[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.

[mercer]

Could you elaborate?

[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.