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

Owusu, Daniel; Pomeroy, Mary A; Lewis, Nathaniel M; Wadhwa, Ashutosh; Yousaf, Anna R; Whitaker, Brett; Dietrich, Elizabeth; Hall, Aron J; Chu, Victoria; Thornburg, Natalie; Christensen, Kimberly; Kiphibane, Tair; Willardson, Sarah; Westergaard, Ryan; Dasu, Trivikram; Pray, Ian W; Bhattacharyya, Sanjib; Dunn, Angela; Tate, Jacqueline E; Kirking, Hannah L; Matanock, Almea

BACKGROUND: To better understand SARS-CoV-2 shedding duration and infectivity, we estimated SARS-CoV-2 RNA shedding duration, described characteristics associated with viral RNA shedding resolution(1), and determined if replication-competent viruses could be recovered ≥10 days after symptom onset among individuals with mild to moderate COVID-19. METHODS: We collected serial nasopharyngeal specimens at various time points from 109 individuals with rRT-PCR-confirmed COVID-19 in Utah and Wisconsin. We calculated probability of viral RNA shedding resolution 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% CI: 1.6–5.6) and longer among those aged ≥50 years (aHR: 0.50; 95% CI: 0.3–0.9) 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.