Fahim Christine, Wang Siyi, Paul Nimitha, Colwill Karen, Dayam Roya, Boyd Jamie M, Ma Huiting, Gruppuso Vincenza, Mrazovac Ana, Firman Jessica, Patel Anjali, Bach Vanessa, de Launay Keelia Quinn, Takaoka Alyson, Grubac Vanja, Gingras Anne-Claude, Straus Sharon E, Mishra Sharmistha
Li Ka Shing Knowledge Institute, Unity Health Toronto, Toronto, Canada.
Dalla Lana School of Public Health, University of Toronto, Toronto, Canada.
PLOS Glob Public Health. 2025 Mar 28;5(3):e0004294. doi: 10.1371/journal.pgph.0004294. eCollection 2025.
Understanding patterns of SARS-CoV-2 seroprevalence among Long-Term Care Home and Retirement Home (LTCH/RH) staff is critical to designing effective public health interventions. We estimated SARS-CoV-2 seroprevalence among LTCH/RH staff in Ontario, Canada between May 2021-October 2022 using a cross-sectional analysis. Eligible participants completed a demographic questionnaire and provided a dried blood spot sample. Positive seroprevalence was defined as the proportion of individuals in a population who were positive for a SARS-CoV-2 infection, determined using anti-nucleocapsid total IgG antibodies analyzed with a validated chemiluminescent ELISA. We report age-adjusted prevalence ratios [PR; confidence interval, CI] by participant socio-demographic, household, neighbourhood, and occupational characteristics and stratified the analyses over two time periods (period 1: 2021-05-17 to 2021-12-31; period 2: 2022-01-02 to 2022-10-25). A total of 603 staff were included in our analysis; n=235 (39%) were enrolled in period 1 and n=368 (61%) were enrolled in period 2. Seroprevalence was 24% and 44% in periods 1 and 2, respectively. Age-adjusted prevalence ratios were nearly 2-fold higher among Black [PR 1.78; CI 1.28-2.48], East and Southeast Asian [PR 1.55, CI 1.18-2.04] and other racialized participants [PR 1.42, CI 1.03-1.96] compared to White participants. We did not observe a pattern across household characteristics, although we observed a trend towards higher seropositivity among participants living in COVID-19 hotspots. Prevalence ratios were lower for participants in higher income neighbourhoods [PR 0.72, CI 0.58-0.98]. We did not observe variability in seroprevalence across occupational characteristics with the exception of paid sick leave which was higher among participants with home-provided paid sick leave at the time of the survey [PR 0.58, CI 0.45-0.75]. Among LTCH/RH staff, we found important sources of variability of SARS-CoV-2 seroprevalence and strong correlations with socioeconomic disparities. Our findings show the importance of designing equity-rooted health interventions that recognize the intersection between community and the workplace.
了解长期护理院和养老院（LTCH/RH）工作人员中新冠病毒血清流行模式对于设计有效的公共卫生干预措施至关重要。我们于2021年5月至2022年10月期间，采用横断面分析方法对加拿大安大略省LTCH/RH工作人员中的新冠病毒血清流行率进行了估计。符合条件的参与者完成了一份人口统计学问卷，并提供了一份干血斑样本。血清阳性率定义为人群中新冠病毒感染呈阳性的个体比例，通过使用经过验证的化学发光酶联免疫吸附测定法分析抗核衣壳总IgG抗体来确定。我们按参与者的社会人口统计学、家庭、社区和职业特征报告了年龄调整后的患病率比值[PR；置信区间，CI]，并将分析分为两个时间段（时间段1：2021年5月17日至2021年12月31日；时间段2：2022年1月2日至2022年10月25日）。我们的分析共纳入了603名工作人员；235名（39%）在时间段1入组，368名（61%）在时间段2入组。时间段1和2的血清阳性率分别为24%和44%。与白人参与者相比，黑人[PR 1.78；CI 1.28 - 2.48]、东亚和东南亚人[PR 1.55，CI 1.18 - 2.04]以及其他种族化参与者[PR 1.42，CI 1.03 - 1.96]的年龄调整患病率比值高出近两倍。尽管我们观察到居住在新冠疫情热点地区的参与者血清阳性率有升高趋势，但未发现家庭特征方面的规律。高收入社区参与者的患病率比值较低[PR 0.72，CI 0.58 - 0.98]。除了带薪病假外，我们未观察到职业特征方面血清阳性率的差异，在调查时，由雇主提供带薪病假的参与者的患病率比值较低[PR 0.58，CI 0.45 - 0.75]。在LTCH/RH工作人员中，我们发现了新冠病毒血清流行率差异的重要来源，并与社会经济差距存在强烈关联。我们的研究结果表明，设计基于公平的健康干预措施很重要，这种措施要认识到社区与工作场所之间的交叉点。
