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. 2021 Aug:7:100148.
doi: 10.1016/j.lanepe.2021.100148. Epub 2021 Jun 7.

Exposures associated with SARS-CoV-2 infection in France: A nationwide online case-control study

Simon Galmiche  1 , Tiffany Charmet  1 , Laura Schaeffer  1 , Juliette Paireau  2   3 , Rebecca Grant  1   3 , Olivia Chény  4   5 , Cassandre Von Platen  5 , Alexandra Maurizot  6 , Carole Blanc  6 , Annika Dinis  6 , Sophie Martin  6 , Faïza Omar  7 , Christophe David  7 , Alexandra Septfons  3 , Simon Cauchemez  2 , Fabrice Carrat  8 , Alexandra Mailles  3 , Daniel Levy-Bruhl  3 , Arnaud Fontanet  1   9
Affiliations

Exposures associated with SARS-CoV-2 infection in France: A nationwide online case-control study

Simon Galmiche et al. Lancet Reg Health Eur. 2021 Aug.

Abstract

Background: We aimed to assess the role of different setting and activities in acquiring SARS-CoV-2 infection.

Methods: In this nationwide case-control study, cases were SARS-CoV-2 infected adults recruited between 27 October and 30 November 2020. Controls were individuals from the Ipsos market research database matched to cases by age, sex, region, population density and time period. Participants completed an online questionnaire on recent activity-related exposures.

Findings: Among 3426 cases and 1713 controls, in multivariable analysis, we found an increased risk of infection associated with any additional person living in the household (adjusted-OR: 1•16; 95%CI: 1•11-1•21); having children attending day-care (aOR: 1•31; 95%CI: 1•02-1•62), kindergarten (aOR: 1•27; 95%CI: 1•09-1•45), middle school (aOR: 1•30; 95%CI: 1•15-1•47), or high school (aOR: 1•18; 95%CI: 1•05-1•34); with attending professional (aOR: 1•15; 95%CI: 1•04-1•26) or private gatherings (aOR: 1•57; 95%CI: 1•45-1•71); and with having frequented bars and restaurants (aOR: 1•95; 95%CI: 1•76-2•15), or having practiced indoor sports activities (aOR: 1•36; 95%CI: 1•15-1•62). We found no increase in risk associated with frequenting shops, cultural or religious gatherings, or with transportation, except for carpooling (aOR: 1•47; 95%CI: 1•28-1•69). Teleworking was associated with decreased risk of infection (aOR: 0•65; 95%CI: 0•56-0•75).

Interpretation: Places and activities during which infection prevention and control measures may be difficult to fully enforce were those with increased risk of infection. Children attending day-care, kindergarten, middle and high schools, but not primary schools, were potential sources of infection for the household.

Funding: Institut Pasteur, Research & Action Emerging Infectious Diseases (REACTing), Fondation de France (Alliance" Tous unis contre le virus").

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Conflict of interest statement

AF and SC are members of the COVID-19 Scientific Advisory Council to the Government of France. All other authors have nothing to declare.

Figures

Fig. 1
Fig. 1
Timeline showing the epidemic curve of positive SARS-CoV-2 cases in France, as well as the periods covering the different control measures in France, and the period covered by the questionnaires sent to the study participants.
See this image and copyright information in PMC

References

    1. Zhu N., Zhang D., Wang W. A Novel Coronavirus from Patients with Pneumonia in China, 2019. N Engl J Med. 2020;382:727–733. - PMC - PubMed
    1. Flaxman S., Mishra S., Gandy A. Estimating the effects of non-pharmaceutical interventions on COVID-19 in Europe. Nature. 2020;584:257–261. - PubMed
    1. Salje H., Tran Kiem C., Lefrancq N. Estimating the burden of SARS-CoV-2 in France. Science. 2020;369:208–211. - PMC - PubMed
    1. World Health Organization.Transmission of SARS-CoV-2: implications for infection prevention precautions [Internet] 2020. Available from: https://www.who.int/publications-detail-redirect/modes-of-transmission-o...
    1. Alwan N.A., Burgess R.A., Ashworth S. Scientific consensus on the COVID-19 pandemic: we need to act now. Lancet. 2020;396:e71–e72. - PMC - PubMed