Reinfection With Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Patients Undergoing Serial Laboratory Testing

Reinfection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was infrequent, occurring in 63 (0.7%) of 9119 patients but was associated with 2 deaths. Reinfection appeared to be milder than primary infection. Background A better understanding of reinfection after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has become one of the healthcare priorities in the current pandemic. We determined the rate of reinfection, associated factors, and mortality during follow-up in a cohort of patients with SARS-CoV-2 infection. Methods We analyzed 9119 patients with SARS-CoV-2 infection who received serial tests in total of 62 healthcare facilities in the United States between 1 December 2019 and 13 November 2020. Reinfection was defined by 2 positive tests separated by interval of >90 days and resolution of first infection was confirmed by 2 or more consecutive negative tests. We performed logistic regression analysis to identify demographic and clinical characteristics associated with reinfection. Results Reinfection was identified in 0.7% (n = 63, 95% confidence interval [CI]: .5%-.9%) during follow-up of 9119 patients with SARS-CoV-2 infection. The mean period (+/- standard deviation [SD]) between 2 positive tests was 116 +/- 21 days. A logistic regression analysis identified that asthma (odds ratio [OR] 1.9, 95% CI: 1.1-3.2) and nicotine dependence/tobacco use (OR 2.7, 95% CI: 1.6-4.5) were associated with reinfection. There was a significantly lower rate of pneumonia, heart failure, and acute kidney injury observed with reinfection compared with primary infection among the 63 patients with reinfection There were 2 deaths (3.2%) associated with reinfection. Conclusions We identified a low rate of reinfection confirmed by laboratory tests in a large cohort of patients with SARS-CoV-2 infection. Although reinfection appeared to be milder than primary infection, there was associated mortality.

Automated summary

Reinfection with SARS-CoV-2 is rare but has been associated with mortality. The severity of reinfection appears to be milder, with fewer cases of severe illness compared to primary infection. Risk factors for reinfection include asthma and nicotine dependence/tobacco use.