1887
  1. Home
  2. Eurosurveillance
  3. Volume 26, Issue 50, 16/Dec/2021
  4. Article
Surveillance Open Access
Like 0
Download

Abstract

Background

Serosurveys for SARS-CoV-2 aim to estimate the proportion of the population that has been infected.

Aim

This observational study assesses the seroprevalence of SARS-CoV-2 antibodies in Ontario, Canada during the first pandemic wave.

Methods

Using an orthogonal approach, we tested 8,902 residual specimens from the Public Health Ontario laboratory over three time periods during March–June 2020 and stratified results by age group, sex and region. We adjusted for antibody test sensitivity/specificity and compared with reported PCR-confirmed COVID-19 cases.

Results

Adjusted seroprevalence was 0.5% (95% confidence interval (CI): 0.1–1.5) from 27 March–30 April, 1.5% (95% CI: 0.7–2.2) from 26–31 May, and 1.1% (95% CI: 0.8–1.3) from 5–30 June 2020. Adjusted estimates were highest in individuals aged ≥ 60 years in March–April (1.3%; 95% CI: 0.2–4.6), in those aged 20–59 years in May (2.1%; 95% CI: 0.8–3.4) and in those aged ≥ 60 years in June (1.6%; 95% CI: 1.1–2.1). Regional seroprevalence varied, and was highest for Toronto in March–April (0.9%; 95% CI: 0.1–3.1), for Toronto in May (3.2%; 95% CI: 1.0–5.3) and for Toronto (1.5%; 95% CI: 0.9–2.1) and Central East in June (1.5%; 95% CI: 1.0–2.0). We estimate that COVID-19 cases detected by PCR in Ontario underestimated SARS-CoV-2 infections by a factor of 4.9.

Conclusions

Our results indicate low population seroprevalence in Ontario, suggesting that public health measures were effective at limiting the spread of SARS-CoV-2 during the first pandemic wave.

© Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Loading

Article metrics loading...

/content/10.2807/1560-7917.ES.2021.26.50.2001559
2021-12-16
2024-11-23
http://instance.metastore.ingenta.com/content/10.2807/1560-7917.ES.2021.26.50.2001559
Loading
Loading full text...

Full text loading...

/deliver/fulltext/eurosurveillance/26/50/eurosurv-26-50-6.html?itemId=/content/10.2807/1560-7917.ES.2021.26.50.2001559&mimeType=html&fmt=ahah

References

  1. ProMED-mail. Undiagnosed pneumonia - China (Hubei): Request for information. International Society for Infectious Diseases. 30 Dec 2019. Available from: https://promedmail.org/promed-post/?id=6864153
  2. World Health Organization (WHO). Coronavirus disease (COVID-2019) situation reports. Geneva: WHO; 2019. Available from: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/situation-reports
  3. Ontario Ministry of Health. Emergency planning and preparedness COVID-19 - Coronavirus disease. Toronto: Ontario Ministry of Health. [Accessed: 7 Aug 2020]. Available from: http://www.health.gov.on.ca/en/pro/programs/publichealth/coronavirus/2019_coronavirus.aspx
  4. Marchand-Senécal X, Kozak R, Mubareka S, Salt N, Gubbay JB, Eshaghi A, et al. Diagnosis and management of first case of COVID-19 in Canada: lessons applied from SARS-CoV-1. Clin Infect Dis. 2020;71(16):2207-10.  https://doi.org/10.1093/cid/ciaa227  PMID: 32147731 
  5. Ontario Ministry of Health. Enhanced public health measures for COVID-19. Toronto: Ontario Ministry of Health; 2020. Available from: http://www.health.gov.on.ca/en/pro/programs/publichealth/coronavirus/docs/memos/CMOH_Memo_Enhanced_Public_Health_Measures_for_COVID-19_March_12_2020.pdf
  6. Government of Canada. Prime Minister announces temporary border agreement with the United States. Ottawa: Government of Canada; 2020. Available from: https://pm.gc.ca/en/news/news-releases/2020/03/20/prime-minister-announces-temporary-border-agreement-united-states
  7. Public Health Ontario (PHO). Daily Epidemiological Summary: COVID-19 in Ontario: January 15, 2020 to July 31, 2020. Toronto: PHO; 2020. Available from: https://files.ontario.ca/moh-covid-19-report-en-2020-08-01.pdf
  8. Li R, Pei S, Chen B, Song Y, Zhang T, Yang W, et al. Substantial undocumented infection facilitates the rapid dissemination of novel coronavirus (SARS-CoV-2). Science. 2020;368(6490):489-93.  https://doi.org/10.1126/science.abb3221  PMID: 32179701 
  9. Lee S, Kim T, Lee E, Lee C, Kim H, Rhee H, et al. Clinical course and molecular viral shedding among asymptomatic and symptomatic patients with SARS-CoV-2 Infection in a community treatment center in the Republic of Korea. JAMA Intern Med. 2020;180(11):1447-52.  https://doi.org/10.1001/jamainternmed.2020.3862  PMID: 32780793 
  10. Government of Canada. Statement from Health Canada on COVID-19 serological tests. Ottawa: Government of Canada; 2020. Available from: https://www.canada.ca/en/health-canada/news/2020/05/statement-from-health-canada-on-covid-19-serological-tests.html
  11. Centers for Disease Control and Prevention (CDC). Serology surveillance strategy. Atlanta: CDC. [Accessed: 7 Aug 2020]. Available from: https://www.cdc.gov/coronavirus/2019-ncov/covid-data/serology-surveillance/index.html
  12. World Health Organization (WHO). Population-based age-stratified seroepidemiological investigation protocol for COVID-19 virus infection, 17 March 2020. Geneva: WHO; 2020. Available from: https://apps.who.int/iris/handle/10665/331656
  13. Public Health Ontario (PHO). COVID-19 Seroprevalence in Ontario: March 27, 2020 to June 30, 2020. Toronto: PHO; 2020. Available from: https://www.publichealthontario.ca/-/media/documents/ncov/epi/2020/07/covid-19-epi-seroprevalence-in-ontario.pdf?la=en
  14. Centers for Disease Control and Prevention (CDC). Interim Guidelines for COVID-19 Antibody Testing. Atlanta: CDC; 2020. Available from: https://www.cdc.gov/coronavirus/2019-ncov/lab/resources/antibody-tests-guidelines.html
  15. Ontario Ministry of Health and Long-Term Care: IntelliHEALTH ONTARIO. Population estimates (2007-2020) and projections (2020).
  16. Public Health England (PHE). Evaluation of the Abbott SARS-CoV-2 IgG for the detection of anti-SARS-CoV-2 antibodies. London: PHE; 2020. Available from: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/890566/Evaluation_of_Abbott_SARS_CoV_2_IgG_PHE.pdf
  17. Van Caeseele P, Bailey D, Forgie SE, Dingle TC, Krajden M, Canadian Public Health Laboratory Network, et al.SARS-CoV-2 (COVID-19) serology: implications for clinical practice, laboratory medicine and public health. CMAJ. 2020;192(34):E973-9.  https://doi.org/10.1503/cmaj.201588  PMID: 32753391 
  18. University of Toronto. Ontario COVID-19 Health System Response. Toronto: University of Toronto; 2021. Available from: https://jcb.utoronto.ca/wp-content/uploads/2021/05/Ontario-COVID-19-Health-System-Response-Bioethics-Table-Charter-and-Terms-of-Reference.pdf
  19. Public Health Ontario (PHO). Daily epidemiologic summary. COVID-19 in Ontario: January 15, 2020 to June 16, 2020. Toronto: PHO; 2020. Available from: https://files.ontario.ca/moh-covid-19-report-en-2020-06-17.pdf
  20. Statistics Canada. Population estimates, quarterly (Table 17-10-0009-01). Ottawa: Statistics Canada. [Accessed: 5 Aug 2020]. Available from: https://www150.statcan.gc.ca/t1/tbl1/en/tv.action?pid=1710000901
  21. Public Health Ontario (PHO). Epidemiological summary. Evolution of COVID-19 case growth in Ontario. Toronto: PHO; 2020. Available from: https://www.publichealthontario.ca/-/media/documents/ncov/epi/covid-19-epi-evolution-case-growth-ontario.pdf?la=en
  22. Public Health Ontario (PHO). Enhanced epidemiological summary. COVID-19 case fatality, case identification, and attack rates in Ontario. Toronto: PHO; 2020. Available from: https://www.publichealthontario.ca/-/media/documents/ncov/epi/2020/06/covid19-epi-case-identification-age-only-template.pdf?la=en
  23. COVID-19 Immunity Task Force. COVID-19 Seroprevalence Report – August 19, 2020. Montréal: COVID-19 Immunity Task Force; 2020. Available from: https://www.covid19immunitytaskforce.ca
  24. Skowronski DM, Sekirov I, Sabaiduc S, Zou M, Morshed M, Lawrence D, et al. Low SARS-CoV-2 sero-prevalence based on anonymized residual sero-survey before and after first wave measures in British Columbia, Canada, March-May 2020. medRxiv. 2020:2020.07.13.20153148. Preprint.  https://doi.org/10.1101/2020.07.13.20153148 
  25. Havers FP, Reed C, Lim T, Montgomery JM, Klena JD, Hall AJ, et al. Seroprevalence of antibodies to SARS-CoV-2 in 10 sites in the United States, March 23-May 12, 2020. JAMA Intern Med. 2020;180(12):1576.  https://doi.org/10.1001/jamainternmed.2020.4130  PMID: 32692365 
  26. Fischer B, Knabbe C, Vollmer T. SARS-CoV-2 IgG seroprevalence in blood donors located in three different federal states, Germany, March to June 2020. Euro Surveill. 2020;25(28).  https://doi.org/10.2807/1560-7917.ES.2020.25.28.2001285  PMID: 32700672 
  27. Norwegian Institute of Public Health. Seroprevalence of SARS-CoV-2 in the Norwegian population measured in residual sera collected in April/May 2020 and August 2019. Oslo: Norwegian Institute of Public Health; 2020. Available from: https://www.fhi.no/en/publ/2020/seroprevalence-of-sars-cov-2-in-the-norwegian-population--measured-in-resid
  28. Stadlbauer D, Tan J, Jiang K, Hernandez M, Fabre S, Amanat F, et al. Seroconversion of a city: Longitudinal monitoring of SARS-CoV-2 seroprevalence in New York City. medRxiv. 2020;2020.06.28.20142190. Preprint.  https://doi.org/10.1101/2020.06.28.20142190 
  29. New York City (NYC) Health. COVID-19: data summary. New York: NYC.gov; 2020. Available from: https://www1.nyc.gov/site/doh/covid/covid-19-data.page
  30. Johns Hopkins University. Developing a national strategy for serology (antibody testing) in the United States. Baltimore: Johns Hopkins University; 2020. Available from: https://www.centerforhealthsecurity.org/our-work/pubs_archive/pubs-pdfs/2020/200422-national-strategy-serology.pdf
  31. Bolotin S, Tran V, Osman S, Brown KA, Buchan SA, Joh E, et al. SARS-CoV-2 seroprevalence survey estimates are affected by anti-nucleocapsid antibody decline. J Infect Dis. 2021;223(8):1334-8.  https://doi.org/10.1093/infdis/jiaa796  PMID: 33400794 
  32. Government of Ontario. How Ontario is responding to COVID-19. Toronto: Government of Ontario; 2020. Available from: https://www.ontario.ca/page/how-ontario-is-responding-covid-19#section-3
  33. Public Health Ontario (PHO). Ontario COVID-19 Data Tool. Toronto: PHO; 2020; Available from: https://www.publichealthontario.ca/en/data-and-analysis/infectious-disease/covid-19-data-surveillance/covid-19-data-tool
  34. Public Health Ontario (PHO). COVID-19 in Ontario: A summary of wave 1 transmission patterns and case identification. Toronto: PHO; 2020. Available from: https://www.publichealthontario.ca/-/media/documents/ncov/epi/2020/08/covid-19-wave-1-transmission-patterns-epi-summary.pdf?la=en
  35. Public Health Ontario (PHO). Technical Notes COVID-19 Data Tool. Toronto: PHO; 2020. Available from: https://www.publichealthontario.ca/-/media/data-files/covid-19-data-tool-technical-notes.pdf?la=en
  36. Office of the Premier. Statement from Premier Ford, Minister Elliott, and Minister Lecce on the 2019 Novel Coronavirus (COVID-19). Toronto: Ontario.ca. 12 March 2020. Available from: https://news.ontario.ca/en/statement/56270/title
  37. Public Health Ontario (PHO). COVID-19 in Ontario: January 15, 2020 to June 30, 2020. Toronto; PHO; 2020. Available from: https://files.ontario.ca/moh-covid-19-report-en-2020-07-01.pdf
Assessment of population infection with SARS-CoV-2 in Ontario, Canada, March to June 2020
<p class="citation"> <span>Citation style for this article:</span> <span class="meta-value authors"> <a href="/search?value1=Shelly+Bolotin&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Bolotin Shelly</a>, <a href="/search?value1=Vanessa+Tran&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Tran Vanessa</a>, <a href="/search?value1=Shelley+L+Deeks&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Deeks Shelley L</a>, <a href="/search?value1=Adriana+Peci&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Peci Adriana</a>, <a href="/search?value1=Kevin+A+Brown&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Brown Kevin A</a>, <a href="/search?value1=Sarah+A+Buchan&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Buchan Sarah A</a>, <a href="/search?value1=Katherene+Ogbulafor&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Ogbulafor Katherene</a>, <a href="/search?value1=Tubani+Ramoutar&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Ramoutar Tubani</a>, <a href="/search?value1=Michelle+Nguyen&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Nguyen Michelle</a>, <a href="/search?value1=Rakesh+Thakkar&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Thakkar Rakesh</a>, <a href="/search?value1=Reynato+DelaCruz&option1=author&noRedirect=true" class="nonDisambigAuthorLink">DelaCruz Reynato</a>, <a href="/search?value1=Reem+Mustfa&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Mustfa Reem</a>, <a href="/search?value1=Jocelyn+Maregmen&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Maregmen Jocelyn</a>, <a href="/search?value1=Orville+Woods&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Woods Orville</a>, <a href="/search?value1=Ted+Krasna&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Krasna Ted</a>, <a href="/search?value1=Kirby+Cronin&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Cronin Kirby</a>, <a href="/search?value1=Selma+Osman&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Osman Selma</a>, <a href="/search?value1=Eugene+Joh&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Joh Eugene</a>, <a href="/search?value1=Vanessa+G+Allen&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Allen Vanessa G</a></span>. Assessment of population infection with SARS-CoV-2 in Ontario, Canada, March to June 2020. <a href="/content/ecdc">Euro Surveill.</a> 2021;26(50):pii=2001559. <a href="https://doi.org/10.2807/1560-7917.ES.2021.26.50.2001559" title="doi link" target="_blank">https://doi.org/10.2807/1560-7917.ES.2021.26.50.2001559</a> <span class="ES_Article_citation"> <span class="generated">Received</span>: 18 Aug 2020;&nbsp;&nbsp; <span class="generated">Accepted</span>: 14 Mar 2021 </span> </p>
/content/10.2807/1560-7917.ES.2021.26.50.2001559
/content/10.2807/1560-7917.ES.2021.26.50.2001559
Loading

Data & Media loading...

Submit comment
Close
Comment moderation successfully completed
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error