Increased close proximity airborne transmission of the SARS-CoV-2 Delta variant

Alex Mikszewski; Luca Stabile; Giorgio Buonanno; Lidia Morawska

doi:10.1016/j.scitotenv.2021.151499

Increased close proximity airborne transmission of the SARS-CoV-2 Delta variant

Sci Total Environ. 2022 Apr 10:816:151499. doi: 10.1016/j.scitotenv.2021.151499. Epub 2021 Nov 6.

Authors

Alex Mikszewski¹, Luca Stabile², Giorgio Buonanno³, Lidia Morawska⁴

Affiliations

¹ International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Qld, Australia; CIUS Building Performance Lab, The City University of New York, New York 10001, NY, USA.
² Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, FR, Italy.
³ International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Qld, Australia; Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, FR, Italy.
⁴ International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Qld, Australia; Global Centre for Clean Air Research (GCARE), Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom.. Electronic address: l.morawska@qut.edu.au.

Abstract

The Delta variant of SARS-CoV-2 causes higher viral loads in infected hosts, increasing the risk of close proximity airborne transmission through breathing, speaking and coughing. We performed a Monte Carlo simulation using a social contact network and exponential dose-response model to quantify the close proximity reproduction number of both wild-type SARS-CoV-2 and the Delta variant. We estimate more than twice as many Delta variant cases will reproduce infection in their close proximity contacts (64%) versus the wild-type SARS-CoV-2 (29%). Occupational health guidelines must consider close proximity airborne transmission and recommend improved personal respiratory protection for high-risk workers.

Keywords: Airborne transmission; Close contact; Overdispersion; SARS-CoV-2 Delta variant.

MeSH terms

COVID-19*
Humans
SARS-CoV-2*

Supplementary concepts

SARS-CoV-2 variants