Covid-19: How it Spreads and How it can be Slowed

Palmpilot

Palmpilot

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I wonder if (and hope that) the intensive study of COVID19 will advance valuable research on how to combat other virus maladies such as flu and common cold.
 
AggieMike88 said:
I wonder if (and hope that) the intensive study of COVID19 will advance valuable research on how to combat other virus maladies such as flu and common cold.
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I think so. Too bad it takes a pandemic to get interest in antivirals, anti-bacterials, or anti-fungals. I hope that, if this ends soon, we continue the studies.
 
Cap'n Jack said:
I think so. Too bad it takes a pandemic to get interest in antivirals, anti-bacterials, or anti-fungals. I hope that, if this ends soon, we continue the studies.
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What makes you think that “interest “ in developing antimicrobials has somehow been lacking? During my professional career development of antibiotics of all sorts was robust, but the bugs always seem to keep ahead of us.
 
wrbix said:
What makes you think that “interest “ in developing antimicrobials has somehow been lacking? During my professional career development of antibiotics of all sorts was robust, but the bugs always seem to keep ahead of us.
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Interest and funding need to go hand and hand. There was robust work on a vaccine for sars-1 but the damn bug went dormant (probably mutated out of existence) after 7 months of havoc and funding went by way of interest and no vaccine done. Same could be said for Ebola vaccine. But none of those came close to reaching pandemic status of sars-2. But highly more percentage wise they were far more deadly.
but COVID19 has the world by a grip. It’s ability to spread and longer incubation period matched with ability to kill makes it quite a target for research. Hence some serious big bucks are getting spent. Hopefully they find one as it IMO will be the only thing that allows some normalcy.
 
benyflyguy said:
Interest and funding need to go hand and hand. There was robust work on a vaccine for sars-1 but the damn bug went dormant (probably mutated out of existence) after 7 months of havoc and funding went by way of interest and no vaccine done. Same could be said for Ebola vaccine. But none of those came close to reaching pandemic status of sars-2. But highly more percentage wise they were far more deadly.
but COVID19 has the world by a grip. It’s ability to spread and longer incubation period matched with ability to kill makes it quite a target for research. Hence some serious big bucks are getting spent. Hopefully they find one as it IMO will be the only thing that allows some normalcy.
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Agree entirely.
CapnJack seemed to make the implication that antimicrobial development (not vaccine) was of little interest to big Pharma, which I think is not the case. What?, we are on fourth generation beta lactams, third? macrolides, effective antiretrovirals, new antifungals, influenza antivirals, work continues on Ebola antivirals, and others with which I’m sure I’m even less conversant.
 
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wrbix said:
What makes you think that “interest “ in developing antimicrobials has somehow been lacking? During my professional career development of antibiotics of all sorts was robust, but the bugs always seem to keep ahead of us.
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That's why we need to keep up the development.
wrbix said:
Agree entirely.
CapnJack seemed to make the implication that antimicrobial development (not vaccine) was of little interest to big Pharma, which I think is not the case. What?, we are on fourth generation beta lactams, third? macrolides, effective antiretrovirals, new antifungals, influenza antivirals, work continues on Ebola antivirals, and others with which I’m sure I’m even less conversant.
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Because during my professional career, I've seen big pharma (and small pharma) move away from this area. It's been years since I've worked with anyone working in this area.

There is some on-going work, but not nearly as much as there used to be. Many of the classes you mentioned have been known for decades, few truly novel classes have been developed. Most of the companies listed in the first link are very small.
https://www.pewtrusts.org/en/resear...antibiotics-currently-in-clinical-development
https://www.who.int/news-room/detai...-efforts-to-contain-drug-resistant-infections

As @benyflyguy mentioned, SARS-1 work dried up with the need (or lack thereof).
 
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bbchien said:
The great irony is that if 100% of humans did absolutely nothing for 20 days, the pandemic would be over.
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Except for the little detail of how many would subsequently die of starvation or lack of emergency medical care, etc., if we tried anything like that.

We could have it under far better control if we could just fix stupid.
 
wrbix said:
but the bugs always seem to keep ahead of us.
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So very true! While part of my work concerns vector-borne diseases the statement by Dr. Jerome Goddard rings true ... "there are some things out there that we cannot kill." The other option then is containment. That's where people should use more wisdom. As grandma would say, "an ounce of prevention is worth a pound of cure." Sadly, it appears our society don't understand that truth.
 
Jeff Oslick said:
Except for the little detail of how many would subsequently die of starvation or lack of emergency medical care, etc., if we tried anything like that.

We could have it under far better control if we could just fix stupid.
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nobody is dying of starvation in 20 days. Medical care, that is a legitimate concern. The number of non disease cv-19 excess deaths due to things like mental heatlth, unspotted cancer, is something that will probably never be known, other than it it significant.

On the other hand, this weekend the CDC did update mortality rates model for CV-19 and they are astonishingly low. The numbers change constantly so I will just link the page and you can read it. What is clear is 1) the initial WHO estimate was very high. 2) it is certainly weighted against the elderly and sick and 3) if you are young and healthy, the risk of dying may be lower than driving a car.

https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scenarios.html
 
bflynn said:
...What is clear is 1) the initial WHO estimate was very high....
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If you're talking about the 3.4% number the WHO gave, that was stated as a percentage of reported cases. The percentage of total infections, if known, would have been lower.

"Globally, about 3.4% of reported COVID-19 cases have died," WHO Director-General Dr. Tedros Adhanom Ghebreyesus said at a press conference in Geneva on Tuesday.
​
https://abcnews.go.com/Internationa...amble-outbreak-case-numbers/story?id=69381834

(Scroll down to the 5:45 AM report.)
 
The WHO has a .37 IFR, but they also have a 20% asymptomatic rate. We have already seen from antibody testing in NYC that the asymptomatic rate is at least 50%, if not higher. If they have the asymptomatic rate wrong, their IFR is going to be too high because they'll be missing cases.

I saw an overall rate of .26% on the CDC page on Friday, 01% this morning and now it's .034%.

My read right now is that warmer weather is tamping this down, like it does with the common cold. I would expect to start seeing cases in the southern hemisphere start ramping up and we'll be OK until Oct or Nov. If we have a vaccine by then, we should be able to get through next winter without quarantining healthy people.
 
Palmpilot said:
If you're talking about the 3.4% number the WHO gave, that was stated as a percentage of reported cases. The percentage of total infections, if known, would have been lower.

"Globally, about 3.4% of reported COVID-19 cases have died," WHO Director-General Dr. Tedros Adhanom Ghebreyesus said at a press conference in Geneva on Tuesday.
​
https://abcnews.go.com/Internationa...amble-outbreak-case-numbers/story?id=69381834

(Scroll down to the 5:45 AM report.)
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The symptomatic case fatality rate, iow the rate of those who
- present with symptoms
- are subsequently found to be positive for infection with SARS-Cov2

seems to be remarkably stable across the different outbreaks. Its lower if the population infected trends younger and with fewer comorbidities (e.g. the ski-town outbreaks) and higher if the population skews older (e.g. if it involves nursing homes).

If the data gets muddled between symptomatic patients and asymptomatic carriers (like most data in the US), you can see swings in the rate based on how many asymptomatic patients you pick up with surveillance activities (e.g. by testing all the prison guards in a large facility). That is also why it is a fools errand to make any decisions based on the 'positivity rate' as that rate is mostly dependent on who you test.

The only people obsessed about the 'true infection fatality rate' are those who try to minimize the significance of this thing. While the IFR is interesting from a epidemiological perspective, it doesn't matter all that much for the 55 year old diabetic who shows up coughing and with shortness of breath in ER triage (If we follow the logic of some engaged in this discussion, he is just part of the expendables who 'would have died anyway' so he doesn't really matter).

Until we figure out a way to record and analyse the 'case' numbers with information on:
- date of specimen collection
- date of symptom onset
- reason for specimen collection (symptomatic/outbreak tracing/asymptomatic screening)

....we are going to chase our tail. We have a neighboring county that sat at a total of 5 cases for a month. Then last week the national guard came in and tested all staff and residents in the counties nursing homes and just like that, the number 'doubled'. It's still a tiny number and everyone involved in public health locally knows why it did what it did, but someone from the outside who just looks at rows in a spreadsheet could be led to believe that 'there is a new hot-spot'.
 
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bflynn said:
nobody is dying of starvation in 20 days.
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It isn't just the US, for a total lockdown to work, it would have to be global. A) not gonna happen; and B) while the US might survive it, the global economy would be dragged so far down the crapper it would take a decade to recover.

We're stuck with riding this one out and trying to convince selfish people to be a little less selfish.
 
weilke said:
The only people obsessed about the 'true infection fatality rate' are those who try to minimize the significance of this thing. While the IFR is interesting from a epidemiological perspective, it doesn't matter all that much for the 55 year old diabetic who shows up coughing and with shortness of breath in ER triage (If we follow the logic of some engaged in this discussion, he is just part of the expendables who 'would have died anyway' so he doesn't really matter).
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Why would you go this route? Of course individuals affected don't care about statistics and rates. Your logic would say that nobody cares about the woman who got breast cancer because she's just a statistic. Disgusting line of thought.

The interesting part of the IFR is how it breaks out across age groups. If you're under 50, the IFR is .05% (.0005). You are more likely to die in a car wreck than die of covid. These are the people that should be out there, yet we have them cowering at home like it's the plague. But even from 50-65, it's 0.2%, including those with additional conditions.

Yes, that doesn't help the person who catches it any more than it helps the poor person who dies in a car wreck. But we don't quarantine ourselves because we might have a car accident, so why are we telling the young people to live in fear?

Covid isn't a death sentence. If that is trying to minimize it, it's because the media has already blown it out of proportion and it needs to be minimized to bring it back down to reality.
 
Let’s all remember that just because young healthy folk are less likely to die, they are just as likely (if not more so in their travels) to carry and transmit this highly transmissible virus to more vulnerable people....this is the reason to practice socially responsible behavior
 
A non-peer reviewed manuscript isn't worth the paper it isn't written on. What the second article says is pretty dead on, at least what I read of it. This isn't rocket science gents. COVID19 have two ways it can spread. The big one is aerosols. What makes this virus a sneaky bastich is that you can feel completely healthy and give off these aerosols. So wear a mask to protect those around you. If you're giving off virus a mask will reduce the number of aerosol particles, the velocity at which they emerge and the distance they travel. Stay 6 feet from anyone. if you have to go near someone make it for the briefest time possible.

But COVID has another trick up its nasty viral sleeve. It can persist on surfaces like it's nobody's business. It is less likely that you'll picket up forma surface, but possible. So wash your hands.

That's it gents. Stay home if you can. Go out as little as you can. If you do go out and you're going to be in the vicinity of others, wear a mask. Stay as far away as you can. Stay near others as little as you can.
 
bflynn said:
Why would you go this route? Of course individuals affected don't care about statistics and rates. Your logic would say that nobody cares about the woman who got breast cancer because she's just a statistic. Disgusting line of thought.
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Diagnosis and treatment of breast cancer is one of the things I do for a living. And yes, there is a lively discussion on who to screen and who to treat for breast cancer. There are in fact those who advocate not to do anything once a woman has reached an arbitrarily set age limit as doing so 'doesn't affect all cause mortality'. Just like the covid thing, making those pronouncements is much easier to if you dont have breasts yourself and you never have to explain that attitude to a patient face to face.

In PA, 46% of hospitalizations for covid are in the <65 age group, so while the odds are lower, the higher prevalence of the infection in the younger and more active age groups drives hospitalizations.
As for the specious comparison with traffic deaths: If we just limit the apples to oranges comparison to anyone under 75*, covid within the span of 2 months has eclipsed all road deaths in the state for 2018# . So yeah, if road deaths in PA were up to 1500 at the end of February, we would probably see some 'no road orders'.






* with drivers >75 accounting for less than 1% of road miles driven
# the most current year PennDot has on their website.
 
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wrbix said:
What makes you think that “interest “ in developing antimicrobials has somehow been lacking? During my professional career development of antibiotics of all sorts was robust, but the bugs always seem to keep ahead of us.
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The economics of antibiotic development is actually pretty dismal, which which is why there have been almost no new antibiotic classes developed in the last few decades. Drugs that are intended to be taken infrequently, for short durations, are just not good profit centers. Drugs for chronic conditions like allergy, degenerative diseases (arthritis, dementia, GI conditions, etc.) are much more profitable. Antibiotic development is an area where market forces don't work very well, and where public support is more appropriate. And the dismal economics also hold for antivirals, which are often less effective and more difficult to develop, except when you have a serious pandemic crisis like AIDS, SARS, or COVID. The science is doable if there is financial support. Research doesn't happen for free, unfortunately. And much of what we need is not just applied research, but basic research to uncover novel foundational ideas that can be exploited for tomorrow's technologies. Things that come to mind include, in no particular order, restriction endonucleases (led to recombinant DNA technology), thermophilic polymerases (led to PCR, DNA sequencing, and genome sequencing), CRISPR (led to powerful, custom, gene-editing). I could go on...I was in this ball game for many, many years, with basic research funding flat or slashed in the last two decades.
 
chemgeek said:
The economics of antibiotic development is actually pretty dismal, which which is why there have been almost no new antibiotic classes developed in the last few decades. Drugs that are intended to be taken infrequently, for short durations, are just not good profit centers. Drugs for chronic conditions like allergy, degenerative diseases (arthritis, dementia, GI conditions, etc.) are much more profitable. Antibiotic development is an area where market forces don't work very well, and where public support is more appropriate. And the dismal economics also hold for antivirals, which are often less effective and more difficult to develop, except when you have a serious pandemic crisis like AIDS, SARS, or COVID. The science is doable if there is financial support. Research doesn't happen for free, unfortunately. And much of what we need is not just applied research, but basic research to uncover novel foundational ideas that can be exploited for tomorrow's technologies. Things that come to mind include, in no particular order, restriction endonucleases (led to recombinant DNA technology), thermophilic polymerases (led to PCR, DNA sequencing, and genome sequencing), CRISPR (led to powerful, custom, gene-editing). I could go on...I was in this ball game for many, many years, with basic research funding flat or slashed in the last two decades.
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^^^^^^
What he says.
 
bbchien said:
Be sequestered x3 weeks....
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It would require members of a household to be sequestered from each other. As NY found out, if you lock everyone in their house, you will end up with a majority of cases as a result of in-household transmission.
 
The reason for 3 weeks, is, sequestered in the house, one of transmission is covered....(roughly, 11 days x 2)
 
I took the nasal swab test this afternoon along with the rest of my coworkers and it was not pleasant! :nonod:

48hrs til we get our results...
 
Chemgeek says it right. Antibiotic development is neither hot nor sexy, no one values it and no one will pay for it. Hasn’t been a new class of antibiotics since I started in science. In the mean time bugs are rapidly acquiring resistance to everything we got. Stan Falco said it right, our bugs’ll get us in the end. My might have lucked out on this one if that drug from Gilead Biosciences pans out. Those who own Gilead Biosciences will have lucked out too.
 
Experts urge caution in interpreting COVID-19 antibody tests
False positive results are cause for concern

https://medicine.wustl.edu/news/experts-urge-caution-in-interpreting-covid-19-antibody-tests/

Excerpt:

Many people are anxious to get people back to work, but antibody tests may give some people a false sense of security. The problem is that even a highly accurate antibody test like the one we use in our laboratory has false positives and false negatives. When the true rate of infection in a community is very low, you will have more false positives than true positives, no matter how good the test is. In Missouri, we think that fewer than 1% of the population has been infected. In our research, we estimated that if we screened asymptomatic individuals, only one out of seven positive antibody tests in Missouri would be true positives, even with a highly accurate test. So, the other six people may think they’re protected and let their guard down, and then they could get infected and spread the disease. Widespread antibody testing could do more harm than good if people do not understand the limitations of such testing. ​
 
This paper was published in Nature yesterday:

The effect of large-scale anti-contagion policies on the COVID-19 pandemic

Abstract

Governments around the world are responding to the novel coronavirus (COVID-19) pandemic1 with unprecedented policies designed to slow the growth rate of infections. Many actions, such as closing schools and restricting populations to their homes, impose large and visible costs on society, but their benefits cannot be directly observed and are currently understood only through process-based simulations2–4. Here, we compile new data on 1,717 local, regional, and national non-pharmaceutical interventions deployed in the ongoing pandemic across localities in China, South Korea, Italy, Iran, France, and the United States (US). We then apply reduced-form econometric methods, commonly used to measure the effect of policies on economic growth5,6, to empirically evaluate the effect that these anti-contagion policies have had on the growth rate of infections. In the absence of policy actions, we estimate that early infections of COVID-19 exhibit exponential growth rates of roughly 38% per day. We find that anti-contagion policies have significantly and substantially slowed this growth. Some policies have different impacts on different populations, but we obtain consistent evidence that the policy packages now deployed are achieving large, beneficial, and measurable health outcomes. We estimate that across these six countries, interventions prevented or delayed on the order of 62 million confirmed cases, corresponding to averting roughly 530 million total infections. These findings may help inform whether or when these policies should be deployed, intensified, or lifted, and they can support decision-making in the other 180+ countries where COVID-19 has been reported7.

Full paper (unedited preview):

https://www.nature.com/articles/s41586-020-2404-8_reference.pdf
 
I wonder what a similar study of, say, influenza, would find...
 
Bob Noel said:
I wonder what a similar study of, say, influenza, would find...
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Influenza is a tenth less infective and far less lethal, the degree to which depending on who you cite. Also, we can vaccinate against most strains of influenza. The only reason it continues to be a concern is because new viral strains appear every year. That's what happens when a virus has multiple chromosomes.
 
steingar said:
Influenza is a tenth less infective and far less lethal...
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Which doesn't change my interest.

btw - it would be awesome if you could cite your source for making those claims about influenza and why you think they are more accurate than information that can be found on the CDC site.

another btw - the families of the more than 34,000 people that died in the 2018-2019 fu season might have a different view of the flu's lethality
 
Bob Noel said:
Which doesn't change my interest.
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What interests you is of almost no interest to me.

Bob Noel said:
another btw - the families of the more than 34,000 people that died in the 2018-2019 fu season might have a different view of the flu's lethality
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Vaccines against influenza are widely available. They are not always entirely effective though, the vaccination process involves a little prognostication that isn't always entirely accurate. To the best of my knowledge most deaths from influenza are among sensitive and institutionalized populations. It is easily avoided (Mrs. Steingar had the flu last year and with a few common sense measures I didn't get it) and can be medicated (Tamiflu reduces the symptomatic period by a third).

Coronavirus cannot at present be either immunized against or medicated (unless you believe the stuff about hydrochloroquine. I don't, though it looks as though the original paper against was hinky). It is highly infective and far more lethal, against both sensitive populations and some not so sensitive. The measures we've taken have substantially slowed the rate of infection and likely saved tens of thousands (possibly hundreds of thousands) of lives. And I promise you that the relaxation of measures I've witnessed recently is going to cost a lot of lives.
 
Is it too much to ask someone to cite your source for making claims about influenza?

Is it inappropriate?
 
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