Inferring Risks of Coronavirus Transmission from Community Household Data

The response of many governments to the COVID-19 pandemic has involved measures to control within- and between-household transmission, providing motivation to improve understanding of the absolute and relative risks in these contexts. Here, we perform exploratory, residual-based, and transmission-dynamic household analysis of the Office for National Statistics (ONS) COVID-19 Infection Survey (CIS) data from 26 April 2020 to 8 March 2021 in England. This provides evidence for: (i) temporally varying rates of introduction of infection into households broadly following the trajectory of the overall epidemic; (ii) Susceptible-Infectious Transmission Probabilities (SITPs) of within-household transmission in the 15-35% range; (iii) the emergence of the B.1.1.7 variant, being around 50% more infectious within households; (iv) significantly (in the range 25-300%) more risk of bringing infection into the household for workers in patient-facing roles; (v) increased risk for secondary school-age children of bringing the infection into the household when schools are open (in the range 64-235%); (vi) increased risk for primary school-age children of bringing the infection into the household when schools were open in late autumn 2020 (around 40%).