Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.
School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Elife. 2023 Jul 18;12:e84753. doi: 10.7554/eLife.84753.
Households are an important location for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission, especially during periods when travel and work was restricted to essential services. We aimed to assess the association of close-range contact patterns with SARS-CoV-2 transmission.
We deployed proximity sensors for two weeks to measure face-to-face interactions between household members after SARS-CoV-2 was identified in the household, in South Africa, 2020-2021. We calculated the duration, frequency, and average duration of close-range proximity events with SARS-CoV-2 index cases. We assessed the association of contact parameters with SARS-CoV-2 transmission using mixed effects logistic regression accounting for index and household member characteristics.
We included 340 individuals (88 SARS-CoV-2 index cases and 252 household members). On multivariable analysis, factors associated with SARS-CoV-2 acquisition were index cases with minimum C value <30 (aOR 16.8 95% CI 3.1-93.1) vs >35, and female contacts (aOR 2.5 95% CI 1.3-5.0). No contact parameters were associated with acquisition (aOR 1.0-1.1) for any of the duration, frequency, cumulative time in contact, or average duration parameters.
We did not find an association between close-range proximity events and SARS-CoV-2 household transmission. Our findings may be due to study limitations, that droplet-mediated transmission during close-proximity contacts plays a smaller role than airborne transmission of SARS-CoV-2 in the household, or due to high contact rates in households.
Wellcome Trust (Grant number 221003/Z/20/Z) in collaboration with the Foreign, Commonwealth, and Development Office, United Kingdom.
家庭是严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）传播的重要场所，尤其是在旅行和工作仅限于基本服务的时期。我们旨在评估近距离接触模式与 SARS-CoV-2 传播之间的关联。
我们在南非部署了近距离传感器，以在家庭中发现 SARS-CoV-2 后的两周内测量家庭成员之间的面对面互动。我们计算了 SARS-CoV-2 指数病例的近距离接近事件的持续时间、频率和平均持续时间。我们使用混合效应逻辑回归评估了接触参数与 SARS-CoV-2 传播的相关性，同时考虑了指数病例和家庭成员的特征。
我们纳入了 340 人（88 例 SARS-CoV-2 指数病例和 252 名家庭成员）。多变量分析表明，与 SARS-CoV-2 感染相关的因素包括指数病例的最小 C 值<30（比值比 16.8，95%置信区间 3.1-93.1）与>35，以及女性接触者（比值比 2.5，95%置信区间 1.3-5.0）。对于任何持续时间、频率、累积接触时间或平均持续时间参数，没有接触参数与感染（比值比 1.0-1.1）相关。
我们没有发现近距离接触事件与 SARS-CoV-2 家庭传播之间的关联。我们的发现可能是由于研究的局限性，即近距离接触期间的飞沫传播在家庭中 SARS-CoV-2 的空气传播中作用较小，或者是由于家庭中的接触率较高。
惠康信托基金（Grant number 221003/Z/20/Z）与英国外交、联邦和发展办公室合作。
