Many hospital workers infected with coronavirus don't show symptoms

(HealthDay)—A new study of 13 U.S. medical centers finds that 6% of staff tested positive for prior infection with the new coronavirus, with almost half (44%) having no idea they'd ever contracted SARS-CoV-2.

In the study, blood antibody testing of more than 3,200 doctors, nurses and other hospital staff was conducted between early April and mid-June. About 1 in 16 of the tests came up positive, researchers found, and 29% of those positive results arose in people who said they'd had no symptoms suggestive of COVID-19.

Infection rates among staff also varied widely between hospitals, ranging from just 0.8% at one center to more than 31% at another. According to the study author, that likely reflects the level of coronavirus circulating in the city each hospital served.

One thing was clear, however: Use of masks, gowns, gloves and other protective gear by staff kept infection rates down. And when hospitals faced shortages of personal protective equipment (PPE), COVID-19 infections rose.

"A higher percentage of participants who reported a PPE shortage had detectable SARS-CoV-2 antibodies [9%] than did those who did not report a PPE shortage [6%]," reported researchers led by Dr. Wesley Self of Vanderbilt University Medical Center in Nashville, Tenn. About 12% of the workers interviewed in the study said they'd already encountered some form of PPE shortage at their medical center.

One emergency physician working on the frontlines of the pandemic agreed that prevention is key.

"Having an adequate supply of PPE is vital in order to mitigate the increased risk that all health care workers face on the frontlines," explained Dr. Robert Glatter, who practices at Lenox Hill Hospital in New York City.

"This represents one of the major ongoing challenges that has confronted hospitals and medical centers as the pandemic continues," he said.

Frequent testing of frontline health care workers is also crucial to curbing outbreaks early on because "a high proportion of personnel with antibodies did not suspect that they had been previously infected," Self's group said.

"What's important is that health care workers don't become a reservoir for asymptomatic spread of infection within the hospital setting or in the community," Glatter said. "As a result, we must invest in frequent testing of such vital workers."

The new study was published Aug. 31 in Morbidity and Mortality Weekly Report, a journal of the U.S. Centers for Disease Control and Prevention.

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