epicenters Program.
"Factors presumed to contribute most to infection risk among healthcare providers, including caring for COVID-19 patients, were not associated with increased risk in this study," said study co-author Sujan Reddy MD, an infectious disease specialist at the CDC. "The highest risks to healthcare workers may be from exposures in the community."
The study did, however, have some important caveats. Since infection control practices were not standardized across the various healthcare sites, the study could not determine the level of effectiveness of personal protective equipment (N95 respirator, surgical mask, gowns, face shields). Nor could the study determine whether certain infection control practices, such as frequent disinfection of surfaces in exam rooms, were better than others in preventing infection spread.
Confirming evidence from other studies, this study found that Black Americans who were healthcare personnel were more likely to test positive for COVID-19 infections than their white counterparts. This may be due to existing disparities in community exposure rather than from healthcare-associated exposures.
"We're proud of this very important collaborative clinical work with our research colleagues," said Mohan Suntha, MD, MBA, President and CEO of UMMS. "We have made the safety of our team members a top priority throughout this pandemic, and it is incredibly gratifying to see that our efforts to prevent the spread of COVID-19 in hospitals have worked. This is also another example of the importance of the partnership between our academic-focused health care System and the groundbreaking discovery-based medicine work happening every day at the UM School of Medicine."
"As front-line and support staff at hospitals and health systems continue to tirelessly battle COVID-19, they can draw reassurance in this important research finding that the infection control measures in place protected themselves and their families," said E. Albert Reece, MD, PhD, MBA, Executive Vice President for Medical Affairs, UM Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor and Dean, University of Maryland School of Medicine. "We need to know that we are doing all we can to protect our healthcare heroes, from providing them with adequate protective gear to giving them early access to vaccines."