Department of Obstetrics and Gynaecology, Aalborg University Hospital, Reberbansgade, Aalborg, Denmark.
Department of Cardiology, Nordsjællands Hospital, Dyrehavevej, Hillerød, Denmark.
Clin Infect Dis. 2022 Jan 7;74(1):1-7. doi: 10.1093/cid/ciab340.
Households are high-risk settings for the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Severity of coronavirus disease 2019 (COVID-19) is likely associated with the infectious dose of SARS-CoV-2 exposure. We therefore aimed to assess the association between SARS-CoV-2 exposure within households and COVID-19 severity.
We performed a Danish, nationwide, register-based, cohort study including laboratory-confirmed SARS-CoV-2-infected individuals from 22 February 2020 to 6 October 2020. Household exposure to SARS-CoV-2 was defined as having 1 individual test positive for SARS-CoV-2 within the household. Cox proportional hazards models were used to estimate the association between "critical COVID-19" within and between households with and without secondary cases.
From 15 063 multiperson households, 19 773 SARS-CoV-2-positive individuals were included; 11 632 were categorized as index cases without any secondary household cases; 3431 as index cases with secondary cases, that is, 22.8% of multiperson households; and 4710 as secondary cases. Critical COVID-19 occurred in 2.9% of index cases living with no secondary cases, 4.9% of index cases with secondary cases, and 1.3% of secondary cases. The adjusted hazard ratio for critical COVID-19 among index cases vs secondary cases within the same household was 2.50 (95% confidence interval [CI], 1.88-3.34), 2.27 (95% CI, 1.77-2.93) for index cases in households with no secondary cases vs secondary cases, and 1.1 (95% CI, .93-1.30) for index cases with secondary cases vs index cases without secondary cases.
We found no increased hazard ratio of critical COVID-19 among household members of infected SARS-CoV-2 index cases.
家庭是严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）传播的高风险环境。2019 年冠状病毒病（COVID-19）的严重程度可能与 SARS-CoV-2 暴露的感染剂量有关。因此，我们旨在评估家庭内 SARS-CoV-2 暴露与 COVID-19 严重程度之间的关系。
我们进行了一项丹麦全国范围内基于登记的队列研究，纳入了 2020 年 2 月 22 日至 2020 年 10 月 6 日期间实验室确诊的 SARS-CoV-2 感染个体。家庭内 SARS-CoV-2 暴露定义为家庭内有 1 名个体 SARS-CoV-2 检测呈阳性。使用 Cox 比例风险模型来估计家庭内和家庭间有和没有继发病例的“严重 COVID-19”之间的关联。
在 15063 个多人家庭中，有 19773 名 SARS-CoV-2 阳性个体被纳入研究；11632 名被归类为没有任何家庭继发病例的索引病例；3431 名被归类为索引病例有继发病例，即 22.8%的多人家庭；4710 名被归类为继发病例。没有继发病例的同住索引病例中严重 COVID-19 的发生率为 2.9%，有继发病例的同住索引病例中为 4.9%，继发病例中为 1.3%。同一家庭内索引病例与继发病例相比，严重 COVID-19 的调整后危险比为 2.50（95%置信区间[CI]，1.88-3.34），无继发病例的家庭内索引病例与继发病例相比为 2.27（95% CI，1.77-2.93），有继发病例的索引病例与无继发病例的索引病例相比为 1.1（95% CI，0.93-1.30）。
我们没有发现感染 SARS-CoV-2 的索引病例的家庭内成员严重 COVID-19 的危险比增加。
