The French Connection: The First Large Population-Based Contact Survey in France Relevant for the Spread of Infectious Diseases

PLoS One. 2015 Jul 15;10(7):e0133203. doi: 10.1371/journal.pone.0133203. eCollection 2015.


Background: Empirical social contact patterns are essential to understand the spread of infectious diseases. To date, no such data existed for France. Although infectious diseases are frequently seasonal, the temporal variation of contact patterns has not been documented hitherto.

Methods: COMES-F is the first French large-scale population survey, carried out over 3 different periods (February-March, April, April-May) with some participants common to the first and the last period. Participants described their contacts for 2 consecutive days, and reported separately on professional contacts when typically over 20 per day.

Results: 2033 participants reported 38 881 contacts (weighted median [first quartile-third quartile]: 8[5-14] per day), and 54 378 contacts with supplementary professional contacts (9[5-17]). Contrary to age, gender, household size, holidays, weekend and occupation, period of the year had little influence on the number of contacts or the mixing patterns. Contact patterns were highly assortative with age, irrespective of the location of the contact, and gender, with women having 8% more contacts than men. Although most contacts occurred at home and at school, the inclusion of professional contacts modified the structure of the mixing patterns. Holidays and weekends reduced dramatically the number of contacts, and as proxies for school closure, reduced R0 by 33% and 28%, respectively. Thus, school closures could have an important impact on the spread of close contact infections in France.

Conclusions: Despite no clear evidence for temporal variation, trends suggest that more studies are needed. Age and gender were found important determinants of the mixing patterns. Gender differences in mixing patterns might help explain gender differences in the epidemiology of infectious diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Child
  • Child, Preschool
  • Communicable Diseases / epidemiology*
  • Communicable Diseases / transmission
  • Female
  • France / epidemiology
  • Holidays
  • Humans
  • Infant
  • Male
  • Middle Aged
  • Schools
  • Seasons
  • Surveys and Questionnaires
  • Young Adult

Grants and funding

GlaxoSmithKline provided an unconditional grant to Université Catholique de Lille to which belong SK. GB acknowledges support from a bilateral special research fund from Hasselt University (BOF14BL07). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.