Background To estimate the infectious period of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in older adults with underlying conditions, we assessed duration of coronavirus disease 2019 (COVID-19) symptoms, reverse-transcription polymerase chain reaction (RT-PCR) positivity, and culture positivity among nursing home residents. Methods We enrolled residents within 15 days of their first positive SARS-CoV-2 test (diagnosis) at an Arkansas facility from July 7 to 15, 2020 and instead them for 42 days. Every 3 days for 21 days and then weekly, we assessed COVID-19 symptoms, collected specimens (oropharyngeal, anterior nares, and saliva), and reviewed medical charts. Blood for serology was collected on days 0, 6, 12, 21, and 42. Infectivity was defined by positive culture. Duration of culture positivity was compared with duration of COVID-19 symptoms and RT-PCR positivity. Data were summarized using measures of central tendency, frequencies, and proportions. Results We enrolled 17 of 39 (44%) eligible residents. Median participant age was 82 years (range, 58–97 years). All had ≥3 underlying conditions. Median duration of RT-PCR positivity was 22 days (interquartile range [IQR], 8–31 days) from diagnosis; median duration of symptoms was 42 days (IQR, 28–49 days). Of 9 (53%) participants with any culture-positive specimens, 1 (11%) severely immunocompromised participant remained culture-positive 19 days from diagnosis; 8 of 9 (89%) were culture-positive ≤8 days from diagnosis. Seroconversion occurred in 12 of 12 (100%) surviving participants with ≥1 blood specimen; all participants were culture-negative before seroconversion. Conclusions Duration of infectivity was considerably shorter than duration of symptoms and RT-PCR positivity. Severe immunocompromise may prolong SARS-CoV-2 infectivity. Seroconversion indicated noninfectivity in this cohort.

中文翻译：

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2020 年 6 月至 8 月，17 名疗养院居民出现严重急性呼吸综合征冠状病毒 2 的感染期——阿肯色州

背景 为了估计严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 在有潜在疾病的老年人中的感染期，我们评估了 2019 年冠状病毒病 (COVID-19) 症状的持续时间、逆转录聚合酶链反应 (RT- PCR) 阳性和疗养院居民的文化阳性。方法 我们于 2020 年 7 月 7 日至 15 日在阿肯色州的一家设施中招募了首次阳性 SARS-CoV-2 测试（诊断）后 15 天内的居民，而不是 42 天。每 3 天，持续 21 天，然后每周，我们评估 COVID-19 症状，收集标本（口咽、前鼻孔和唾液），并查看病历。在第 0、6、12、21 和 42 天收集用于血清学的血液。感染性由阳性培养定义。将培养阳性的持续时间与 COVID-19 症状的持续时间和 RT-PCR 阳性进行比较。使用集中趋势、频率和比例的度量来总结数据。结果 我们招募了 39 名 (44%) 符合条件的居民中的 17 名。参与者的中位年龄为 82 岁（范围为 58-97 岁）。所有人都有≥3个潜在条件。RT-PCR 阳性的中位持续时间为诊断后 22 天（四分位距 [IQR]，8-31 天）；症状的中位持续时间为 42 天（IQR，28-49 天）。在 9 名（53%）有任何培养阳性标本的参与者中，1 名（11%）严重免疫功能低下的参与者在诊断后 19 天仍保持培养阳性；9 人中有 8 人（89%）在诊断后 8 天内培养呈阳性。12 名 (100%) 存活的参与者中，有 12 名（100%）≥1 个血液样本发生了血清转换；所有参与者在血清转换前均为培养阴性。结论 感染持续时间明显短于症状持续时间和 RT-PCR 阳性。严重的免疫功能受损可能会延长 SARS-CoV-2 的传染性。血清转化表明该队列没有感染性。