Persistent SARS-CoV-2 RNA Shedding Without Evidence of Infectiousness: A Cohort Study of Individuals With COVID-19

Background. To better understand severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) shedding and infectivity, we estimated SARS-CoV-2 RNA shedding duration, described participant characteristics associated with the first negative rRT-PCR test (resolution), and determined if replication-competent viruses was recoverable >= 10 days after symptom onset. Methods. We collected serial nasopharyngeal specimens from 109 individuals with rRT-PCR-confirmed COVID-19 in Utah and Wisconsin. We calculated viral RNA shedding resolution probability using the Kaplan-Meier estimator and evaluated characteristics associated with shedding resolution using Cox proportional hazards regression. We attempted viral culture for 35 rRT-PCR-positive nasopharyngeal specimens collected >= 10 days after symptom onset. Results. The likelihood of viral RNA shedding resolution at 10 days after symptom onset was approximately 3%. Time to shedding resolution was shorter among participants aged <18 years (adjusted hazards ratio [aHR], 3.01; 95% confidence interval [CI], 1.6-5.6) and longer among those aged >= 50 years (aHR, 0.50; 95% CI, .3-.9) compared to participants aged 18-49 years. No replication-competent viruses were recovered. Conclusions. Although most patients were positive for SARS-CoV-2 for >= 10 days after symptom onset, our findings suggest that individuals with mild to moderate COVID-19 are unlikely to be infectious >= 10 days after symptom onset.