[Tenoke]

>The general issue with this measure of mortality (dead/infected) is that you're assuming that the infected won't die.

On the other hand, there are also a lot of infected who only have a mild version and are never checked and recorded, which swings it in the other direction.

Edit: Seems like the parent post later edited their post to mention the above.

[scarmig]

In the case of the Diamond Princess, all infections, mild to severe, have been identified. Out of ~800 infected, 4 have died, which suggests that with the best case scenario the mortality rate is 0.5%.

This also should be read with the context that cruise ship passengers tend to be older.

Also, that number will climb a bit.

The biggest risk isn't the bare mortality rate when properly treated, but the actual mortality rate when the healthcare system is loaded to capacity and there are additional patients to handle. And since the worst patients end up in respirators for a week or more... Well, it makes the problem of load balancing keepalives very literal.

[zaroth]

I think it’s also safe to assume that all ~3,700 people onboard were exposed to the virus, so it gives an idea of the exposure vs infection rate as well.

[scarmig]

Agreed. Hypothetically, there was a quarantine going on, but it was pretty half assed.

[learc83]

As you said cruise ships skew much older than the general population, so this tells us very little about the actual mortality rate. All 4 people who died were in their 80s.

[zaroth]

IMO it’s one of the best data points we have. As I understand it, everyone on the ship was exposed, everyone was tested, we know exactly how many people became infected, and under close to ideal treatment conditions, there have been (so far) 4 fatalities of elderly patients.

Yes, this doesn’t tell you what happens with less than ideal care (higher fatality rates), or under different populations (lower fatality rates) but it’s a world of difference from the 10% fatality rates being tossed around elsewhere in this thread.

4/800 = 0.5%. And if you accept the very reasonable likelihood that actually everyone on the ship was exposed, 4/3700 = 0.1%.

[learc83]

>but it’s a world of difference from the 10% fatality rates being tossed around elsewhere in this thread.

I agree.

I misspoke when I said very little. I was taking issue with the OPs assertion that 0.5% was a best case mortality rate. I should have said it's closer to an upper bound assuming ideal treatment, since it looks like this is much worse for the elderly.

[scarmig]

Best case was ambiguous phrasing, but I intended it to mean "in the case of the best possible treatment."

[beauzero]

That seems to be the numbers (0.5%) coming out of S. Korea, which I believe has the best publicly available numbers. See https://corona-live.com so far it seems accurate and the linked supporting articles are from "internet reliable" sources ...not fringe.

[gammadens]

I came to say that the diamond princess is kind of an ideal case for getting a handle on things because it's a largish finite closedish population, kind of like why ecologists often love islands.

One thing that's puzzling to me though is even though the infected rate from the diamond princess is reported at 700+, the recovery rate is still reported at 10+. So what's going on with the other 690+ people? Are they still sick in a way they could still deteriorate? It's confusing because the cfr based on dead and recovered is still pretty high.

Again, though, the diamond princess is helping to clarify things, because nonreporting and nonpresenting aren't issues for the most part.

[TheOtherHobbes]

Which makes it more or less identical to flu.

There are around 400,000 deaths from flu globally, every year. (The numbers vary by quite a bit.) And that's after vaccination efforts.

So far I'm seeing no evidence to persuade me this is significantly deadlier. Everything that has been said about COVID-19 - the stress on healthcare, and so on - has already been happening during flu waves. For decades.

The real difference is the scale of the response. Flu's effect on the economy is a little more than a rounding error, but not by much.

Because of the measures taken, this is likely to have very significant negative economic and social effects which will last far longer than the danger of infection.

[inferiorhuman]

Which makes it more or less identical to flu.

No, it makes it about 5x worse than a typical flu season (10x worse than what America is seeing this year).

[learc83]

5x worse than a typical flu season. We have atypical flu seasons all the time.

[drcode]

However, we're also talking about older people who were healthy enough to travel on a cruise, a large number of people over 80 wouldn't do this.

[gizmo686]

.5% is far lower then the commonly reported mortality rate. That it occured in an older (and therefore more at risk) strengthens the evidence that other estimates are overstating the mortality.

Of course, within the population of old people, I would expect cruise goers to be relativly healthy; so I would expect this population to be more vulnerable then the general public, but less vulnerable then their age based demographics.

[mzs]

It will be very useful data but how many have recovered? We need to wait at least two more weeks.

[nik_s]

Thank you - I came to the same conclusion while still editing my post - I think my edit and your post coincided. I clarified this edit in my original post.

[patall]

But that could be said about any disease. As is, it is mortality given that you have symptoms which is a pretty good measure to have. For everything else, you need some many more parameters, better tests etc. Even a test for antibodies in blood which would be the gold standard can fail. Also, we do not know how many people are naturally immune to the disease. May be 10 world wide, maybe 10%, who knows?

[learc83]

>But that could be said about any disease.

With diseases that have been better studied, we have large population studies to determine how many people have been infected for every 1 person reported.

>As is, it is mortality given that you have symptoms which is a pretty good measure to have

We don't know that because we have no idea how many people have mild to moderate symptoms and haven't been tested.

At best it's mortality given that you are severe enough to seek treatment.

[marcosdumay]

> mortality given that you have symptoms which is a pretty good measure to have

It's a very bad metric to estimate the impact of an epidemics. It's way worse than useless for that, it can only lead to baseless panic.

It's a pretty good metric for many uses, just not for this one.

[swader999]

In the hardest hit areas like Wuhan, almost everyone has been tested.

[Reason077]

> "Wuhan, almost everyone has been tested"

Very doubtful. This is a city of 11 million people. I doubt they would have the kits or lab capacity to test even 1% of the population so far.

[joosters]

Reference for that, please?

[swader999]

In the who presentation, Dr Bruce Aylward mentioned this. I'll try to dig up the exact spot in the clip for you. At 1:07:44 this is discussed in depth: https://youtu.be/-o0q1XMRKYM

[joosters]

Thanks for the link! He says that there have been door to door testing of temperatures, and I'd nitpick by saying that's not quite the same thing as testing everyone for the virus, but it is better coverage than I had realised.

[JoeAltmaier]

Surprised! I worry about unintended consequences. During an epidemic, officials visit every home! Potentially spreading the virus unintentionally thru healthcare personnel. Don't know if I'd open the door to somebody who admits having visited thousands of people before getting to me...

[swader999]

I suspect this played out on the diamond princess.

[swader999]

Yeah he's rolling with what he's got. The antibody studies that come at the tail of these things would be definitive.

[learc83]

Here's a response I wrote earlier to that.

After he said that someone else from the WHO contradicted him.

"The claim was quickly challenged by an infectious diseases expert who serves on a committee that advises the WHO’s health emergencies program.

Gary Kobinger, director of the Infectious Disease Research Center at Laval University in Quebec, said it would be highly unusual for there not to be mild or symptom-free cases that are being missed. He pointed to the fact that outbreaks have popped up in countries far from China — including Iran and Italy — because people with mild infections were not detected and traveled to other places.

'There are mild cases that are undetected. This is why it’s spreading. Otherwise it would not be spreading because we would know where those cases are and they would be contained and that would be the end of it,' said Kobinger, who insisted that mild, undetected infections cannot be ruled out until people who haven’t been diagnosed with the illness can be tested for antibodies to the virus.

'As long as we do not have good serology data, I think that it is completely speculative to say that there are no undetected cases,' Kobinger said."

What Dr. Aylward says makes no sense and reads more like a PR fluff piece designed to praise China to keep them happy, and as Kobinger points out he's probably wrong. From the same press conference he says this "If I had COVID-19, I’d want to be treated in China."

Which is obviously bullshit.

[palmstroem]

He gives more detailed numbers about Guandong: at the height of the epidemic, they performed 320000 tests, of which less than 0.5% were positive, which means that they missed less than 200 cases. In other words, Aylward thinks the Chinese numbers are basically correct. Even though of course not all cases are detected, we are not looking at magnitudes more undetected cases driving up the infections in the background.

[learc83]

>320000 tests, of which less than 0.5% were positive, which means that they missed less than 200 cases

That doesn't follow from your premise and it doesn't match what he said.

"Of 320,000 tests performed, just under 0.5% were positive for the virus at the peak of transmission there, he said — which suggests that only 1 case out of 200 was being missed."

And even based on what he said the conclusion he's drawing doesn't follow either. From other sources the 320,000 was from a community sample. Guangdong has a population of 113 million, a 0.5% infection rate is over half a million people.

Even assuming it's not a random community sample, and it's from people who self selected, so the infection rate is much higher than the general population, there is still room for an order of magnitude more mild cases than are showing up in official numbers.