SARS-CoV-2 Transmission Risk Among National Basketball Association Players, Staff, and Vendors Exposed to Individuals With Positive Test Results After COVID-19 Recovery During the 2020 Regular and Postseason

Abstract

IMPORTANCE Clinical data are lacking regarding the risk of viral transmission from individuals who have positive reverse-transcription-polymerase chain reaction (RT-PCR) SARS-CoV-2 test results after recovery from COVID-19. OBJECTIVE To describe case characteristics, including viral dynamics and transmission of infection, for individuals who have clinically recovered from SARS-CoV-2 infection but continued to have positive test results following discontinuation of isolation precautions. DESIGN, SETTING, AND PARTICIPANTS This retrospective cohort study used data collected from June 11, 2020, to October 19, 2020, as part of the National Basketball Association (NBA) closed campus occupational health program in Orlando, Florida, which required daily RT-PCR testing and ad hoc serological testing for SARS-CoV-2 IgG antibodies. Nearly 4000 NBA players, staff, and vendors participated in the NBA's regular and postseason occupational health program in Orlando. Persistent positive cases were those who recovered from a documented SARS-CoV-2 infection, satisfied US Centers for Disease Control and Prevention criteria for discontinuation of isolation precautions, and had at least 1 postinfection positive RT-PCR test(s) result. EXPOSURES Person-days of participation in indoor, unmasked activities that involved direct exposure between persistent positive cases and noninfected individuals. MAIN OUTCOMES AND MEASURES Transmission of SARS-CoV-2 following interaction with persistent positive individuals, as measured by the number of new COVID-19 cases in the Orlando campus program.RESULTS Among 3648 individuals who participated, 36 (1%) were persistent positive cases, most of whom were younger than 30 years (24 [67%]) and male (34 [94%]). Antibodies were detected in 33 individuals (91.7%); all remained asymptomatic following the index persistent positive RT-PCR result. Cycle threshold values for persistent positive RT-PCR test results were typically above the Roche cobas SARS-CoV-2 limit of detection. Cases were monitored for up to 100 days (mean [SD], 51 [23.9] days), during which there were at least 1480 person-days of direct exposure activities, with no transmission events or secondary infections of SARS-CoV-2 detected (0 new cases). CONCLUSIONS AND RELEVANCEIn this retrospective cohort study of the 2020 NBA closed campus occupational health program, recovered individuals who continued to test positive for SARS-CoV-2 following discontinuation of isolation were not infectious to others. These findings support time-based US Centers of Disease Control and Prevention recommendations for ending isolation.

Results from a Test-to-Release from Isolation Strategy Among Fully Vaccinated National Football League Players and Staff Members with COVID-19 — United States, December 14–19, 2021

“…† † Although Ct values are not a measure of infectiousness (https://www.cdc.gov/coronavirus/2019-ncov/lab/faqs.html) a Ct cutoff of 35 was chosen by NFL based on higher Ct values correlating with limited culturable virus using alternative RT-PCR tests (https://academic.oup.com/cid/article/73/11/e3884/6018217).NFL's test-to-release from isolation strategy, approximately one half of fully vaccinated persons with COVID-19 had negative or Ct≥35 RT-PCR test results after 5 full days of isolation (i.e., on day 6), and 84% by day 10. CDC advises that persons with access to tests might use an antigen test toward the end of the 5-day isolation period(10), because RT-PCR tests can continue to return positive results with high Ct values intermittently after an initial positive result(4). Ct values are not a validated measure of infectiousness; however, the data from this study indicate that persons can receive a positive test result after a 5-day isolation period.…”

The required size of cluster randomized trials of nonpharmaceutical interventions in epidemic settings

“…For example, some schools, universities, long‐term care facilities, and workplaces have proposed or implemented universal testing strategies. 26 , 27 , 28 , 29 We consider this setting first, followed by settings where a simple random sample (without replacement) is chosen for testing, independently at each time point.…”

SARS-CoV-2 Transmission and Prevention in the Era of the Delta Variant

“… 84 The National Basketball Association (NBA) had a closed environment for their 2020 season, with systematic and frequent testing allowing for detailed descriptions of transmission in this setting that included nearly 4,000 individuals. 85 Their policies allowed individuals with infection to discontinue isolation at 10 days after symptom onset or first positive PCR test. They found no secondary infections after that time, despite 36 individuals remaining persistently PCR positive on nasopharyngeal testing.…”