School of Population and Global Health, McGill University, Montreal, Canada.
Canadian Blood Services, Ottawa, Canada.
Int J Epidemiol. 2024 Apr 11;53(3). doi: 10.1093/ije/dyae078.
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.
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.
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.
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.
在加拿大最大的 COVID-19 血清学研究中，自 2020 年以来一直在监测献血者血液中的 SARS-CoV-2 抗体。没有研究分析过在大流行期间，抗-N 血清阳性（近期感染的标志物）与地理和社会人口特征之间的关联变化。
使用具有空间效应的贝叶斯多层次模型，并以普查分区为水平，我们分析了在不同变体占主导地位的三个时期（Delta 之前、Delta 和奥密克戎期间）中，SARS-CoV-2 抗-N 血清阳性的相关性变化。我们按地理区域、个体特征（年龄、性别、种族）和社区因素（城市化、物质匮乏和社会匮乏）分析了差异。数据来自 2020 年 12 月至 2022 年 11 月期间来自四个地区（安大略省、不列颠哥伦比亚省[BC]、草原地区和大西洋地区）的 420319 份献血。
在 Delta 和 Delta 波期间，少数族裔、男性和物质匮乏社区的个体的血清阳性率更高。随着大量人群感染，这些亚组差异在奥密克戎波中消失了。在所有波中，血清阳性率在年轻个体和社会剥夺程度较低的个体中较高。草原地区的农村居民血清阳性率较高，但在其他地区则不然。与广义线性模型相比，具有空间效应的多层次模型在预测 SARS-CoV-2 抗-N 血清阳性率的地理区域时具有更好的拟合度和更低的误差。
近期 COVID-19 感染的相关因素在大流行期间发生了演变。在奥密克戎波期间，许多差异有所减少，但可能需要采取公共卫生干预措施，以解决年轻人和社会剥夺程度较低的人负担过重的问题。
