Coronavirus - worldwide spread and control

[Adrian]

One cannot exclude that there might be something about northern Italy that makes the virus more lethal. Or maybe the Italy scenario is the norm in unprepared countries and the virus just happened to arrive in Italy before it arrived elsewhere.

I wondered if there was some factor of family size or to be more accurate the number of people (and age range) living in a house where I think keeping distance and avoiding spread would be very hard. I get the impression in the UK we have low numbers in each house but don't know any real stats,

 

[lansbergen]

Dear Lansbergen, do you recall a link to this? I would be interested to read more about the virus being found in sewage.
A question: does high heat, as in cooking, kill the virus? How about freezing temperature?
As I posted elsewhere, a recommendation I read in La Presse (montreal) was to wash vegetables with dish soap.

https://www.h2owaternetwerk.nl/h2o-actueel/kwr-vindt-coronavirus-in-rioolwater

In Dutch

 

[lunarainbows]

@strategist @Adrian thanks.
If I remember correctly, Spain is also following a similar path to Italy? Which is why it is confusing that the UK should diverge.

But yes there are possibly quite a few differences between Italy and the UK. Number of people in each house could differ, in London there could be a higher percentage of young people compared to parts of Lombardy and they may be been the ones socialising so much. The air pollution is bad in London though - i don’t know how bad it is in Northern Italy but it’s definitely bad in London.

The other thing is I’m finding it difficult to square with what I have heard is happening in London hospitals, firsthand from the doctor I met last week in person as well as what I also know from those who live in my area of London. The two nearest hospitals to me seem to already be at, or over, capacity. Our medical treatment isn’t anywhere near as good as Northern Italy’s in terms of number beds, doctors, or ventilators - so we would be expected to reach capacity much sooner. This would have also made me expect to see more deaths in the UK.

 

[lunarainbows]

 

[Adrian]

The air pollution is bad in London though - i don’t know how bad it is in Northern Italy but it’s definitely bad in London.

I believe air quality is poor in northern Italy as well. Smoking rates are higher in Italy.

Its probably also worth looking at mortality rates rather than numbers of deaths. The number of people identified with Cov19 will indicate spread rates. There was also a paper looking at age ranges associated with spread patterns.

 

[lunarainbows]

@strategist In terms of people being on overcrowded hospitals, if that is a factor, I think it could be a similar situation in the UK, if not now then in the future. And possibly worse in the UK due to lack of beds, hospitals closed down over past few years etc. And I think here too, people are dying in their homes. I don’t know how many, as we don’t know the scale of the problem. But see this article that came out today:

https://www.theguardian.com/world/2020/mar/25/london-woman-36-dies-of-suspected-covid-19-after-being-told-she-is-not-priority?

Edit: merged with later post
Another thing is the dire lack of PPE among staff in the Uk, as far as I’m aware this was not as bad in Italy. I’ve been posting quite a few articles about it..Doctors and nurses have been on the TV saying they are sharing masks, re using surgical masks, just have aprons and gloves sometimes etc. With doctors threatening to walk out over lack of PPE and writing articles whistleblowing about it. So that’s another factor I thought about, doctors contracting it and then potentially passing it onto more vulnerable patients. And it’s bad in the Care sector too.

 

[lunarainbows]

I believe air quality is poor in northern Italy as well. Smoking rates are higher in Italy.

Its probably also worth looking at mortality rates rather than numbers of deaths. The number of people identified with Cov19 will indicate spread rates. There was also a paper looking at age ranges associated with spread patterns.

Mortality rate is when death has been scaled to size of the population?
I read something today; about this, about looking at number of deaths rather than scaling it:



Sorry I’m also a bit confused about your statement. Why would looking at mortality rate be better than total no of deaths? (I’ve got brain fog right now and also very sleepy, so I’m quite confused)- I don’t quite understand what you mean about spread.

 

[Hip]

Hi, Hip.

Thanks for your clear explanation, as always. I've just done this calculation myself using today's data (25th March), and notice that the interval for deaths to double from 233 (on the 22nd) to 465 (on 25th) was 3 days. So inputting that data I get a figure of 2,362,052 people infected in UK today. Or 67,000,000 / 2,362,052 = 1 in 28.3 people. So keep washing your hands people!

I am now wondering if this rapidly doubling of the UK death count really reflects the increases in the number of infected.

It occurred to me that the UK death count might be accelerating not just because of increasing numbers of infected people, but perhaps also because of a shortage of ventilators in NHS hospitals. We know from Italy's experience that when there are not enough ventilators to go round, the death rate climbs dramatically.

I heard one story in the UK of a hospital having seven coronavirus patients needing a ventilator, but only one machine, so for the other six patients, the doctor "had to let them go" (let them die). Whether this is an isolated incident I am not sure. Apparently the NHS has 8,175 ventilators at the moment, including those borrowed from the private health sector.

 

[lunarainbows]

I am wondering if this rapidly doubling UK death count really reflects the increases in the number of infected.

It occurred to me that the UK death count might be accelerating not just because of increasing numbers of infected people, but perhaps also because of a shortage of ventilators in NHS hospitals. We know from Italy's experience that when there are not enough ventilators to go round, the death rate climbs dramatically.

I heard one story in the UK of a hospital having seven coronavirus patients needing a ventilator, but only one machine, so for the other six patients, the doctor "had to let them go" (let them die). Whether this is an isolated incident I am not sure. Apparently the NHS has 8,175 ventilators at the moment, including those borrowed from the private health sector.

The UK’s death rate is not doubling as rapidly compared to Italy or (I think) Spain either (see my above posts). Which I was surprised about but there could be many reasons. It was on that trajectory but slowed down over the last 4 days.

 

[Hip]

The UK’s death rate is not doubling as rapidly compared to Italy or (I think) Spain either (see my above posts). Which I was surprised about but there could be many reasons. It was on that trajectory but slowed down over the last 4 days.

It does seem to have slowed a little in the last few days.

There's a good historical graph of UK death numbers on this page (see the graph "Total Coronavirus Deaths in the United Kingdom" half way down the page). If you run your mouse along the graph curve, it gives the day by day number of deaths.

 

[Sasha]

This is a very ignorant question from me, but is a single particle of virus enough to get infected, or not? And if not, why not?

I'm wondering how to interpret the advice about 'close contact' being 15 minutes at less than a metre etc. and the idea that less intense contact is probably less dangerous. I'm wondering if that's to do with the amount of virus you'd be exposed to, or the probability that you'd be exposed to at least a single particle of it.

It appears from responses above that I'm not the only one who is wondering this! @Jonathan Edwards ?

 

[lunarainbows]

Ok. Just catching up on Newsnight. Tonight on BBC. Re death rates in the UK.

“Department of health is changing how it’s compiling and releasing these figures.

It turns out these deaths may not be the number of deaths that have taken place over the last 24 hours. The department of health, the NHS, needs to have consent from the families of the people who died, to release the figures. So it’s not exactly a like for like figure every day”.

Is this similar to other countries?
I thought to report deaths, it is usually anonymous so wouldn’t need consent from each family?

 

[lunarainbows]

Also, Newsnight, I didn’t watch this part as too tired, but Times Columnist and retweeted by Newsnight editor:

 

[mango]

I really hope Swedish politicians and decision makers are feeling the pressure of the world watching. Maybe that will make them reconsider and change strategies?

The Guardian: "Swedish PM warned over 'Russian roulette-style' Covid-19 strategy
Health experts ‘deeply concerned’ about Sweden’s response"

Financial Times: "Sweden bucks global trend with experimental virus strategy
Fewer restrictions than other leading countries and schools remain open"

 

[Cheshire]

About modelling:

Mathematics of life and death: How disease models shape national shutdowns and other pandemic policies

The Netherlands has so far chosen a softer set of measures than most Western European countries; it was late to close its schools and restaurants and hasn’t ordered a full lockdown. In a 16 March speech, Prime Minister Mark Rutte rejected “working endlessly to contain the virus” and “shutting down the country completely.” Instead, he opted for “controlled spread” of the virus among the groups least at risk of severe illness while making sure the health system isn’t swamped with COVID-19 patients. He called on the public to respect RIVM’s expertise on how to thread that needle. Wallinga’s models predict that the number of infected people needing hospitalization, his most important metric, will taper off by the end of the week. But if the models are wrong, the demand for intensive care beds could outstrip supply, as it has, tragically, in Italy and Spain.

COVID-19 isn’t the first infectious disease scientists have modeled—Ebola and Zika are recent examples—but never has so much depended on their work. Entire cities and countries have been locked down based on hastily done forecasts that often haven’t been peer reviewed. “It has suddenly become very visible how much the response to infectious diseases is based on models,” Wallinga says. For the modelers, “it’s a huge responsibility,” says epidemiologist Caitlin Rivers of the Johns Hopkins University Center for Health Security, who co-authored a report about the future of outbreak modeling in the United States that her center released yesterday.

https://www.sciencemag.org/news/202...se-models-shape-national-shutdowns-and-other#

Coronavirus exposes the problems and pitfalls of modelling
Models based on assumptions in the absence of data can be over-speculative and ‘open to gross over-interpretation’

The lessons to be learned from the coronavirus pandemic will keep scholars and university lecturers busy for decades to come. Chief among them is the value of modelling, and the fact that an uncritical reliance on their findings can lead you badly astray.

Take a recent model from Oxford University. It assessed how well different outbreak scenarios fitted the rise in coronavirus deaths in the UK and Italy. The most extreme UK scenario assumed that only a tiny fraction of people were at risk of serious illness. It also estimated that, as of last week, 68% of the population had been exposed to the virus. The study, which has not been published or peer-reviewed, unleashed a flurry of headlines declaring that coronavirus may have infected half of the people in Britain. That is 34 million people.

https://www.theguardian.com/science...xposes-the-problems-and-pitfalls-of-modelling

 

[Amw66]

I wondered if there was some factor of family size or to be more accurate the number of people (and age range) living in a house where I think keeping distance and avoiding spread would be very hard. I get the impression in the UK we have low numbers in each house but don't know any real stats,

Pollution . Lombardy is the heart of industrial Italy.
I read somewhere that the virus can attach itself to some molecules common on pollution and be viable for longer. Sorry can't remember source.
It's also colder and temperature / humidity seems to be being promoted as a factor affecting longevity

 

[Jonathan Edwards]

I'm wondering how to interpret the advice about 'close contact' being 15 minutes at less than a metre etc. and the idea that less intense contact is probably less dangerous. I'm wondering if that's to do with the amount of virus you'd be exposed to, or the probability that you'd be exposed to at least a single particle of it.

I agree. This makes no particular sense. I think it was intended to give an idea of risk. But it is hard to see how it can be based on evidence. I have a suspicion it was largely intended to reassure people that getting close to a passer by need not induce panic. That advice had clearly been turned around - we are not supposed to get within 2 metres for however short a time now.

Edit: From the comment on Hong Kong policy it rather looks as if 15 minutes was intended to be the time talking to someone with the virus needed to be darned sure you got it too!

 

[Jonathan Edwards]

I am thinking that the difference between the UK and Italy may be that almost the entire outbreak in Italy came from a single case in the north imported from China, whereas the ongoing outbreak in the UK comes from dozens of cases seeded across the country on return from Italy.

This may give a different dynamic if it is important what the local infection rate is at the time of lockdown. In Italy there was a high local concentration. Maybe once above a certain level it is very hard to slow things down in a short period. In the UK there has been a high concentration in London (Southwark) and West Midlands but in much of the country documented rates are still around 1:25,000.

My gut feeling today is that numbers of people needing hospitalisation will continue to climb steeply for at least a week in London and some other centres (probably Glasgow) but with luck in much of the rest of the country the trail will go cold much as it did for the early cases from China. I suspect overload of ITU in London is going to be severe. However, from what I hear, casualty departments in other areas are actually very quiet because nobody is coming in with minor problems and ITU facilities are not yet under strain. They may be if patients are transferred though.

Looking at other countries there seems to be support for the idea that getting control is not too difficult in areas where local concentration is not too high. Once above a certain density really hard lockdown is needed as in Wuhan. Which adds to the idea that the initial UK government policy was totally irresponsible.

 

[Marco]

Evidence doesn't appear to be the main driver of public policy in many countries :

Policymakers can’t say when lockdowns will be lifted — or even what they’re meant to accomplish.

https://www.politico.eu/article/coronavirus-endgame/

 

[Keela Too]

I imagine that kissing an COVID infected friend the sofa all evening, would transfer a higher initial viral load to an uninfected person, than might be received if you were unlucky enough to pick up the virus walking past the same infected person outside.

So getting “infected” might not mean the same thing every time. Depending on how much of the virus was received, the outcomes could potentially be very different.

Simple mathematics would surely indicate that the body can cope better with a small initial infection.

For sake of argument if the smallest viable infection is say 10 particles, and if a person could potentially pick up millions of particles kissing all evening, then it’s easy to see how the body has much more TIME to fight the infection if the initial dose is very small.

10 virus particles versus maybe 1 000 000?

How much time will it take for the virus to replicate from 10 to 1 000 000?
That’s the extra time the body has to mount a defence.

And as we have seen with country graphs of the number of infected people, the early increases seem slow, compared to what happens once the numbers increase.

The time to contain an infection (either in the body, or in a country) is when the numbers are low.

So everything that we can do to reduce the transfer of viral particles now (isolation, social distancing, masks, washing hands, decontaminating surfaces etc.) will help. If we can’t fully contain the virus, it is no doubt still worth trying to ensure that people who do become infected receive only a low initial viral load.

This is one of the reasons that I think home-sewn masks are still useful for protection. They may not PREVENT the wearer getting an infection, but if they manage to reduce the initial dose of virus, then they buy the mask wearer more time.

The people I’m worried about are the health care providers given minimal defences, and who are working in an environment where they can pick up repeated viral doses. They need full protection!