Cross-Canada Variability in Blood Donor SARS-CoV-2 Seroprevalence by Social Determinants of Health

O’Brien, Sheila F; Caffrey, Niamh; Yi, Qilong; Bolotin, Shelly; Janjua, Naveed; Binka, Mawuena; Quach, Caroline; Stein, Derek; Lang, Amanda; Colquhoun, Amy; Pambrun, Chantale; Reedman, Cassandra N.; Drews, Steven J.

doi:10.1128/spectrum.03356-22

Cited by 4 publications

(2 citation statements)

References 48 publications

(57 reference statements)

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“…Samples were randomly selected for serologic testing from approximately last two weeks of each month from January 2021 to December 2021 and from all weeks from January 2022 to November 2022. As previously described, 13 a straight random sample was applied until June 2021, after which stratification by age group was applied to enable a smaller monthly sample size. Samples were tested for anti-nucleocapsid antibodies using the Roche Elecsys ® Anti-SARS-CoV-2 assay.…”

Section: Methodsmentioning

confidence: 99%

“… 12–15 Reports found that anti-N seropositivity was associated with younger age, belonging to a visible minority, being from a more materially deprived neighbourhood, or from a less socially deprived neighbourhood. 12 , 13 These findings help to identify disparities in SARS-CoV-2 infection and can inform resource allocation. However, the evolution of correlates of seropositivity through Omicron has not been analysed, urban and rural differences in seropositivity have not been explored, and geographic variability in seropositivity at the sub-provincial level has not been published.…”

Section: Introductionmentioning

confidence: 95%

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Temporal trends in disparities in COVID-19 seropositivity among Canadian blood donors

Yu,

Knight,

Gibson

et al. 2024

International Journal of Epidemiology

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Background In Canada’s largest COVID-19 serological study, SARS-CoV-2 antibodies in blood donors have been monitored since 2020. No study has analysed changes in the association between anti-N seropositivity (a marker of recent infection) and geographic and sociodemographic characteristics over the pandemic. Methods Using Bayesian multi-level models with spatial effects at the census division level, we analysed changes in correlates of SARS-CoV-2 anti-N seropositivity across three periods in which different variants predominated (pre-Delta, Delta and Omicron). We analysed disparities by geographic area, individual traits (age, sex, race) and neighbourhood factors (urbanicity, material deprivation and social deprivation). Data were from 420 319 blood donations across four regions (Ontario, British Columbia [BC], the Prairies and the Atlantic region) from December 2020 to November 2022. Results Seropositivity was higher for racialized minorities, males and individuals in more materially deprived neighbourhoods in the pre-Delta and Delta waves. These subgroup differences dissipated in the Omicron wave as large swaths of the population became infected. Across all waves, seropositivity was higher in younger individuals and those with lower neighbourhood social deprivation. Rural residents had high seropositivity in the Prairies, but not other regions. Compared to generalized linear models, multi-level models with spatial effects had better fit and lower error when predicting SARS-CoV-2 anti-N seropositivity by geographic region. Conclusions Correlates of recent COVID-19 infection have evolved over the pandemic. Many disparities lessened during the Omicron wave, but public health intervention may be warranted to address persistently higher burden among young people and those with less social deprivation.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 95%

Temporal trends in disparities in COVID-19 seropositivity among Canadian blood donors

Yu,

Knight,

Gibson

et al. 2024

International Journal of Epidemiology

View full text Add to dashboard Cite

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SARS-CoV-2 vaccination in Canadian blood donors: Insight into donor representativeness of the general population

O'Brien,

Goldman,

Ehsani-Moghaddam

et al. 2024

Vaccine: X

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Riding high: seroprevalence of SARS-CoV-2 after 4 pandemic waves in Manitoba, Canada, April 2020–February 2022

Duong,

Burtniak,

Gretchen

et al. 2023

BMC Public Health

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Background Canada is emerging from the largest SARS-CoV-2 Omicron wave to date, with over 3.3 million confirmed cases. Unfortunately, PCR confirmed cases illuminate only a small portion of infections in the community and underestimate true disease burden. Population based seroprevalence studies, which measure antibody levels against a virus can more accurately estimate infection rates in the community and identify geographical and epidemiological trends to inform public health responses. Methods The Manitoba COVID-19 Seroprevalence (MCS) study is a population-based cross-sectional study to assess the prevalence of SARS-CoV-2 antibodies across the province. Residual convenience specimens (n = 14,901) were tested for anti-SARS-CoV-2 nucleocapsid and spike IgG antibodies from April 1, 2020 to February 31, 2022. We estimated the monthly and cumulative prevalence using an exponential decay model, accounting for population demographics, sensitivity/specificity, and antibody waning. This approach generated estimates of natural infection as well as total antibody including vaccine-induced immunity within the community. Findings After four waves of the pandemic, 60.1% (95%CI-56.6–63.7) of Manitobans have generated SARS-CoV-2 antibodies due to natural exposure independent of vaccination. Geographical analysis indicates a large portion of provincial prevalence stems from increased transmission in the Northern (92.3%) and Southern (71.8%) regional health authorities. Despite the high mortality rates reported by Manitoba, infection fatality ratios (IFR) peaked at 0.67% and declined to 0.20% following the Omicron wave, indicating parity with other national and international jurisdictions. Manitoba has achieved 93.4% (95%CI- 91.5–95.1) total antibody when including vaccination. Interpretation Our data shows that more than 3 in 5 Manitobans have been infected by SARS-CoV-2 after four waves of the pandemic. This study also identifies key geographical and age specific prevalence rates that have contributed greatly to the overall severity of the pandemic in Manitoba and will inform jurisdictions considering reduction of public health measures.

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Cross-Canada Variability in Blood Donor SARS-CoV-2 Seroprevalence by Social Determinants of Health

Abstract: Canadian blood donors are a healthy adult population that shows clear disparities associated with racialization and material deprivation. This underscores the pervasiveness of the socioeconomic gradient on SARS-CoV-2 infections in Canada.

Cited by 4 publications

References 48 publications

Temporal trends in disparities in COVID-19 seropositivity among Canadian blood donors

Temporal trends in disparities in COVID-19 seropositivity among Canadian blood donors

SARS-CoV-2 vaccination in Canadian blood donors: Insight into donor representativeness of the general population

Riding high: seroprevalence of SARS-CoV-2 after 4 pandemic waves in Manitoba, Canada, April 2020–February 2022

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