Predictors of incident SARS-CoV-2 infections in an international prospective cohort study

Gregory Nah; Eric Vittinghoff; Gregory M Marcus; David Wen; Anthony Lin; Jeffrey Olgin; Noah Peyser; Sidney Aung; Sean Joyce; Vivian Yang; Janet Hwang; Robert Avram; Geoffrey H Tison; Alexis Beatty; Ryan Runge; Xochitl Butcher; Cathy Horner; Helena Eitel; Mark Pletcher

doi:10.1136/bmjopen-2021-052025

BMJ Open (Sep 2021)

Predictors of incident SARS-CoV-2 infections in an international prospective cohort study

Gregory Nah,
Eric Vittinghoff,
Gregory M Marcus,
David Wen,
Anthony Lin,
Jeffrey Olgin,
Noah Peyser,
Sidney Aung,
Sean Joyce,
Vivian Yang,
Janet Hwang,
Robert Avram,
Geoffrey H Tison,
Alexis Beatty,
Ryan Runge,
Xochitl Butcher,
Cathy Horner,
Helena Eitel,
Mark Pletcher

Affiliations

Gregory Nah: Department of Medicine, University of California San Francisco, San Francisco, California, USA
Eric Vittinghoff: 2 Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California, USA
Gregory M Marcus: 3 Department of Cardiac Electrophysiology, Division of Cardiology, University of California San Francisco, San Francisco, California, USA
David Wen: Department of Medicine, University of California San Francisco, San Francisco, California, USA
Anthony Lin: Department of Pathology, Weill Cornell Medical College, New York, New York, USA
Jeffrey Olgin: Department of Medicine, University of California San Francisco, San Francisco, California, USA
Noah Peyser: Department of Medicine, University of California San Francisco, San Francisco, California, USA
Sidney Aung: Department of Medicine, University of California San Francisco, San Francisco, California, USA
Sean Joyce: Department of Medicine, University of California San Francisco, San Francisco, California, USA
Vivian Yang: Department of Medicine, University of California San Francisco, San Francisco, California, USA
Janet Hwang: Department of Medicine, University of California San Francisco, San Francisco, California, USA
Robert Avram: Department of Medicine, University of California San Francisco, San Francisco, California, USA
Geoffrey H Tison: Department of Medicine, University of California San Francisco, San Francisco, California, USA
Alexis Beatty: Department of Medicine, University of California San Francisco, San Francisco, California, USA
Ryan Runge: Department of Medicine, University of California San Francisco, San Francisco, California, USA
Xochitl Butcher: Department of Medicine, University of California San Francisco, San Francisco, California, USA
Cathy Horner: Department of Medicine, University of California San Francisco, San Francisco, California, USA
Helena Eitel: Department of Medicine, University of California San Francisco, San Francisco, California, USA
Mark Pletcher: Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California, USA

DOI: https://doi.org/10.1136/bmjopen-2021-052025
Journal volume & issue: Vol. 11, no. 9

Abstract

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Objective Until effective treatments and vaccines are made readily and widely available, preventative behavioural health measures will be central to the SARS-CoV-2 public health response. While current recommendations are grounded in general infectious disease prevention practices, it is still not entirely understood which particular behaviours or exposures meaningfully affect one’s own risk of incident SARS-CoV-2 infection. Our objective is to identify individual-level factors associated with one’s personal risk of contracting SARS-CoV-2.Design Prospective cohort study of adult participants from 26 March 2020 to 8 October 2020.Setting The COVID-19 Citizen Science Study, an international, community and mobile-based study collecting daily, weekly and monthly surveys in a prospective and time-updated manner.Participants All adult participants over the age of 18 years were eligible for enrolment.Primary outcome measure The primary outcome was incident SARS-CoV-2 infection confirmed via PCR or antigen testing.Results 28 575 unique participants contributed 2 479 149 participant-days of data across 99 different countries. Of these participants without a history of SARS-CoV-2 infection at the time of enrolment, 112 developed an incident infection. Pooled logistic regression models showed that increased age was associated with lower risk (OR 0.98 per year, 95% CI 0.97 to 1.00, p=0.019), whereas increased number of non-household contacts (OR 1.10 per 10 contacts, 95% CI 1.01 to 1.20, p=0.024), attending events of at least 10 people (OR 1.26 per 10 events, 95% CI 1.07 to 1.50, p=0.007) and restaurant visits (OR 1.95 per 10 visits, 95% CI 1.42 to 2.68, p<0.001) were associated with significantly higher risk of incident SARS-CoV-2 infection.Conclusions Our study identified three modifiable health behaviours, namely the number of non-household contacts, attending large gatherings and restaurant visits, which may meaningfully influence individual-level risk of contracting SARS-CoV-2.

Published in BMJ Open

ISSN: 2044-6055 (Online)
Publisher: BMJ Publishing Group
Country of publisher: United Kingdom
LCC subjects: Medicine
Website: https://bmjopen.bmj.com

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