Changes in contact patterns shape the dynamics of the COVID-19 outbreak in China

Intense non-pharmaceutical interventions were put in place in China to stop
transmission of the novel coronavirus disease (COVID-19). As transmission intensifies
in other countries, the interplay between age, contact patterns, social distancing,
susceptibility to infection, and COVID-19 dynamics remains unclear. To answer these
questions, we analyze contact surveys data for Wuhan and Shanghai before and during
the outbreak and contact tracing information from Hunan Province. Daily contacts were
reduced 7-8-fold during the COVID-19 social distancing period, with most interactions
restricted to the household. We find that children 0-14 years are less susceptible to
SARS-CoV-2 infection than adults 15-64 years of age (odds ratio 0.34, 95%CI 0.24-0.49),
while in contrast, individuals over 65 years are more susceptible to infection (odds ratio
1.47, 95%CI: 1.12-1.92). Based on these data, we build a transmission model to study
the impact of social distancing and school closure on transmission. We find that social
distancing alone, as implemented in China during the outbreak, is sufficient to control
COVID-19. While proactive school closures cannot interrupt transmission on their own,
they can reduce peak incidence by 40-60% and delay the epidemic.

*Full text link:
https://science.sciencemag.org/content/early/2020/05/04/science.abb8001