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Infectivity, susceptibility, and risk factors associated with SARS-CoV-2 transmission under intensive contact tracing in Hunan, China

Authors :
Lu Liang
Kai Wang
Xinghui Chen
Zhiyuan Chen
Wei Wang
Marco Ajelli
Ziyan Liu
Kaiwei Luo
Yonghong Zhou
Huilin Shi
Hongjie Yu
Jinxin Guo
Wen Zheng
Alessandro Vespignani
Lidong Gao
Xinhua Chen
Yan Wang
Cécile Viboud
Lingshuang Ren
Han Yan
Jing Li
Maria Litvinova
Shixiong Hu
Kaiyuan Sun
Zhihong Deng
Mei Li
Ge Zeng
Hao Yang
Qianlai Sun
Source :
Nature Communications, Vol 12, Iss 1, Pp 1-11 (2021), Nature Communications, medRxiv
Publication Year :
2021
Publisher :
Nature Portfolio, 2021.

Abstract

Several mechanisms driving SARS-CoV-2 transmission remain unclear. Based on individual records of 1178 potential SARS-CoV-2 infectors and their 15,648 contacts in Hunan, China, we estimated key transmission parameters. The mean generation time was estimated to be 5.7 (median: 5.5, IQR: 4.5, 6.8) days, with infectiousness peaking 1.8 days before symptom onset, with 95% of transmission events occurring between 8.8 days before and 9.5 days after symptom onset. Most transmission events occurred during the pre-symptomatic phase (59.2%). SARS-CoV-2 susceptibility to infection increases with age, while transmissibility is not significantly different between age groups and between symptomatic and asymptomatic individuals. Contacts in households and exposure to first-generation cases are associated with higher odds of transmission. Our findings support the hypothesis that children can effectively transmit SARS-CoV-2 and highlight how pre-symptomatic and asymptomatic transmission can hinder control efforts.<br />Detailed knowledge of COVID-19 epidemiology is needed to inform public health responses. Here, the authors use large-scale contact tracing data to provide empirical estimates of key parameters, and show that susceptibility increases with age but transmissibility does not vary significantly.

Details

Language :
English
ISSN :
20411723
Volume :
12
Issue :
1
Database :
OpenAIRE
Journal :
Nature Communications
Accession number :
edsair.doi.dedup.....df0f4cd8ee917fdbc365d78654150a67