A 25-year old Nevada patient was confirmed to have been infected with the coronavirus twice, marking the first case of reinfection in the US and the fourth case globally. The case was published in a preprint on the Social Science Research Network (SSRN), and the researchers have also submitted their paper to the journal The Lancet Infectious Diseases.
This past week, researchers reported the first three reinfection cases in two patients in Europe and a patient in Hongkong. The patients developed a milder form of COVID-19 or were symptomatic the second time around. However, according to the new case study, the Nevada patient has developed more severe symptoms the second time he was infected.
The 25-year old patient first tested positive for the virus in mid-April after having typical symptoms of the disease such as headache, cough, sore throat, nausea, and diarrhea. His symptoms had resolved within ten days, and later tested negative for the virus twice.
However, at the end of May, the patient had tested positive for the coronavirus again, 48 days after he tested positive the first time. This time he had developed a fever, headache, dizziness, cough, nausea, diarrhea, and within a week, he was hospitalized as his blood oxygen levels dropped and needed oxygen support.
The researchers analyzed the genomes of the viruses from both times of infection. They found that the viruses had undergone natural mutations, as seen from differences in their genes. Their findings strongly suggest that the patient was infected with two slightly different versions of the coronavirus, rather than a prolonged infection with a single virus.
The authors wrote that it is difficult to find these cases in the US and elsewhere because there isn’t a comprehensive sequencing of coronavirus genomes for every person who tested positive.
“It is important to note that this is a singular finding. It does not provide any information to us with regard to the generalizability of this phenomenon.” “If reinfection is possible on such a short timeline, there may be implications for the efficacy of vaccines developed to fight the disease. It may also have implications for herd immunity… After one recovers from COVID-19, we still do not know how much immunity is built up, how long it may last, or how well antibodies play a role in protection against reinfection.”Mark Pandori, the Nevada State Public Health Laboratory director and co-author of the study