2019-nCoV / Corona virus Pt 2

[pipelineaudio]

Want to take a guess what's almost certainly happening in India right now?

Some of our engineering group are there and saying there's some lockdowns going on, 4000 people of interest

But still not making any sense, the Ganges should be choked with dead bodies by now and its not

They were worried about us! That seems to backwards. India is like a tinder pile for plagues and yet they are way behind allegedly

 

[Giordano]

Out of curiosity, how many single virusus does it usually need to get infected? I guess a single one is not enough, is it?

Depends on the type of virus. Smallpox? Very very few. Influenza? Quite a bit more (most influenza virus particles are in fact defective). 2019-Covid? Not clear yet AFAIK. Probably a lot more than one.

 

[portlandatheist]

It means I have a greater than 99% chance of NOT dying of Covid 19. Stupid or deluded would be to let THAT interfere in my life.

Maybe. But you also have a very high likelihood of losing a dear family member or friend to this as we all do.

 

[pipelineaudio]

Is there a graph somewhere that shows current R0 or rates of change? Seems like there could be some really cool interactive graphs that could be used for all these remote math classes that are about to happen

 

[Giordano]

I think no one is modelling this. Even at the worst only a total of 20% of the population is symptomatic and not all at the same time. Even allowing for a peak of 50% of cases over 4 weeks and duration of illness of 2 weeks this would suggest that at peak only 5% of the population will be symptomatic.

They are modeling 60% infected as a worse case, particularly if nothing effective is done:
https://nymag.com/intelligencer/202...oronavirus-model-210m-infected-1-7m-dead.html

I don't think that number is likely if there is at least a moderate response from people, the health system, and the government, but even your scenario predicts "only" 1.6 million Americans symptomatic at peak (overwhelming the health care system) with associated deaths. Plus given asymptomatic cases appear to be infectious, it is the asymptomatic number that is most important for modeling the growth of the epidemic.

But my real point is not a panic but the opposite: the earlier we puts into place serious control efforts, including quarantines, the much lower the total infected rate as well as the number of infected at one time, and the number dead total. The numbers can still drop to a tenth of these predictions. We can do this if we are not stupid.

By the time one looks around and thinks "My god this really is bad, we have to do something drastic about it. Quarantine people, etc." it is too late.

 

[Armitage72]

Spraying disinfectants in public places is a great example of how public relations drive South Koreas response.

I don't know about other countries, but back in 2014 the EPA established special testing protocols that were necessary to claim that an antimicrobial product would be effective when applied by fogger or mister. There were concerns that the reduced particle size and different coverage characteristics resulting from this application method would make the product less effective than conventional application. I've only been able to find one disinfectant specifically approved by the EPA for fogging, and the label says that fogging will only kill two bacteria and one spore. Anything else requires applying the liquid to a surface normally by cloth or coarse spray (median droplet size 400 nm or greater).
Customers at work keep asking if our disinfectants can be fogged and I have to keep telling them no and explaining why.

 

[Giordano]

I think we pretty well understand how it is spread. Droplets not aerosols. One or two days before onset of symptoms, but viral shedding is prolonged up to 3 weeks. Prolonged survival on surfaces.
The WHO view

https://www.who.int/docs/default-so...0306-sitrep-46-covid-19.pdf?sfvrsn=96b04adf_2

Even droplets are actually released as aerosols:

"NIOSH defines aerosols as a suspension of tiny particles or droplets in the air. Aerosol transmission has been defined as person-to-person transmission of pathogens through the air by means of inhalation of infectious particles. Particles up to 100 μm in size are considered inhalable (inspirable)."

More importantly is the distinction between droplet transmission (aerosols of bigger droplets such as 2019-Covid appears to depend on) vs airborne transmission by aerosols of much smaller droplets (such as occurs with smallpox). The latter can transmit disease much further distances from the infectious person than the former.

 

[Skeptic Ginger]

I think we pretty well understand how it is spread. Droplets not aerosols. One or two days before onset of symptoms, but viral shedding is prolonged up to 3 weeks. Prolonged survival on surfaces.
The WHO view

https://www.who.int/docs/default-so...0306-sitrep-46-covid-19.pdf?sfvrsn=96b04adf_2

You so don't know what you are talking about.

First, I wasn't talking about route of transmission. I was talking about who has spread it to whom, because we have no clue how the infection got from a known patient to patients miles away who had no known contact.

Fred Hutch epidemiological tracing of the pandemic

The seeming sudden appearance of outbreaks across the US are not due to a sudden influx of cases. Instead, transmission chains have been percolating for 4-8 weeks now, and we're just now starting to see exponential growth pick up steam.

This is why we need more drastic social distancing like closing scholls and large gatherings.

We recently modeled projections for the burden of infections and deaths in two Washington state counties through April 7. The model shows that any social distancing that results in reduced transmission rates will slow the rate of growth of the epidemic, but only large changes in contact rate can interrupt ongoing ... I've been hugely impressed by the thoughtful and deliberate actions taken to enact social distancing and combat the COVID-19 outbreak in Seattle and Washington state. People like Gov. Jay Inslee and Mayor Jenny Durkan have taken a science-based approach to their actions.

People don't like to be inconvenienced. Better to wishfully think and ignore the science.

Second, several sources like Johns Hopkins dispute the hasty conclusion aerosols are not involved.

Johns Hopkins - Coronavirus vs flu

A possible difference: COVID-19 might be spread through the airborne route (see details below under Differences)....

While both the flu and COVID-19 may be transmitted in similar ways (see the Similarities section above), there is also a possible difference: COVID-19 might be spread through the airborne route, meaning that tiny droplets remaining in the air could cause disease in others even after the ill person is no longer near.

Third, we know children with mild influenza spread it to more vulnerable populations. Without widespread serosurveys you cannot draw conclusions about how children are being impacted by the virus. Anything else is magical incompetrump thinking.

 

[Cheetah]

Speech from President of South Africa notes:

Government of South Africa declared a National State of Disaster

▪Infected as of Sunday: 61
▪Internal Transmission Occuring
▪Limit Contact between Persons
▪Travel Ban from High Risk (italy iran south korea spain germany uk usa, china as of 18 mar 2020)

*South Africans are to Refrain from travelling to*
▪UK/USA/Europe/China/Iran/South Korea
▪People who visited High Risk areas as of mid Feb - are required to come in for testing

*South Africa has 72 ports of entry land/sea/airport*
▪53 Land Ports, 35 Shut down as of Monday
▪2 out of 8 sea port closed for passengers
▪Non essential travel prohibited
▪*Non essential domestic travel to be stopped*

*GROUPS OF PEOPLE*
▪Limit contact groups of people
▪Gatherings of more than 100pax = prohibited
▪All mass celebration public holidays cancelled
▪Organizers to put in place stringent measures for <100pax events

*SCHOOLS*
▪Schools will be closed from Wed 18 Mar
▪Schools will remain closed till after Easter
(July Holidays shortened by week ?)

*BUSINESS*
▪Mining retail banking farming to introduce measures for hygene control
▪Shopping Malls / Entertainment centres to bolster hygene control

*Citizens to Change behaviour*
▪Wash Hands frequently with soap + water or hand sanitizers for minimum 20sec
▪Cover nose/mouth cough/sneeze with tissue/flexed elbow
▪Avoid anyone with flulike symptoms
▪Minimize physical contact
▪Use Elbow greeting *no shaking hands*

_The Government thanks businesses who have taken steps to protect their employees_

 

[Planigale]

They are modeling 60% infected as a worse case, particularly if nothing effective is done:
https://nymag.com/intelligencer/202...oronavirus-model-210m-infected-1-7m-dead.html

I don't think that number is likely if there is at least a moderate response from people, the health system, and the government, but even your scenario predicts "only" 1.6 million Americans symptomatic at peak (overwhelming the health care system) with associated deaths. Plus given asymptomatic cases appear to be infectious, it is the asymptomatic number that is most important for modeling the growth of the epidemic.

But my real point is not a panic but the opposite: the earlier we puts into place serious control efforts, including quarantines, the much lower the total infected rate as well as the number of infected at one time, and the number dead total. The numbers can still drop to a tenth of these predictions. We can do this if we are not stupid.

By the time one looks around and thinks "My god this really is bad, we have to do something drastic about it. Quarantine people, etc." it is too late.

Infected is not equivalent to symptomatic. Most (80%?) infected are asymptomatic. The UK is modelling 80% infected, 20% infected symptomatic, 10% requiring hospital care (average LoS 1 week), 5% requiring ITU care. Half of cases presenting over 4 weeks at the peak. So at peak 2% of population requiring hospital care. Currently we cannot alter any figure except how long the peak is spread over, if we double the duration of the peak this means weekly hospital admissions are halved.

 

[Giordano]

Yes, it needs to be slowed but not stopped. If you stop it now it peaks in winter with the same severity but with the added load of flu etc. Delaying the peak is not the best option, the best option is to flatten it, the same total workload but spread over 8 or 12 weeks rather than over 4 weeks.

Not by most definitions of severity. The disease course in a given infected individual might be the same but fewer individuals will be infected and their chance of being treated will be much greater.

Again, one is not just flattening the peak and spreading it, but also reducing the area under the curve (the number of people who will get sick or die).
There will be an extra premium on developing particularly effective flu vaccines and distributing them. But these are already in the works and is done every year.

 

[Giordano]

Infected is not equivalent to symptomatic. Most (80%?) infected are asymptomatic. The UK is modelling 80% infected, 20% infected symptomatic, 10% requiring hospital care (average LoS 1 week), 5% requiring ITU care. Half of cases presenting over 4 weeks at the peak. So at peak 2% of population requiring hospital care. Currently we cannot alter any figure except how long the peak is spread over, if we double the duration of the peak this means weekly hospital admissions are halved.

I thought I made that clear in the post you quoted. Or my other posts in this thread. Sorry if I didn't. So I will restate what I had said in the post you quoted. For modeling of the course of infection the number of asymptomatic cases appear to be very important for this coronavirus. Asymptomatic individuals appear to shed virus and infect others. This appears to be one reason it has been so hard to prevent this virus establishing itself in location after location.

80% become infected (your number although I thought you were just claiming that my quote of a 60% value was too high?), etc, etc. 66 million people are in the UK. Those percentiles represent enormous numbers of seriously ill and dead people. Widespread and effective quarantine would reduce that number, not just spread it out longer.

 

[Skeptic Ginger]

Infected is not equivalent to symptomatic. Most (80%?) infected are asymptomatic. The UK is modelling 80% infected, 20% infected symptomatic, 10% requiring hospital care (average LoS 1 week), 5% requiring ITU care. Half of cases presenting over 4 weeks at the peak. So at peak 2% of population requiring hospital care. Currently we cannot alter any figure except how long the peak is spread over, if we double the duration of the peak this means weekly hospital admissions are halved.

More unsupportable crap.

Again, research varies between no one being asymptomatic to lots of asymptomatic cases. There is zero evidence of such a huge number of asymptomatic persons as 80% being asymptomatic.

 

[Planigale]

Not by most definitions of severity. The disease course in a given infected individual might be the same but fewer individuals will be infected and their chance of being treated will be much greater.

Again, one is not just flattening the peak and spreading it, but also reducing the area under the curve (the number of people who will get sick or die).
There will be an extra premium on developing particularly effective flu vaccines and distributing them. But these are already in the works and is done every year.

No the modelling shows the same severity. The same number infected, the same outcome, and the same peak. Why should the area under the curve change? The susceptible population is the same, the virus is the same, the outcome the same. All you can do is spread the time over which it happens. We have no treatment, it is unclear that ITU makes much difference to mortality. (Arguably a winter peak is worse because of the added other winter infections.)

We never know how good the flu vaccine will be, they always try to make the best match. Arguably with the experts and companies distracted by dealing with SARS CoV 2 the resources for flu will be less. (Indeed they will be beginning to manufacture this winter's flu vaccine now.)

 

[Planigale]

More unsupportable crap.

Again, research varies between no one being asymptomatic to lots of asymptomatic cases. There is zero evidence of such a huge number of asymptomatic persons as 80% being asymptomatic.

From the same WHO document I referenced above suggesting children are not significant spreaders of SARS CoV 2.

While the range of symptoms for the two viruses is similar, the fraction with severe disease appears to be different. For COVID-19, data to date suggest that 80% of infections are mild or asymptomatic, 15% are severe infection, requiring oxygen and 5% are critical infections, requiring ventilation. These fractions of severe and critical infection would be higher than what is observed for influenza infection.

So this is supported by WHO. Feel free to contact them and tell them they are publishing crap.

 

[Giordano]

No the modelling shows the same severity. The same number infected, the same outcome, and the same peak. Why should the area under the curve change? The susceptible population is the same, the virus is the same, the outcome the same. All you can do is spread the time over which it happens. We have no treatment, it is unclear that ITU makes much difference to mortality. (Arguably a winter peak is worse because of the added other winter infections.)

We never know how good the flu vaccine will be, they always try to make the best match. Arguably with the experts and companies distracted by dealing with SARS CoV 2 the resources for flu will be less. (Indeed they will be beginning to manufacture this winter's flu vaccine now.)

I am beginning to feel like an advertiser for the NY Times, but here is the link again:
https://www.nytimes.com/interactive...l?action=click&module=Opinion&pgtype=Homepage

Check out the total number of deaths. One reason for the reduction in deaths is that the heath care system can much better keep up with the lower rate of infection. You have posted as much but you haven't appeared to recognize the importance of this on the death rate.

To quote the article: "What matters is not only the total number of infections but also whether many occur at once. Overloaded hospitals and shortages of ventilators in intensive care units would result in people dying unnecessarily from the coronavirus as well as from heart attacks and other ailments."

What do you mean by ITU?

Further it provides for much more opportunities to identify and isolate specifically the infected individuals. To the point where further transmission can be substantially reduced in a given community.

 

[RecoveringYuppy]

ITU similar to ICU. Intensive Therapy, Intensive Treatment.

 

[The Atheist]

But now I see a counter argument that children might catch and spread the virus but show no symptoms and do not become sick. Lockdown.

That's the drum I've been banging, and Japan seems to provide ample evidence it's the simplest way to slow infection rates.

They don't seem to have done much outside of shutting schools and have only 35 new cases today, against hundreds or thousands in other countries.

The problem is that quarantine is not a cure. When you come out of quarantine you remain susceptible.

That's a question I've been asking that hasn't had an answer yet - what happens after the lockdowns? It zooms back into life.

Out of curiosity, how many single virusus does it usually need to get infected? I guess a single one is not enough, is it?

Bit hard to tell, but more than norovirus (10 particles) and probably less than influenza.

Want to take a guess what's almost certainly happening in India right now?

No I don't - it's too scary to consider. Another one I've been beating for some time. They will have millions die.
_____________________________

For Americans thinking it's all too much trouble, read this for a minute and be aware of the tsunami about to hit:

https://theintercept.com/2020/03/14...ntlines-of-the-effort-to-contain-coronavirus/

 

[Giordano]

[snip]

We never know how good the flu vaccine will be, they always try to make the best match. Arguably with the experts and companies distracted by dealing with SARS CoV 2 the resources for flu will be less. (Indeed they will be beginning to manufacture this winter's flu vaccine now.)

There are many different agencies and companies that even now make lots of different vaccines. Large amounts of influenza virus are synthesized every year. And as you point out production of influenza vaccine is already in process for next winter, whereas any coronavirus vaccine will not even be available for big scale production until after that. There is no suggestion that the vaccine production capacity will be limited to one or the other or that the basic research arms of these resources will be "distracted." In fact they undoubtedly realize the importance of having vaccines to both and appear to be working on just that.

Sure the effectiveness of influenza vaccine varies with the year but if most people are vaccinated even less than fully effective vaccines can break the transmission cycle and result in much lower numbers of infections.

 

[dann]

Does it sound likely that this remedy will be effective against the new coronavirus?
Cuban drug used to tackle COVID-19 (RadioRebelde.cu, Marth 13, 2020)
Costa Rica press spreads Cuba has antiviral for Covid-19 (Prensa Latina, March 13, 2020)
Cuba has medicines for thousands of possible cases of COVID-19 (OnCubaNews, March 13, 2020)

It seems to work when used against the common cold, but that's not exactly the same thing, of course:
Prevention of experimental coronavirus colds with intranasal alpha-2b interferon (PubMed, 1986)