Eurosurv. SARS-CoV-2 infection in schools in a northern French city: a retrospective serological cohort study in an area of high transmission, France,

[tetano]

• Arnaud Fontanet[SUP]1,2[/SUP] , Laura Tondeur[SUP]1[/SUP] , Rebecca Grant[SUP]1[/SUP] , Sarah Temmam[SUP]3[/SUP] , Yoann Madec[SUP]1[/SUP] , Thomas Bigot[SUP]4[/SUP] , Ludivine Grzelak[SUP]5,6,7[/SUP] , Isabelle Cailleau[SUP]8[/SUP] , Camille Besombes[SUP]1[/SUP] , Marie-No?lle Ungeheuer[SUP]9[/SUP] , Charlotte Renaudat[SUP]9[/SUP] , Blanca Liliana Perlaza[SUP]9[/SUP] , Laurence Arowas[SUP]9[/SUP] , Nathalie Jolly[SUP]10[/SUP] , Sandrine Fernandes Pellerin[SUP]10[/SUP] , Lucie Kuhmel[SUP]11[/SUP] , Isabelle Staropoli[SUP]5,6,12[/SUP] , Christ?le Huon[SUP]3[/SUP] , Kuang-Yu Chen[SUP]13[/SUP] , Bernadette Crescenzo-Chaigne[SUP]6,7,14[/SUP] , Sandie Munier[SUP]6,7,14[/SUP] , Pierre Charneau[SUP]15,16[/SUP] , Caroline Demeret[SUP]14[/SUP] , Timoth?e Bruel[SUP]5,6,12[/SUP] , Marc Eloit[SUP]3,17[/SUP] , Olivier Schwartz[SUP]5,6,12[/SUP] , Bruno Hoen[SUP]1,8 [/SUP]

Background

Children?s role in SARS-CoV-2 epidemiology remains unclear. We investigated an initially unnoticed SARS-CoV-2 outbreak linked to schools in northern France, beginning as early as mid-January 2020.

Aims

This retrospective observational study documents the extent of SARS-CoV-2 transmission, linked to an affected high school (n?=?664 participants) and primary schools (n?=?1,340 study participants), in the context of unsuspected SARS-CoV-2 circulation and limited control measures.

Methods

Between 30 March and 30 April 2020, all school staff, as well as pupils and their parents and relatives were invited for SARS-CoV-2 antibody testing and to complete a questionnaire covering symptom history since 13 January 2020.

Results

In the high school, infection attack rates were 38.1% (91/239), 43.4% (23/53), and 59.3% (16/27), in pupils, teachers, and non-teaching staff respectively vs 10.1% (23/228) and 12.0% (14/117) in the pupils? parents and relatives (p?<?0.001). Among the six primary schools, three children attending separate schools at the outbreak start, while symptomatic, might have introduced SARS-CoV-2 there, but symptomatic secondary cases related to them could not be definitely identified. In the primary schools overall, antibody prevalence in pupils sharing classes with symptomatic cases was higher than in pupils from other classes: 15/65 (23.1%) vs 30/445 (6.7%) (p?<?0.001). Among 46 SARS-CoV-2 seropositive pupils <?12?years?old, 20 were asymptomatic. Whether past HKU1 and OC43 seasonal coronavirus infection protected against SARS-CoV-2 infection in 6?11?year olds could not be inferred.

Conclusions

Viral circulation can occur in high and primary schools so keeping them open requires consideration of appropriate control measures and enhanced surveillance.

full article

https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2021.26.15.2001695#html_fulltext