The Wuhan Coronavirus

This morning's (3/25) reports from the five hardest hit provinces in China

Place cases recov'd deaths active

1. Hubei 67,801 60,811 3161 3827
2. Guangdong 1,433 1,336 8 89
3. Henan 1,274 1,250 22 2
4. Zhejiang 1,241 1,221 1 19
5. Hunan 1,018 1,014 4 0

The death RATES can be bracketed by assuming all pending cases die or that all pending cases recover, both being less likely than that some do and some don't.

1. Hubei 4.7% 4.9% 10.3%
2. Guangdong 0.6% 0.6% 6.8%
3. Henan 1.7% 1.7% 1.9%
4. Zhejiang 0.1% 0.1% 1.6%
5. Hunan 0.4% 0.4% 0.4%

So, unless a whole bunch of new cases appear -- and the meejah are doing their best to raise this possibility -- the Wuhan epicenter (Hubei province) will probably run about 5% mortality. Probably because the govt there at first tried to conceal it and only took action after it was 'too big to fail.' None of the other high-case provinces touch this. Only neighboring Henan comes close, at just under 2%. Guangdong is currently at 0.6% and only if every pending case is mortal might it become as high as 6.8%. In Hunan, where all cases are resolved at this point, the mortality is less than half a percent.

Testing, one, two, three.

Some more about testing,
Bureaucracy strikes again!

The Dreaded Red Squamish

As an aid to another discussion elsewhere regarding the latest pandemic, consider the effect of screening for the Dreaded Red Squamish of which, unbeknownst even to Health Care Professionals, infects 5% of the population.

The test, which includes the person administering it, the instruments, conditions, and all what have you, is known to be 95% sensitive -- of those with the Squamish, the test will come back positive 95% of the time -- and 95% specific -- of those without the Squamish, the test will come back negative 95% of the time.

Perceptive Reader will notice that this means a 5% risk of a false positive and a 5% risk of a false negative. The Usual Suspects may cry, "No fair!" because they want Daddy and Mommy to ensure 100% perfect. [When do we want it? Now!] But the sensitivity is about normal for lab tests while the specificity is actually better than normal. (As an example of lack of specificity is the well-known ability of drug testing to detect the consumption of poppy seed bagels.) It is also hard to imagine that the 15,000th test will be performed with the same sprightly verve and enthusiasm as the 1st.

Now, test a million people for the Red Squamish, just in case.

 

 Of the 950,000 folks who are not infected. nearly all (95%) get a clean bill of health and of the 50,000 infected souls, nearly all (95%) get a red card. But along the way 2500 infected people go undetected, while 47,000 uninfected get red carded nonetheless. Perhaps they ate a poppy seed bagel that morning, or the test was run late at night by a dog-tired technician. In any case, you will notice that half of all those getting flagged are not in fact infected.

Consequently, the media reports that the infection rate is 9.5% [(47,500+47,500)/1,000,000] rather than 5%, although what they really mean is that the test-positive rate is 9.5%. 

 

This also affects estimates of the mortality rates. It's not called the Dreaded Red Squamish for nothing. But the denominator has been inflated by the false positives, so deaths will be divided by 95,000 rather than the [unknown] 50,000. There will be 47,000 "recoveries" of people who never actually had the disease. OTOH, some of the undetected 2,500 may also shuffle off the coil of mortality, but these will be assigned to collateral conditions (heart disease, asthma, etc.)

Those unfamiliar with the exigencies of measurement systems analysis are too likely to take test results as given.

Type I and Type II errors are universal. They apply to any decision process. In law, Type I is convicting the innocent and Type II is freeing the guilty. In the FDA, they are (I) withholding approval from a safe and effective medical device or (II) approving an unsafe or inneffective medical device. In product inspection you can (I) approve defective product or (II) reject conforming product. You can decide (I) not to kiss a willing girl or (II) to kiss an unwilling one.

What differs among these cases and others are the consequences of the errors. We try to avoid Type I error in trials and sending innocent people to jail; but we would rather avoid Type II error in FDA approvals. In the latter case, if we approve a device that turns out to be unsafe, people may die. People may also die if a safe and effective device is withheld from the market -- but they don't die on the front page. 

 

You can't improve by making the decision rule more stringent. That will only shift the errors between I and II. It's like Whack-a-Mole. Drive down one type of error and you'll drive up the other. You have to change the decision rules themselves.

Of course, none of this means the Dreaded Red Squamish is not dreadful. It only means the numbers may lead to unreasonable panic or to complacency. 

 

Or both.

One Flu Over

This is an excerpt from "Places Where the Roads Don't Go," which appeared in the collection Captive Dreams.

One Flu Over

It was five years later, during the big epidemic, when everyone went about wearing those face-masks and getting their shots, when we all met again.  Jared had contracted the flu and had fallen deathly ill.  And while he was not as close to me as he was to Kyle, still he had dated my sister and we knew each other better than most.  

The worst of it was over by then and the airports were open once more, so I caught a regional to Newark, rented a car, and drove down to Princeton Hospital.  Traffic was light and people still tended to avoid one another.  Like soldiers in the waning days of a war, those lucky enough to have escaped so far had no desire to become the last fatality.  It was, sadly, the smoothest trip that anyone had ever taken down the Jersey Turnpike.  

The University Medical Center stood on a side street, past an old cemetery, which struck me as bad feng shui for a hospital.  I drove through to the parking lot and walked back to the main building.  It was a chilly, blustery spring quite in keeping with the mood of the country.  The information desk was enclosed within a Plexiglas shell under positive air pressure so germs would not waft into the booth.  I presented my certificate of inoculation and passed through the sanitizing airlock into the main hospital.  The UV lamps, air jets, and gas spray were supposed to sterilize visitors, but I thought they might be only to reassure them.  It certainly cut down on the number of visitors. 

Maggie Tam

For a very long time, the Incomparable Marge knew nothing of her paternal grandparents, save that she had been named for the grandmother and, according to her father, this grandmother had been half-Choctaw. Nor had she been told the name of his father. Then. one day, back in the era of paper and postage, we secured her father's application for a Card of Social Security and one of the questions required the names of Claude's father and mother. And there stood her grandparental names: Jasper Moses White and Maggie Tam. The rest of this post is a cautionary tale for those searching Olde Recordes.

The Rule of Two

Back in the 70s, when TOF first dipped his toe in the endless swamp of geneology, he interviewed his grandfather, Pop-Pop.

Family history is lived forward, but often discovered backward. So in good Aristotelian fashion, one starts with the living and peels back the onion generation by generation, resolving contradictions and oral traditions along the way. Bits and pieces accumulate, not always in logical order. In the course of the interview, several things ancestral emerged.

• Pop-pop had never known his paternal grandfather, who had died when his father was only ten.
• He was no longer certain of that grandfather's name, but thought it might have been James or John.
• He had married Anne Lynch, who had worked for "a miller and his wife."
• They had all lived in Washington, NJ, where the railroad yards were.
• His grandfather had been killed on the railroad when he was caught between two coal cars and crushed to death, sometime he thought in the 1880s. 

The railyards in Washington NJ, c. 1880s

At the Eleventh Hour

... of the 11th day of the 11th month of 1918, the guns in Europe fell silent at last. The United States built a wall inscribed with the names of servicemen killed or missing in the nine years' war in Vietnam. In three-and-a-half years, the Allies in WW1 suffered deaths amounting to 103 Vietnam walls. That's just over 2.5 Vietnam walls every month.

Harry Singley, TOF's grandfather
"Guv"

Today is the 101st anniversary of the Armistice, an event nearly forgotten today. Harry Singley, 304th Engineers, describes the day in a letter published in the local paper:

"It was on Sept. 26 when the big drive started in the Argonne Forest and I saw all kinds of things that I never witnessed before.  We started out on the night of the 25th.  At 9 o'clock we commenced a tank road and worked our way almost to the German's front line trenches.  At 2:30 one of the greatest of all barrages was opened.  It was said that between 3500 and 4000 guns, some of them of very large calibre, went off at that hour just like clock work.  We worked on this road under shell fire until about 3:45 and then went back until the infantry went over the top at 5 o'clock.  We followed with the tanks.  That is the way the Americans started and kept pounding and pushing ahead until the great day on Nov. 11.  ...

Harry Singley, 304th Engineers,
Rainbow Division

It was some life.  I am proud that I went through it, for nobody on the Hill [i.e., Fountain Hill, PA] will have anything on me...  I was a little with sneezing or tear gas.  It made me sick but I remained with the company for I did not like to leave my detachment at any time for if something would happen, I thought, there would be plenty of help.  I felt much better in a few days.  A small piece of shrapnel splinter hit me below the knee.  Otherwise I was lucky. ..."

"Somebody will wake up soon when the boys get back to the States....

 #

TECHNICALLY, it was only an armistice, and 21 years later, they had to do it all over again. Since then, Armistice Day has been expanded to include all veterans of all wars. As he has generally done on Veteran's day, TOF appends here a short account of veterans in my own and in the Incomparable Marge's families.

TOF in uniform, Artillery ROTC, Caisson Ball 1965
with Sweet Sharon

TOF himself is not a veteran.  The closest he got was two years of Artillery ROTC in which he achieved the alleged rank of cadet staff sergeant (so he knows how to call down fire on your location.  You have been warned.) But he was classified 4F by a wise military. This was at the height of the Vietnam War, toward which TOF had expressed opposition, though unlike other opponents, it was LBJ's inept micromanagement that irritated him, along with Sec. McNamara's weird obsession with corporate-like numbers crunching. He never imagined, as others did, that the victory of Ho Chi Minh would be rainbows and fluffy bunnies, rather than re-education camps and boat people.