Scientists have confirmed the first case of coronavirus reinfection in the United States: a 25-year-old Nevada man whose second round of the virus was more severe than the first.
The findings were published Monday in the medical journal The Lancet.
The man, who remains unnamed, first tested positive in April before recovering and testing negative in May. Then in June, he tested positive for the virus again, developing symptoms of COVID-19 a second time.
According to the case study, his second infection included more severe symptoms than the first time around, including fever, cough and dizziness.
The researchers sequenced the RNA from both virus samples and found they were two different strains, making it a true reinfection.
Scientists have not concluded why someone might contract the virus twice or if some people are more predisposed to reinfection. The Nevada case marks the fifth case globally of reinfection, and scientists say