Hacker News Reader

Comment by ajross | Hacker News Reader

Then how does that square with the data from the west, which broadly confirms the CFR China reported originally? Why are Italians dying like flies to this thing the Chinese were able to hide?

This "The CFR is much lower!" thing is rapidly becoming a conspiracy-level fallacy... It's probably true that there are a bunch of unmeasured cases (a reasonable study yesterday guessed at a 6x undercount) and that the CFR is currently overstated because of sampling problems with test availability.

It is absolutely not possible that there were a million cases in Hubei in december. Not from this disease. Come on, folks.

View on HN

Italy, China, U.S. most likely determine cases the same way so far. No wonder CFR is similar. However, these tests are limited compared to serologic tests:

> The test kits in use in the U.S. described in the articles detect viral genetic material—RNA, in the case of coronaviruses—which can be infectious material or noninfectious fragments. Once the patient has recovered and the RNA has been cleared, the tests will be negative. If we’re trying to ascertain what proportion of the population has been infected and experienced asymptomatic, mild or more serious infections, such post-infection testing yields “false negatives.”

> Additional, essential information will need to come from “serological tests” that measure antibodies in blood, which will tell us whether a person has been recently infected with SARS-CoV-2 and recovered. (Note that antibodies take about 10-14 days from exposure to the virus to appear.)

https://www.wsj.com/articles/do-antibody-testing-to-understa...

http://archive.vn/SJkJu

> The mortality rate is thought to be ≤2%, but precise numbers uncertain due to a lack of available serological testing.

https://www.hopkinsguides.com/hopkins/view/Johns_Hopkins_ABX...

So just to be clear, since you're mostly just quoting sources: those data do not corroborate a 1M infection undercount in China in December. They match what we're seeing, probably with a much more moderate (e.g. 6x) undercount of active infections.

How does a disease that's close to 3x more contagious than the flu stop at 80k people in the densely populated cities of China?

The current numbers are the ones that don't add up. Even John Hopkins estimates up to 500k cases in the US at the moment.

Everybody knows the real number of cases is greater than the confirmed number of cases, everywhere, regardless of what country is reporting the numbers.

how would you know that ? Can you provide sources to backup this claim ? I'm interested to know.

Nobody knows. Anybody that cites numbers is pulling them from a very biased sample. With the exception of a few countries, most of the testing is done on a very self-selected set of people. Those with symptoms who were ill enough to get tested and willing deal with a with a 14 day quarantine if they turned up positive.

Even counties with good, pervasive testing can’t test for how many people already had it and are carrying antibodies.

We are flying very blind here. Treat all numbers with a huge grain of salt.

https://www.youtube.com/watch?v=mCa0JXEwDEk

It's by definition. If you can see 3 ducks in your house, that means there are 3 or more ducks in your house including the ones you didn't see.

No it's about knowing how diseases spread. This is not a new disease. the mortality rates come from the ratio of known deaths to known infections. Obviously not all cases are known especially in the USA where we don't even have enough tests to test people coming in with severe symptoms.

That is the thing. Nobody knows because we have no earthly clue how many people have it currently or had it in the past few months. People quoting “death rates” are pulling the denominator (number of deaths) for that rate out of their ass. Same for transmission rate. Any rate requires a good denominator—we have zero clue what that number is. We have little testing here in the states, and my understanding is we currently do not have a way to test if you previously had it.

We are making massive social and economic changes based on very unclear data. People are sitting at home with nothing to do but watch live streaming YouTube videos of “confirmed cases” on a map or looking at some website showing the same and freaking the fuck out. But it is all based on crap data.

We can “pause” our global economy for a short while (week or two) but any more than that is going to have massive issues. Those toilet paper memes are funny until you run out yourself. Not having baby wipes in stock isn’t very funny. People are going to start getting into physical violence in stores over that shit (if it hasn’t happened already). People are gonna relapse into addiction. People are going to mill themselves. Supply chains are going to fall apart.

We can’t make massive sweeping changes like this for very long without a solid understanding how how pervasive this virus is.

All I said was things don't add up. If anything we agree in some regards?

Yes we agree. I’m just elaborating even more :-)

Is CFR in doubt? As I understand this, CFR means "number of people dead from this disease, in the hospital" / "number of people entering the medical system with this disease". Defined that way, there is really no room for the figure to be wrong.

I think we're looking for a different measure (IFR?) which is "how likely is it on average for someone in the population to die from this?". That's the number we don't know because we don't know the number of infected people.

What we do know is that in the places where the disease has gotten out of hand, the medical system becomes overloaded. That's the real, immediate, present problem and whether it's a problem or not doesn't depend on the CFR. Note that most of the existing hospitalized cases in Italy are _still_ on ventilation. So although they don't show up in the CFR, they're still taking up medical resources and some number of them will eventually not make it. (Source: watch the many videos on Youtube from the Drs working in the Red Zones).

Reply on news.ycombinator.com