"Available data indicate that persons with mild to moderate COVID-19 remain infectious no longer than 10 days after symptom onset."
"Persons with more severe to critical illness or severe immunocompromise likely remain infectious no longer than 20 days after symptom onset."
but 88% are clear after 10 days and 95% after 15.
but 88% are clear after 10 days and 95% after 15.
A large contact tracing study found high-risk household and hospital contacts did not develop infection if their exposure to a case patient started 6 days or more after the case patient’s illness onset.
!!! Even though no live, replication-competent virus has been found 3 weeks after symptom onset, PCR tests can still pop positive for up to 12 weeks.
"These findings strengthen the justification for relying on a symptom based, rather than test-based strategy for ending isolation of these patients, so that persons who are by current evidence no longer infectious are not kept unnecessarily isolated."
CDC recommendations: 
