50% – 75% of cases of Covid-19 are asymptomatic • Hacker News Board

Re: 50% – 75% of cases of Covid-19 are asymptomatic

#181

Post by neuronic » Tue, Mar 17, 2020, 9:50 AM UTC

piokoch wrote: post #173

nostromo wrote: post #26

I wonder if this will be like H1N1. At first we only identified extreme cases and we had these terrifying reported fatality rates. Then we identify more and more mild or asymptomatic cases and the rates drop and drop. We’ve already seen how CFR was reported as 3 or 4%. Then on the cruise ship full of people over 60 it’s 0.7%. If there are lots of mild or asymptomatic cases it will likely be much lower. H1N1 was ident…

In Italy more than 300 people die every day, the overall mortality rate is between 3% and 8% this is 10 times more than 0.4%. Even if 50%-75% are asymptomatic, there is still large percentage of critical cases that need ICU treatment and currently we are not prepared for it. For me the title should be 25% of cases require treatment in hospital and we are not able to put 25% of population into hospitals, so, very like…

That's assuming that all reported cases make up all ACTUAL cases. This is likely completely wrong. What if a much much larger chunk of Italy is already infected and simply not showing symptoms? You would never get permission for a test.

Estimates, I found them on Germany's top Robert Koch Institute website [1], suggest that Wuhan underreported cases by a factor between 4.5x and 11.1x (3 separate studies with different factors).

[1] https://www.rki.de/DE/Content/InfAZ/N/Neuartiges_Coronavirus...

Re: 50% – 75% of cases of Covid-19 are asymptomatic

#182

Post by imtringued » Tue, Mar 17, 2020, 9:58 AM UTC

kevingadd wrote: post #116

GreaterFool wrote: post #115

I keep hearing “masks are useless”. If every person who has any cough or any chest tightness or any sore throat, however mild, put on a mask, wouldn’t that stop the spread? I live in Japan. It started here earlier but didn’t explode. Nothing is closed. Business as usual. everyone wears masks. Most cases in Hokkaido. Maybe because it is much colder there and easy to overexposed and tax the immune system.

I think some of the logic behind "masks are useless" is that if people believe masks will prevent it, they'll get too reckless about going out as long as they have a mask. Sadly many people wear masks incorrectly and other people will wear masks that don't actually block viral particulates while out there acting more dangerously than otherwise, spreading disease. IIRC anything below N95 isn't going to do much, and fr…

Masks prevent sneezing from reaching other people.

Re: 50% – 75% of cases of Covid-19 are asymptomatic

#183

Post by trymas » Tue, Mar 17, 2020, 10:01 AM UTC

TeMPOraL wrote: post #180

trymas wrote: post #162

Earlier quoted context omitted.

I agree that everybody who can work remotely is a bit privileged compared to someone who cannot, and in general tech employers are richer and more liberal. As I said in my reply above, some employers or employees need a cultural shift. Either employers put pressure on employees to not get sick leave (which is illegal and unethical), or as you say some employees think that they are "temporarily embarrassed millionaire…

I'm not talking about getting a sick note rejected. I'm asking, would you realistically go and get a sick note for a runny noise and feeling generally unwell? Would you feel secure at your job if you did that 20 times a year?

I do not see what the problem is. People with small children get sick leaves many times per year, because children get ill in kindergarten very often. I know women who will get 5-10 one to two day sick leaves per year due to menstruation cramps.

People are not robots, people get ill. I have very good employer which would never question employees job security due to illness. If you do not - search for a better one, join a union and/or inform your colleagues that their rights are protected by law.

The horror stories I hear about evil employers - usually the employers themselves would be the first to take sick leaves or have luxury long lasting holidays that the employees cannot enjoy. Such employees are conditioned to slave away and forget that their rights are protected by law.

Re: 50% – 75% of cases of Covid-19 are asymptomatic

#184

Post by notahacker » Tue, Mar 17, 2020, 10:03 AM UTC

neuronic wrote: post #181

piokoch wrote: post #173

Earlier quoted context omitted.

In Italy more than 300 people die every day, the overall mortality rate is between 3% and 8% this is 10 times more than 0.4%. Even if 50%-75% are asymptomatic, there is still large percentage of critical cases that need ICU treatment and currently we are not prepared for it. For me the title should be 25% of cases require treatment in hospital and we are not able to put 25% of population into hospitals, so, very like…

That's assuming that all reported cases make up all ACTUAL cases. This is likely completely wrong. What if a much much larger chunk of Italy is already infected and simply not showing symptoms? You would never get permission for a test. Estimates, I found them on Germany's top Robert Koch Institute website [1], suggest that Wuhan underreported cases by a factor between 4.5x and 11.1x (3 separate studies with differen…

I don't think anyone knowledgeable is assuming reported cases make up all or even a significant proportion of infected cases (I myself am in recovery from moderate lung inflammation which is probably COVID-19, but even with very-obviously-not-regular-flu symptoms don't figure in my country's stats because tests are reserved for those requiring hospitalisation)

Even if it was actually the case that nearly everyone in Italy had it in which case the casualty rates would be much lower than current estimates, the proportion of cases needing ventilators is sufficiently high to overload Italy's healthcare system (so the risk is similar, we're just looking at different risk factors i.e. the disease being less deadly but much more efficient at spreading than current estimates). Knowing that would make it easier to shift from containment to building more ventilators as a strategy, I guess

Re: 50% – 75% of cases of Covid-19 are asymptomatic

#185

Post by TheOtherHobbes » Tue, Mar 17, 2020, 10:07 AM UTC

easytiger wrote: post #163

nostromo wrote: post #26

I wonder if this will be like H1N1. At first we only identified extreme cases and we had these terrifying reported fatality rates. Then we identify more and more mild or asymptomatic cases and the rates drop and drop. We’ve already seen how CFR was reported as 3 or 4%. Then on the cruise ship full of people over 60 it’s 0.7%. If there are lots of mild or asymptomatic cases it will likely be much lower. H1N1 was ident…

The WHO predicted that 150 million people would be killed by avian flu https://www.google.com/amp/s/amp.theguardian.com/world/2005/... Using the same logic that had lead to the severe predictions for cv19. For swine flu they promoted and stood by a CFR of 60%. Again turned out to be nonsense; nonsense known at the time to others https://jech.bmj.com/content/62/6/555.abstract

When it comes to these estimates, the WHO seem to be really bad at their job.

But the reality now is that no matter what the estimated CFR is, Covid-19 guarantees that without containment there will be significantly more people in need of hospital care than there will be beds and support staff. And that will affect the final mortality rate, and push it higher than a normal flu season.

Re: 50% – 75% of cases of Covid-19 are asymptomatic

#186

Post by adam-a » Tue, Mar 17, 2020, 10:09 AM UTC

jader201 wrote: post #4

In case this thread doesn’t gain momentum, some more (potentially interesting) discussion on Reddit [1]. Particularly this post [2]: > I wonder if they plan to follow up and monitor... From the Diamond Princess they initially found 50% of people had no symptoms. However upon following them over the course of weeks that dropped down to about 18%. Due to the long incubation period it can take some time to determine if…

I read the Diamond Princess study and the 19% figure is not based on following up with departed passengers. They're using some probability estimation based on the 50% discovered cases, I assume they're trying to account for people who had mild symptoms but not at the time they were tested. They identify flaws in the study though: the passengers were mostly old, so they are more likely to be symptomatic. They also didn't test everyone on the boat, only vulnerable, or symptomatic people, so their base numbers are missing some number of asymptomatic cases. It's not a great study really but I think you could take 19% as a low bound on the figure and in wider society 50% is plausible.

Re: 50% – 75% of cases of Covid-19 are asymptomatic

#187

Post by notahacker » Tue, Mar 17, 2020, 10:11 AM UTC

easytiger wrote: post #163

nostromo wrote: post #26

I wonder if this will be like H1N1. At first we only identified extreme cases and we had these terrifying reported fatality rates. Then we identify more and more mild or asymptomatic cases and the rates drop and drop. We’ve already seen how CFR was reported as 3 or 4%. Then on the cruise ship full of people over 60 it’s 0.7%. If there are lots of mild or asymptomatic cases it will likely be much lower. H1N1 was ident…

The WHO predicted that 150 million people would be killed by avian flu https://www.google.com/amp/s/amp.theguardian.com/world/2005/... Using the same logic that had lead to the severe predictions for cv19. For swine flu they promoted and stood by a CFR of 60%. Again turned out to be nonsense; nonsense known at the time to others https://jech.bmj.com/content/62/6/555.abstract

Overestimates of the severity of the threat have much less harmful consequences than underestimates. For a start, actual casualty statistics are not independent from mitigation actions taken.

Re: 50% – 75% of cases of Covid-19 are asymptomatic

#188

Post by notahacker » Tue, Mar 17, 2020, 10:14 AM UTC

endogui wrote: post #86

lgats wrote: post #71

Earlier quoted context omitted.

How are the South Korean's coming up with such few positives if the disease is presumably spreading among the 70% with no symptoms?

Most "asymptomatic" people will show symptoms within two weeks, so aggressive cluster/contact tracing works. South Korean local goveenment staff are following the credit card use, transit use, and other daily movements (CCTV logs) for every confirmed case, then issue two week self-isolation orders to those who shared a workplace, restaurant, cafe, church, or elevator with the confirmed case. Since most cases get a sh…

Yup. Apparent efficacy of the South Korean approach versus more generalised 'self-isolate if you have symptoms' instructions would be a point in favour of the disease being often asymptomatic [for extended periods]

Re: 50% – 75% of cases of Covid-19 are asymptomatic

#189

Post by carlmr » Tue, Mar 17, 2020, 10:15 AM UTC

khazhoux wrote: post #151

md224 wrote: post #93

Earlier quoted context omitted.

> I suspect the true numbers are about 10x-50x the reported confirmed cases. This is good in that it means the death rate is also off by that factor, but bad in that there will not be enough fear/incentive for the primary carriers (young adults) to adhere to adequate social distancing. If the death rate is off by 10x-50x, isn't this approaching the death rate of seasonal influenza, in which case we didn't actually ne…

I expect an interesting side effect of all this is a reassessment of our tolerance for the "usual" influenza death rate. It's shockingly high. Could we save thousands of lives a year by people stopping going to work when they're sick, not going to grocery store when they're sick, etc?

Just people washing their hands and not working when sick would probably help a lot with the seasonal flu. But maybe another idea would be to get more people to use the flu vaccine every year.

Re: 50% – 75% of cases of Covid-19 are asymptomatic

#190

Post by slurms » Tue, Mar 17, 2020, 10:15 AM UTC

lend000 wrote: post #63

I'm not a confirmed case, but I'm a 90% sure case based on symptoms and symptoms of people I have been in close contact with, and so far the experience has been relatively mild, in the literal sense. The primary discomfort has likely been the anxiety of how the tightness in my chest might progress (which ironically can also cause chest tightness). I'm in a low risk group. I had lethargy and high fever the first day o…

> "high contact exposure to my suspected source"

An attempt at levity, but sounds to me like you're saying you hooked up with a girl, despite her being sick...