The Grapevine

Recovered Coronavirus Patients Start Testing Positive For COVID-19 Again

Officials confirmed that some members of the U.S. Navy tested positive for the novel coronavirus after recovery. Health experts said the cases are unlikely to be reinfections because there have been problems with testing tools. 

The U.S. Pacific Fleet said 14 sailors were aboard the USS Theodore Roosevelt when they appeared with the virus for a second time. Prior to the latest test, the patients "met rigorous recovery criteria" as they recovered from their first coronavirus infection, NBC News reported Wednesday.

The returning COVID-19 cases sparked concerns that other previous patients might still be carrying and catching the virus. But some experts explained that some people appeared positive twice because of the test used.

In the U.S., most of the diagnostic tests for COVID-19 focus on the virus' RNA or genetic code. Other methods to identify infection look for proteins from the virus. 

The Centers for Disease Control and Prevention (CDC) explained that "detection of viral RNA does not necessarily mean that infectious virus is present." That means results may return positive for the coronavirus because the tool used detected remnants of the virus from the first infection, which are no longer able to affect people.

"It's possible that people could shed remnants of the virus for some period of time," William Schaffner, an infectious disease expert at Vanderbilt University Medical Center in Nashville, said. "That doesn't mean anything is wrong with them or that they are contagious." 

A recent study in South Korea provided evidence that recovered COVID-19 patients who had “second infections” can no longer infect others. Researchers at the Korean Centers for Disease Control and Prevention looked into viral samples from 285 patients and found the virus was even unable to grow in the lab.

"What we're finding more and more is that the fragments of virus that are being picked up on these swabs weeks later are not able to replicate," Ania Wajnberg, associate director of medicine at the Icahn School of Medicine at Mount Sinai in New York City, said. "They're not live virus."

However, other health experts noted the medical community have yet to fully understand how the novel coronavirus infects people and its long-term effects. Latest records show there are now 4.9 million confirmed COVID-19 cases worldwide and over 1.9 million recovered patients. 

Coronavirus COVID-19 Test Kit A medical staff displays a test kit to detect the novel coronavirus at a COVID-19 screening-drive, at the Amsterdam UMC in Amsterdam The Netherlands, on March 24, 2020. ROBIN VAN LONKHUIJSEN/ANP/AFP via Getty Images

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