The impact of the lockdown and the re opening of schools and day cares on the epidemiology of SARS CoV 2 and other respiratory infections in children A nationwide register study in Finland
Background Nationwide restrictions started in Finland in March to prevent the spread of COVID 19, leading to school and day care closures. The aim of this study is to describe the effect of closures and re openings on the respiratory pathogen epidemiology. Methods Laboratory confirmed cases of SARS CoV 2; respiratory syncytial virus (RSV) influenza (A B) parainfluenza adeno and rhinoviruses; Mycoplasma pneumoniae; and Streptococcus pneumoniae in children were collected from the National Infectious Disease Register over the period of 2017 2020. Weekly incidences (weeks 1 to 35) with 95% confidence intervals (CIs) were calculated per 100 000 children in 2020 and compared by incidence rate ratios (IRRs) to corresponding periods in 2017 2019. Findings The lockdown had immediate impact on the incidences of respiratory pathogens except SARS CoV 2. Week after the lockdown began IRR was 0*3 (CI 0*3 0*4) and next week the IRR was 0*1 (0*1 0*2) The incidence of SARS CoV 2 started to decline eight weeks after the lockdown began. The highest recorded weekly incidence of SARS CoV 2 was 7*2/100 000 children. The effect of the lockdown lasted until late summer. Rhinovirus and SARS CoV 2 began to increase before the schools or day cares opened in August. The re opening of schools seemed to have no impact on the incidence of any pathogen. Interpretation Our results suggest that general social distancing, including school and day care closures, played a crucial role in reducing infections, and the effect lasted for several weeks. The re opening of schools and day care centres seems to have had no immediate impact on the incidences of any respiratory pathogens. Funding This study had no funding source.
EClinicalMedicine