MONDAY, Dec. 20, 2021 (HealthDay News) -- The Test-to-Stay (TTS) strategy, whereby unvaccinated students, teachers, and staff members could remain in school with specific COVID-19-related exposure if specific conditions were met, seems effective for reducing lost in-person learning days, according to research published in the Dec. 17 early-release issue of the U.S. Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report.
Natsumi Nemoto, M.P.H., from the CDC Foundation COVID-19 Corps in Waukegan, Illinois, and colleagues evaluated the TTS strategy after implementation in 90 schools in Lake County during Aug. 9 to Oct. 29, 2021. The researchers identified 258 COVID-19 cases reported during the implementation period. The secondary attack risk was 1.5 percent among 1,035 students and staff members enrolled in TTS. All 16 of these secondary cases were in students and none appeared to transmit severe acute respiratory syndrome coronavirus 2 to other school-based contacts. Nine tertiary cases were detected among household contacts of the 16 cases, four of whom were fully vaccinated. Among TTS schools, up to 8,152 in-person learning days were saved, assuming a maximum of eight missed school days for every 10-day quarantine period.
Kimberly Harris-McCoy, M.S.P.H., from the Los Angeles County Department of Public Health, and colleagues evaluated a TTS strategy implemented by the Los Angeles County Department of Public Health. During Sept. 20 to Oct. 31, 2021, 432 of 2,067 schools implemented TTS. The researchers observed no increased incidence of COVID-19 in TTS schools after implementation of TTS; no tertiary transmission was identified in 20 outbreaks detected in TTS schools. Non-TTS schools lost an estimated 92,455 in-person school days while students were in quarantine, compared with no lost school days in TTS schools
"These findings reinforce the usefulness of TTS for helping to maintain in-person learning in schools," Harris-McCoy and colleagues write.