Chevalier Joshua M, Sy Karla Therese L, Girdwood Sarah J, Khan Shaukat, Albert Heidi, Toporowski Amy, Hannay Emma, Carmona Sergio, Nichols Brooke E
Department of Global Health, Boston University School of Public Health, Boston, Massachusetts, United States of America.
Department of Epidemiology, Boston University School of Public Health, Boston, Massachusetts, United States of America.
PLOS Glob Public Health. 2022 May 16;2(5):e0000086. doi: 10.1371/journal.pgph.0000086. eCollection 2022.
Countries around the world have implemented restrictions on mobility, especially cross-border travel to reduce or prevent SARS-CoV-2 community transmission. Rapid antigen testing (Ag-RDT), with on-site administration and rapid turnaround time may provide a valuable screening measure to ease cross-border travel while minimizing risk of local transmission. To maximize impact, we developed an optimal Ag-RDT screening algorithm for cross-border entry. Using a previously developed mathematical model, we determined the daily number of imported COVID-19 cases that would generate no more than a relative 1% increase in cases over one month for different effective reproductive numbers (Rt) and COVID-19 prevalence within the recipient country. We then developed an algorithm-for differing levels of Rt, arrivals per day, mode of travel, and SARS-CoV-2 prevalence amongst travelers-to determine the minimum proportion of people that would need Ag-RDT testing at border crossings to ensure no greater than the relative 1% community spread increase. When daily international arrivals and/or COVID-19 prevalence amongst arrivals increases, the proportion of arrivals required to test using Ag-RDT increases. At very high numbers of international arrivals/COVID-19 prevalence, Ag-RDT testing is not sufficient to prevent increased community spread, especially when recipient country prevalence and Rt are low. In these cases, Ag-RDT screening would need to be supplemented with other measures to prevent an increase in community transmission. An efficient Ag-RDT algorithm for SARS-CoV-2 testing depends strongly on the epidemic status within the recipient country, volume of travel, proportion of land and air arrivals, test sensitivity, and COVID-19 prevalence among travelers.
世界各国都实施了出行限制措施，尤其是跨境旅行限制，以减少或防止严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的社区传播。快速抗原检测（Ag-RDT）具有现场操作和快速出结果的特点，可能为缓解跨境旅行提供一种有价值的筛查措施，同时将本地传播风险降至最低。为了实现最大影响，我们开发了一种用于跨境入境的最佳Ag-RDT筛查算法。我们使用先前开发的数学模型，针对不同的有效繁殖数（Rt）和受援国境内的新冠病毒病患病率，确定了在一个月内不会导致病例数相对增加超过1%的每日输入性新冠病毒病病例数。然后，我们针对不同水平的Rt、每日抵达人数、旅行方式以及旅行者中的SARS-CoV-2患病率开发了一种算法，以确定在边境口岸需要进行Ag-RDT检测的人员的最小比例，以确保社区传播增加不超过相对1%。当每日国际抵达人数和/或抵达者中的新冠病毒病患病率增加时，需要使用Ag-RDT进行检测的抵达者比例也会增加。在国际抵达人数/新冠病毒病患病率非常高的情况下，Ag-RDT检测不足以防止社区传播增加，尤其是当受援国患病率和Rt较低时。在这些情况下，需要用其他措施补充Ag-RDT筛查，以防止社区传播增加。一种有效的用于SARS-CoV-2检测的Ag-RDT算法在很大程度上取决于受援国的疫情状况、旅行量、陆地和航空抵达的比例、检测灵敏度以及旅行者中的新冠病毒病患病率。
