Public Health Laboratory, Alberta Precision Laboratories, Calgary, Canada.
Division of Infectious Diseases, Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, Canada.
Infect Dis (Lond). 2022 Sep;54(9):666-676. doi: 10.1080/23744235.2022.2080250. Epub 2022 May 31.
The COVID-19 pandemic has necessitated the need to rapidly make public health decisions. We systematically evaluated SARS-CoV-2 seropositivity to understand local COVID-19 epidemiology and support evidence-based public health decision making.
Residual blood samples were collected for SARS-CoV-2 receptor binding domain (RBD) IgG testing over a 1-5 day period monthly from 26 February 2021-9 July 2021 from six clinical laboratories across the province of Alberta, Canada. Monthly crude and adjusted (for age and gender) seropositivity were calculated. Results were linked to provincial administrative, laboratory, and vaccine databases.
60,632 individual blood samples were tested. Vaccination data were available for 98.8% of samples. Adjusted RBD IgG positivity rose from 11.9% (95% confidence interval [CI] 11.9-12.0%) in March 2021 to 70.2% (95% CI 70.2-70.3%) in July 2021 ( < .0001). Seropositivity rose from 9.4% (95% CI 9.3-9.4%) in March 2021 to 20.2% (95% CI 20.1-20.2%) in July 2021 in unvaccinated Albertans. Unvaccinated seropositive individuals were from geographic areas with significantly ( < .001) lower median household income, lower proportion of married/common-law relationships, larger average household size and higher proportions of visible minorities compared to seronegative unvaccinated individuals. In July 2021, the age groups with the lowest and highest seropositivity in unvaccinated Albertans were those ≥80 years (12.0%, 95% CI 5.3-18.6%) and 20-29 years (24.2%, 95% CI 19.6-28.8%), respectively. Of seropositive unvaccinated individuals, 50.2% (95% CI 45.9-54.5%) had no record of prior SARS-CoV-2 molecular testing.
Longitudinal surveillance of SARS-CoV-2 seropositivity with data linkage is valuable for decision-making during the pandemic.
COVID-19 大流行迫使我们需要迅速做出公共卫生决策。我们系统地评估了 SARS-CoV-2 血清阳性率，以了解当地 COVID-19 的流行病学情况，并为循证公共卫生决策提供支持。
2021 年 2 月 26 日至 7 月 9 日期间，从加拿大艾伯塔省的六个临床实验室每月采集 1-5 天的剩余血液样本进行 SARS-CoV-2 受体结合域（RBD）IgG 检测。计算每月的粗阳性率和调整后的阳性率（按年龄和性别调整）。结果与省级行政、实验室和疫苗数据库相关联。
共检测了 60632 份个体血样。98.8%的样本可获得疫苗接种数据。调整后的 RBD IgG 阳性率从 2021 年 3 月的 11.9%（95%置信区间[CI]，11.9-12.0%）上升至 2021 年 7 月的 70.2%（95%CI，70.2-70.3%）（<0.0001）。在未接种疫苗的艾伯塔人中，血清阳性率从 2021 年 3 月的 9.4%（95%CI，9.3-9.4%）上升至 7 月的 20.2%（95%CI，20.1-20.2%）。与血清阴性的未接种疫苗者相比，血清阳性的未接种疫苗者来自地理区域，这些区域的家庭收入中位数显著较低（<0.001），已婚/同居关系比例较低，平均家庭规模较大，少数族裔比例较高。在 2021 年 7 月，未接种疫苗的艾伯塔人中血清阳性率最低和最高的年龄组分别为≥80 岁（12.0%，95%CI，5.3-18.6%）和 20-29 岁（24.2%，95%CI，19.6-28.8%）。在血清阳性的未接种疫苗者中，50.2%（95%CI，45.9-54.5%）没有 SARS-CoV-2 分子检测的记录。
通过数据链接对 SARS-CoV-2 血清阳性率进行纵向监测，对大流行期间的决策制定具有重要价值。
