Among 249 front-line health care workers who cared for patients with coronavirus disease 2019 (COVID-19) during the first month of the pandemic in Tennessee, 8% tested positive for COVID-19 antibodies by serology testing. This suggests they had contracted COVID-19 in the first several weeks of taking care of COVID-19 patients, according to a Vanderbilt University Medical Center press release.

The IVY Research Network completed initial studies evaluating the epidemiology of COVID-19 in health care workers and patients. Among the health care workers with positive serology results, 42% reported no symptoms of a respiratory illness in the prior 2 months.

The findings indicate that front-line health care workers are at high risk for COVID-19 and that many health care workers with the virus may not have typical symptoms of a respiratory infection, according to the study authors.

“Our results suggest that screening health care workers for COVID-19 even when they don’t have any symptoms could be important to prevent the spread of the virus within hospitals,” said lead study investigator Wesley Self, MD, associate professor of Emergency Medicine at Vanderbilt University Medical Center, in a press release.

In a separate study, the IVY investigators evaluated 350 patients across 11 medical centers in the United States who tested positive for COVID-19. They found 54% of these patients reported no close contact with another person known to have COVID-19 in the 2 weeks before getting sick.

“With over half of COVID-19 patients not identifying a clear source of their infection, this study reinforces the need for practical measures to reduce the spread of the virus, such as social distancing and the use of face coverings when out in public,” Self said in a press release.

Additionally, 40% of COVID-19 patients in the study remained symptomatic 2 weeks after a positive COVID-19 test, showing that patients with COVID-19 tend to remain ill longer than with other respiratory infections, such as influenza, according to the press release.

About half of health care workers positive for COVID-19 by serology have no symptoms. Vanderbilt University. Published July 9, 2020. Accessed July 15, 2020.