OBJECTIVES We evaluated the impact of a test-to-stay (TTS) program on within-school transmission and missed school days in optionally masked kindergarten through 12th grade schools during a period of high community severe acute respiratory syndrome coronavirus 2 transmission. METHODS Close contacts of those with confirmed severe acute respiratory syndrome coronavirus 2 infection were eligible for enrollment in the TTS program if exposure to a nonhousehold contact occurred between November 11, 2021 and January 28, 2022. Consented participants avoided school exclusion if they remained asymptomatic and rapid antigen testing at prespecified intervals remained negative. Primary outcomes included within-school tertiary attack rate (test positivity among close contacts of positive TTS participants) and school days saved among TTS participants. We estimated the number of additional school-acquired cases resulting from TTS and eliminating school exclusion. RESULTS A total of 1675 participants tested positive or received at least 1 negative test between days 5 and 7 and completed follow-up; 92% were students and 91% were exposed to an unmasked primary case. We identified 201 positive cases. We observed a tertiary attack rate of 10% (95% confidence interval: 6%-19%), and 7272 (89%) of potentially missed days were saved through TTS implementation. We estimated 1 additional school-acquired case for every 21 TTS participants remaining in school buildings during the entire study period. CONCLUSIONS Even in the setting of high community transmission, a TTS strategy resulted in substantial reduction in missed school days in optionally masked schools.

中文翻译：

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SARS-CoV-2 暴露后测试留校：选择性蒙面 K-12 学校的缓解策略。


目标 我们评估了在社区严重急性呼吸综合征冠状病毒 2 病毒高传播期间，测试留校 (TTS) 计划对可选佩戴口罩的幼儿园至 12 年级学校的校内传播和旷课的影响。方法 如果在 2021 年 11 月 11 日至 2022 年 1 月 28 日期间接触过非家庭接触者，则已确诊的严重急性呼吸综合征冠状病毒 2 感染者的密切接触者有资格参加 TTS 计划。如果同意的参与者仍然无症状并且按预定时间间隔进行的快速抗原检测仍呈阴性。主要结果包括校内三级发病率（阳性 TTS 参与者的密切接触者中的测试呈阳性）和 TTS 参与者节省的上学时间。我们估计了因 TTS 和消除学校排斥而导致的额外学校感染病例数量。结果 共有 1675 名参与者在第 5 天至第 7 天期间检测呈阳性或至少接受 1 次检测呈阴性，并完成了随访； 92% 是学生，91% 接触过未掩饰的原发病例。我们发现了 201 例阳性病例。我们观察到三次攻击率为 10%（95% 置信区间：6%-19%），并且通过 TTS 实施节省了 7272 (89%) 可能错过的天数。我们估计，在整个研究期间，每 21 名留在学校建筑中的 TTS 参与者就会增加 1 例学校获得性病例。结论 即使在社区传播率较高的情况下，TTS 策略也能大幅减少可选佩戴口罩学校的缺课天数。