Department of Biomedical Informatics, Harvard Medical School, Harvard University, Boston, MA, United States.
Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China (Hong Kong).
J Med Internet Res. 2024 Jan 4;26:e44249. doi: 10.2196/44249.
The correlates responsible for the temporal changes of intrahousehold SARS-CoV-2 transmission in the United States have been understudied mainly due to a lack of available surveillance data. Specifically, early analyses of SARS-CoV-2 household secondary attack rates (SARs) were small in sample size and conducted cross-sectionally at single time points. From these limited data, it has been difficult to assess the role that different risk factors have had on intrahousehold disease transmission in different stages of the ongoing COVID-19 pandemic, particularly in children and youth.
This study aimed to estimate the transmission dynamic and infectivity of SARS-CoV-2 among pediatric and young adult index cases (age 0 to 25 years) in the United States through the initial waves of the pandemic.
Using administrative claims, we analyzed 19 million SARS-CoV-2 test records between January 2020 and February 2021. We identified 36,241 households with pediatric index cases and calculated household SARs utilizing complete case information. Using a retrospective cohort design, we estimated the household SARS-CoV-2 transmission between 4 index age groups (0 to 4 years, 5 to 11 years, 12 to 17 years, and 18 to 25 years) while adjusting for sex, family size, quarter of first SARS-CoV-2 positive record, and residential regions of the index cases.
After filtering all household records for greater than one member in a household and missing information, only 36,241 (0.85%) of 4,270,130 households with a pediatric case remained in the analysis. Index cases aged between 0 and 17 years were a minority of the total index cases (n=11,484, 11%). The overall SAR of SARS-CoV-2 was 23.04% (95% CI 21.88-24.19). As a comparison, the SAR for all ages (0 to 65+ years) was 32.4% (95% CI 32.1-32.8), higher than the SAR for the population between 0 and 25 years of age. The highest SAR of 38.3% was observed in April 2020 (95% CI 31.6-45), while the lowest SAR of 15.6% was observed in September 2020 (95% CI 13.9-17.3). It consistently decreased from 32% to 21.1% as the age of index groups increased. In a multiple logistic regression analysis, we found that the youngest pediatric age group (0 to 4 years) had 1.69 times (95% CI 1.42-2.00) the odds of SARS-CoV-2 transmission to any family members when compared with the oldest group (18 to 25 years). Family size was significantly associated with household viral transmission (odds ratio 2.66, 95% CI 2.58-2.74).
Using retrospective claims data, the pediatric index transmission of SARS-CoV-2 during the initial waves of the COVID-19 pandemic in the United States was associated with location and family characteristics. Pediatric SAR (0 to 25 years) was less than the SAR for all age other groups. Less than 1% (n=36,241) of all household data were retained in the retrospective study for complete case analysis, perhaps biasing our findings. We have provided measures of baseline household pediatric transmission for tracking and comparing the infectivity of later SARS-CoV-2 variants.
在美国，负责家庭内部 SARS-CoV-2 传播随时间变化的相关因素主要由于缺乏可用的监测数据而研究不足。具体来说，家庭二次感染率 (SAR) 的早期分析样本量较小，并且在单个时间点进行横断面研究。从这些有限的数据中，很难评估不同的危险因素在 COVID-19 大流行的不同阶段对家庭内疾病传播的作用，尤其是在儿童和青少年中。
本研究旨在通过大流行的初始阶段，估计美国儿科和青年指数病例（0 至 25 岁）之间 SARS-CoV-2 的传播动态和传染性。
使用行政索赔数据，我们分析了 2020 年 1 月至 2021 年 2 月期间的 1900 万份 SARS-CoV-2 检测记录。我们确定了 36241 户有儿科指数病例的家庭，并利用完整病例信息计算了家庭 SAR。使用回顾性队列设计，我们在调整了性别、家庭规模、首次 SARS-CoV-2 阳性记录的季度和指数病例的居住地区后，估计了 4 个指数年龄组（0 至 4 岁、5 至 11 岁、12 至 17 岁和 18 至 25 岁）之间的家庭 SARS-CoV-2 传播。
在过滤掉家庭中所有成员大于 1 名的家庭记录和缺失信息后，只有 36241 户（0.85%）的家庭有儿科病例留在分析中。0 至 17 岁的指数病例在总指数病例中占少数（n=11484，11%）。SARS-CoV-2 的总体 SAR 为 23.04%（95%CI 21.88-24.19）。相比之下，所有年龄段（0 至 65+岁）的 SAR 为 32.4%（95%CI 32.1-32.8），高于 0 至 25 岁人群的 SAR。38.3%的最高 SAR 出现在 2020 年 4 月（95%CI 31.6-45），而最低 SAR 为 15.6%，出现在 2020 年 9 月（95%CI 13.9-17.3）。随着指数组年龄的增加，SAR 从 32%逐渐降至 21.1%。在多因素逻辑回归分析中，我们发现最年轻的儿科年龄组（0 至 4 岁）与最年长的组（18 至 25 岁）相比，任何家庭成员的 SARS-CoV-2 传播几率为 1.69 倍（95%CI 1.42-2.00）。家庭规模与家庭内病毒传播显著相关（比值比 2.66，95%CI 2.58-2.74）。
使用回顾性索赔数据，美国 COVID-19 大流行初期家庭内部 SARS-CoV-2 传播的儿科指数与位置和家庭特征有关。儿科 SAR（0 至 25 岁）低于所有其他年龄组的 SAR。少于 1%（n=36241）的家庭数据保留在回顾性研究中进行完整病例分析，这可能会使我们的发现产生偏差。我们提供了家庭儿科传播的基线指标，用于跟踪和比较后续 SARS-CoV-2 变异体的传染性。
