COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, GA, USA.
Denver Public Health, Denver, CO, USA.
Public Health Rep. 2022 Jan-Feb;137(1):128-136. doi: 10.1177/00333549211055137. Epub 2021 Nov 9.
The number of SARS-CoV-2 infections is underestimated in surveillance data. Various approaches to assess the seroprevalence of antibodies to SARS-CoV-2 have different resource requirements and generalizability. We estimated the seroprevalence of antibodies to SARS-CoV-2 in Denver County, Colorado, via a cluster-sampled community survey.
We estimated the overall seroprevalence of antibodies to SARS-CoV-2 via a community seroprevalence survey in Denver County in July 2020, described patterns associated with seroprevalence, and compared results with cumulative COVID-19 incidence as reported to the health department during the same period. In addition, we compared seroprevalence as assessed with a temporally and geographically concordant convenience sample of residual clinical specimens from a commercial laboratory.
Based on 404 specimens collected through the community survey, 8.0% (95% CI, 3.9%-15.7%) of Denver County residents had antibodies to SARS-CoV-2, an infection rate of about 7 times that of the 1.1% cumulative reported COVID-19 incidence during this period. The estimated infection-to-reported case ratio was highest among children (34.7; 95% CI, 11.1-91.2) and males (10.8; 95% CI, 5.7-19.3). Seroprevalence was highest among males of Black race or Hispanic ethnicity and was associated with previous COVID-19-compatible illness, a previous positive SARS-CoV-2 test result, and close contact with someone who had confirmed SARS-CoV-2 infection. Testing of 1598 residual clinical specimens yielded a seroprevalence of 6.8% (95% CI, 5.0%-9.2%); the difference between the 2 estimates was 1.2 percentage points (95% CI, -3.6 to 12.2 percentage points).
Testing residual clinical specimens provided a similar seroprevalence estimate yet yielded limited insight into the local epidemiology of COVID-19 and might be less representative of the source population than a cluster-sampled community survey. Awareness of the limitations of various sampling strategies is necessary when interpreting findings from seroprevalence assessments.
监测数据中 SARS-CoV-2 感染人数被低估。评估 SARS-CoV-2 抗体血清流行率的各种方法具有不同的资源要求和通用性。我们通过在科罗拉多州丹佛县进行的聚类抽样社区调查来估计 SARS-CoV-2 抗体的血清流行率。
我们通过 2020 年 7 月在丹佛县进行的社区血清流行率调查来估计 SARS-CoV-2 抗体的总体血清流行率，描述与血清流行率相关的模式，并将结果与同期向卫生部门报告的累积 COVID-19 发病率进行比较。此外，我们还比较了通过与商业实验室的时间和地理上一致的剩余临床标本的随机抽样得出的血清流行率。
基于社区调查中收集的 404 份标本，丹佛县居民中有 8.0%（95%CI，3.9%-15.7%）有 SARS-CoV-2 抗体，感染率约为同期报告的 1.1%累积 COVID-19 发病率的 7 倍。在儿童（34.7；95%CI，11.1-91.2）和男性（10.8；95%CI，5.7-19.3）中，估计的感染与报告病例的比例最高。黑人和西班牙裔男性的血清流行率最高，与以前的 COVID-19 一致的疾病、以前 SARS-CoV-2 检测结果阳性和与已确认 SARS-CoV-2 感染的人密切接触有关。对 1598 份剩余临床标本的检测得出的血清流行率为 6.8%（95%CI，5.0%-9.2%）；这两个估计值之间的差异为 1.2 个百分点（95%CI，-3.6 至 12.2 个百分点）。
测试剩余的临床标本提供了相似的血清流行率估计，但对 COVID-19 的本地流行病学的了解有限，并且可能不如聚类抽样的社区调查更能代表源人群。在解释血清流行率评估的结果时，需要意识到各种抽样策略的局限性。
