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Thread: Disease and pandemics thread (because it's science)

  1. #1141
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    Quote Originally Posted by Selfsim View Post
    There's always a reason for avoiding hearing the penny dropping, eh? There's a cause .. right there!
    Which doesn't change the big important points:
    1) Banning cigarettes right now would have only a tiny effect on the course of the pandemic over the coming months, at either a population level or an individual level.
    2) The management of this pandemic depends as much on understanding behaviour as it does on understanding epidemiology. It's going to be very difficult to sustain the necessary behavioural changes to drive R0 below 1. So we go for the least draconian methods that have the largest effect. We don't go for the most draconian methods that have the least effect.

    As I used to say to cancer patients contemplating urgent major surgery, "Now actually isn't the time to give up smoking."

    Grant Hutchison

  2. #1142
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    In the few months to a year timescale, I agree the key issue is going to be finding sustainable behaviors that drive R0 below 1. That's going to require knoweldge, and probably trial and error. Luckily, we have a lot of countries engaged in the trials, we can learn from what has worked elsewhere. It's quite a tightrope, because we can lock down for a month or so, but then we will start to see the economic impacts, and they could have their own dire consequences (not the least of which is the worst of all possible consequences-- war). So we have to find a way to alter behavior that not only fights viral spread, but also maintains the economy and fairness to groups with less power. It is a time for smart and unbiased minds to control policy, let's hope that happens. Maybe the one silver lining is that scientists, who have grown accustomed to being ignored recently, are starting to be appreciated a bit more.

  3. #1143
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    Regarding smoking.
    Unfortunately I'm a smoker. I have been for most of my life. I'm not a particularly heavy smoker and I lead a relatively active outdoor lifestyle. I work outdoors every day in all weathers doing physical labour.
    I have tried to quit on many occasions but always get sucked back in. I've managed to stop smoking cigarettes for nearly a year now, but somehow switched to cigars. My next appointment with a stop smoking advisor is scheduled for the 3rd April but that will presumably be cancelled under the circumstances. I was using the drug Champix last year which helped immensely and I did not smoke anything while taking it. After the course finished is when I went back to cigars. Unfortunately Champix is a prescription drug so without the required meetings, I cannot get hold of it.

    If the government were to ban sales of tobacco, it might be just the thing to prevent me having access to the damn things. Certainly forcing shops to hide them from display helped and bans on indoor smoking help too. I never used to hold those opinions but I need a lot of help. It is an insidious drug and the psychological aspects are much more influential than the physical nicotine hit.

    Having grown up through an era of rampant advertising and product placement in movies and television, I don't hold myself entirely responsible for my condition. But I wish to regain control of my life, and will power is not as simple as as the strong men make it sound.

    In the current world environment, I am regarded as a key worker so self isolation is not an option if I want to keep my income. There is no extra financial incentive to keep working and risking exposure but also no alternative.

    It is slightly irritating to see people self isolate on full sick pay, use the time to panic buy all the stock from the shops while I must keep working on hours that prevent me getting to the shops until late afternoon when virtually nothing is left.

    As a great man once said, "what a day to give up glue sniffing!"

  4. #1144
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    Quote Originally Posted by headrush View Post

    As a great man once said, "what a day to give up glue sniffing!"
    Looks like I chose the wrong week to quit amphetamines.
    As above, so below

  5. #1145
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    Quote Originally Posted by Jens View Post
    Looks like I chose the wrong week to quit amphetamines.
    I thought of this response weeks ago. It is very hard to post in this thread lately. Saving my mental health by posting in research thread.
    Do good work. —Virgil Ivan "Gus" Grissom

  6. #1146
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    I have a UK colleague who flew to Thailand mid January. (Through Dubai and Bankok airports) within days he had a high fever for several days with persistent cough, and felt he was going to die. But he recovered without medical intervention, returned to UK 11 days ago, served his time isolated and now seems fit and well, he is 74. Not tested and so far cannot be tested for antibodies.
    sicut vis videre esto
    When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
    Originally Posted by Ken G

  7. #1147
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    Good hand-washing technique is going to be key to keeping yourself safe, and driving down R0. It's actually a skill that needs to be acquired and practised. There are several videos available, but this one is the best I've seen to demonstrate the various components of the technique, and why they're all important:
    https://www.youtube.com/watch?v=4UyucwRzp00

    Grant Hutchison

  8. #1148
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    I saw a video recently in which a Youtuber created a paper face mask from a paper towel and two elastic bands, all stapled together. That seems so simple it's either brilliant or worthless.

  9. #1149
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    Quote Originally Posted by grant hutchison View Post
    Good hand-washing technique is going to be key to keeping yourself safe, and driving down R0. It's actually a skill that needs to be acquired and practised. There are several videos available, but this one is the best I've seen to demonstrate the various components of the technique, and why they're all important:
    https://www.youtube.com/watch?v=4UyucwRzp00
    Such a simple and effective demonstration, I'm going to show that video to my whole family.

  10. #1150
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    Quote Originally Posted by schlaugh View Post
    I saw a video recently in which a Youtuber created a paper face mask from a paper towel and two elastic bands, all stapled together. That seems so simple it's either brilliant or worthless.
    Oh dear. Not all paper is the same. Paper towel is designed for absorbency, not particulate filtering. Almost anything is better than a paper towel, it turns out.
    The best particulate filter in your home is probably your vacuum cleaner bag, but you'll struggle to breathe through it. Dish towels and cotton T-shirt fabric seem to be the best compromised between filtration and breathing resistance.
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2440799/
    https://www.researchgate.net/publica...uenza_Pandemic

    Of course, home-made masks don't fit as well as surgical masks (which have pleats and a compressible nose-piece). Then again, most people I've seen in the street (blessedly few in my part of the world) aren't wearing their surgical mask properly anyway. Then again, wearing a surgical mask in the street is more of an expression of willingness and anxiety than an actual personal/public health measure.
    But if you have someone with COVID-19 in your household, an improvised mask would appear to be better than no mask, when you're at close quarters.

    Grant Hutchison

  11. #1151
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    Assuming that quarantine has been in place for more than 14 days on Italy, what is the mechanics of exponential increase in rates?
    Clusters of medical establishments which are still active?
    Are measures of protecting patients completely ineffective?
    Thanks for your input and thoughts.

  12. #1152
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    It has certainly taken a surprisingly long time, but Italy has just today seen a decline in new cases. They also saw a decline in deaths, which is surprising since it is so unrelated to new cases.
    Last edited by Ken G; 2020-Mar-22 at 07:09 PM.

  13. #1153
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    China not only instituted a lock-down, but did door-to-door checks to identify potential cases who were then tested. I've seen a WHO official suggesting that all these people were then removed from their homes and isolated in groups elsewhere, but I can't at present turn up confirmation of that. But measures like that damp down the potential for the disease to circulate in large apartment blocks, where residents can comply with a ban on leaving their building, while still infecting each other (for instance, in a shared laundry facility).
    Also, Italy is having a rather biphasic outbreak, with some indication (or so I read, I haven't seen a graph) that the rate of increase is beginning to moderate in the north, while cases begin to increase in the south (where, up to now, the population has been less compliant with lock-down measures).

    The difference between Italy and South Korea is no doubt multifactorial, but South Korea seems to have found itself dealing with an outbreak predominantly among young people, which it picked up early by testing and contact tracing. Italy probably had a circulating pool of disease among the young, unnoticed for several weeks. It's common in Italy for young people to commute relatively long distances to work in the city (where they have multiple social interactions), and then return home to multigenerational residences. So Italy found itself dealing with a massive outbreak among older people.

    Grant Hutchison

  14. #1154
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    I am really curious to know what's happening in North Korea related to the pandemic. I understand they locked down their borders, ceased military flights for a while, halted military training and released some quarantined foreigners.

  15. #1155
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    A recent paper looking at the persistence and viability of SARS-CoV-2 on surfaces and in aerosols.
    Viable virus obtainable for up to three days from plastic and steel surfaces, 24 hours from cardboard and four hours from copper, but with exponential declines during those periods.

    This is useful information with regard to handling groceries and other packages, I think, because it tells us that we can simply set stuff aside unopened, wash our hands, wait out the approximate time scale, and then handle the packages without worrying.
    (The aerosol information is less useful, I think, since the aerosols were artificially maintained in a humid environment in order to investigate virus persistence. In the real world, the aerosol will have precipitated long before the virus loses viability.)

    Grant Hutchison

  16. #1156
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    It is strange that the study does not include Silver which for its antibacterial properties is used in some if not all ventilators.

  17. #1157
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    Quote Originally Posted by grant hutchison View Post
    Good hand-washing technique is going to be key to keeping yourself safe, and driving down R0. It's actually a skill that needs to be acquired and practised. There are several videos available, but this one is the best I've seen to demonstrate the various components of the technique, and why they're all important:
    https://www.youtube.com/watch?v=4UyucwRzp00
    Also sort of leaves one with the impression that the 'black stuff' is actually sufficient to neutralise the pathogen in the first place. I have my doubts about some of the liquid handwash remaining on the shelves of pharmacies (etc) at the moment.

    Get this ... I happened to visit a pharmacy yesterday. I noticed a babies dummy (soother?) on the floor .. so did the checkout attendant (unfortunately). She picked it up in her bare hands whilst I offered my 'advice' about not doing that!!! Her counterarguments were (i) the amount of cash she'd been handling all day and (ii) that it was only a baby's dummy after all, both of which she seemed to think justified her actions!!

  18. #1158
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    Quote Originally Posted by Selfsim View Post
    Also sort of leaves one with the impression that the 'black stuff' is actually sufficient to neutralise the pathogen in the first place. I have my doubts about some of the liquid handwash remaining on the shelves of pharmacies (etc) at the moment.
    Soap is soap, and soap is very effective against viruses with lipid coats, like coronavirus. The trick is to get the soap to all parts of your hands, which is a learned technique.

    Grant Hutchison

  19. #1159
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    Quote Originally Posted by grant hutchison View Post
    Also, Italy is having a rather biphasic outbreak, with some indication (or so I read, I haven't seen a graph) that the rate of increase is beginning to moderate in the north, while cases begin to increase in the south (where, up to now, the population has been less compliant with lock-down measures).
    While disregarding rules is more of an issue in the south, there is also the fact that there have been large movements of people (workers and students) from the north to the south after the disease was already quite widespread in the north. There have been surges of these migrations after events like closing the universities, announcing that travel would be restricted, closing factories etc. So these people are probably seeding a new surge in some of the southern regions.

    A couple of regions (Campania and Basilicata, I think) have announced that they are going to stop people entering or leaving. I don't know how effective that will be. Not just because it is the south, but also because these are largely rural areas with many small roads across the borders that would be hard to police.

  20. #1160
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    Quote Originally Posted by grant hutchison View Post
    Soap is soap, and soap is very effective against viruses with lipid coats, like coronavirus.
    I've noticed some 'hand-soaps' don't lather (in soft water) .. which is very suspicious.

  21. #1161
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    Quote Originally Posted by a1call View Post
    It is strange that the study does not include Silver which for its antibacterial properties is used in some if not all ventilators.
    I can't think of a ventilator I've used that contained any silver parts, and many of them will still be in use. There's some evidence that silver coatings on endotracheal tubes reduce the incidence of bacterial pneumonia in ventilated patients, but the ventilators themselves are isolated from the patient by paired filters and disposable tubing.

    Grant Hutchison

  22. #1162
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    Quote Originally Posted by Selfsim View Post
    I've noticed some 'hand-soaps' don't lather (in soft water) .. which is very suspicious.
    Not necessarily. Most of the lather you get from a bar of soap (or a soap-less skin cleanser) is actually produced by an added foaming agent. You can lather up a pure soap solution if you shake it vigorously in a bottle, but the lather is unimpressive and short-lived. I guess you'd need to read the ingredients list on your hand-wash, but probably with a chemical manual to hand.

    Grant Hutchison

  23. #1163
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    Quote Originally Posted by grant hutchison View Post
    I can't think of a ventilator I've used that contained any silver parts, and many of them will still be in use. There's some evidence that silver coatings on endotracheal tubes reduce the incidence of bacterial pneumonia in ventilated patients, but the ventilators themselves are isolated from the patient by paired filters and disposable tubing.

    Grant Hutchison
    Yes, that's what I was referring to, thank you for the correction:

    Silver is also used in some medical applications, such as urinary catheters (where tentative evidence indicates it reduces catheter-related urinary tract infections) and in endotracheal breathing tubes (where evidence suggests it reduces ventilator-associated pneumonia).
    https://en.m.wikipedia.org/wiki/Silver

    Still seems like a worthy/relevant metal/material to study the novel-Coronavirus persistence on, IMHO.

  24. #1164
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    Here's an important number coming out of Italy-- 6% of all cases reported to the medical community are serious or critical, which I interpret as meaning requiring ventilators. I believe an average time on the ventilator is about a week. So this tells you how long you need to stretch out the infection curve if your plan is to achieve widespread (say 50%) herd immunity without overtaxing your medical capacity (which leads to even worse death rates). But a key missing number is the number of people acquiring immunity without ever reporting to the medical community at all. Let's say f is the fraction of people who acquire immunity who do report to the medical community and get counted in that 6% figure. I would tend to imagine f is something like 50%, but I really have no idea.

    Then if your population is N, and the number of ventilators you have is V, then to saturate your ventilators you need to keep it to 16V/f new infections per week. That means an amount of time at a level of constant new infections per week of 0.5*Nf/(16V) weeks. In the US, for example, N is 300 million and V is about 100,000, so that's some 100f weeks. That's ls long as the vaccination timeframe for any f above about 50%, so any "herd immunity" strategy risks oversubscribing the healthcare capacity unless you think f is below about 50%. You can build more ventilators, and you probably will want to do that because this calculation assumes maximally efficient distribution and I don't know if they can really be moved around that easily. Also, you can't really control the infection rate that carefully. Worse, this kind of plan assumes that the number of people that will spend time on ventilators is some 0.5*Nf/16, so a bit over 1% of the population of any developed country (and I shudder to imagine the state in the third world). In the US, that means millions of people will get that experience, and the death toll will certainly flirt with a million, even if the timeframe for it to happen is spread out to require a year. I've heard strategies like extending it to a few months, that's not going to produce herd immunity without overtaxing the ventilators by a factor of several, which is wartime triage.

    So my conclusion is that herd immunity makes no sense as a national strategy except by innoculation or as the virus mutates into the general pool. If faced with exponential growth, there is no way to control it so you achieve herd immunity without just letting it run rampant and overtaxing your healthcare system, while producing millions of deaths (since most won't get the care they need). Hence you must prevent exponential growth, but if you're going to do that, there's no need (and no way) to regulate it perfectly such that herd immunity is achieved on about a year timescale. Instead, if you are going to attack R0, it makes more sense to attack it all out, and never achieve herd immunity except by innoculation. What an all-out attack on R0 looks like in a sustainable way is not yet known, but China and South Korea are going to be the vanguards for figuring that out, while Italy will test how those measures work in Europe. The US will just have to watch all this and try to stay a week or two behind in its actions, unless it burns up that grace period and ends up in the vanguard itself-- which seems quite possible at this point.
    Last edited by Ken G; 2020-Mar-22 at 11:34 PM.

  25. #1165
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    The thing about the herd immunity threshold is that it varies with R0: the proportion of a randomly mixing homegeneous population that must be immune in order to prevent disease spread is 1-1/R0.
    So even a tiny amount of immunity in the population can make a difference if other measures (social distancing, handwashing, self-isolation) can push R0 close to 1.
    And if you isolate the part of the population most at risk of winding up on an ICU ventilator (which is what's being implemented in the UK today), then you can afford to have more new infections per week without running out of ventilators.
    (And if we were to find an antiviral cocktail that is effective in moderating the COVID-19 pneumonia, then that would allow us to accept more infections per week without running out of ventilators, too. But of course we can't pin our hopes on that.)
    It's a fine balancing act, though, and it's becoming evident that we don't have enough control over the behavioural aspects to actually make this into a long flat curve. What looks like happening is a cycle of imposing and relaxing draconian measures, with the infection returning when the measures are relaxed. In the UK, the latest calculations reportedly show that that such a cycle would need to go on for two years (presumably damping with time), before the social measures could come off and stay off. But if you want any kind of social freedom in the meantime, then every little bit of herd immunity acquired along the way is helpful.

    Grant Hutchison

  26. #1166
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    Quote Originally Posted by Strange View Post
    While disregarding rules is more of an issue in the south, there is also the fact that there have been large movements of people (workers and students) from the north to the south after the disease was already quite widespread in the north. There have been surges of these migrations after events like closing the universities, announcing that travel would be restricted, closing factories etc. So these people are probably seeding a new surge in some of the southern regions.
    Ah, yes, thanks.
    We're reproducing that in the UK at present, with folk in camper vans turning up in droves in the Scottish Highlands and Wales.

    Grant Hutchison

  27. #1167
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    Quote Originally Posted by a1call View Post
    It is strange that the study does not include Silver which for its antibacterial properties is used in some if not all ventilators.
    The scammers pushing silver as a cure thank you. Look up Jim Bakker.
    Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.

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    Quote Originally Posted by Strange View Post
    A couple of regions (Campania and Basilicata, I think) have announced that they are going to stop people entering or leaving. I don't know how effective that will be. Not just because it is the south, but also because these are largely rural areas with many small roads across the borders that would be hard to police.
    Most Australian states have closed their borders to non essential travel or will be closing them by Wednesday night. Tasmania, Western Australia, South Australia and the Northern Territory have already closed their borders and Queensland closes them on Wednesday. The only borders open after that will be Victoria, NSW and the ACT. While Australia has long borders you would have to drive quite a long way to avoid the authorities.

    I feel sorry for the police/medical people who will have to shoulder the burden as domestic violence and alcohol induced crime will increase around here, as if they don't have enough problems already. Somehow I don't think the police will pussyfoot around with people who break the law.

  29. #1169
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    Quote Originally Posted by grant hutchison View Post
    Ah, yes, thanks.
    We're reproducing that in the UK at present, with folk in camper vans turning up in droves in the Scottish Highlands and Wales.

    Grant Hutchison
    At least those in Italy have some justification because they are returning home. If they were to isolate for 2 weeks then there would be less of a problem. But, hey, it’s the south!

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    A couple of interesting articles. From Arstechnica, a detailed article on possible antiviral and immune modulation treatments, with a good deal of information on the virus and possible approaches. Given the concerted effort, I expect there will be antivirals coming out of this, but the questions will be how long they will take to develop, and how effective.

    https://arstechnica.com/science/2020...ctive-therapy/

    And here is an article on vaccine testing and why it is difficult to accelerate it, with possible dangers due to accelerated testing. I will note this comes from a site that discusses politics, but it appears to me that this article in particular largely focuses on technical concerns. It points out that vaccines are normally tested on healthy people, not as an attempt at emergency treatment, so have the potential of hurting otherwise healthy people. It mentions some past examples of vaccines with severe unexpected side effects. In this case, for some vaccine tests, they are either bypassing or shortening animal tests. They mention that bad results could embolden antivaxxers. On the other hand, this is a disease that is killing people, so many would be willing to take a risk. Also, testers potentially could help save others by their action. And finally, it mentions that with the various approaches being tried, experts think it is likely more than one approach will eventually be successful.

    https://www.politico.com/news/2020/0...ackfire-139854
    Last edited by Van Rijn; 2020-Mar-23 at 07:30 AM.

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