An investigation into the rates of transmission of SARS-CoV-2 during the first 6 weeks of the 2020-2021 academic year in primary and post-primary schools in Cork and Kerry, Ireland.

Background: Schools in Ireland closed in March 2020 as part of a national strategy to contain the spread of severe acute respiratory syndrome (SARS-CoV-2). The extent to which schools contribute to the overall propagation of SARS-CoV-2 was continuing to evolve internationally.

Aims: To examine regional data on SARS-CoV-2 transmission in primary, post-primary and special schools in Cork and Kerry, two counties in southwest Ireland, during the first 6 weeks of the 2020-2021 academic year and determine the rate of in-school transmission.

Methods: Data were obtained from the Computerised Infectious Disease Reporting (CIDR) system and supplemented with digital records from the regional Department of Public Health (Dept PH) and from the Health Service Executive (HSE) Covid Care Tracker application. The positivity rate among school close contacts was calculated to determine the rate of in-school SARS-CoV-2 transmission.

Results: The overall rate of in-school transmission of SARS-CoV-2 was low at 4.1%. Positivity rates among students and staff who were close contacts were similarly low (3.1% vs. 6.9%, p = 0.07). One secondary case of coronavirus disease 2019 (COVID-19) emerged, on average, for every 7.6 infectious days spent by an index case in school. Schools accounted for 2.2% of all notified cases of COVID-19 in the region during the observation period.

Conclusions: During the first 6 weeks of the academic year, the rate of in-school SARS-CoV-2 transmission in the region was low, and schools did not contribute substantially to the overall burden of COVID-19.