90の日記： CDC、COVID-19の隔離期間に関する方針変更。軽症中等症は発症後10日、重症は20日

https://www.cdc.gov/coronavirus/2019-ncov/hcp/duration-isolation.html

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.

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 (Cheng et al., 2020).

Specimens from patients who recovered from an initial COVID-19 illness and subsequently developed new symptoms and retested positive by RT-PCR did not have replication-competent virus detected (Korea CDC, 2020; Lu et al., 2020).

などなど。切り刻んでない詳細はリンク先へ。発熱スクリーニングにしても入院やホテル待機にしても、発症後のアクションの甲斐が全然なさそう。