COVID-19 in children and the effect of schools reopening on potential transmission to household members.

AIM: The effect of reopening schools on children's contribution to SARS-CoV-2 transmission, especially within households, remains controversial. This study describes the clinical presentation of a large ambulatory COVID-19 paediatric cohort and evaluates the role of children in household transmission prior to and following school reopening. METHODS: A retrospective database cohort study was conducted in a large Health Maintenance Organization in Israel. Data of all paediatric, laboratory-confirmed Coronavirus cases between 28/2/2020 and 20/6/2020 were extracted. All cases were analysed for household contacts and primary cases within each family cluster. RESULTS: A total of 1,032 cases under 18 years old (median age 12 years) were included. Of these cases, 432 (41.9%) were asymptomatic; 122 (11.8%) cases acquired the infection at school, and 45 of them were part of two school clusters; 846 children had at least one positive household contact, in 498 family clusters, and among them, 293 primary cases were identified. Only 27 (9.2%) primary cases were under 18 years of age and six (2%) were below 10. The proportion of primary cases did not change after the re-opening of educational facilities. CONCLUSION: Children, particularly under 10 years of age, are less likely to be the vector for SARS-CoV-2 infection within household settings. Opening educational facilities did not change transmission dynamics.