免责声明:本网站持续更新。在所有内容翻译完成之前,其中一些内容可能为英文。

重要更新:医疗保健设施
为了应对COVID-19免疫接种,CDC更新了有效运行医疗保健系统的选择方法。了解更多
更新
根据B.1.617.2 (Delta) 变种病毒的新证据,CDC更新了全剂量接种疫苗人群指导方针。CDC建议所有教师、工作人员、学生和K-12学校的访客,无论疫苗接种状况如何,均应在室内普遍佩戴口罩。孩子们应在秋季恢复全日制实地校园学习,并采取分层预防策略。
更新
白宫宣布,从2021年11月8日起,进入美国的国际旅行者必须接种疫苗。要进入美国,接种的疫苗必须是FDA批准或授权以及列入WHO紧急使用清单的疫苗。点击此处获取更多信息。
更新
自2021年11月8日开始,进入美国的旅行要求将会改变。点击此处获取更多信息。

检疫隔离和医学隔离相关信息

检疫隔离和医学隔离相关信息

检疫隔离和医学隔离: 了解COVID-19接触或生病后的最新建议

CDC为何缩短普通人群的医学隔离和检疫隔离周期

由奥密克戎变种病毒导致的COVID-19病例随着流感和其他呼吸道病毒感染的季节性增加而有所增加。大量病例的可能性已引起人们对疾病造成的社会影响以及对医学隔离和检疫隔离要求的严重担忧[1]。CDC一直在监测新兴科学,了解人们感染奥密克戎病毒后何时和多长时间具有最大传染性,以及COVID-19疫苗和加强针对预防奥密克戎感染的有效性。CDC还考虑了与疫情心理健康影响和遵守预防干预措施的相关数据。

包括对来自17个国家113项研究的回顾在内的数据表明,大多数SARS-CoV-2传播发生在感染过程的早期[2,3]。传染性在症状发作前一天左右达到高峰,并在症状发作后一周内下降,平均传染性和传播风险期在症状出现前2-3天及症状出现后8天[2,3]。这些数据来自对先前SARS-CoV-2变种病毒(包括德尔塔)的研究。科学在发展,特别是对于奥密克戎变种,一些报告表明,与之前的变种相比,奥密克戎的潜伏期更短(2-4 天),确定为从感染到症状出现之间的时间[4-6]。对于所有SARS-CoV-2变种,已接种疫苗者的住院率和死亡率要低得多;来自南非的初步数据表明,与其他变种相比,奥密克戎感染者的住院率和死亡率较低[7-9]。据初步估计,在完成辉瑞-生物科技疫苗初始系列接种后,由于奥密克戎变种,疫苗对症状性感染和疾病的有效性会较低,但接种加强针后,疫苗有效性得以改善,这表明加强针对于提高因奥密克戎变种感染而住院和死亡的保护很重要[10-14]。 奥密克戎变种的传播可能会加剧人员短缺,增加供应链挑战,从而危及工业、教育和其他系统,而这些系统对维持社会和经济的运转至关重要。疫情还对美国成年人的心理健康产生了负面影响[15],主要源于经济和社会问题[16]。尽管很多人愿意自我隔离,但医学隔离和检疫隔离都具有挑战性;尤其是在许多感染无症状的情况下[17]。研究表明,只有一小部分人 (25-30%) 会隔离10天整[18,19]

1月4日,CDC更新了COVID-19隔离和检疫隔离建议,将隔离(无症状和轻症感染者)和检疫隔离期缩短为5天,以专注于感染者最具传染性的时期,之后则继续佩戴口罩5天。这些更新后的建议也满足了人们的社交和健康需求、加快返工,且有利于关键基础设施的维护。初步数据表明,奥密克戎变种的传染性是德尔塔变种的三倍 [20]。由于建议的隔离和检疫隔离期更短,人们在结束隔离或检疫隔离后继续在之后的5天佩戴 贴合良好的口罩并采取额外预防措施至关重要 [21]。此外,只应在感染者在不使用退烧药的情况下至少24小时不发烧且其他症状消失的情况下结束隔离。来自英国的建模数据进一步强化了佩戴口罩的重要性;在阳性检测结果后的第5天之后,预计31%的感染者仍具有传染性 [22]。佩戴口罩并采取分层预防策略(例如接种所有建议的免疫接种剂量剂加强针、保持身体距离、筛检和改善 通风)是预防COVID-19并降低其传播的关键。

常见问题

参考资料
  1. 美国奥密克戎变种感染的潜在快速增加 | CDC
  2. Meyerowitz EA, Richterman A, Gandhi RT, Sax PE. Transmission of SARS-CoV-2: a review of viral, host, and environmental factors. Ann Intern Med.external icon 2020 Sep 17: M20-5008.
  3. Peeling RW, Heymann DL, Teo Y, Garcia PJ. Diagnostics for COVID-19: moving from pandemic response to control. Lancet. Published online December 20, 2021: https://doi.org/10.1016/S0140-6736(21)02346-1external icon
  4. Centers for Disease Control and Prevention. Investigation of a SARS-CoV-2-B.1.1.1.529 (Omicron) Variant Cluster—Nebraska- November-December 2021.  MMWR Early Release. Vol. 70. December 28, 2021.
  5. Brandel LT, MacDonald E, Veneti L, Ravio T, Lange H, Naseer U, et al. Outbreak caused by SARS-CoV-2 Omicron variant in Norway, November to December 2021.Euro Surveill.2021;26(50):pii=2101147 https://doi.org/10.2807/1560-7917.ES.2021.26.50.2101147external icon
  6. Lee JJ, Choe YJ, Jeong H, Kim M, Kim S, Yoo H, et al. Importation and transmission of SARS-CoV-2 B1.1.529 (Omicron) variant of concern in Korea, November 2021. J Korean Med Sci. 2021 Dec 27;36(50):e346 https://doi.org/10.3346/jkms.2021.36.e346external icon eISSN 1598-6357·pISSN 1011-8934
  7. Maslo C, Friedland R, Toubkin M, Laubscher A, Akaloo T, Kama B. Characteristics and outcomes of hospitalized patients in South Africa during the COVID-19 Omicron wave compared with previous waves. Published online December 30, 2021. https://doi.org/10.1001/jama.2021.24868external icon
  8. Christensen PA, Olsen R, Long SW, Snehal R, Davis JJ, Saavedra MO, et al. Early signals of significantly increased vaccine breakthrough, decreased hospitalization rates and less severe disease in patients with COVID-19 caused by the Omicron variant of SARS-CoV-2 in Houston TX. medRxiv. https://www.medrxiv.org/content/10.1101/2021.12.30.21268560v2external icon
  9. Lewnard JA, Hong VX, Patel MM, Kahn R, Lipsitch M, Tartof SY. Clinical outcomes among patients infected with Omicron (B.1.1.529) SARS-CoV-2 variant in southern California. medRxiv. 2022. https://www.medrxiv.org/content/10.1101/2022.01.11.22269045v1external icon
  10. Andrews N, Stowe J, Kirsebom F, Toffa S, Rickeard T, Gallagher E, et al. Effectiveness of COVID-19 vaccines against the Omicron (B.1.1.529) variant of concern. medRxiv.2021. https://doi.org/10.1101/2021.12.14.21267615external icon
  11. Collie S, Champion J, Moultrie H, Bekker LG, Gray G. Effectiveness of BNT162b2 vaccine against Omicron variant in SA.NEJM. December 29, 2021 https://doi.org/10.1056/NEJMc2119270external icon
  12. Hansen CH, Schelde AB, Moustsen-Helm IR, Emborg HD, Krause TG, Mølbak K, et al. Vaccine effectiveness against SARS CoV2 infection with the Omicron variant Danish study. medRxiv. https://doi.org/10.1101/2021.12.20.21267966external icon
  13. Nemet I, Kliker L, Lustig Y, Zuckerman N, Erster O, Cohen C, et al. Third BNT162b2 vaccination neutralization of SARS-CoV-2 Omicron Infection. NEJM. December 29, 2021 https://doi.org/10.1056/NEJMc2119358external icon
  14. Schmidt F, Muecksch F, Weisblum Y, Da Silva J, Bednarski E, Cho A, et al. Plasma neutralization of the SARS-CoV-2 omicron variant. NEJM. December 30, 2021. https://doi.org/10.1056/NEJMc2119641external icon
  15. Ettman CK, Abdalla SM, Cohen GH, Sampson L, Vivier PM, Galea S. Prevalence of depression symptoms in US adults before and during the COVID-19 pandemic. JAMA Network Open2020;3(9):e2019686. https://doi.org/10.1001/jamanetworkopen.2020.19686external icon
  16. Kämpfen F, Kohler IV, Ciancio A, Bruine de Bruin W, Maurer J, Kohler H-P. Predictors of mental health during the Covid-19 pandemic in the US: Role of economic concerns, health worries and social distancing. PLoS ONE 2020 15 (11): e0241895. https://doi.org/10.1371/journal.pone.0241895external icon
  17. Ma Q, Liu J, Liu Q, Kang L, Liu R, Jing Q, et al. Global percentage of asymptomatic SARS-CoV-2 infections among the tested population and individuals with confirmed COVID-19 diagnosis. JAMA Netw Open2021;4(12):e2137257. https://doi.org/10.1001/jamanetworkopen.2021.37257external icon
  18. Smith LE, Potts HWW, Amlôt R, Fear NT, Michie S, Rubin GJ. Adherence to the test, trace, and isolate system in the UK: results from 37 nationally representative surveys. : BMJ 2021;372:n608 http://dx.doi.org/10.1136/bmj.n608external icon
  19. Smith LE, Amlôt R, lambert H, Oliver I, Robin C, Yardley L, Rubin GJ. Factors associated with adherence to self-isolation and lockdown measures in the UK: a cross-sectional survey. Public Health 2020. 187:41-52. https://doi.org/10.1016/j.puhe.2020.07.024external icon
  20. Ito K, Piantham C, Nishiura H. Relative instantaneous reproduction number of Omicron SARS-CoV-2 variant with respect to the Delta variant in Denmark. J Med Virol. 2021 Dec 30. https://doi.org/10.1002/jmv.27560external icon
  21. Science Brief: Community Use of Masks to Control the Spread of SARS-CoV-2 | CDC
  22. Bays D, Whiteley T, Pindar M, Taylor J, Walker B, Williams H, Finnie TJR, Gent N. Mitigating isolation: the use of rapid antigen testing to reduce the impact of self-isolation periods. medRxiv. 2021. https://doi.org/10.1101/2021.12.23.21268326external icon