FrogReaver
The most respectful and polite poster ever
You had the hypothesis: "If 5 times the people have it than are confirmed as having it (presumably most of those cases would be milder) then you have a much lower mortality rate."
In other words, you are suggesting that far more than 80% of the cases are mild, and that in fact the outbreaks are 500% large than have been documented. This would suggest that perhaps 96% of the cases are mild, and we are catching only the 4% most severe and only like a 5th of the mild cases. And it's possible to believe that in say the USA where testing has been limited so far,
I'm with this so far.
but in cases like South Korea that pattern of the disease is in fact impossible. Because if the disease had that pattern, South Korea with its wide nets of testing would be detecting all of those mild cases.
So just read an article to find out how many they have tested compared to how many have been confirmed.
South Korea's rapid coronavirus testing, far ahead of the US, could be saving lives
It's an amazing response overall in South Korea!
But more on topic the article says they've tested 240,000 and found 8000 with it. They have had 800+ recoveries and less than 80 deaths. That's less than a 1% mortality rate (unless I'm calculating that incorrectly). If their hospitals get overloaded that number could start to drastically rise.
With an R0 that high and a disease spreading that widely, they'd get lower and lower numbers of negative tests. Most tests would be turning up positive. But that isn't being observed. Instead, as they casts their nets wider, they get fewer and fewer positives.
That's fair but from what I read it's suspected that even with their testing that they have about twice as many people with it than they have confirmed.
And again, in fact R0 was high enough that the disease was spreading everywhere sufficiently to see the real numbers of cases be 5 times that observed, then we'd see very different things than we see. The R0 is in fact fairly well constrained at this point. It might be 2.5, it might be 4, but it very unlikely to be wildly off that.
Or South Korea had it for a week or 2 before the first few cases were confirmed - which throws that timeline off a bit and thus the rate of infection values off as well - right?
Similarly, so is the mortality rate assuming sufficient care is available. It might be 2%. It might be 3.6%. But it's very unlikely to be wildly off that.
In South Korea it's looking like less than 1% at least for now?
Now, left untreated, we have very good reason so suspect that it's much higher than 3.4%. Those numbers assume that those requiring oxygen can receive it. If they can't, experience shows mortality rate shoots up over 5%. And of course, different demographics in a population will effect the observed rate as well.
Based on the South Korea model I'm not seeing how we get to 3.4%.
Now if hospitals get flooded and can't keep up I have no idea how high it could go. 5% might not be unreasonable in that scenario.
Well in the sense that we would expect early on in an epidemic if you have spotty documentation for cases to be about 240 times more than deaths if in fact the R0 is around 3, and the mortality rate is around 3.4, and the disease takes 5-7 days to incubate, and then another 12-14 days to become lethal, then yes.
However, the R0 and mortality rate that we have are being increasingly tightly constrained.
Seems to depend a lot on early social distancing especially of the most at risk populations.