Category: COVID through 2022

All my various postings tracking the COVID-19 pandemic through the end of 2022.

Post #610: An observation on masks

Source:  CNBC

CNBC has a long article about the end of the lockdown in Wuhan province, China.  Lots of pictures.

I challenge you to find a single individual not wearing a mask, in any of the pictures in that article.

And, I’m pretty sure that the entire flight crew pictured above is wearing KN95 masks, the Chinese-made equivalent of the N95 that is (for now) in such short supply in the US.

Not only is everybody wearing some kind of mask, I infer from this that critical personnel are wearing masks capable of filtering out aerosol particles.  The same masks we’d give to medical workers here.

And back in the USA, we still don’t have a mandatory mask ordinance in any state.  In fact, so far, I’ve only heard of one, for one Texas city.  We need to wake up and get with the program.

Post #609: What goes around comes around, in a good way

https://www.gofundme.com/f/pay-it-back-to-vienna-business

About a dozen Vienna businesses made large donations when this young man was trying to raise money for a cancer charity, a year ago.

Now he’s decided to try to raise money to pay them back, via GoFundMe

Even if you don’t donate, at least go read the story.

Post #608: Somebody in Vienna steps up on the mask issue

The US CDC wants us all to wear some sort of mask when in public, around others.  That was last Friday’s change in guidance to the public.
Some people don’t have a mask.  And, there’s a cultural (racial) barrier to wearing home-made masks in public .  And, frankly, I think most of us would prefer any commercially-produced mask to ginning one up at home.
I have been informed that one Vienna dental practice will be giving away two free masks per family, for a limited time period.  I don’t want to post the location until I am sure this is a general offer to the public, and not merely an offer to patients of that dentist that has somehow become more broadly known.  If it is a general offer to the public, I will post it.
Either way, I’m glad to see somebody stepping up.
I think, all things considered, we need an indoor public area mask ordinance here in the Town of Vienna.  Every employee in a public-facing position should wear a mask.  Every shopper should wear a mask.  If social distancing alone were enough, we would not have the CDC and the Governor of Virginia telling us to wear masks in public.

Post #607: Hydroxychloroquine? Maybe it works. Maybe it even works well.

Ionophore transmitting metal ion across cell membrane.  Source:  Wikipedia

I’m going to keep updating this continuously, so you might check back in a few hours.

Back in Post #562 (March 19 2020), I reviewed the evidence for hydroxychloroquine, as one of three drugs that might prove useful for COVID-19.  Search “An old drug that works in vitro (in a test tube).  Not yet proven in humans, but it sure looks like it ought to work”.  I was flip enough to describe it as “Golly, that’s like “take two aspirin and call me in the morning.”“.

It certainly had potent anti-viral properties in vitro against SARS (2003) and SARS-CoV-2 (COVID-19).  The drug was already known to concentrate in certain organs, including the lungs.  A small study in France suggested some efficacy in humans.  The Chinese had included it as one of very few drugs approved, in that country, for COVID-19.

All the elements of likely effectiveness were in place.  (And, separately, as it turns out, virtually all of those older-line malaria drugs, and the current malaria drug of choice, also have significant anti-viral properties, suggesting some underlying mechanism behind all of them. )

So I’ve been looking for further evidence to pop up.

There are now two separate reports — case studies from one physician, and professional society endorsement — suggesting that it does work.  It’s well worth your while to check out both of them.  One physician says that the drug must be used with zinc to be effective.  That’s a new one on me, and I’d love to understand what the presumed mechanism of action is there.

First, here’s an LA physician.  He’s the guy who says, combine with zinc.  His results sound a little too good to be true, based on the efficacy of other anti-virals in late-stage illness.  But you never know.  I’m going to spend a little time to see if I can track down the presumed mechanism that involves zinc.

Second, here’s no less an authority than the American Thoracic Society of New York (a physician professional society) endorsing off-label use for severely ill COVID-19 patients.  (The actual guidance document, referenced there, is literally from the American Thoracic Society.)

Just thought I’d pass along a little good news for a change.  And let you know that, despite what you may read, yes, there was a good chance this would work.  But nobody anticipated the results that the LA doctor reported, with combined with zinc.  Don’t get your hopes up, but he does seem to be a legit doc, legitimately taking care of COVID-19 patients.

Be aware that there are also studies showing no effect.  So the evidence is far from crystal clear.  No less an authority than Dr. Anthony Fauci says we should not assume that this is a “knockout drug”.

But I have to say, for that LA doc to say — eight hours later the patients taking the drug in combination with zinc were symptom-free.  That’s a strong claim and is easily tested.  And a requirement for requirement that something else be present — something already found in varying levels in the body — would be a plausible way to explain variations in success rates across studies, and then a claim of huge impact with explicit supplementation.

Update 1:  Well, about that zinc thing.  Sure enough, there was already a clinical trial underway using a combination with zinc.  The don’t do stuff like that at random, so presumably some smart cookie had some understanding of probable mechanism of action.  That was an observational trial for using this drug prophylactically (to prevent healthcare workers from getting coronavirus).  But at the bottom of the listing is a raft of scholarly articles on this.

Update 2:  And here’s an MD from New York who, separately, identified this drug, in combination with zinc, as an effective medication at preventing hospitalization of COVID-19 patients.  It’s always good to see some independent confirmation, even if it’s just a series of 200 cases for one physician.

OK, weirdly, zinc does in fact bind to hydroxychloroquine.  That’s been flagged as a potential drug-drug interaction.

And, it does potentiate the uptake of zinc by human cells, and that response is unique to zinc (as opposed to other metals.).

Apparently the FDA quietly approved the use of hydroxychloroquine for COVID-19 more than week ago, on an emergency basis.  I didn’t know that.  So it’s not even an off-label use now.

Aha!  Here’s an explanation for a potential mechanism right here, based on a couple of scholarly studies — read the comments.  If true, hyroxycholoroquine’s main role in humans is as a zinc ionophore — something that transports zinc ions across the cell membrane and therefore substantially raises within-cell zinc concentration.  Heck, it’s already been demonstrated in vitro. 

Ah, here’s what an ionophore is.  Interestingly, Wikipedia does not list a single zinc ionophore.

Based on this, if it really is the zinc, any consumable zinc ionophore that concentrates in lung tissue would be helpful.  Makes me wonder if there others that are as effective as hydroxycholorquine.  Makes me wonder if the reason that all those old-line (and current) anti-malarials have the same underlying mechanism of action.

Hilarious:  Quercitin is a zinc ionophore.  That’s a flavonoid, which you first met in my post on folk medicine (Post #552).  In fact, that’s the single most common flavonoid in the diet.  I think I’ll get my order in at Amazon before that’s vacuumed off the shelves.  Pretty sure I’ve got some zinc pills around here somewhere …

Two other zinc ionophores I’ve never heard of, but in vitro anti-viral activity was demonstrated.

So in addition to “eat your fruits and vegetables” (flavonoids), we can add green tea (epigallocatechin-gallate, another flavonoid) and zinc pills to my roster of folk medicines.

That’s not medical advice.  That’s just what I’m going to do, based on the observation that zinc supplementation apparently greatly enhances the effectiveness of hydroxychloroquine, and that zinc apparently does show in-vitro anti-viral effectiveness, if it can be transported into cells in high enough concentration.

Probably can’t hurt, if done in moderation.  Might help.  Why not?

Post #606: US Census: If you’ve gotten “the postcard”, you’re being unhelpful

Look familiar?  If so, you’re being a bad person.

We have all gotten our notices in the mail by now requesting that we get on-line and fill in the US Census.  I’ve neglected mine.  Which is kind of horrifying, considering that I’ve actually done a bit of survey work professionally. And used the Census data professionally.

When I finally got “the postcard”, I knew I was being a bad actor.  Assuming that Census does this in a standard manner, getting “the postcard” is a mark of shame.  So it was time to fill in the Census.  Which I have now done.

I timed it.  It took me 10 minutes, for the four people in my household.  Which is typical.  But I messed something up, so I thought I might mention that.

The plain language of the Census form says to count all individuals who were staying in your house on April 1.  But that’s not correct.  If you have a child who was supposed to be away at college on April 1, you are NOT supposed to report them as living in your household in April 1.  Even though they were.  They will be counted as they usually are, in their respective college towns.

Here’s a link go the US Census page on that.

Unsurprisingly, the last question specifically addresses that.  Census gives you the opportunity to flag that college student, so that Census can (somehow) identify them based on some college reporting them.  Presumably, because Census will find a person with my daughter’s exact name and date of birth, at some college near to my home, they’ll take her off of the count for my household, and retain it on the count for the college.

Now let me explain the postcard of shame.  I’m assuming Census uses standard survey protocols.  Typically, in a mail survey, you’ll get a first notice in the form of a full letter.  If you don’t fill it in, there will be a followup in the form of a short letter, saying, in effect, please read the prior letter.

But only the truly uncooperative get the postcard.  The postcard is typically used for the second followup.  The practical reason for using a postcard for second followup is that, by that time, you’re not worth the price of a first-class stamp.  If you’ve been enough of a jerk as to ignore the first and second notices to do what you are legally obligated to do, chances are you aren’t going to cooperate no matter what.

In other words, by the time you get to second followup, the likely yield is so low that you’re practically just not worth bothering with.  But it’s still cheaper than having to send out the paper-copy Census form.

And vastly cheaper than having in-person followup, which I’m not even sure they are going to be able to do this time.  Census taker was always a somewhat hazardous occupation.  Now, it’s not even clear they are or should send people door-to-door, to deal with the least-cooperative people among us.

The upshot is that the US Census is among the many things that COVID-19 has scrambled.  It’s a pretty good guess that a lot of people are not going to be counted.  Do your part to fix that.  Get on line and fill out your Census form today.

Getting our fair share of Federal, state, and local government money — not to mention our seats in the U.S. House of Representatives — all depend on that Census count.  The information they ask for is minimal.  Name, date of birth, sex and race/national origin for every person in the household.  And do you own or rent the place where you live.  That’s it.  Get it done.

 

Post #605B: Answer key for Post #605

1:  Total tests required = number of batches, plus all persons in one batch.

Batches = 500/10.  Persons in a batch = 10.  So:

1A: (500/10) + 10 = 50 + 10 = 60 tests needed under TTTT.

1B: 500 – 60 = 440 tests saved.

1C:  440/500 = .88 = 88% reduction in tests

2)  Total tests required = number of batches, plus all persons in one batch.

2A: T = (E/N) + N

2B:  E = 500, N = 10, T = (500/10) + 10 = 60.

3)  Optimum batch size is the square root of total employment E

3A)

T = E*N-1 + N  (formula from step 2)

dT/dN = -1*E*N-2 + 1 (calculate the first derivative (slope) with respect batch size).

Now minimize the number of tests by finding the point where the derivative is zero.

-1*E*N-2 + 1 = 0  (Set derivative to zero).

-1*E*N-2 = -1  (Subtract 1 from both sides).

E*N-2 = 1 (divide by -1).

E = N2 (multiply through by N-squared).

N = SQRT(E)  (Take square roots)

The optimum batch size is the square root of total hospital employment E.

Second derivative is positive by inspection, so this is a minimum.

3B)  For Euler Hospital’s 500 employees:

Optimum batch size:  SQRT(500) = 22.36

Number of tests = 2*SQRT(500) = 44.72

Ignoring rounding.

4)  Download this Excel file: TTTT numerical analysis

The answer is somewhere between 22 and 23 for the optimum batch, requiring a around 44.73 tests.  So that matches the calculus result to within rounding error.

5)  Gauss Hospital in Binary, Arkansas.

5A) 2*SQRT(256) = 32 tests required for optimized TTTT

5B)  Gauss hospital should consider using a binary search instead.  At each step, divide the employees in half, test both halves, and repeat on whichever half tests positive.  Employees at each phase:

  1. 256, divide in two, test both
  2. 128, ditto
  3. 64, and so on …
  4. 32
  5. 16
  6. 8
  7. 4
  8. 2

5C) On the eight tier, you have two employees, you test them both, and one of them is positive.  You have a total of 8 tiers (8 rounds of testing), each tier requires two tests, so this requires a total of 16 tests.

6) It matters much more to larger hospitals.

Flat-footed testing of every employee required E tests.  Optimized TTTT requires 2*SQRT(E) tests.  Calculate the ratio of the two — the smaller that is, the more that optimized TTTT saves you, in percentage terms.  Either calculate that for a few different values of E (numerical analysis approach), or inspect the derivative of that with respect to E (loosely termed here the calculus-of-variations approach).

Ratio = 2*SQRT(E) / E

Ratio = 2*E1/2*E-1 (re-expressed using exponent notation) 

Ratio = 2*E-1/2  (when you multiply the numbers, you add the exponents)

dRatio/dE = -E-3/2  (take the derivative, and note that it is always negative)

So the ratio falls as E gets larger.

Examples:

50 beds, ratio = .28, optimized TTTT requires 28% as much testing as the just-test-everybody approach.

500 beds, ratio = .09, optimized TTTT requires 9% as much testing.  (Recall from question 1 that standard TTTT had 88% savings, so standard TTTT only required 12% as much testing.  So, true to its name, optimized TTTT not only requires less testing than test-everybody, it requires less testing than standard TTTT).

5000 beds, ratio = .03, optimized TTTT requires 3% as much testing

7)  The worst-case scenario occurs if your infected employers are spread as thinly as possible across your population.

7A)  To find 2 infected employee:  50 batches, plus 10 in two batches = 70 total.

7B) To find 10 infected employees:  50 batches, plus 10 in 10 batches = 150 total

7B) To find 60 infected employees:  50 batches, plus 10 in … well, there’s only 50 batches so … that’s 550 tests?  No,wait, that’s dumb.  You end up having to test everybody anyway.  The batch tests are a waste.

Just test everybody from the get-go.  The answer is 500 tests.

8)  We’ve just shown that the TTTT method still functions, even if you have more than one infected employee, it just requires more tests.  And, it can be wasteful if you reach the point where you’re going to have to test every employee anyway.

Optimized TTTT simply wastes fewer tests in the case of 60 sick employees, because you only have 23 wasted batch tests.  But note that optimized TTTT, due to the higher batch size, becomes wasteful at lower infection rates.  With optimized TTTT, in this example, once you have 23 infected hospital employees, you end up testing everybody.

Binary search will eventually find everybody, but it is a total and hugely inefficient waste of time at high infection rates, because instead of performing two tests at each tier, you have to test every group.  It doesn’t let you discard groups of people until you get way down the tier structure.

Let me just hack through it with 32 sick employees at Gauss General.  Worst case scenario, it requires 190 tests.  You don’t rule out anyone until you get to the next-to-the-last tier.  If you knew the infection rate was this high, you’d just go straight to smaller batches (start at tier 6) and only use 128 tests.

  1. 256, 2 batches, 128/batch, 2 tests required
  2. 256, 4 batches, 64/batch, 4 tests required.
  3. 256, 8 batches, 32/batch, 8 tests required
  4. 256, 16 batches, 16/batch, 16 tests required
  5. 256, 32 batches, 8/batch, 32 tests required  — at this point, every group has one.
  6. 256, 64 batches, 4/batch, 64 tests required — half the test are now negative
  7. 128, 64 batches, 2/batch, 64 tests required — you have isolated the 32.

 

Post #605: Real-world word problems: Teutonic two-tier testing

Source:  Wikipedia.

I’m writing this one just in case your kids ever wonder what math is good for.

Germany has had a remarkably rational, effective, and organized response to the COVID-19 pandemic.  One thing I found out yesterday is that they test every hospital employee for the virus.

I was floored.  How can they do that? U.S. hospitals have about 5.2 million employees on payroll.  If you toss in volunteers, and physicians and others with hospital privileges, it’s safe to say that, in the U.S., you’d be talking about testing at least 6,000,000 people on a routine basis.

That would require about six times more tests than the US has done, in total, so far.  Just to do one round of testing on all US hospital employees. US public health labs have done fewer than 200, 000 test.  If you toss in a guess as to all the testing done in private labs, you’d still come up with somewhere in the neighborhood of 1,000,000.

How on earth can Germany do that, then?  I mean, sure, they probably have more test per capita than we do.  But, still, that’s a pretty big gap between what the entire U.S. lab system appears to be able to do, and what the Germans routinely do.

What’s their secret? Continue reading Post #605: Real-world word problems: Teutonic two-tier testing

Post #604: Daily increase in cases to 4/5/2020. Hmm.

I’m relying on the NY Times extract of the John’s Hopkins coronavirus counts, for this. Plus the 6 PM count as posted on the Hopkins map.

I added a seven day moving average to try to smooth out the day-to-day variations.  On any given day, that’s just the sum of counts for the last seven days, divided by seven.  Sometimes that lets your eye perceive any change in the trend that might otherwise get lost amid the daily ups-and-downs.  (But that smoothness comes at a cost of being “late”, in the sense that if there is some change, the seven-day moving average takes seven days to reflect that fully.)

For Virginia as a whole, by eye, we’re still in the “exponential growth” phase.  That gray line is “concave upwards”, like the side of a bowl.  And it could just be wishful thinking on my part, but the Fairfax seven-day moving average appears qualitatively different.  That looks concave-downward to me — like the peak of a hill. Starting to break away from exponential growth, by eye, sometime around 3/28-ish or so.

Obviously, that could be wishful thinking.  You eye can play tricks on you. And we’d need another week to at least to confirm it.  But for now, at least, Fairfax County does not appear to be experiencing exponential growth.  We’re getting more new cases each day, sure.  And total cases continue to rise.  But not, for the moment, at an accelerating rate.

Well, we’ll see.

Please wear a face covering of some sort when your are in public, near others.

 

Post #603: No, our local hospitals don’t want your homemade mask.

Following on to my prior post, I’m already getting blowback because people think that any home-made masks need to go to hospital workers.   The upshot is that we’re going to have a bunch of older people, around Vienna, who refuse to mask up because they think they need to give any home-made mask to the local hospitals.

Let’s ask the Inova health care system.  We don’t even have to ask, because they’ve already addressed this issue.  Note the boldface.  That’s a dead giveaway that this issue has already become a nuisance for them.  They really, really don’t want you bothering them with your home-made mask.

They want your money.  They want your blood.  And if you have it, they will accept full, unopened boxes of genuine surgical masks and gloves.

They don’t want your homemade mask.  They have genuine N95s and surgical masks.  Even if we get to the point where they have to re-use N95s, those will be VASTLY BETTER than any mask your or I could make.  It would be frankly illegal for them to use home-made mask if they have any other alternative whatsoever.  If you look at CDC guidance on this issue, of all the things hospitals are allowed to do, use of homemade masks is dead last, following going bare-faced behind a face shield.

Use of homemade masks puts hospital staff at unnecessary risk, so long as there is any other alternative.  The only time hospitals can legally consider use of home-made masks is in the event that the only alternative would be to go bare-faced, i.e., literally no protection.

And now that a) everybody knows how to re-used N95s safely, and b) we are going to allow China to flood the US with cheap KN95s, not only does Inova not need your home-made mask, they will never need your home-made mask.

If you want to make a mask, absolutely the best thing you can do with it, in this situation, is wear it.

Rule #1:  Don’t be the dumbass who fills the next empty hospital bed.  Do what the CDC now tells you to do.  Wash your hands, keep your distance, no crowds, disinfect high-touch household surfaces, and so on.

And now they’re telling you to wear a mask when you go out of your house.  The best thing you can possibly do, right now, is to follow the CDC’s guidance.