Duration of Viral Nucleic Acid Shedding and Early Reinfection with the Severe Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Health Care Workers and First Responders

We estimated the distributions of duration of SARS-CoV-2 nucleic acid shedding and time to reinfection among 137 persons with at least two positive nucleic acid amplification test (NAAT) results from March to September 2020. We analyzed gaps of varying length between subsequent positive and negative NAAT results and estimated a mean duration of nucleic acid shedding of 30.1 (95% CI 26.3, 34.5) days. The mean time to reinfection was 89.1 (95% CI 75.3, 103.5) days. Together, these indicate that a 90-day period between positive NAAT results can reliably define reinfection in immunocompetent persons although reinfection can occur at shorter intervals.