Many frontline health care workers who care for Covid-19 patients may be infected and not even know it, researchers led by the Centers for Disease Control and Prevention reported Monday. And because the infections are undetected, they can potentially be spread to patients, coworkers, and others in the community.
Their survey of more than 3,200 health workers found 6% had antibodies to coronavirus, indicating they had been infected with the virus. But 69% of them had never been diagnosed with such an infection, 44% did not believe they had ever been infected and 29% said they never had any symptoms.
“A high proportion of SARS-CoV-2 infections among healthcare personnel appear to go undetected,” the team at academic medical centers across the country, including the CDC Covid-19 Response Team, wrote in the CDC’s weekly report.
“Consistent with persons in the general population with SARS-CoV-2 infection, many frontline HCP [health care personnel] with SARS-CoV-2 infection might be asymptomatic or minimally symptomatic during infection, and infection might be unrecognized, " they continued.
More on the study: The researchers analyzed blood samples taken between April 3 and June 19 from 3,248 frontline health care workers at 13 academic medical centers across the country. The samples were tested for antibodies to the SARS-CoV-2 virus and participants were asked about potential symptoms of Covid-19, previous testing for a coronavirus infection, and their use of personal protective equipment in the week prior.
Participants who reported always wearing a face covering — a surgical mask, N95 respirator, or powered air purifying respirator — while caring for patients had lower infection rates compared with those who did not.
But personal protective equipment wasn’t always available. In eight of the 13 medical centers, more than 10% of participants reported a PPE shortage. Shortages of N95 respirators were those most commonly reported —5% of those surveyed said there was a shortage where they worked.
“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%),” the researchers wrote. “A high proportion of personnel with antibodies did not suspect that they had been previously infected.”
Requiring face coverings, having teams dedicated exclusively to caring for patients with coronavirus, better screening and testing might all help, the team concluded.