Prediction of SARS-CoV-2 transmission dynamics based on population-level cycle threshold values: An epidemic transmission and machine learning modeling study

  1. Afraz Arif Khan
  2. Hind Sbihi
  3. Michael A Irvine
  4. Agatha N Jassem
  5. Yayuk Joffres
  6. Braeden Klaver
  7. Naveed Janjua
  8. Aamir Bharmal
  9. Carmen H Ng
  10. Chris D Fjell
  11. Miguel Imperial
  12. Amanda Wilmer
  13. John Galbraith
  14. Marc G Romney
  15. Bonnie Henry
  16. Linda MN Hoang
  17. Mel Krajden
  18. Catherine A Hogan  Is a corresponding author
  1. BC Centre for Disease Control, Canada
  2. Fraser Health, Canada
  3. LifeLabs, Canada
  4. Kelowna General Hospital, Canada
  5. Victoria General Hospital, Canada
  6. St. Paul's Hospital, Canada
  7. Ministry of Health, Canada

Abstract

Polymerase chain reaction (PCR) cycle threshold (Ct) values can be used to estimate the viral burden of Severe Acute Respiratory Syndrome Coronavirus type 2 (SARS-CoV-2) and predict population-level epidemic trends. We investigated the use of epidemic transmission modeling and machine learning (ML) based on Ct value distribution for SARS-CoV-2 incidence prediction in British Columbia, Canada during an Omicron subvariant BA.1-predominant period from November 2021 to January 2022. Using real-world data, we developed an epidemic transmission model that was first validated on outbreak data, and subsequently fitted to province-level data to predict incidence. Using simulated data, we developed a ML pipeline including five models to predict the reproductive number as a measure of transmission potential based on Ct value distribution, and validated it on out-of-sample province-level data. The epidemic transmission model demonstrated accurate prediction with the real incidence falling within the 95% credible interval of the predicted MCMC chains for both the long-term care facility outbreak, and province-level data. The ML models demonstrated good performance with a median mean squared error (MSE) lower than 0.17 across all models, and improved performance with increasing sample size. The variability of the Ct distribution around the mean was the strongest predictor of the reproductive number. These modeling approaches demonstrated utility for incidence and reproductive number prediction, and have potential to complement traditional surveillance in real time to guide public health interventions.

Data availability

The genomic sequencing data are publicly available in GISAID under the submitter British Columbia Center for Disease Control Public Health Laboratory (BCCDC PHL). The individual level demographic and epidemiological data can be made accessible following the data governance and data access policy guidelines (http://www.bccdc.ca/about/accountability/data-access-requests). The code for this study is available separately (https://github.com/Afraz496/Vital-E-paper).

Article and author information

Author details

  1. Afraz Arif Khan

    BC Centre for Disease Control, Vancouver, Canada
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5545-2851
  2. Hind Sbihi

    BC Centre for Disease Control, Vancouver, Canada
    Competing interests
    No competing interests declared.
  3. Michael A Irvine

    BC Centre for Disease Control, Vancouver, Canada
    Competing interests
    No competing interests declared.
  4. Agatha N Jassem

    BC Centre for Disease Control, Vancouver, Canada
    Competing interests
    No competing interests declared.
  5. Yayuk Joffres

    BC Centre for Disease Control, Vancouver, Canada
    Competing interests
    No competing interests declared.
  6. Braeden Klaver

    BC Centre for Disease Control, Vancouver, Canada
    Competing interests
    No competing interests declared.
  7. Naveed Janjua

    BC Centre for Disease Control, Vancouver, Canada
    Competing interests
    No competing interests declared.
  8. Aamir Bharmal

    BC Centre for Disease Control, Vancouver, Canada
    Competing interests
    No competing interests declared.
  9. Carmen H Ng

    Fraser Health, Vancouver, Canada
    Competing interests
    No competing interests declared.
  10. Chris D Fjell

    BC Centre for Disease Control, Vancouver, Canada
    Competing interests
    No competing interests declared.
  11. Miguel Imperial

    LifeLabs, Surrey, Canada
    Competing interests
    Miguel Imperial, Miguel Imperial is affiliated with LifeLabs. The author has no other competing interests to declare..
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4061-7940
  12. Amanda Wilmer

    Division of Medical Microbiology, Kelowna General Hospital, Kelowna, Canada
    Competing interests
    No competing interests declared.
  13. John Galbraith

    Division of Microbiology and Molecular Diagnostics, Victoria General Hospital, Victoria, Canada
    Competing interests
    No competing interests declared.
  14. Marc G Romney

    Division of Medical Microbiology and Virology, St. Paul's Hospital, Vancouver, Canada
    Competing interests
    No competing interests declared.
  15. Bonnie Henry

    Ministry of Health, Victoria, Canada
    Competing interests
    No competing interests declared.
  16. Linda MN Hoang

    BC Centre for Disease Control, Vancouver, Canada
    Competing interests
    No competing interests declared.
  17. Mel Krajden

    BC Centre for Disease Control, Vancouver, Canada
    Competing interests
    No competing interests declared.
  18. Catherine A Hogan

    BC Centre for Disease Control, Vancouver, Canada
    For correspondence
    catherine.hogan@bccdc.ca
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-1977-253X

Funding

BCCDC Foundation for Public Health (Public Health Rapid SARS-CoV-2 Vaccine Research Initiative in BC)

  • Catherine A Hogan

Genome British Columbia (Public Health Rapid SARS-CoV-2 Vaccine Research Initiative in BC)

  • Catherine A Hogan

Michael Smith Health Research BC (Public Health Rapid SARS-CoV-2 Vaccine Research Initiative in BC)

  • Catherine A Hogan

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Copyright

© 2026, Khan et al.

This article is distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use and redistribution provided that the original author and source are credited.

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  1. Afraz Arif Khan
  2. Hind Sbihi
  3. Michael A Irvine
  4. Agatha N Jassem
  5. Yayuk Joffres
  6. Braeden Klaver
  7. Naveed Janjua
  8. Aamir Bharmal
  9. Carmen H Ng
  10. Chris D Fjell
  11. Miguel Imperial
  12. Amanda Wilmer
  13. John Galbraith
  14. Marc G Romney
  15. Bonnie Henry
  16. Linda MN Hoang
  17. Mel Krajden
  18. Catherine A Hogan
(2026)
Prediction of SARS-CoV-2 transmission dynamics based on population-level cycle threshold values: An epidemic transmission and machine learning modeling study
eLife 15:e95666.
https://doi.org/10.7554/eLife.95666

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https://doi.org/10.7554/eLife.95666