
Serial COVID-19 testing of 50,000 children in 714 German daycare facilities over 1 year didn't result in increased infections and averted 7 to 20 days of post-exposure quarantine per child, according to a study published today in Pediatrics.
University Hospital Cologne researchers led the study, which linked polymerase chain reaction (PCR) COVID-19 test results with data on reported infections to evaluate the change in infection frequency with serial testing ("test-to-stay" approach) versus quarantine among children aged 2 to 6 years from March 2021 to April 2022.
From weeks 11 to 36 in 2021, daycares quarantined exposed children for up to 14 days, switching to the test-to-stay strategy from week 37 in 2021 to week 14 in 2022. Under test-to-stay, COVID-exposed children were tested with single PCRs for 5 days.
The study period spanned the Alpha, Beta, and Omicron BA.1 and BA.2 variants. The 7-day incidence of COVID-19 in Cologne ranged from about 9 per 100,000 people in week 25 of 2021 to 2,573 per 100,000 in week 9 of 2022.
While quarantine reduces COVID spread, it can lead to impaired cognitive development, executive functions, and mental and physical health.
"Furthermore, quarantine was shown to negatively impact parents, increasing negative mood or likelihood of losing temper and punishment," the study authors wrote. "Additionally, high-frequent and unexpected disruption of daycare attendance impacts workforce participation of parents because of the necessity of at-home childcare."
Test-to-stay appears safe, effective
Of the 219,885 pooled PCRs performed, 2.9% were positive for COVID-19, and 17,208 infections were reported.
This approach offers a promising option to avoid use of quarantine after exposure to respiratory pathogens in daycare settings.
The test-to-stay strategy avoided an estimated 7 to 20 days of quarantine per child, with no significant increase in infections. A regression-discontinuity-in-time analysis suggested a 26% reduction in COVID-19 cases. The results held true regardless of 7-day incidence, season, variant, or socioeconomic status.
"Our analyses provide evidence that suggest safety of the test-to-stay approach compared with quarantine measures," the researchers wrote. "This approach offers a promising option to avoid use of quarantine after exposure to respiratory pathogens in daycare settings."