Institute and Outpatient Clinic for Occupational, Social and Environmental Medicine, University Hospital, LMU Munich, 80336, Munich, Germany.
Center for International Health (CIH), University Hospital, LMU Munich, 80336, Munich, Germany.
BMC Infect Dis. 2021 Sep 8;21(1):925. doi: 10.1186/s12879-021-06589-4.
In the 2nd year of the COVID-19 pandemic, knowledge about the dynamics of the infection in the general population is still limited. Such information is essential for health planners, as many of those infected show no or only mild symptoms and thus, escape the surveillance system. We therefore aimed to describe the course of the pandemic in the Munich general population living in private households from April 2020 to January 2021.
The KoCo19 baseline study took place from April to June 2020 including 5313 participants (age 14 years and above). From November 2020 to January 2021, we could again measure SARS-CoV-2 antibody status in 4433 of the baseline participants (response 83%). Participants were offered a self-sampling kit to take a capillary blood sample (dry blood spot; DBS). Blood was analysed using the Elecsys® Anti-SARS-CoV-2 assay (Roche). Questionnaire information on socio-demographics and potential risk factors assessed at baseline was available for all participants. In addition, follow-up information on health-risk taking behaviour and number of personal contacts outside the household (N = 2768) as well as leisure time activities (N = 1263) were collected in summer 2020.
Weighted and adjusted (for specificity and sensitivity) SARS-CoV-2 sero-prevalence at follow-up was 3.6% (95% CI 2.9-4.3%) as compared to 1.8% (95% CI 1.3-3.4%) at baseline. 91% of those tested positive at baseline were also antibody-positive at follow-up. While sero-prevalence increased from early November 2020 to January 2021, no indication of geospatial clustering across the city of Munich was found, although cases clustered within households. Taking baseline result and time to follow-up into account, men and participants in the age group 20-34 years were at the highest risk of sero-positivity. In the sensitivity analyses, differences in health-risk taking behaviour, number of personal contacts and leisure time activities partly explained these differences.
The number of citizens in Munich with SARS-CoV-2 antibodies was still below 5% during the 2nd wave of the pandemic. Antibodies remained present in the majority of SARS-CoV-2 sero-positive baseline participants. Besides age and sex, potentially confounded by differences in behaviour, no major risk factors could be identified. Non-pharmaceutical public health measures are thus still important.
在 COVID-19 大流行的第二年，公众对感染动态的了解仍然有限。这些信息对于卫生规划者来说至关重要，因为许多感染者没有或只有轻微的症状，从而逃脱了监测系统。因此，我们旨在描述 2020 年 4 月至 2021 年 1 月期间慕尼黑普通人群在家中感染的情况。
KoCo19 基线研究于 2020 年 4 月至 6 月进行，共纳入 5313 名参与者（年龄在 14 岁及以上）。2020 年 11 月至 2021 年 1 月，我们可以再次对 4433 名基线参与者的 SARS-CoV-2 抗体状况进行测量（应答率为 83%）。参与者可选择自行采集毛细血管血样（干血斑；DBS）。使用 Elecsys® Anti-SARS-CoV-2 测定法（罗氏）对血液进行分析。所有参与者都可获得基线时的社会人口统计学和潜在风险因素的问卷调查信息。此外，在 2020 年夏季还收集了 2768 名参与者的健康风险行为和家庭外个人接触次数（N=2768）以及 1263 名参与者的休闲活动信息。
与基线时的 1.8%（95%CI 1.3-3.4%）相比，随访时的加权和调整（特异性和敏感性）SARS-CoV-2 血清阳性率为 3.6%（95%CI 2.9-4.3%）。基线时检测呈阳性的 91%的人在随访时也呈抗体阳性。虽然血清阳性率从 2020 年 11 月初到 2021 年 1 月有所增加，但没有发现慕尼黑全市的地理空间聚集的迹象，尽管病例在家庭内聚集。考虑到基线结果和随访时间，男性和 20-34 岁年龄组的参与者感染血清阳性的风险最高。在敏感性分析中，健康风险行为、个人接触次数和休闲活动的差异部分解释了这些差异。
在大流行的第二波期间，慕尼黑市具有 SARS-CoV-2 抗体的市民人数仍低于 5%。在大多数 SARS-CoV-2 血清阳性的基线参与者中仍然存在抗体。除了年龄和性别（可能因行为差异而受到影响）外，没有发现主要的危险因素。因此，非药物公共卫生措施仍然很重要。
