Metadata about: Introduction and Goals: SARS-CoV-2 is transmitted both in the community and within households. Social distancing and lockdowns reduce community transmission but do not directly address household transmission. We provide quantitative measures of household transmission based on empirical data, and estimate the contribution of households to overall spread. We highlight policy implications from our analysis of household transmission, and more generally, of changes in contact patterns under social distancing. Methods: We investigate the household secondary attack rate (SAR) for SARS-CoV-2, as well as R_h, which is the average number of within-household infections caused by a single index case. We estimate the SAR through a meta-analysis of previous studies. Taking a Bayesian approach, we correct estimates for the false-negative rate (FNR) of testing and compute posterior credible intervals for SAR. We estimate R_h using results from population testing in Vo', Italy and contact tracing data that we curate from Singapore. The code and data behind our analysis are publicly available at: https://github.com/andrewilyas/covid-household-transmission. Results: Our analysis of eight recent attack rate studies yields an SAR estimate of 0.28 (0.10, 0.61). From contact tracing data, we infer an R_h value of 0.32 (0.22, 0.42). Blanket testing data from Vo' yields an R_h estimate of 0.37 (0.34, 040) and a CRI estimate of 0.5 after correcting for FNR and asymptomatic cases. Interpretation: Our estimates of R_h suggest that household transmission was a small fraction (5%-35%) of R before social distancing but a large fraction after (30%-55%). This suggests that household transmission may be an effective target for interventions. A remaining uncertainty is whether household infections actually contribute to further community transmission or are contained within households. This can be estimated given high-quality contact tracing data. More broadly, our study points to emerging contact patterns (i.e., increased time at home relative to the community) playing a role in transmission of SARS-CoV-2. We briefly highlight another instance of this phenomenon (differences in contact between essential workers and the rest of the population), provide coarse estimates of its effect on transmission, and discuss how future data could enable a more reliable estimate.

Graph IRI	Count
http://ns.inria.fr/covid19/graph/entityfishing	8
http://ns.inria.fr/covid19/graph/articles	3

Faceted Search & Find service v1.13.91

This work is licensed under a Creative Commons Attribution-Share Alike 3.0 Unported License.
OpenLink Virtuoso version 07.20.3229 as of Jul 10 2020, on Linux (x86_64-pc-linux-gnu), Single-Server Edition (94 GB total memory)
Copyright © 2009-2024 OpenLink Software