Global Health Emergency Declared, Viral Shedding, & Germany Case
Welcome to another MedCram update on the coronavirus. As of yesterday, it was 170 deaths and 7,783 confirmed infectious cases. This update is for January 31st, 2020. So overnight, we’ve gone to unfortunately 213 deaths and 9,776 confirmed infections. Most of those in mainland China. This data is coming from the WHO and other healthcare agencies coming together. It’s about a 26 percent increase in the number of confirmed infections and a 26% increase in the number of deaths.
Now, I noticed I’ve got a lot of comments about the potential fallacy of dividing the numerator here, which is the number of deaths, which is current divided by the number of infections, which may have not matured to the effect that they may have caused mortality because it may be too early in the course, and I understand that, and a lot of people do understand that.
The problem is though is the incubation period can vary quite long. And so, you know, do you go back one week to see what the case infection rate is? Do you go back three days? And so, if you really want to figure out what this is, of course you wait to the very end until the epidemic is over, which will hopefully be very soon, and then you take that numerator and divide it by that denominator, and you will get yet what the case fatality rate is.
Unfortunately, we can’t do that in the middle of it. And as we’ll talk about very shortly, the incubation may not be as long as we think, which is fortunately a good thing. However, there’s a trade-off in this situation as we’ll talk about in the Germany case very shortly, where there may be asymptomatic shedding of the virus.
And that brings us to the other point is: Yes, well, there may be an underestimation of the mortality rate by looking at the current numerator and divided by the current denominator, there’s also the possibility of way overestimating the mortality rate if there’s a bunch of asymptomatic infections, where people get it and they get better, then this denominator down here is actually way bigger than we think it is. If that’s the case, well, then this mortality rate is much less than 2%.
It’s hard to say exactly what it is at this point. Suffice to say, that if you want to look at an easy way of comparing how the mortality rate is changing over time, simply take the current fatality rate and divided by the current estimated infection rate.
We’re probably underestimating both the numerator and the denominator here because there’s just not enough kits to go around to test everybody. If you think about it in China, they’re not going to be testing people who might have a little bit of malaise if they’ve got a hospital full of people who had pneumonia. Those are the ones that are going to get tested. So what you may be seeing here in China is people who are very ill getting tested for the coronavirus, and that may make the mortality rate go higher because you’re selectively testing people that are sicker whereas here in the United States, we’re testing anybody who sneezes wrong that’s come from China.
And so we maybe picking up a lot of asymptomatic cases, and that may be the reason why all of the deaths that we are seeing are almost exclusively from China, and nobody outside of China, and in the United States, nobody has really come down with a serious illness.
So these are observations. These are not facts. We don’t know yet. These are hypotheses. So to keep it simple. We’re going to go ahead with the current mortality rate divided by the current infection rate. Not saying that that is the mortality rate, but it’s certainly a way to track it. And so you’re comparing apples to apples.
But the total infection rate is way past SARS. Now, we are treading on new territory when it comes to viral epidemics, and that brings us to the other news which of course the WHO has now said that this is a serious global emergency in terms of a virus.
Now the other big news today is in Riverside, which is close to home for me because that’s the county that I work in, in Southern California, and I actually worked with the public health officer for Riverside County – Dr. Kaiser, who today had to forcibly quarantine a patient who was on the March Air Reserve Base who wanted to leave, and of course that caused him to be in isolation until deemed unnecessary, or two weeks.
So what they’re currently doing right now at March Air Reserve Base is this plane, which has about a 195 passengers are now voluntarily, (except for one because he tried to leave) staying on the base for 72 hours, and during that time they’re doing a lot of screening; they are checking for temperature; they’re doing nasal swabs. At the end of those 72 hours, if everything is an Okay, then they are free to go.
Of course, you may say Ha, they are in Southern California, let them stay in Southern California. Well, these people are from all over the United States, and I’m sure as soon as they are let go, they will be coming to your area of the woods.
So let’s explore a little bit about what’s happened in terms of our knowledge over the last couple of days over this virus, and how it behaves in terms of incubation period and in terms of the type of illnesses that it causes, and also the ability for it to shed, because there’s a lot of interesting information that we’re about to get into here that has been published recently in the New England Journal of Medicine, and it’s hot off the press.
We will give you a link in the description below, but let’s get into that. Okay, so this is a drawing that is based on a figure in that New England Journal of Medicine article, and what we’ve got is five people here. We got the index patient, and we’ve got Patient One, Two, Three, Four.
This is all happening in Germany, and these are all dates in January here below. Okay. So the first thing that happened here is that there was a business meeting that was occurring, and this index patient here was actually from China, and they flew over to Germany to attend a business meeting, and this meeting occurred over the period of the 19th to the 22nd. So who was that that business meeting? Well, these two people here who are German natives attended at the business meeting with index patient.
Everything was fine. Nobody was having symptoms, and the index patient, while she hopped on a flight on the 22nd and goes back to China and starts developing symptoms almost immediately after she gets on the flight. Okay. She goes back to China and of course, there’s the big rage of what’s going on, and she has the symptoms. So what does she do? She goes and gets tested and she goes and gets tested over here on the 26th.
Meanwhile, what happens is Patient Number One who was at the meeting; he starts developing symptoms on the 24th, mild symptoms. So cough, fever, malaise, all the sorts of things that you would assume would go along with the flu, and his symptoms get worse, and then they get better.
Now, the index patient. She gets tested here on the 26th, PCR, and it’s positive. Soon as it gets positive, she goes back, and she calls her company, and they do it a trace-back to try to figure out all the people that she may have come in contact with, so they can figure out where to test. And of course by this point, Patient Number One: well, yeah, I had a little bit of flu symptoms, but I’m fine now, so they check him the next day on the 27th. PCR positive! Boom! But he’s asymptomatic. He’s gotten better for it’s mild symptoms; they’re really not that bad anymore.
Nevertheless, they go ahead and they test him, they check for viral loads. They see if there’s virus in his saliva, virus in his sputum. And guess what? He has a high viral load, even though he is not symptomatic. In other words, he is contagious, and they find up to ten to the eighth viral particles per milliliter. That’s pretty high.
Well, guess what? Patient Two, Three and Four? They all start developing symptoms as well during the same time. Patient Two symptoms last a little bit longer, and they test on the 28th, of course when he turns out positive all hell breaks loose, and they’re like, wow what’s going on here? And so, a whole bunch of other people get tested, and so sure enough Patient Two has a positive PCR. But remember this Patient Number Two attended the same meetings, and so it’s very possible that this is how it worked.
Okay, but here’s the point that should blow you away. Patient Three and Four never attended the meetings; however, Patient Three and Four did have contact with Patient Number One, and they can actually map out when patient Three and Four had contact with Patient Number One, and all of these contacts were before the patient actually had symptoms. So, in other words, Three and Four started to develop symptoms, but they started to develop symptoms later, about a day later.
So they develop symptoms on January 25th, January 26th. And of course, they got tested with everybody else because they were all freaking out of course, and sure enough PCR was positive. So here’s the take-home message. Number one: it looks as though the incubation period here is fairly short. So that’s a good thing. That means that you’re going to find out quickly whether or not the patient has a virus. What’s bad about this though is that you’re able to spread the virus both before and after it seems you have symptoms. The fact we know that Patient Three and Four got their virus from a patient who got it from the index patient here, and they got it before they had symptoms.
So this begs the question, and it’s a very interesting question about what are we doing at March Air Reserve Base? Yes, if we were to watch them for 72 hours, which of course is three days, we should be able to pick up if any of them have symptoms, fevers, anything of that nature. But the question is do we release them after 72 hours if they’re all clean? And I think the debate is still going on that. Should you hold them for two weeks? Yeah, that would be safer for everybody. But you have to weigh the practicalities of holding them for 72 hours versus two weeks. And do you really need to do that? If it looks as though the incubation period is pretty short.
So what are the big take-home messages from this New England Journal of Medicine article? Number one: the incubation period seems to be relatively short, maybe three or four days, could be longer, could be shorter. But that seems to be what we’re seeing here. Number two: even though you’re asymptomatic, it seems pretty clear that you’re able to shed and infect somebody else with the virus. Number three: it seems as though at least here in this short cohort of four people that all of these people had very mild symptoms. Everyone here so far is not in the hospital. They’re not on a ventilator. They seem to be doing just fine. These were healthy people though in Germany. So it’s sometimes hard to actually generalize this to everyone. Alright, more updates as they come. Thank you for joining us!