COVID-19的测试准确性(CT扫描与RT-PCR)、加利福尼亚新案例

Testing Accuracy for COVID-19 (CT Scan vs. RT-PCR), New California Cases (Lecture 27)

Welcome to another MedCram update. Let’s talk about California and testing. But before we do, let’s just review. Total confirmed 82,164; total deaths 2801; total recovered 32,897. We see more of a continuation of what we’ve been seeing in the past.

欢迎来到另一个MedCram更新。让我们谈谈加利福尼亚和测试。但是在我们做之前,我们先回顾一下。总计确认82,164;总死亡人数2801;共追回32,897。我们看到的是过去所看到内容的延续。

Let’s go to the Worldometer. We are going to talk a little bit about testing today and also the positivity rate. In UK, they have well over seven thousand tests, of which only 13 positive, and that’s a very low positivity rate of course. In Italy, where they actually have an outbreak, they’ve done over 9,000 tests, of which only 470 are positive; it’s about a 5% positivity rate. In France, 2.2 positivity rate; in Austria, 321 tests, of which two are positive. And then in the United States, notice, we have only done 445 concluded tests, of which 14 are positive, and that’s around 3.1 positivity rate.

让我们去看一下Worldometer。我们将在今天谈论一些测试以及阳性率。在英国,他们进行了超过7,000项测试,其中只有13项阳性,这当然是非常低的阳性率。在实际爆发的意大利,他们进行了9,000多次检测,其中只有470例为阳性。阳性率约为5%。在法国,阳性率为2.2。在奥地利,有321项测试,其中两项是肯定的。然后在美国,请注意,我们只完成了445项总结测试,其中14项呈阳性,这大约是3.1阳性率。

These tests are not as sensitive as you may think. They could go to be surprised that the sensitivity on these tests are only around 70 percent, and so it is possible to have a negative test and to still be infected with the coronavirus.

这些测试并不像您想象的那样敏感。他们可能会惊讶地发现,这些测试的敏感性仅为70%左右,因此有可能进行阴性测试并仍然感染冠状病毒。

We see that there are so far 334 new cases and one death in South Korea. And the number of confirmed cases is expected to jump in the coming days as health authorities have started testing more than 210,000 members of this church in Daegu.

我们看到,到目前为止,韩国有334例新病例,另有1例死亡。随着卫生当局已开始测试大邱这座教堂的21万多名成员,预计确诊病例数将在未来几天内激增。

If we look at the numbers coming out of China and the rest of the world in terms of total deaths, that seems to be leveling off, and if we look at the number of daily new cases outside of China, that has hit its highest amount ever on February 26th, with daily cases of 569.

如果以总死亡人数来看,来自中国和世界其他地区的人数似乎正在趋于稳定,如果我们查看XX以外的每日新增病例数,则达到了最高水平。于2月26日发布,每天有569例。

I want to go to a local site, Eyewitness News, here in Southern California. A new case that has been detected in Northern California in a resident who has not traveled overseas. A couple of things that I want you to be aware of. This patient is a resident of Solano County; turns out that Solano county is the home to Travis Air Force Base where Americans returning from overseas were quarantined. The patient was transferred back on February 19, so that was about a week ago from undisclosed hospital to UC Davis Health, and that is the hospital in Sacramento for the University of California Davis. The patient had already been intubated, was on a ventilator, and was given droplet precaution orders because of undiagnosed and suspected viral conditions. So there are other viruses that can do this.

我想去南加州的一个本地站点,目击者新闻。在北加州的一个未曾出国旅行的居民中发现了一个新病例。我希望您注意几件事。该患者是索拉诺县的居民;原来,索拉诺县是特拉维斯空军基地的所在地,在那里,从海外归国的美国人被隔离。该患者于2月19日被转移回医院,大约是一周前从一家未公开的医院转移到UC Davis Health,那是位于加州大学戴维斯分校萨克拉曼多的医院。该患者已经被插管,正在呼吸机上,并且由于未诊断和怀疑的病毒状况而被给予了滴剂预防措施。因此,还有其他病毒可以做到这一点。

Now at the time, it seems as though UC Davis has asked the CDC for testing, but this was not done at the time. And if you go to the CDC website, it tells you what their requirements are for testing although they do put a disclaimer that they will look at a case-by-case basis. But essentially unless you travel to Wuhan or that part of China, they weren’t really going to be doing that kind of testing, so it’s unclear how eventually UC Davis was able to get the CDC to test this patient.

当时,看来加州大学戴维斯分校已要求CDC进行测试,但当时尚未完成。如果您访问CDC网站,它会告诉您他们对测试的要求,尽管他们确实声明免责声明他们将视具体情况而定。但基本上除非您前往XX那部分地区,否则他们真的不会进行这种测试,因此目前尚不清楚UC Davis最终如何能够让CDC对该患者进行测试。

But they did, and eventually, on Sunday, the CDC ordered the covid-19 testing of the patient. At that time, the patient was put into airborne precautions. What does this mean? It means that anybody going into that room had to have an n-95 mask, and had to go into contact-isolation precautions. That means they would have to wear a gown, gloves. They may even have to wear eyewear protection. If they were not able to do that, then they would have to under something called peppers, where they basically go in with a mask that was vented.

但是他们这样做了,最终,CDC于周日下令对患者进行covid-19测试。当时,患者被置于空中预防措施。这是什么意思?这意味着进入该房间的任何人都必须戴n-95口罩,并必须采取接触隔离措施。这意味着他们将不得不穿礼服,手套。他们甚至可能需要戴眼镜保护装置。如果他们不能做到这一点,那么他们将不得不在一种叫做胡椒粉的东西下,他们基本上要戴上一个通风口罩。

From Sunday to Wednesday, it took for the CDC to confirm. Finally, the patient’s test was positive. The small number of employees were to go home and monitor their temperature for any kind of fever or things of that nature. And the key here is to recognize apparently this patient had NO travel to that part of the world.

从星期日到星期三,疾病预防控制中心需要进行确认。最终,患者的检测结果为阳性。少数员工要回家,并监测自己的体温,以检查是否有发烧或类似性质的事情。而且这里的关键是要认识到该患者显然没有去过世界的那个地方。

They go on to say here at this time, the patient’s exposure is unknown. It’s possible that this could be an instance of what they call community-spread of covid-19, which would be the first time that this is happening in the United States. It’s also possible, however, they said that the patient may have been exposed to a returned traveler who was infected.

他们此时在这里继续说,病人的暴露情况未知。这很可能是他们所说的covid-19社区传播的一个实例,这将是美国第一次发生这种情况。但是,他们也有可能说患者可能已经接触了被感染的返回旅行者。

Of course, this brings up the issue of anybody that comes in with fever, or signs, and symptoms of a viral illness, and shortness of breath, could be potentially a carrier of this novel coronavirus. And that’s why it’s really important to have lots of personal protective equipment at hospitals where they belong instead of running out at hospital. So it’s really important that hospitals have the ability to acquire personal protective equipment because you don’t want to show up to a hospital where the employees there, or the doctors, or the nurses don’t have the adequate amount of protection so that they don’t pass the virus onto anybody else that might show up at that hospital. So please do not take masks and protective equipment from hospitals for your own use.

当然,这会引起任何发烧,体征,病毒性疾病的症状和呼吸急促的问题,可能是这种新型冠状病毒的携带者。这就是为什么在其所属的医院拥有大量个人防护设备而不是在医院中耗尽所致,这一点非常重要。因此,医院具有购买个人防护设备的能力非常重要,因为您不想去那里的员工,医生或护士没有足够保护量的医院就诊。不要将病毒传播给可能出现在该医院的其他任何人。因此,请勿自用医院的口罩和防护设备。

But this really brings up a big issue, and that is how do you test people for coronavirus? How do you know quickly whether or not this person that’s coming in has this virus? Obviously, if we see here in this case, it took them from Wednesday, when they actually got the positive test, all the way from Sunday, when they first ordered the tests. You can see that that’s not the optimal situation, especially when we add to the situation that this test is not really that sensitive, meaning that if you have a negative test, you can absolutely rule it out.

但这确实带来了一个大问题,那就是如何测试人们的冠状病毒?您如何迅速知道这个进来的人是否患有这种病毒?显然,如果我们在这种情况下看到的话,它们是从星期三开始的,那时他们才真正获得了积极的测试,一直到周日他们第一次下令测试。您会看到这不是最佳的情况,尤其是当我们加上这种测试并非真的那么敏感的情况时,这意味着如果您的测试阴性,则可以绝对排除。

So enter a study that I think is going to be important, and that is this Science Daily News article, which talks about this article that was just published in Radiology called CT Provides the Best Diagnosis for COVID-19. I will put a link to it in the description below.

因此,请输入一项我认为将很重要的研究,这就是《科学日报》的这篇文章,该文章讨论的是刚刚发表在放射学上的这篇文章,名为《 CT提供COVID-19的最佳诊断》。我将在下面的描述中添加一个链接。

Basically what they did is in China, they looked at over a thousand patients, and they did this reverse-transcription-polymerase-chain-reaction, which is what RT-PCR stands for. This is where you look for the actual RNA of the patient and compared it to the classical findings that they see on CT scan.

他们所做的基本上是在XX,他们检查了超过一千名患者,并进行了逆转录聚合酶链反应,这就是RT-PCR的代表。在这里,您可以寻找患者的实际RNA,并将其与他们在CT扫描中看到的经典发现进行比较。

Here’s another news item of the same article. So the title is CT Provides Best Diagnosis for COVID-19. And it says the study from China shows that chest CT demonstrates better sensitivity than this blood test looking for the actual PCR of the virus.

这是同一篇文章的另一则新闻。因此,标题是“ CT为COVID-19提供最佳诊断”。它说,来自XX的研究表明,胸部CT表现出比实际进行该病毒PCR的血液检查更好的敏感性。

Remember that halfway through the epidemic last month, they changed the criteria, the definition, for the diagnosis of COVID-19. As you can see here in a study of more than a thousand patients that was published in the journal article Radiology, which I would link to so you can look at it for yourself, chest CT actually outperformed blood testing in the diagnosis of 2019 novel coronavirus, and this was looked at in Wuhan, China.

请记住,上个月流行病已经过半,他们改变了诊断COVID-19的标准和定义。正如您在此处发表的一篇关于放射学的杂志上发表的一项针对一千多名患者的研究中所看到的那样,我可以将其链接到上面,以便您可以自己查看一下,在诊断2019年新型冠状病毒时,胸部CT实际优于血液检测,这是在中国武汉研究的。

So it’s important to understand that you have to make an early diagnosis of COVID-19 if you’re going to isolate, and you’re going to prevent the spread of that disease. As we talked about earlier in an early JAMA article, 41 percent of patients who contracted COVID-19 did so in the hospital, and the majority of those, 41 percent, were healthcare workers.

因此,重要的是要理解,如果您要隔离,必须对COVID-19进行早期诊断,并要防止该疾病的传播。正如我们在早期的JAMA文章中早先提到的那样,感染COVID-19的患者中有41%在医院这样做,而其中大多数(41%)是医护人员。

According to the latest guidelines by the Chinese government, the diagnosis must be confirmed by reverse transcriptase-polymerase-chain-reaction, or the gene sequencing. They say here, however, that those throat samples are only about 30 to 60 percent positive at initial presentation. Having a low sensitivity implies that there’s going to be a lot of people who will be negative initially, and you’re going to miss those people. Those people are going to come through into your hospital and potentially infect other people, specifically people who are there to help and causing them to be taken out of work and put into isolation most likely.

根据xxxx的最新指南,必须通过逆转录酶-聚合酶链反应或基因测序来确诊。但是他们在这里说,这些喉咙样本在初次出现时仅阳性约30%至60%。敏感度低意味着最初会有很多人消极,而您会想念这些人。这些人将进入您的医院,并可能感染其他人,特别是那些在那里寻求帮助的人,这些人最有可能导致他们失业和孤立。

And so they say here that early diagnosis of COVID-19 is crucial for the disease treatment and control. Compared to RT-PCR, that is the genetic testing, they say here that chest CT Imaging may be a more reliable, practical, and rapid method to diagnose and assess COVID-19, especially in the epidemic area.

因此,他们在这里说,COVID-19的早期诊断对于疾病的治疗和控制至关重要。他们说,与RT-PCR相比,这是基因检测,他们认为,胸部CT成像可能是诊断和评估COVID-19的更可靠,实用和快速的方法,尤其是在流行区域。

So why did they think that? Well, let’s take a look and see the study. There were over a thousand patients who underwent both CT chest and RT-PCR tests from January 6 to February 6th, and what they did was they looked at all of those people who had a positive PCR, and there was about 601 of those. And everybody that had a positive CT scan, and there were 888 of those.

那么他们为什么这么认为呢?好吧,让我们看一下研究。从1月6日到2月6日,有1000多名患者同时接受了CT胸部检查和RT-PCR检查,他们所做的是,他们检查了所有PCR阳性的人,其中大约601人。每个CT扫描都呈阳性的人中,有888人。

And then they asked the question. What’s the sensitivity? What’s the specificity? And what’s the accuracy? And what they found was that about eighty-one percent of patients with a negative RT-PCR but a positive CT scan were reclassified as highly likely or probable cases with COVID-19 based on the comprehensive analysis of clinical symptoms, typical CT manifestations, and dynamic CT follow-ups. What they mean by that? It was getting worse and they were consistent. They also found in a lot of these that the initial test may have been negative, but that follow-up tests turned positive, confirming in a lot of these cases the original CT findings.

然后他们问了这个问题。灵敏度是多少?具体是什么?准确度是多少?他们发现,根据对临床症状,典型CT表现和临床表现的综合分析,约有81%的RT-PCR阴性但CT扫描阳性的患者被重新分类为COVID-19的高可能性或可​​能性病例。动态CT随访。那是什么意思?情况越来越糟,他们是一致的。他们还从许多此类检查中发现,最初的检查可能是阴性的,但后续检查却变成了阳性,从而在许多情况下证实了最初的CT检查结果。

Let’s review those results. The results showed that 59 percent of these patients that they tested had PCR results that were positive, 88% had positive CT scans. They said that the sensitivity, and this is something that you want to be very very high in this situation, because something that is very sensitive, it means that if it is negative, you can practically rule it out, and as it turned out that sensitivity of chest CT was 97 percent based on positive RT-PCR results.

让我们回顾一下这些结果。结果表明,他们测试的这些患者中有59%的PCR结果为阳性,88%的CT扫描为阳性。他们说敏感度很高,在这种情况下,这是您希望非常高的水平,因为非常敏感,这意味着如果它是负数,您实际上可以排除它,事实证明,根据RT-PCR阳性结果,胸部CT的敏感性为97%。

In patients with negative RT-PCR results, 75 percent of those patients had positive CT findings, and of those 48 percent were highly likely cases. So what we’re seeing here is that CT scans may be the way to get a quick screening of whether or not your patient with fever is likely to have COVID-19. But the question is what are the findings on CT? It’s good enough to know that you should get a CT, but what is it that you should be looking for?

在RT-PCR结果阴性的患者中,有75%的患者CT表现为阳性,其中48%的可能性很高。因此,我们在这里看到的是CT扫描可能是快速筛查发烧患者是否可能患有COVID-19的方法。但是问题是CT的发现是什么?知道您应该获得CT足够了,但是您应该寻找什么呢?

I’m going to link in the description below a YouTube video describes the findings on CT scan of known cases of covid-19, and that concludes our update for today. Realize that many of these videos are made the evening before they get released because I am still working in the Intensive Care Unit, seeing patients every single day. And so this is something that I do at the end of the day because we, as healthcare providers, run on the frontline, and we have to be prepared. Thanks for joining us.

我将链接到下面的描述中,YT视频描述了已知covid-19病例的CT扫描结果,并总结了今天的最新情况。请注意,由于我仍在重症监护室工作,每天都在看病人,所以许多视频都是在发布前的晚上制作的。因此,这是我一天结束时要做的事情,因为我们作为医疗保健提供者在前线工作,我们必须做好准备。感谢您加入我们。

MedCramChina

View all posts

Add comment

Your email address will not be published. Required fields are marked *

error: Content is protected !!