Accumulating evidence supports ending isolation and precautions for adults with laboratory-confirmed COVID-19 using a symptom-based strategy. This update incorporates recent evidence to inform the duration of isolation and precautions recommended to prevent transmission of SARS-CoV-2 to others, while limiting unnecessary prolonged isolation and unnecessary use of laboratory testing resources. This interim guidance is based upon information available to date and will be updated as new information becomes available. //

Summary of Key Findings

1. Concentrations of SARS-CoV-2 RNA in upper respiratory specimens decline after onset of symptoms. (39,56,61,63,64,66)
2. The likelihood of recovering replication-competent virus also declines after onset of symptoms. For patients with mild to moderate COVID-19, replication-competent virus has not been recovered after 10 days following symptom onset. (1,8,31,36,42,61,66) Recovery of replication-competent virus between 10 and 20 days after symptom onset has been reported in some adults with severe COVID-19; some of these cases were immunocompromised. (56) However, in this series of patients, it was estimated that 88% and 95% of their specimens no longer yielded replication-competent virus after 10 and 15 days, respectively, following symptom onset. Detection of sub-genomic SARS-CoV-2 RNA or recovery of replication-competent virus has been reported in severely immunocompromised patients (e.g., patients with chronic lymphocytic leukemia and acquired hypogammaglobulinemia, lymphoma and immunochemotherapy, hematopoietic stem-cell transplant, chimeric antigen receptor T-cell therapy, or AIDS) beyond 20 days, and as long as 143 days after a positive SARS-CoV-2 test result. (2,6,7,14,74)
3. In a large contact tracing study, no contacts at high risk of exposure developed infection if their exposure to a case patient started 6 days or more after the case patient’s infection onset. (12)
   Recovered patients can continue to have SARS-CoV-2 RNA detected in their upper respiratory specimens for up to 12 weeks after symptom onset. (31,33,34) Investigation of 285 “persistently positive” adults, which included 126 adults who had developed recurrent symptoms, found no secondary infections among 790 contacts to these case patients. Efforts to isolate replication-competent virus from 108 of these 285 case patients were unsuccessful. (31)