A man from Nevada appears to be the first confirmed case of COVID-19 re-infection in the country, researchers say.
The case is detailed in an online pre-print, a study that has yet to be peer-reviewed before being officially published.
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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 fell ill in late May. The second time around, her illness was more serious, according to the case report.
Researchers at the University of Nevada, the Reno School of Medicine and the Nevada State Public Health Laboratory reported that genetic sequencing of the virus revealed that it had been infected with a slightly different strain, indicating true reinfection.
Reinfection with the coronavirus appears to be rare. It is the first case reported among nearly 6 million cases in the country to date.
“The evidence so far suggests that if you have been infected and cured then you are protected for a while,” said Dr Ashish Jha, director of the Harvard Global Health Institute. “We don’t know for how long, and we’re going to find individual cases of people for whom that isn’t true.”
Indeed, on Monday, a case of COVID-19 reinfection was reported in Hong Kong – the first confirmation of this type of reinfection during the pandemic. Two European patients, one in Belgium and one in the Netherlands, were also reportedly reinfected this week with the virus.
But in these cases, the patients did not get sick the second time around, or they developed much milder forms of the disease than their first infection.
“You would expect the second time around people to have much milder symptoms, or ideally no symptoms,” Jha said. This is because the immune system should be able to mount a more robust response, and the Hong Kong case was “completely consistent with that”.
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In the case of Nevada, however, the man got sicker the second time around. When he was first infected, he exhibited typical symptoms of the coronavirus: headache, cough, sore throat, nausea and diarrhea. In about 10 days, the symptoms subsided and he tested negative for the virus.
But a month later, on May 28, he started to feel sick again, feeling dizzy and the previous symptoms.
The disease did not clear up quickly this time. Within a week, his blood oxygen levels had fallen dangerously low. He needed help breathing and was hospitalized. Once again the man has tested positive for SARS-CoV-2, the virus that causes COVID-19.
“This is of great concern,” said Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center in Nashville.
“If this type of re-infection is common, then we need to be concerned about the strength of the protection we will get from the vaccines,” Schaffner said.
If reinfection was common, however, “we would have seen it,” Jha said. “There are so many diseases in our country.”
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