Asymptomatic Transmission & Incubation Period (Coronavirus Lecture 6)
Welcome to another Medcram update. So where are we currently? Well as it stands, the number of deaths is up from 132 to currently 170, and the number infected globally to a current 7,783. Now, these numbers have to be taken with a grain of salt.
First of all, I’m going to give you a link where you can get an update at any time of day on the number of cases, and it’s updated by Johns Hopkins University, and the link to that is in the description below.
首先，我将为您提供一个链接，您可以在该链接上随时获取案件数量的最新信息，该信息由约翰·霍普金斯大学（Johns Hopkins University）更新，其链接在下面的描述中。
The other thing though is that there is a real shortage of the tests. So that’s going to affect both the numerator here in terms of deaths and also the denominator. Obviously, when someone is very sick, they’re going to be wanting to make sure that they know whether or not this is the novel coronavirus.
As it stands right now, good news is a lot of these countries outside of China have really been static in terms of the number of cases. USA is still at five; Canada is still at three.
One thing that shows the concern here in terms of spreading the disease is the case of the 10-year old that was essentially asymptomatic. Let’s talk about that. So apparently this 10-year-old child with his parents, also grandparents, flew from Shenzhen all the way up to Wuhan, and this was around the end of December, and they were there of course for the New Year. And after about three to four days, they came down with symptoms. At that time, there was a little bit of interest in about, you know, 20 to 30 cases of pneumonia that have been undiagnosed in the hospital, but it wasn’t certainly the international level of news as it is today.
Both the parents and the grandparents became ill, and in further review of this, it seems as though the family went to actually go visit some loved ones that were in the hospital the time. So the parents and the grandparents became ill, and they were tested, and by about this point, of course, if you add 3 to 4 days to December 29, they knew that they were dealing with a viral outbreak, and of course, they tested positive for the novel coronavirus, and the grandparents were tested, and of course they turned out to be positive for the novel coronavirus.
While the parents insisted that their 10-year-old boy be tested even though he was asymptomatic, and they didn’t want to test the boy because he wasn’t showing any signs of illness, but they went ahead and tested him anyway, and the 10-year-old child tested. Guess what? Positive for the novel coronavirus even though he was completely asymptomatic, didn’t have fever, cough, shortness of breath.
When they did a CAT scan though, they looked, they found that he actually had signs of pneumonia. So here’s this thing where people can be asymptomatic, have very mild disease, but be shedding the virus.
And of course, this is concerning with the recent news of this plane taking our diplomats from China back and landing at the March Air Force Reserve Base, and it is there that they are all under voluntary quarantine for at least three days where they’re being checked out and actually having nasal swabs and things of that nature, but the question really comes down to is how good of a quarantine can we do? And how good of a blockade or lockdown can we do? How well can we screen people coming in through the airports if people may not have fevers, may not have these sorts of symptoms, and they’re coming in with the virus, and they’re shedding it and it’s spreading.
Interestingly, a couple of points that I want to show is it only took about three to four days to show symptoms in the parents and the grandparents. That’s a pretty short incubation period, so this 10-year-old shows that it’s possible, and I think this is the basis for the health minister in China saying that there may be some cases where this can spread even though people may be asymptomatic.
It also highlights something else as well. What they’re noticing is that the young may have a milder course, whereas the elderly have a more severe course. It’s kind of a dichotomy. I saw one article that brought this up, and you’ve got this continuum, whereas on one side you have SARS, which actually was a coronavirus, and the other side you have flu, and what is the continuum here? Well with SARS, this was a very severe disease, but you couldn’t really spread it unless you were symptomatic. So SARS basically allowed authorities to isolate it and to prevent its spread, so severe, however, not going to spread in an asymptomatic patient.
Take the ether extreme here, which is the flu, where generally speaking you get the flu, you take some over-the-counter medication; not a big deal, but you can spread the flu when you’re asymptomatic. It has more of a shedding. And so the question is where exactly in this continuum is this new coronavirus going to be? Certainly, it has some of the components on this end, which is where you can have it be asymptomatic, but you can shed it, whereas we can see very clearly that this thing does have a mortality rate, especially in the old. So I think time is going to tell on which side this coronavirus is going to come down on. Again, go to the Johns Hopkins website, and you can get immediate updates, and it will map out, and we’ll show you where things are spreading. Well, this is the update. Thanks for joining us!