摘要
背景
专业养老院内SARS-CoV-2会迅速传播。当我们在一个专业养老院内确认了一名COVID-19患者后,我们分析了其传播,并评估了在该机构居民中进行基于症状的筛查是否充分和有效。
方法
我们进行了两个系列的时点感染率调查,间隔1周。在该调查中,征得居民同意后,我们开展了鼻咽及口咽拭子SARS-CoV-2检测,包括rRT-PCR、病毒培养及基因组测序。我们记录了在检测之前14日出现症状的情况。无症状但病毒检测为阳性的居民会在7日后被重新评估。SARS-CoV-2感染的居民被根据症状分成4类:典型症状者(发热、咳嗽、呼吸困难),仅有非典型症状者,症状前或无症状者。
结果
在该专业养老院出现第一个阳性病例后的23日,89个居民中57人(64%)出现SARS-CoV-2阳性。在参与时点感染率调查的76个居民中,48人(63%)病毒检测为阳性。在这48个居民中,27人(56%)在检测时无症状;24人后来出现症状(至出现症状中位时间为4日)。在这24个症状前居民中,rRT-PCR的中位循环值为23.1,从17个居民中发现了活病毒。截止到4月3号,在57个感染了SARS-CoV-2的居民中,11人住院治疗(其中3人在重症监护室),另外15人去世(死亡率为26%)。在34个被测序的居民中,27人(79%)的病毒序列可以分为两个聚类,其间仅有一个核苷酸的差异。
结论
有证据表明该专业养老院发生了SARS-CoV-2迅速而广泛的传播。一多半的阳性居民在检测时还是无症状者,但非常可能已具备传播能力。在SARS-CoV-2已经进入该机构后,控制传染的策略如果仅仅集中在有症状居民不足以防止其传播。
作者信息
Melissa M. Arons, R.N., Kelly M. Hatfield, M.S.P.H., Sujan C. Reddy, M.D., Anne Kimball, M.D., Allison James, Ph.D., Jesica R. Jacobs, Ph.D., Joanne Taylor, Ph.D., Kevin Spicer, M.D., Ana C. Bardossy, M.D., Lisa P. Oakley, Ph.D., Sukarma Tanwar, M.Med., Jonathan W. Dyal, M.D., Josh Harney, M.S., Zeshan Chisty, M.P.H., Jeneita M. Bell, M.D., Mark Methner, Ph.D., Prabasaj Paul, Ph.D., Christina M. Carlson, Ph.D., Heather P. McLaughlin, Ph.D., Natalie Thornburg, Ph.D., Suxiang Tong, Ph.D., Azaibi Tamin, Ph.D., Ying Tao, Ph.D., Anna Uehara, Ph.D., Jennifer Harcourt, Ph.D., Shauna Clark, R.N., Claire Brostrom-Smith, M.S.N., Libby C. Page, M.P.H., Meagan Kay, D.V.M., James Lewis, M.D., Patty Montgomery, M.P.H., Nimalie D. Stone, M.D., Thomas A. Clark, M.D., Margaret A. Honein, Ph.D., Jeffrey S. Duchin, M.D., and John A. Jernigan, M.D. for the Public Health–Seattle and King County and CDC COVID-19 Investigation Team*
From the Centers for Disease Control and Prevention COVID-19 Emergency Response (M.M.A., K.M.H., S.C.R., A.K., A.J., J.R.J., J.T., K.S., A.C.B., L.P.O., S. Tanwar, J.W.D., J. Harney, Z.C., J.M.B., M.M., P.P., C.M.C., H.P.M.L., N.T., S. Tong, A.T., Y.T., A.U., J. Harcourt, N.D.S., T.A.C., M.A.H., J.A.J.), and the Epidemic Intelligence Service (M.M.A., A.K., A.J., J.T., A.C.B., L.P.O., S. Tanwar, J.W.D.) and the Laboratory Leadership Service (J.R.J., C.M.C.), Centers for Disease Control and Prevention — all in Atlanta; and Public Health — Seattle & King County (S.C., C.B.-S., L.C.P., M.K., J.L., J.S.D.) and the University of Washington, Department of Medicine (J.S.D.), Seattle, the Washington State Public Health Laboratory, Shoreline (J.S.D.), and the Washington State Department of Health, Tumwater (P.M.) — all in Washington. Address reprint requests to Dr. Jernigan at the Centers for Disease Control and Prevention, 1600 Clifton Rd., Mailstop A-31, Atlanta, GA 30333, or at jqj9@cdc.gov.
*A complete list of the investigators is included in the Supplementary Appendix, available at NEJM.org.
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