But that's deaths. Apparently a large part of surviving SARS patients still have significant health problems. And that's a coronavirus too.

That was largely caused by high dose of hormone used during treatment. I can be wrong but hormone is no longer used that often/much in the current outbreak.

That is helpful to know, thanks.

Also a question if it will be able to mutate in a larger population, given its long incubation period without symptoms it has more opportunity. I don't know how likely this is. Another question is how long will it continue to expand in reach in China and much affect it will have on the economy.

Question of mutation invariably comes up. I recommend this article: http://www.virology.ws/2020/01/23/a-lesson-from-sars-cov-for...

Summary: We know of deletion event in SARS Orf8, and amino acid change in ebola glycoprotein. In both cases, it decreased viral replication or virulence.

> even if half the people get infected

You say "even" as if it's a conservative estimate, but to me 50% of the country's population being infected by the same virus sounds extreme. Wouldn't this be on the extreme side?

Could be, yeah. The issue is that India is right next door and if it goes there, that's another 1.4 billion to worry about.

It seems to be as infectious as a cold. So no.

This is incorrect.

If we assume that this virus is as infectious as the common cold, we can expect the infection rate within a household to be approximately 25% of contacts. That means that of the people you LIVE with, 25% will catch it from you.

50% infection rate in a large, distributed population like China would be very extreme.

I never said 50% of the population have the same cold at once. 50% catching it over a 6 month period is very reasonable.

Over any time frame, it's still quite extreme. To use influenza as a proxy, which has virulence comparable to the cold, the yearly incidence rate in China is <35 per 100,000. Even if this is a full 100x worse, we aren't even getting close to 50% infection rate over the season or a 6 month time frame.

Replying myself to add reference, here:

https://www.ijidonline.com/article/S1201-9712(19)30354-6/pdf

This is all well understood, and studied in considerable depth.

The media overreaction is typical, but here at HN we are better than that and we should strive to rely on established science (where available). No need to throw out extreme or unreasonable numbers!

See my other comment. I was comparing to one of the viruses that causes a COLD not influenza.

Colds are quite different to flues.

Of course in many ways they are different, but not in the important ones for this discussion.

I used influenza because it was convenient in terms of available research, I could grab in a minute or two, but I'm sure if you care to look you can find similar data for rhinovirus.

Rhinovirus and influenza have very comparable R0's. R0 is the epidemiological measure of the "contagion" factor of a pathogen.

I was comparing with a cold not with influenza.

We could try to make the comparison you are suggesting instead. But to make a valid comparison we need to consider:

Is influenza infectious for 10 days before any symptoms show?

How many people get the influenza vaccine each year? I.e. is there some herd immunity built up?

The symptoms of influenza are universally nasty for everyone infected. No one with the flu is walking around and going to work (if you think do then you don't have the influenza virus you have a cold). It seems that at least some people with this new corona virus just have cold like symptoms and therefore will not by default be self-isolating like people with influenza naturally do.

I'm not making anecdotal conclusions or assumptions about whether people walk around or go into work, I'm simply stating the facts here based on considerable research.

Influenza is a useful proxy for the cold, because we have plenty of data on influenza strains with R0 very close to the cold.

Perhaps the most contagious disease we've ever encountered, the measles, has an R0 around 18. Before the 1960's, when the vaccine was licensed, we saw incidence rates as high as the .8% range yearly for measles. That is 20x more than influenza, but still orders of magnitude short of the 50% number you threw out there.

The cold and influenza both range from R0=1.3, to perhaps 6 on the very high end of estimates. 50% just isn't reasonable by any measure.

As for comparisons to this nCoV, it's still very early days and there are many unknowns. Still, there is no evidence to support an R0 even remotely close to the measles. 50% simply isn't plausible or reasonable, based on everything we know about viruses and epidemics.

Not to mention people and the government are being a lot more careful than if this was a common cold.

But how long can they keep that up?

Have you ever been in a room or walking down the street and see every other person have a cold? That is extreme.

Those colds that you’re seeing represent common symptoms of many viruses (metapneumovirus, paraflu, influenza, rhinovirus, RSV, etc, etc ... and many of these have multiple subtypes which can be concurrently circulating). In other words, you’re noticing common symptoms not necessarily the same virus.

> Those colds that you’re seeing represent common symptoms of many viruses

And not just that. I have a septum deviation, so I basically have a runny nose all winter long, even though, most of the time, no viruses are involved.

It's worth fixing that, surgery has come a long way. I had it surgically corrected last year and the energy boost from better breathing while physically active, better sleeping, and the lack of annoying people with my snoring are well worth it.

Can't agree enough.

Even directly after surgery, with all the related inflammation and dried blood and gross up there, I immediately noticed a massive airflow difference.

Do it.

I've read that you can carry it for 1-2 weeks without showing symptoms. That might significantly change how the virus spreads compared to flu.

Peak cold symptoms last about 3 days. I never said 50% of the population have the same cold at once. 50% catching it over a 6 month period is very reasonable.

> Chances are you're going to be fine, if you get it, but it'll be a long and painful 2 weeks.

They've reported that strong symptoms occur in only 25% of cases, so if you get it chances are you're just experiencing having a cold (which is caused by a coronavirus).

A relevant question is also, if most deaths really are among immunocompromised, elderly or very young, then how many of those 2% would have been killed by the flu or similar if coronavirus hadn't shown up? 14 million dead is terrible by any measure, but I'm wondering how much of a change over the norm it actually represents.

I'm not an epidemiologist. Anyway, I looked up the most recent CDC flu death estimates for 2018-2019[1]:

34157 dead from 35520883 infected, let's see how much hire a 2% corona virus mortality rate is above the normal flu mortality rate in the US:

>>> .02 / (34157 / 35520883.) 20.798596480955588

About 21 times higher.

[1]https://www.cdc.gov/flu/about/burden/index.html

It's 3-4 orders of magnitude more deadly than the normal seasonal flu. The mortality rate is similar to SARS, but with far more infections.

The above comment saying that it "mostly" impacts elderly is a bit vague. The fact that within the first 100 deaths were multiple young healthy people means it is dangerous for the entire population. People in their 30s and 40s are not "old".

There was a single death of someone in their 30s out of 100+. And I don't even know if its been confirmed if they were immunocomprimised or not. Every other person to die was 47 or above, many of who had previous health issues. 1 out of 100 is is a pretty good indication that it mostly dangerous to the older population. The fact that no young children to have died yet, which also tend to be a vulnerable group for viruses like influenza and SARS is also worth noting.

Also, you should be more precise in your wording. 3-4 orders of magnitude worse than the flu is absolutely not true. The mortality rate for the flu is around 14.3 per 100,000. With this as a baseline, 4 orders of magnitude is 143%, which isn't actually possible unless you are aware of people being able to die more than once. Even 3 orders of magnitude is 14.3%, which is higher than SARS. The current estimate is around 2%, which is more like 2 orders of magnitude.

"50% of the deaths were under 47"... fixed that for you. Also implying people over 47 are elderly and not worthy caring about? Most middle managers, craftsmen, ceo's, politicians, doctors, professors, military officers would disagree.

50% of deaths were under 47? Do you have a source for this? Because I can't find that anywhere, and the last time anyone reported any numbers it was literally all but 1 were 47 or older.

And I'm not implying that people 47 and older arent worth caring about. But that group is always tends to have more severe health problems, which is why people should take those numbers with a grain of salt.

> It's 3-4 orders of magnitude more deadly than the normal seasonal flu

Citation?

Influenza deaths are 2 per 100,000.

source: https://www.cdc.gov/nchs/fastats/flu.htm

SARS death rate is around 10%

source: https://en.wikipedia.org/wiki/Severe_acute_respiratory_syndr...

You are comparing apples to oranges.

Here's a better set of comparisons:

Deaths per 100,000:

Influenza: 2

SARS: 0.22

https://www.cdc.gov/nchs/fastats/flu.htm, https://en.wikipedia.org/wiki/Severe_acute_respiratory_syndr..., https://en.wikipedia.org/wiki/South_China

% of deaths of hospitalized people:

Influenza: ~10%

SARS: ???

https://www.cdc.gov/flu/about/burden/index.html

% of deaths of diagnosed people (~CFR):

SARS: ~10%

Influenza: 0.1%-10% per strain

https://en.wikipedia.org/wiki/Severe_acute_respiratory_syndr..., https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3809029/

Your 0.22 number is nowhere in your sources, and is obviously off by several orders of magnitude based off of my original sources above.

I think you don't understand how mortality rates are calculated. This also explains why you took two completely unrelated measure and compared them to each other in your original post. Deaths per 100,000 is based on total population.

The SARS mortality rate for China in 2003 was ~0.02 (349 deaths, 1.3billion population). I was being nice to you and using just the population of southern china where the sars outbreak primarily occurred.

Whether that's the most appropriate measure for this comparison isn't clear, which is why included the other measures.

If you limit to just Taiwan or Hong Kong where SARS was pretty bad, you get 0.6 and 4.4 respectively. At that point, it's less of a good comparison as you should apply the same focusing in for influenza.

Also, that's looking at the US mortality rate for influenza which is particularly low. The worldwide average is 5.9, with regions ranging from 4.5-6.2 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6815659/).