Social contact patterns during the COVID-19 pandemic in 21 European countries – evidence from a two-year study

Abstract

Most countries have enacted some restrictions to reduce social contacts to slow down disease transmission during the COVID-19 pandemic. For nearly two years, individuals likely also adopted new behaviours to avoid pathogen exposure based on personal circumstances. We aimed to understand the way in which different factors affect social contacts, a critical step to improving future pandemic responses. The analysis was based on repeated cross-sectional contact survey data collected in 21 European countries between March 2020 and March 2022. We calculated the mean daily contacts reported using a clustered bootstrap by country and by settings (at home, at work, or in other settings). Where data were available, contact rates during the study period were compared with rates recorded prior to the pandemic. We fitted censored individual-level generalized additive mixed models to examine the effects of various factors on the number of social contacts. The survey recorded 463,336 observations from 96,456 participants. In all countries where comparison data were available, contact rates over the previous two years were substantially lower than those seen prior to the pandemic (approximately from over 10 to <5), predominantly due to fewer contacts outside the home. Government restrictions imposed immediate effect on contacts, and these effects lingered after the restrictions were lifted. Across countries, the relationships between national policy, individual perceptions, or personal circumstances determining contacts varied. Our study, coordinated at the regional level, provides important insights into the understanding of the factors associated with social contacts to support future infectious disease outbreak responses.

Dynamics of non-household contacts during the COVID-19 pandemic in 2020 and 2021 in the Netherlands

“…Participants tend to report fewer contacts when they participate in more rounds. This fatigue effect is also seen in the CoMix data of other countries, but the fatigue effect in the Netherlands is found to be extreme compared to these 30 . A complicating factor in interpreting the fatigue effect is that the participant rounds are not equally distributed over the study period.…”

Dynamics of non-household contacts during the COVID-19 pandemic in 2020 and 2021 in the Netherlands

“…Participants tend to report fewer contacts when they participate in more rounds. This fatigue effect is also seen in the CoMix data of other countries, but the fatigue effect in the Netherlands is found to be extreme compared to these 24 . A complicating factor in interpreting the fatigue effect is that the participant rounds are not equally distributed over the study period.…”

Repetition in Social Contact Interactions: Implications in Modelling the Transmission of Respiratory Infectious Diseases in Pre-pandemic & Pandemic Settings

“…Considering the temporal aspect of contact interactions, especially in epidemiological contexts characterised by a high frequency of contact repetition, such as schools and workplaces, could provide valuable insights to develop intervention strategies in these locations. Furthermore, we identified an increase in the proportion of daily contacts, along with a decrease in the total number of contacts during the COVID-19 pandemic, likely caused by the non-pharmaceutical interventions in place at the time [9]. This finding can provide useful insights into setting population-level interventions for future epidemic or pandemic threats, and further underlines the importance of collecting comprehensive contact data in various settings, ensuring a better understanding of different human interactions.…”