The Coming Plague

Laurie Garret has an article out in the Washington Post.  She say that there’s no point in trying to block the spread of Ebola by travel bans.

The problem is, she’s full of crap.  Look, there are two possible scenarios.  In both of them, r, the number of new cases generated by each case, is greater than 1 in parts of West Africa – which is why you get exponential growth, why you have an epidemic.  If r < 1.0, the series converges – a case generates a few extra cases before dying out.

Everything we know so far suggests that even though it is greater than 1.0,  r in West Africa is not all that big (maybe around 2), mostly because of unfortunate local burial customs and incompetent medical personnel.

It seems highly likely that r in US conditions is well under 1.0 which means you can’t get an epidemic. However,  r is probably not zero.  It doesn’t mean that you can’t get a few cases per imported case, from immediate contact and hospital mistakes.  As an example, suppose that on average each case imported to the US generated a total of two other cases before dying out (counting secondary, tertiary, etc infections).  Then, on average, the number of US citizens infected would be twice the number of infected visitors.

Now suppose that a travel ban blocked 80% of sick people trying to fly here from Liberia.  We’d have 80% fewer cases in US citizens: and that would be a good thing. Really it would.  Does Laurie Garret understand this?  Obviously not. She is a senior fellow for global health at the Council on Foreign Relations, but she is incompetent.  Totally useless, like virtually everyone else in public life.

We hear people from the CDC saying that any travel restrictions would backfire, but that’s nonsense too.  One might wonder why they say such goofy things: I would guess that a major reason is that they were taught in school that quarantines are useless (and worse yet, old-fashioned), just as many biologists were taught that parasites are really harmless – have to be, because evolution!

In the other scenario, r > 1.0 in US conditions as well, or at least is greater than 1.0 in some subsets of the US population.  This is very unlikely- even more unlikely considering we can adjust our behavior to make transmission less likely.  But suppose it so, for the sake of argument.  Then you would want – need – to stop all travelers from the risky regions, because even one infected guy would pose a huge risk.  Some say that blocking that spread would be impossible. They’re wrong: it is possible*, although it wouldn’t happen, because we’re too crazy.  In fact, in that scenario, we’d be justified in shooting down every plane that _might_ carry an infected passenger.  This scenario is the one that fits Garrett’s remarks, but if she really believed it, she would be frantically buying canned goods and finding a cave in the Rockies to hide her family in.

*the Atlantic is pretty wide.

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Draft of paper about Amish

Mike Weight and I have a draft of a manuscript about responses to personality tests by Amish and non-Amish young men from the same county in Indiana. We have mentioned this material before on the blog. The paper is getting ready to ship out: we are hoping to take advantage of our readers and solicit comments and criticisms and outrage and whatever. Drs. Charlton and Thompson may be especially knowledgeable about this approach along with many of our anonymous cowards.

Our approach is to use published data from a personality test from 1970 to construct an index of “Amishness” that we call the AQ that is analogous to the well-known IQ of cognitive testing. With that, the whole standard machinery of quantitative genetics is immediately available. Whether or not the genetic model is correct or near correct there is a clear and explicit baseline that alternate models should be able to match. For example the difference in mean AQ between young Amish men and their non-Amish neighbors is about 2.8 standard deviations. In the IQ world this would correspond to a group different of 42 points. In the stature world this would correspond to a height difference of about 8 inches.

Please have a shot at our draft if you are interested at this link.

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The Road Not Taken

A lot of people are bothered by the idea of biological determinism – the idea that given the genetic hand they’ve been dealt, and the environment they experienced, their path in life was essentially inevitable.  When you consider the fates of identical twins raised apart, particularly examples like the Jim twins, you can feel boxed in.  In a philosophical sense, that is:  you are probably thinking too hard if the the fact that your non-existent clone might have gone down much the same life path as you engenders weltschmerz.

If it does, though, there’s a way out of it.  Find a situation with at least two alternate  courses of action that are sure to lead to wildly different outcomes, and make your choice based on a truly random event, such as nuclear decay.  Even if your clone did exactly the same thing, there’s no way of predicting what path he would take*. If you’re feeling wimpy, you can restrict your paths to ones that don’t have a high likelihood of immediate crucifixion.

On the other hand, if you are truly determined, you can pick paths that are chaotic as well, so that infinitesimal difference in your initial actions will eventually lead to big differences in your trajectory.  In that case, though, all bets are off.

I’m thinking that there’s probably already an app for this.

 

*unless the Everett-Berra theory is correct.

 

 

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Disaster in the South Pacific

The 1918 influenza pandemic hit every country on Earth – well, almost every country. It missed American Samoa entirely, which is interesting.  It’s even more interesting when you notice that it hit the neighboring islands of West Samoa harder than anywhere else.

Worldwide,  the Spanish Flu killed 3-5% of the population – lower in most developed countries, which had better supportive therapy.  Medicos had no useful vaccines or  antiviral agents: in fact they mistakenly thought it was caused by a bacterium. Doctors were useless, but nurses were not.

In the South Pacific, the flu was spread by the SS Talune, which regularly visited Tonga, Fiji, American Samoa, and West Samoa.  Crewmen had picked up the flu in New Zealand and spread it to those ports, excepting American Samoa.

The islands of Western Samoa were administered by New Zealand, which had recently seized them from Germany. The administrator (Colonel Robert Logan) had little administrative experience (former sheep farmer) – he felt that he needed approval from Wellington for any action and he received no instructions.  Medical officers also waited for instructions – none came. In addition, plantation interests were important, and they opposed any quarantine, which was also the case in Fiji. So, no quarantine. Thing went very badly: so many were sick (~90% of the population)  that few were left to care for them. Since food was mostly in gardens, rather in cupboards,  people starved while weak.  Europeans were less vulnerable, and those that could helped, but there were relatively few in Western Samoa.  20-25% of the population died, concentrated among young adults, the highest death rate in the world.

American Samoa was physically quite close to Western Samoa, less than 100km. There were close cultural ties: people intermarried and often sailed back and forth.  But the governmental structure was different.  There were no copra plantations in American Samoa, so you didn’t have any powerful business interests lobbying for suicide.  The US Navy ran the colony.  John Martin Poyer, an officer that had retired from active duty due to illness, was brought back to active duty in 1915 to serve as Governor of American Samoa.

Both American Samoa and West Samoa had advance warning of the flu’s danger: they both had wireless sets and occasional mail.

Washington didn’t micro-manage American Samoa, not being all that interested.  A policy of benign neglect was interpreted by Poyer as an opportunity to act on his best judgment, in the finest traditions of the US Navy.  He imposed quarantine. That was harder that it sounds, because of the frequent family visits between West Samoa and American Samoa – but Poyer also had  the support of the local  chiefs, who understood how serious imported epidemics could be.  The people of American Samoa self-blockaded, on top of official quarantine: they sent out canoes to stop any and all visitors.  They never had a single case.

Of course there was a disaster.  Some people will think that it occurred in West Samoa. Others will think that the real disaster was in American Samoa.

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Nurses vs doctors

Medicine, the things that doctors do, was an ineffective pseudoscience until fairly recently. Until 1800 or so, they were wrong about almost everything. Bleeding, cupping, purging, the four humors – useless.   In the 1800s, some began to realize that they were wrong, and became medical nihilists that improved outcomes by doing less.  Some patients themselves came to this realization, as when Civil War casualties hid from the surgeons and had better outcomes.  Sometime in the early 20th century, MDs reached break-even, and became an increasingly positive influence on human health.  As Lewis Thomas said, medicine is the youngest science.

Nursing, on the other hand, has always been useful.  Just making sure that a patient is warm and nourished when too sick to take care of himself has helped many survive. In fact, some of the truly crushing epidemics have been greatly exacerbated when there were too few healthy people to take care of the sick.

Nursing must be old, but it can’t have existed forever.  Whenever it came into existence, it must have changed the selective forces acting on the human immune system. Before nursing, being sufficiently incapacitated would have been uniformly fatal – afterwards, immune responses that involved a period of incapacitation (with eventual recovery) could have been selectively favored.

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The First Men in the Moon

I noticed an article in Slate (Practice Does Not Make Perfect), which made the perfectly sound point that people vary in their abilities, genes have a lot to do with it, and Malcolm Gladwell can’t help being a pinhead.  He was probably born that way.

Of course, the authors cover their hairy asses by saying we don’t know that between-group differences in IQ or whatever are caused by genes. We just happen to live in a world that looks exactly the same as one in which that happened to be the case.  Technically, I think that this is called a modified limited hangout.

But what about the future?  One generally assumes that space colonists, assuming that there ever are any, will be picked individuals, somewhat like existing astronauts – the best out of hordes of applicants. They’ll be smarter than average, healthier than average, saner than average – and not by just a little.

Since all these traits are significantly heritable, some highly so, we have to expect that their descendants will be different – different above the neck.  They’d likely be, on average, smarter than any existing ethnic group. If a Lunar colony really took off, early colonists might account for a disproportionate fraction of the population (just as Puritans do in the US), and the Loonies might continue to have inordinate amounts of the right stuff indefinitely. They’d notice: we’d notice.  We’d worry about the Lunar Peril. They’d sneer at deluded groundlings, and talk about the menace from Earth.

Fantastic, winning-Powerball-with-a-ticket-you-found-in-an-Arab-privy luck has ensured that all existing human populations have the same average IQ (and the same standard deviation!) but there’s no guarantee that our luck will hold as we settle the Moon, and Mars, and the stars beyond.  We will have to make it so: enforce the principle of mediocrity.

We will need to make sure that every such colony has its fair share of morons.

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Forty Days

One of the many interesting aspects of how the US dealt with the AIDS epidemic is what we didn’t do – in particular, quarantine.  Probably you need a decent test before quarantine is practical, but we had ELISA by 1985 and a better Western Blot test by 1987.

There was popular support for a quarantine.

But the public health experts generally opined that such a quarantine would not work.

Of course, they were wrong.  Cuba instituted a rigorous quarantine.  They mandated antiviral treatment for pregnant women and mandated C-sections for those that were HIV-positive.  People positive for any venereal disease were tested for HIV as well.  HIV-infected people must provide the names of all sexual partners for the past sic months.

Compulsory quarantining was relaxed in 1994, but all those testing positive have to go to a sanatorium for 8 weeks of thorough education on the disease.  People who leave after 8 weeks and engage in unsafe sex undergo permanent quarantine.

Cuba did pretty well:  the per-capita death toll was 35 times lower than in the US.

Cuba had some advantages:  the epidemic hit them at least five years later than it did the US (first observed Cuban case in 1986, first noticed cases in the US in 1981).  That meant they were readier when they encountered the virus.  You’d think that because of the epidemic’s late start in Cuba, there would have been a shorter interval without the effective protease inhibitors (which arrived in 1995 in the US) – but they don’t seem to have arrived in Cuba until 2001, so the interval was about the same.

If we had adopted the same strategy as Cuba, it would not have been as effective, largely because of that time lag.  However, it surely would have prevented at least half of the ~600,000 AIDS deaths in the US.  Probably well over half.

I still see people stating that of course quarantine would not have worked: fairly often from dimwitted people with a Masters in Public Health.

My favorite comment was from a libertarian friend who said that although quarantine  certainly would have worked, better to sacrifice a few hundred thousand than validate the idea that the Feds can sometimes tell you what to do with good effect.

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