The novel coronavirus is a long disease. That’s one of the things that makes it so problematic. Apart from having being at least 10x as lethal as the standard flu, and people having no herd immunity against it (so potentially up to 5x as many infectees as during a typical flu season), the average hospital stay lasts several times as long as for flu as well. Multiplied together, the cumulative strain on healthcare systems goes up by two orders of magnitude.
The mortality profile is distinct over time. It is concentrated in the first few days, as the really hopeless cases die off quick. Then recovery improves. But after 3-4 weeks, it begins to go down again. I suppose there’s only so much a body can withstand, such as fighting off a virus while hooked up to a ventilator. We are beginning to see a demonstration of that in South Korea.
As Robert Rohde points out, the CFR in South Korea – which started off really small, thanks to its extensive testing regimen (almost all cases were caught) and excellent healthcare system – has been creeping upwards as of the past week:
A couple of weeks ago, people were excited that South Korea was only showing a 0.6% case-fatality rate.
Today that rate has risen to 1.4%, and the progression analysis suggests that it could still rise over 2%.
South Korea has the second largest number of hospital beds of any OECD country after Japan, and ahead of Germany in third place. 9,478 cases largely concentrated in Daegu was not a large strain on its system and already looks decidedly modest relative to what’s unfolding in Europe and the US. We need to start assuming a CFR of ~2% – not 1% – as the base case scenario in which healthcare systems hold up.