Duke Clinical Research Institute.
Departments of Pediatrics.
Pediatrics. 2022 May 1;149(5). doi: 10.1542/peds.2021-056045.
We evaluated the safety and efficacy of a test-to-stay program for unvaccinated students and staff who experienced an unmasked, in-school exposure to someone with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Serial testing instead of quarantine was offered to asymptomatic contacts. We measured secondary and tertiary transmission rates within participating schools and in-school days preserved for participants.
Participating staff or students from universally masked districts in North Carolina underwent rapid antigen testing at set intervals up to 7 days after known exposure. Collected data included location or setting of exposure, participant symptoms, and school absences up to 14 days after enrollment. Outcomes included tertiary transmission, secondary transmission, and school days saved among test-to-stay participants. A prespecified interim safety analysis occurred after 1 month of enrollment.
We enrolled 367 participants and completed 14-day follow-up on all participants for this analysis. Nearly all (215 of 238, 90%) exposure encounters involved an unmasked index case and an unmasked close contact, with most (353 of 366, 96%) occurring indoors, during lunch (137 of 357, 39%) or athletics (45 of 357, 13%). Secondary attack rate was 1.7% (95% confidence interval: 0.6%-4.7%) based on 883 SARS-CoV-2 serial rapid antigen tests with results from 357 participants; no tertiary cases were identified, and 1628 (92%) school days were saved through test-to-stay program implementation out of 1764 days potentially missed.
After unmasked in-school exposure to SARS-CoV-2, even in a mostly unvaccinated population, a test-to-stay strategy is a safe alternative to quarantine.
我们评估了针对未接种疫苗的学生和教职员工的测试后留观计划的安全性和有效性，这些人在学校内与已确诊的严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）感染者有过无口罩的接触。对无症状接触者提供了替代隔离的连续检测。我们测量了参与学校内的二级和三级传播率以及参与者保留的在校天数。
北卡罗来纳州普遍戴口罩的地区的参与教职员工或学生在已知暴露后的设定间隔时间内进行快速抗原检测，最长可达 7 天。收集的数据包括暴露的地点或环境、参与者的症状以及入学后 14 天的缺勤情况。结果包括测试后留观参与者中的三级传播、二级传播和节省的在校天数。在招生后 1 个月进行了预设的中期安全性分析。
我们共招募了 367 名参与者，并对所有参与者进行了 14 天的随访。几乎所有（238 名中的 215 名，90%）的接触事件涉及未戴口罩的指数病例和未戴口罩的密切接触者，其中大多数（366 名中的 353 名，96%）发生在室内，在午餐时（357 名中的 137 名，39%）或体育活动时（357 名中的 45 名，13%）。根据 357 名参与者的 883 次 SARS-CoV-2 连续快速抗原检测结果，二级攻击率为 1.7%（95%置信区间：0.6%-4.7%）；未发现三级病例，通过实施测试后留观计划，1764 天中可能错过的 1628 天（92%）的学校课程得以保留。
在学校内与 SARS-CoV-2 无口罩暴露后，即使在大多数未接种疫苗的人群中，测试后留观策略也是隔离的安全替代方案。
