Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich and University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland.
Institute of Medical Virology, University of Zurich, Zurich, Switzerland.
Sci Rep. 2023 May 5;13(1):7296. doi: 10.1038/s41598-023-33824-6.
The majority of SARS-CoV-2 transmissions originates from either asymptomatic or presymptomatic individuals. To prevent unnoticed introduction of SARS-CoV-2, many hospitals have implemented universal admission screening during the COVID-19 pandemic. The present study aimed to investigate associations between results of an universal SARS-CoV-2 admission screening and public SARS-CoV-2 incidence. Over a study period of 44 weeks, all patients admitted to a large tertiary care hospital were tested for SARS-CoV-2 by polymerase chain reaction. SARS-CoV-2 positive patients were retrospectively categorized as symptomatic or asymptomatic at admission. Cantonal data were used to calculate weekly incidence rates per 100,000 inhabitants. We used regression models for count data to assess the association of the weekly cantonal incidence rate and the proportion of positive SARS-CoV-2 tests in the canton with (a) the proportion of SARS-CoV-2 positive individuals and (b) the proportion of asymptomatic SARS-CoV-2 infected individuals identified in universal admission screening, respectively. In a 44-week period, a total of 21,508 admission screenings were performed. SARS-CoV-2 PCR was positive in 643 (3.0%) individuals. In 97 (15.0%) individuals, the positive PCR reflected residual viral replication after recent COVID-19, 469 (72.9%) individuals had COVID-19 symptoms and 77 (12.0%) SARS-CoV-2 positive individuals were asymptomatic. Cantonal incidence correlated with the proportion of SARS-CoV-2 positive individuals [rate ratio (RR): 2.03 per 100 point increase of weekly incidence rate, 95%CI 1.92-2.14] and the proportion of asymptomatic SARS-CoV-2 positive individuals (RR: 2.40 per 100 point increase of weekly incidence rate, 95%CI 2.03-2.82). The highest correlation between dynamics in cantonal incidence and results of admission screening was observed at a lag time of one week. Similarly, the proportion of positive SARS-CoV-2 tests in the canton of Zurich correlated with the proportion of SARS-CoV-2 positive individuals (RR: 2.86 per log increase in the proportion of positive SARS-CoV-2 tests in the canton, 95%CI 2.56-3.19) and the proportion of asymptomatic SARS-CoV-2 positive individuals (RR: 6.50 per log increase in the proportion of positive SARS-CoV-2 tests in the canton, 95%CI 3.93-10.75) in admission screening. Around 0.36% of admission screenings were positive in asymptomatic patients. Admission screening results paralleled changes in population incidence with a brief lag.
大多数 SARS-CoV-2 的传播源自无症状或症状前个体。为防止 SARS-CoV-2 被忽视地传入，许多医院在 COVID-19 大流行期间实施了普遍入院筛查。本研究旨在调查普遍 SARS-CoV-2 入院筛查结果与公众 SARS-CoV-2 发病率之间的关联。在 44 周的研究期间，对一家大型三级保健医院的所有入院患者均采用聚合酶链反应进行 SARS-CoV-2 检测。将 SARS-CoV-2 阳性患者在入院时分为有症状或无症状。使用州数据计算每 10 万人的每周发病率。我们使用计数数据的回归模型来评估每周州发病率和州内 SARS-CoV-2 检测阳性比例与 (a) SARS-CoV-2 阳性个体比例和 (b) 普遍入院筛查中无症状 SARS-CoV-2 感染者比例之间的关联。在 44 周期间，共进行了 21508 次入院筛查。SARS-CoV-2 PCR 阳性 643 人（3.0%）。在 97 例（15.0%）中，阳性 PCR 反映了近期 COVID-19 后残留的病毒复制，469 例（72.9%）患者有 COVID-19 症状，77 例（12.0%）SARS-CoV-2 阳性患者无症状。州发病率与 SARS-CoV-2 阳性个体比例相关（率比（RR）：每周发病率增加 100 点，RR：2.03，95%CI 1.92-2.14）和无症状 SARS-CoV-2 阳性个体比例（RR：每周发病率增加 100 点，RR：2.40，95%CI 2.03-2.82）。在滞后一周时，州发病率动态与入院筛查结果之间的相关性最高。同样，苏黎世州的 SARS-CoV-2 检测阳性比例与 SARS-CoV-2 阳性个体比例（RR：苏黎世州 SARS-CoV-2 检测阳性比例每增加 1 个对数，RR：2.86，95%CI 2.56-3.19）和无症状 SARS-CoV-2 阳性个体比例（RR：苏黎世州 SARS-CoV-2 检测阳性比例每增加 1 个对数，RR：6.50，95%CI 3.93-10.75）相关。在无症状患者中，约有 0.36%的入院筛查呈阳性。入院筛查结果与人群发病率的变化相平行，略有滞后。
