What Can the National Basketball Association Tell Us About COVID-19 Isolation Strategies?

Rather than retesting individuals previously infected with SARS-CoV-2 to determine how long they should remain isolated, the CDC recommends a 10-day isolation period for immunocompetent persons with infection not requiring hospitalization. The National Basketball Association (NBA) followed these guidelines during a closed-campus program in 2020 that included daily SARS-CoV-2 testing. In this retrospective cohort study, investigators assessed risk for secondary transmission among those players and staff with repeatedly positive tests after the end of isolation.

Among 3648 program participants, 36 had repeatedly positive PCR tests for SARS-CoV-2. Of these, 33 experienced initial infections prior to entering the campus and 3 were found to be infected during the required quarantine period after entering campus. Despite these positive tests, participants were allowed to participate in mask-free activities (e.g., practice, games) if symptoms had resolved and 10 days had elapsed since initial infection. Tests remained positive for a median 30 days (range, 14–68 days), and cycle threshold values were typically very high (average, 34.1), indicating few copies of viral nucleic acid. Throughout 1480 person-days of direct exposure, no secondary transmissions occurred.