[t2riRXawYxLGGYb]

Soooo....

- SARS started out with a similar <4% estimated fatality rate and was then revised upwards to anywhere from 9-15% later.

- COVID-19 is caused by a different strain of the same virus as SARS.

- The CFR of SARS and COVID-19 appear to be very similar, and more notably, appeared by be very similar when we had around 8,000 infections which is where SARS ended. (Similar meaning the CFR hovers between 4% and 20% of closed cases.)

How are we so sure that this is any less deadly than SARS?

The above suggests to me one of the two is likely to be true:

1. There could have been many more undetected cases of SARS than we knew about, indicting an IFR much lower than it's recorded CFR.

2. COVID-19 could actually end up having an IFR that is similar to SARS (~10%).

But of course, I am no epidemiologist, so I assume there's a flaw in my logic.

Did I miss something, or is this pretty much the same disease as SARS but with a higher R0?

[capkutay]

There's little to no data that backs up your guess.

Studies on COVID-19 estimate that the true IFR is somewhere between 0.1% to 0.39%...why? Because the more we test, the more we find asymptomatic and mild cases. And we're yet to even do the type of serological testing that would give us such a decisive sample. Yet we're ALREADY seeing data that suggests that the IFR is lower than SARS and asymptomatic cases/transmission are common. [0]

I never read anything about SARS being mild or asymptomatic in the majority of patients...in fact it was the opposite. It was so severely symptomatic that the virus killed itself with natural selection. If you had SARS-COV-11 and exhibited high viral load, you were likely too sick to go spread it. The only serological testing they did on SARS-COV-1 deemed asymptomatic cases to be uncommon [1]. Quite the opposite of COVID-19.

0: https://www.cebm.net/covid-19/global-covid-19-case-fatality-...

1: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3035549/

[yread]

I've posted this in an earlier thread but I don't think that low estimates make sense. The virus killed 0.44% of total population of Bergamo

4500/1112187

https://translate.google.com/translate?hl=en&sl=it&u=https:/....

https://en.wikipedia.org/wiki/Province_of_Bergamo

EDIT: and there are harder hit communities: 400/40000 https://www.ecodibergamo.it/stories/valle-brembana/il-grido-...

[ed_balls]

take the age bias into account. 45 for Bergamo and 29.6 for the world.

[mlinsey]

The main study which backs up his guess is the report from the WHO's trip to Wuhan, where they actually did what was suggested above and mass-test random samples from the population, finding a very low incidence of positives. Personally I would find the WHO on a trip to China as not the most reliable of sources, so take it with an enormous grain of salt. But it's one data point.

Meanwhile, your link in [0] flat-out says we don't know the percent of asymptomatic cases. It is well-documented they exist. I have also seen some papers estimating the percent of cases that are asymptomatic as well under 20%, and as high as the 80-90% range, the difference between them making an enormous difference to the implied mortality rate.

A month ago, people pointed to South Korea's 0.5% fatality rate, a country which tests very aggressively, as an indication that the true fatality rate is much lower. Well, they still test just as aggressively, and now their mortality rate has risen to 1.96%. The disease started spreading in a population that skewed young there, and but now the disease has started to hit older demographics who have a much higher mortality rate. And of course, "asymptomatic" cases can also mean pre-symptomatic cases, as happened with the Diamond Princess, which had an observed 46% of positive cases be asymptomatic...only to have this rate fall to ~17% later.

[mantap]

Yeah basically the extreme correlation of mortality with age makes it hard to state a mortality rate. Small changes in the population age distribution create big changes in mortality.

[bbeez]

I’ve seen these reports but I don’t understand the math. The true simple CFR meeting actual deaths as reported over actual cases as reported should be adjusted for the course of disease which would make it in places like Italy well over 10% and in other places perhaps 4-6. % or more and we know China’s data, the only place with a major outbreak where it’s really run its course, is bullshit. How do you get to 0.1%? Maybe I’m missing something here but you’d have to believe there were probably 50-100 times the Number of reported cases that were actual cases which would mean the US would have to have had 50-100 million people already have contracted the disease but 98-99 pct of them had no idea. I’m not seeing that as a passes the smell test possibility. But again maybe I missing something here.

[longtimegoogler]

I am not convinced that this data is conclusive yet.

In two closed environments where everyone was tested, the Diamond Princess and the Washington Choir, the CFR is currently 1.55% and 4.44% respectively, with still cases in critical condition.

Of courses both populations are older, but it seems safe to say that the IFR is much higher than the numbers you quoted for older populations.

[shadowprofile77]

What your safe to say claim misses however is that the CFR drops off dramatically below a certain age, and very dramatically, especially if you compare between people in their mid 40s and blow to people in their mid-60s and above. Thus, your own mention of the populations of both cruise ships heavily tending towards elderly passengers (and infected) would almost certainly skew the CFR very strongly upward, and even with this upward skew, it's still so far resting at a fairly moderate 1.44% in the case of the Diamond Princess. As for the Washington Choir, not sure of why its CFR is almost three times higher, perhaps more of the passengers were older than in the DP? Either way a look at all current aggregate data on fatality counts by age from nearly any region of the world you'd like to look at clearly shows that same near drop off a cliff as soon as you reach age groups below 60.

[longtimegoogler]

Agree for the most part, especially with the claims with respect to SARS having a higher IFR

However, given the high R0 and still somewhat high IFR for older populations and even a relatively high IFR compared with the flu IFR for younger populations this virus still has the potential to wreak havoc.

What we are seeing is that a disease with a high R0 can be much more deadly than a disease with a lower R0 and higher IFR.

[wegs]

This first link is utter nonsense. It bases on things like 6 people having died on Diamond Princess. That number is now 12, and growing.

[taeric]

Did we ever do randomized tests due SARS? You linked one, but I would presume more would be needed for a decision?

[t2riRXawYxLGGYb]

This is good news. Thank you.

[bbeez]

I think there are also several issues that are causing the reported CFR to be understated, that counteract to some degree the “denominator problem” from undiagnosed mild cases. The one that I think is the most important is the simple understanding of cohort analysis which I just don’t ever see explained or included any calculations. The number of cases is rising exponentially, and there’s a six week course roughly to the disease, so the number of deaths at any point in time is six weeks behind the number of diagnosed cases at any point in time and the number of cases is increasing exponentially, so this seems like a big error. I have to say I’m truly surprised by how we are this far into this thing and it doesn’t seem like anybody has even done some of the basic mathematical maneuvering you would need to do to understand this or at least they haven’t done that and explained it very publicly.

[redis_mlc]

> Did I miss something, or is this pretty much the same disease as SARS but with a higher R0?

Yes, SARS-1 and SARS-2 (Covid-19) are more similar than not. But debating IFR, CFR or R0 with the testing data we have is pointless.

You can learn a lot about the nature of SARS-1 by reading about the 2002 warzone in Toronto hospitals, which wiped out whole ICU teams. Sounds just like corona today in Italy or NY.