The frequency of SARS-CoV-2 in stool: A prospective study of healthy preschool children in Sweden

The study investigated the frequency of SARS-CoV-2 among healthy preschool children in two Swedish municipalities, a country where preschools remained uniquely opened throughout the pandemic. Stool samples were obtained from diapers collected at preschools in November-December 2021 and analyzed for SARS-CoV-2 using real-time reverse transcriptase polymerase chain reaction. Additionally, laboratory data concerning COVID-19 in the two regions were reviewed. Sixty-seven percent of invited preschools participated, providing 350 stool samples (Uppsala n=231, Gävle n=119). The children had a median age of 24 months (range 12-72). SARS-CoV-2 was not detected in any stool sample during the study period, which coincided with the initial omicron wave. The first pediatric omicron case appeared nearly two weeks after the first adult case. These findings suggest preschool children did not constitute a silent source nor played a major role in the transmission of SARS-CoV-2 during the first phases of the largest wave of COVID-19, so far.