Reopening schools in the context of increasing COVID-19 community transmission: The French experience

Abstract

Background and objectives: The role of schools in the spread of SARS-CoV-2 infections in the community is still controversial. The objective of our study was to describe the epidemiology of SARS-CoV-2 infections in different pediatric age groups during the first 2 months of the fall back-to-school period, in the context of increasing viral transmission in France.

Methods: Weekly epidemiological data provided by Santé Publique France and the Ministry of National Education were analyzed according to the age groups defined by the different school levels. Weeks (W) 34-42 were considered for analysis.

Results: The PCR positivity rate and incidence rate increased in all age groups during the study period, in an age-dependent manner. At W42, with adults being considered as reference, the risk ratio for a positive PCR test was 0.46 [95% CI: 0.44-0.49] and 0.69 [0.68-0.70] for children aged 0-5 years and 6-17 years, respectively. Similarly, the incidence rate ratio was 0.09 [0.08-0.09], 0.31 [0.30-0.32], 0.64 [0.63-0.66], and 1.07 [1.05-1.10] for children aged 0-5 years, 6-10 years, 11-14 years, and 15-17 years, respectively. Children and adolescents accounted for 1.9% of the newly hospitalized patients between W34 and W42, and for 1.3% of new intensive care admissions. No death was observed. Among infected children and adolescents, the percentage of asymptomatic individuals was 57% at W34 and 48% at W42. The number of schools closed remained low, less than 1% throughout the study period. The number of confirmed cases among school staff was consistent with the data measured in the general population.

Conclusion: In the context of increasing viral transmission in the population, the spread among children and adolescents remained lower than that observed among adults, despite keeping schools open. However, the impact was age-dependent, with data in high schools close to those observed in adults.

Keywords: Adolescents; Children; Lockdown; PCR; SARS-CoV-2.

Fig. 1

Weekly PCR test positivity rates for different age groups. For clarity, the references for each age group are noted in the figure next to the corresponding curve.

Fig. 2

Percentage of children and adolescents between 0 and 18 years of age among newly confirmed COVID-19 cases each week.

Fig. 3

Risk ratio for positive test according to age and by week. Children are grouped into two age groups: 0–5 years (black columns) and 6–17 years (grey columns). The reference group consists of all adults aged 18 and over, indicated by the hatched line (RR = 1). Error bars are 95% confidence intervals.

Fig. 4

Weekly incidence of proven cases of COVID-19 in different age groups in week 34 (grey columns) and week 42 (black columns).

Fig. 5

Percentage of positive PCR tests during week 42 in individuals tested without symptoms (gray columns) or with symptoms (black columns), by age group.