Figure 1.

Flow chart of the clinical research on the contagiousness of children and adults with COVID-19. This cohort study enrolled all 46 pediatric patients admitted to 8 hospitals in Zhejiang Province between 21 January and 29 February 2020. The study enrolled a total of 211 individuals, including 202 family members (from 40 families) and 1 pediatric case with 8 close contacts in a residential school. Four eligible individuals were excluded as the first-generation cases of this family, including both adult and child cases, and 211 individuals were divided into 3 groups according to the first-generation case. The secondary attack rate and R₀ were compared among the groups.