Emerg Infect Dis. 2021 Dec;27(12):2999-3008. doi: 10.3201/eid2712.210505. Epub 2021 Oct 26.
Outcomes and costs of coronavirus disease (COVID-19) contact tracing are limited. During March-May 2020, we constructed transmission chains from 184 index cases and 1,499 contacts in Salt Lake County, Utah, USA, to assess outcomes and estimate staff time and salaries. We estimated 1,102 staff hours and $29,234 spent investigating index cases and contacts. Among contacts, 374 (25%) had COVID-19; secondary case detection rate was ≈31% among first-generation contacts, ≈16% among second- and third-generation contacts, and ≈12% among fourth-, fifth-, and sixth-generation contacts. At initial interview, 51% (187/370) of contacts were COVID-19-positive; 35% (98/277) became positive during 14-day quarantine. Median time from symptom onset to investigation was 7 days for index cases and 4 days for first-generation contacts. Contact tracing reduced the number of cases between contact generations and time between symptom onset and investigation but required substantial resources. Our findings can help jurisdictions allocate resources for contact tracing.
冠状病毒病（COVID-19）接触者追踪的结果和成本有限。2020 年 3 月至 5 月期间，我们在美国犹他州盐湖县从 184 例索引病例和 1499 名接触者构建了传播链，以评估结果并估算工作人员时间和薪资。我们估计调查索引病例和接触者需要 1102 个工时和 29234 美元。在接触者中，有 374 人（25％）患有 COVID-19；第一代接触者中的二代病例检出率约为 31％，第二代和第三代接触者中的检出率约为 16％，第四代、第五代和第六代接触者中的检出率约为 12％。在初次访谈时，有 51％（187/370）的接触者 COVID-19 检测呈阳性；14 天隔离期间，有 35％（98/277）的接触者呈阳性。索引病例的症状出现到调查的中位数时间为 7 天，第一代接触者为 4 天。接触者追踪减少了接触者之间的病例数量和症状出现到调查的时间，但需要大量资源。我们的发现可以帮助司法管辖区为接触者追踪分配资源。
