Nearly half of healthcare staff had COVID-19 with no symptoms

Among the healthcare workers in Tennessee who tested positive for COVID-19 by serology, nearly half had no symptoms.

The results of the serology tests, which are designed to detect COVID-19 antibodies, suggested that the front-line medical staff members had contracted the disease during the first few weeks of caring for infected patients.   

Of those with positive serology results, 42 percent reported no symptoms of a respiratory illness in the prior two months. The research confirms that healthcare staff are at a high risk of COVID-19 infection and indicates that many of these workers do not exhibit the typical symptoms.

Dr. Wesley Self is an associate professor of Emergency Medicine at Vanderbilt University Medical Center and the lead investigator of the IVY Research Network.

“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 Dr. Self.

The IVY Network is a collaborative group of medical centers in the United States that is funded by the CDC to conduct research on severe respiratory infections, including COVID-19 and influenza.

In a separate study, experts with the IVY group studied 350 patients across 11 medical centers who tested positive for COVID-19. Among these patients, 54 percent reported having no close contact with any individual known to have COVID-19 in the two weeks prior to becoming 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,” said Dr. Self.

The researchers also found that 40 percent of COVID-19 patients exhibited symptoms for at least two weeks after testing positive, which shows that COVID-19 persists longer than other respiratory infections like the flu.

“We are continuing to study COVID-19 in front-line health care workers across the country to better understand what may be done to decrease their risk of infection, such as using specific types of personal protective equipment,” said co-investigator Dr. Bo Stubblefield.

The study is published in the journal Clinical Infectious Diseases.

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By Chrissy Sexton, Earth.com Staff Writer