新冠病毒19的无症状和症状前传播有什么区别？
你可能在病毒出现症状前阶段最具传染性，之前你开始出现症状。
2019年12月，当新冠病毒19首次出现时，它是一种全新的冠状病毒（因此最初的名称为“新冠病毒”）冠状病毒)，专家对此知之甚少。现在，六个月过去了，我们对这种病毒的基本知识有了更多的了解主要传播通过呼吸道飞沫的人与人接触，以及老年人和患有基本条件他们患严重疾病的风险更大，但我们仍然不知道一切。
举个例子:世界卫生组织最近在谁能传播病毒的问题上犯了一个错误。在六月八日新闻发布会世卫组织COVID-19大流行技术负责人Maria Van Kerkhove博士说无症状的传播冠状病毒的传播“似乎很罕见”。这一小小的声明引起了轩然大波，与许多公共卫生专家数月来关于无症状传播的说法相矛盾。
Van Kerkhove进一步澄清说，当卫生官员审查最初报告为无症状的病例时，“我们发现许多病例病情非常轻微。”她透露，有些感染者“确实无症状”，但一些国家正在深入调查接触追踪她补充道：“这是非常罕见的。”。
在第二天的问答会上，世卫组织收回了这一说法，斯达范克霍夫强调，无症状传播的实际发生率尚不清楚。她说：“我们所知道的大多数传播是，有症状的人通过感染性飞沫将病毒传播给其他人。”。“但是有一部分人没有出现症状，为了真正了解有多少人没有症状，我们实际上还没有这个答案。”
国家过敏和传染病研究所所长Anthony Fauci医学博士告诉ABC's早上好，美国6月10日，世卫组织称其最初的评论“不正确”。他说，25%至45%的COVID-19感染者可能没有症状，并补充说:“我们从流行病学研究得知，他们可以传染给未感染的人，即使他们没有症状。所以说这是罕见事件是不正确的。”
这里的混乱部分在于“无症状”一词已被普通公众和公共卫生专家广泛用于描述两组不同的新冠病毒-19患者，即被感染且真正无症状的人群和被感染但专家称为“症状前”的人群-两者之间有一个不同点。
无症状和症状前有什么区别？
“无症状是指一个人没有症状，但感染了病毒，”詹妮弗轻，医学博士，纽约大学朗根健康中心的流行病学家，告诉我们健康．“然而，症状前阶段是指一个人被感染，可能正在释放病毒，但尚未出现症状的阶段。”这在冠状病毒方面尤其重要，因为CDC国家在美国，COVID-19患者可能在接触后2至14天出现症状。
本质上，术语“无症状”与时间无关，而“症状前”与时间无关新冠病毒-19试验结果呈阳性，而患者没有症状，我们不知道他们是否会一直保持无症状，或者在一天左右的时间内出现症状，”Lighter博士说。
不幸的是，没有太多的研究区分无症状的新冠病毒-19病例和症状前病例疾病控制和预防中心（CDC）估计，35%的新冠病毒感染者没有症状，但表示这些人与有症状的人一样具有传染性。CDC还估计，40%的传播发生在人们生病之前。一项研究发表在《华尔街日报》上科学得出的结论是，在中国，大约五分之四的确诊冠状病毒感染者可能是不知道自己感染了冠状病毒的人。
如何判断一个人是无症状还是症状前?
坏消息是：你不能。在症状前携带者出现症状之前，这两种携带者的外观和感觉都“正常”。但通过检测，特别是更广泛的检测，目前医生发现检测呈阳性的人在检测时没有任何症状，表明他们不是症状前就是无症状。
该研究所所长、流行病学家Supriya Narasimhan医学博士表示:“新冠病毒的聚合酶链反应(PCR)检测非常敏感，可以检测病毒的遗传信息(RNA)传染病系圣克拉拉谷医疗中心,他告诉健康这意味着即使在无症状或症状前的人群中，它也能检测到病毒。Narasimhan博士解释说：“在症状出现前一周，在整个症状期内，它开始感染病毒，并在患者康复后的六周内继续检测RNA病毒颗粒。”。
基本上，在没有表现出症状但接触过新冠病毒-19的人中PCR检测可以显示他们是否有病毒。在阳性测试后，如果该人继续出现症状，则在测试时他们是症状前期；如果他们从未出现症状，他们就没有症状。
有症状前或无症状的人更具传染性吗？
处于症状前阶段的人具有高度传染性。Narasimhan博士说：“病毒脱落的高峰出现在症状出现之前和之后，症状仍然轻微。”。医学博士桑杰·古普塔，美国有线电视新闻网《纽约时报》首席医学记者此前也曾表示，症状前的人具有高度传染性之前他们会出现症状，如果他们要出现症状的话，”他在一份声明中说最近的美国有线电视新闻网文章．但纳拉辛汗说，对于无症状患者来说，他们传播了多少病毒，传染性有多大，仍然是一个有争议的问题。
然而，从医疗保健的角度来看，必须尽可能区分无症状患者和症状前患者，特别是在为无症状的COVID-19检测呈阳性的患者规划选择性手术时。Narasimhan博士说:“有数据表明，如果我们在病人出现症状前给他们插管进行手术，我们最终可能会伤害他们——他们的手术和呼吸结果会更糟。”这是因为，如果患者在手术后患上COVID-19，他们将在康复过程中对抗疾病。他说:“由于患者体内的病毒载量最高，传染给医护人员的风险也更大。在集中生活设施中调查疫情也非常重要，在那里为每个[居民]提供私人空间可能是不可行的，”Narasimhan博士说。
显然，关于新冠状病毒如何传播，包括无症状携带者和症状前携带者所带来的风险，还有很多需要了解。同时，戴口罩并与他人保持身体距离有助于降低感染风险，无论您或他人是否有症状、无症状或症状前。
截至发稿时，这篇报道中的信息是准确的。然而，随着围绕COVID-19的形势继续发展，一些数据可能自发布以来发生了变化。在《健康》杂志努力使我们的故事尽可能最新的同时，我们也鼓励读者通过使用疾病控制中心,谁，以及他们当地的公共卫生部门作为资源。
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", "gate": "none", "intro_page": true, "uuid": "c5d20a0c-6b54-4691-ac5b-7362b5c9e58c", "brand": "health", "headline": "Quiz: How Much Do You Know About Coronavirus?", "results": [ { "result_starting_range": 0, "button": { "_type": "button", "title": "Start Learning More", "src": "https://x.specialoffers.meredith.com/ats/show.aspx?cr=588&fm=201®source=20571" }, "result_ending_range": 3, "result_description": "Time to bone up on the basic facts about COVID-19. Check out our COVID-19 condition center and subscribe to our daily Healthy Living newsletter and never miss an update.
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