A descriptive study on the potential transmission of COVID-19 to hospitalized patients from a nursery school affiliated with it

Introduction: During the epidemic of the Omicron variant of SARS-CoV-2, nosocomial transmissions from healthcare workers (HCWs) to patients occur frequently. The influence of COVID-19 on hospitalized patients from nursing schools affiliated with the hospitals is a concern but it had not been well studied. Methods: We here describe COVID-19 outbreaks at the nursery school affiliated with an acute-care hospital, during the surges of the Omicron variants on the transmission of SARS-CoV-2 children as well as for the patients who were judged to be the close contacts of patients of COVID-19 by contact investigation by PCR testing. Results: A total of 36 children and five caregivers were diagnosed with COVID-19 during the study period. Of the 206 preschoolers who had close contact with the infected persons, only 16 became positive (7.6%). Secondary transmission from the 36 preschool children to the parents as HCWs occurred in 19 (61%) out of 31 parents. Three hospitalized patients were judged to have unsafe contact with the infected HCWs but this did not result in their infections, making a total of zero transmission from the nursery school to the hospital. Conclusions: Children at the nursery school are potential reservoirs for nosocomial transmissions at the affiliated hospital, but multiple practical measures might have prevented them to occur.