疾病控制和预防中心周一表示，它在网上发布新的指南时犯了一个错误，引用了“越来越多的证据”表明新冠肺炎是通过空气传播的健康专家和公众争先恐后地决定学校和企业是否应该重新考虑缓解措施，以防止病毒的传播。
这一失误是最近几周疾控中心让公众摸不着头脑的几个失误之一。
自7月份以来，该机构在对没有表现出症状的人进行测试的指导上摇摆不定，最终接受了这是一个好主意的建议。
特朗普政府的批评者表示，太多的政治因素在起作用，该机构的摇摆不定正在损害其在公众中的可信度。
“对这些建议的拟议修改的草案版本被错误地公布在该机构的官方网站上。疾控中心目前正在更新其关于SARS-CoV-2(导致新冠肺炎的病毒)空气传播的建议。一旦这个过程完成，更新语言将被公布，”疾病预防控制中心周一表示。
自大流行开始以来，这种病毒在空气中停留多长时间，以及在人们打喷嚏或咳嗽后传播多远，一直是人们猜测的话题。周五，疾控中心悄悄更新了其网站上关于病毒传播方式的页面。
“越来越多的证据表明，水滴和空气中的颗粒可以悬浮在空气中，被其他人吸入，并传播超过6英尺的距离(例如，在唱诗班练习期间、在餐馆或健身班)。总的来说，没有良好通风的室内环境会增加这种风险，”疾控中心周五在一篇已被删除的帖子中表示。
这一评估引发了严重的问题，比如上学或在室内用餐是否安全，因为如果有足够的社交距离，人们可能会摘下口罩。学区长期以来一直在敲响缺乏通风的警钟，包括旧建筑和打不开的窗户。
2014年9月30日，佐治亚州亚特兰大市美国疾病控制和预防中心(CDC)总部的全景。
但在疾病预防控制中心的变化被媒体注意到后不久，疾病预防控制中心删除了该帖子。目前还不清楚疾控中心会就此事发布什么消息。白宫工作队冠状病毒停止举行关于大流行的定期简报，疾病预防控制中心不举办记者招待会。
白宫对疾控中心的不明原因行动不予置评。
唐纳德·特朗普总统公开质疑疾控中心关于病毒的调查结果，经常拒绝戴口罩，并敦促该机构重新制定学校指导方针，以支持重新开放。最近几个月，白宫在卫生和公众服务部任命了一名新闻秘书，他经常贬低疾控中心的研究人员。
疾病预防控制中心去年8月发布了指导意见，建议人们即使暴露在外也不一定需要进行病毒检测，这引起了恐慌。该机构上周收回了这一说法，并回到了今年夏天早些时候的指导意见，即任何接触过的人都需要接受测试。
2020年9月16日，华盛顿，疾病控制和预防中心主任罗伯特·雷德菲尔德博士在参议院拨款委员会听证会上发言时，举起了他的面具。
同样，特朗普上周坚称，该机构的主任罗伯特·雷德菲尔德犯了一个“错误”，他预测大多数美国人要到明年年中才能获得疫苗。
雷德菲尔德的发言人最初发表了一份声明，似乎与总统保持一致，但随后收回了声明，使得雷德菲尔德是否同意总统的观点变得不明朗。
安东尼·福奇博士(Anthony Fauci)在最近几周谈到了这个问题，他说，据信这种病毒不仅通过说话、打喷嚏或咳嗽等飞沫传播，还通过空气中残留的较小飞沫传播。
在最近的一次美国医学会的采访中，美国最高传染病专家福奇说，气溶胶化的程度仍在研究中。
“我们现在需要更加关注室内空气的再循环，”他说。
在接受美国广播公司《今夜世界新闻》采访时，布朗大学公共卫生学院院长阿希什·贾(Ashish Jha)博士说，“我们依赖疾控中心给我们提供直接的科学建议，看到疾控中心来回传递这些信息和困惑，令人非常沮丧。”
“几个月来，我们已经知道COVID在人们咳嗽或打喷嚏时传播，但也在他们通过气溶胶说话和呼吸时传播，”他说。“很高兴看到昨天疾控中心终于承认了大多数科学家很久以前就知道的事情。然后今天他们改变了自己，他们接受了这个建议。对大多数美国人来说，看到疾病预防控制中心发生这种反复和摇摆是非常令人困惑的，”他补充说。
“美国人民依赖疾控中心的明确指导，包括病毒是如何传播的。这种明显是对科学过程的政治干预的摇摆不定，我认为这使得美国人更难知道什么是正确的事情，他们需要做什么来保护自己的安全，”他说。
CDC abruptly removes new guidance on coronavirus airborne transmission
The Centers for Disease Control and Prevention said Monday that it made a mistake when it posted new guidance online citing “growing evidence” that COVID-19 is airborne, sendinghealthexperts and the public scrambling to determine if schools and business should rethink mitigation steps to prevent the spread of the virus.
The misstep is one of several in recent weeks in which the CDC has left the public scratching its head.
Since July, the agency has flip-flopped on its guidance on testing people who don’t show symptoms, finally settling on the recommendation that it’s a good idea.
Critics of the Trump administration say too much politics is at play and that the agency’s wavering is undermining its credibility with the public.
“A draft version of proposed changes to these recommendations was posted in error to the agency’s official website. CDC is currently updating its recommendations regarding airborne transmission of SARS-CoV-2 (the virus that causes COVID-19). Once this process has been completed, the update language will be posted,” the CDC stated Monday.
How long the virus lingers in the air and how far it travels after someone sneezes or coughs has been the subject of much speculation since the beginning of the pandemic. On Friday, the CDC quietly updated a page on its website on how the virus spreads.
“There is growing evidence that droplets and airborne particles can remain suspended in the air and be breathed in by others, and travel distances beyond 6 feet (for example, during choir practice, in restaurants, or in fitness classes). In general, indoor environments without good ventilation increase this risk,” the CDC stated on Friday in a post that has since been taken down.
That assessment raised serious questions about whether such practices as attending school or dining indoors were safe because people would might remove their masks if there is enough social distance. School districts have long been sounding the alarm on the lack of ventilation, including old buildings and windows that won’t open.
A general view of the U.S. Centers for Disease Control and Prevention (CDC) headquarters in Atlanta, Georgia, on September 30, 2014.
But soon after the CDC change was noticed by media outlets, the CDC removed the posting. It remains unclear what CDC might post, if anything, on the matter. The White House task force oncoronavirusstopped holding regular briefings on the pandemic, and CDC does not host press conferences.
The White House had no comment on the unexplained CDC action.
President Donald Trump has publicly challenged the CDC’s findings on the virus, oftentimes refusing to wear a mask and pressing the agency to reframe its guidance on schools to favor reopening. In recent months, the White House installed a press secretary at Health and Human Services who frequently disparaged CDC researchers.
The CDC caused alarm last August when it released guidance suggesting people didn’t necessarily need to get tested for the virus even if they were exposed. The agency last week walked that back and returned to its guidance from earlier in the summer that anyone who has been exposed needs to be tested.
Centers for Disease Control and Prevention Director Dr. Robert Redfield holds up his mask as he speaks at a Senate Appropriations subcommittee hearing, Sept. 16, 2020, in Washington.
Similarly, Trump last week insisted the agency’s director, Robert Redfield, made a “mistake” when he predicted that most Americans wouldn’t have access to a vaccine until the middle of next year.
Redfield’s spokesman initially issued a statement that appeared to realign himself with the president, but then retracted the statement, leaving it unclear whether Redfield agreed with the president.
According to Dr. Anthony Fauci, who has addressed the matter in recent weeks, the virus is believed to spread both through droplets by talking, sneezing or coughing, but also smaller droplets that linger in the air.
In a recent JAMA interview, Fauci, the nation's top infectious disease expert, said the degree of aerosolization is still being researched.
“We need to pay a little more attention now to the recirculation of air indoors,” he said.
In an interview for ABC World News Tonight, Dr. Ashish Jha, dean of Brown University's School of Public Health, said, "We rely on the CDC to give us straightforward scientific advice and it’s been very frustrating to watch all of this back and forth and confusion coming out of the CDC."
"We’ve known for months that COVID is transmitted when people cough or sneeze, but also when they talk and breathe through aerosols," he said. "It was great to see yesterday the CDC finally admit what most of the scientists have known for a long time. And then today they reversed themselves and they took down that recommendation. It’s very confusing for most Americans to see this back-and-forth and the flip-flopping happening at the CDC," he added.
"The American people rely on the CDC for clear guidance, including how the virus is transmitted. And this flip-flopping, which clearly is about political interference in the scientific process, I think makes it much harder for Americans to know what the right things are, what they need to do to keep themselves safe," he said.
