US Confirms First Case of COVID 19 Reinfection

A Nevada man appears to be the nation’s first confirmed case of COVID-19 reinfection, researchers say.

The case is detailed in an online preprint, a study that has not yet been peer reviewed before officially being published, NBC News reports.

The case involves a 25-year-old man living in Reno, Nevada, who first tested positive for COVID-19 in mid-April. He recovered, but got sick again in late May. The second time around, his illness was more severe, the case report said.

Researchers reported that genetic sequencing of the virus revealed that he had been infected with a slightly different strain, indicating a true reinfection.

It’s still unclear why the patient was reinfected. The cause could lie in his immune system, the virus itself, or a combination of the two.

Mark Pandori, director the Nevada State Public Health Laboratory and one of the authors of the report, stressed that reinfection with the coronavirus appears to be rare. This is the first instance reported in the U.S. among the nation’s nearly 6 million cases so far, and “may not be generalizable” to the public, Pandori told NBC News.

Still, he urged caution. “If you’ve had it, you can’t necessarily be considered invulnerable to the infection” again, said Pandori, who is also an associate professor of pathology and lab medicine at the University of Nevada, Reno School of Medicine.

Indeed, on Monday, a case of COVID-19 reinfection was reported in Hong Kong — the first such confirmation of reinfection during the pandemic. Two European patients, one in Belgium and one in the Netherlands, were also reported this week to have been reinfected with the virus.

But in those instances, the patients did not get sick the second time around, or they developed much milder forms of the illness than their first infection.

In the Nevada case, however, the man got sicker the second time. When he was first infected, he had typical symptoms for the coronavirus: headache, cough, sore throat, nausea and diarrhea. Within about 10 days, the symptoms cleared up, and he tested negative for the virus, they report.

But a month later, on May 28, he started feeling sick again, experiencing dizziness as well as the previous symptoms.

The illness did not clear up quickly this time. Within a week, his blood oxygen level fell dangerously low. He needed help breathing, and was hospitalized. Once again, the man tested positive for SARS-CoV-2, the virus that causes COVID-19.

Dr. Michael Mina, an epidemiologist at the Harvard University T.H. Chan School of Public Health, said the findings should not cause alarm NBC News reported.

“The vast majority of people who do get infected a second time will not be sick, and will not end up in the hospital,” Mina said. “It could be that the person just didn’t have a particularly bad first infection and didn’t develop as good of an immune response.”

The case illustrates the need for continued protective practices, such as wearing masks, washing hands and maintaining physical distances, to reduce the risk for second infections.