WASHOE COUNTY, Nevada — A Nevada man has been confirmed to be the first person in the U.S. to catch COVID-19 twice.

What You Need To Know

  • A 25-year-old Nevada man has been confirmed to be the first person in the U.S. to be infected by the coronavirus twice

  • The man's second bout with COVID-19 was symptomatically more severe than the first

  • The case raises further questions about how long immunity lasts in someone who was infected 

  • The case study was published in the medical journal The Lancet

The 25-year-old Washoe County resident first tested positive for the coronavirus in April after developing symptoms that included a sore throat, cough, headache, nausea and diarrhea, according to a case study published Monday in the medical journal The Lancet. The man, who had no underlying medical conditions, recovered and twice tested negative in May. 

However, in late May, he began to feel ill again and went to an urgent-care clinic with a fever, cough and dizziness. In early June, he tested positive again for the virus and was eventually hospitalized.

“The second infection was symptomatically more severe than the first," the study’s authors wrote.

The man has since recovered from his second bout with COVID-19.

But his case raises further questions about how long immunity lasts in someone who was infected and suggests those who have been infected should still continue to follow public safety guidelines. The findings could also be relevant in making a vaccine, the researchers said.

“All individuals, whether previously diagnosed with COVID-19 or not, should take identical precautions to avoid infection with SARS-CoV-2,” the researchers wrote.

To date, there have been five confirmed cases of reinfection worldwide. 

The scientists confirmed that the Nevada man had been infected twice — rather than once with a relapse — by comparing the genetic codes from each infection, which showed “significant differences.”