Mini advent calendar of Xrisks: Pandemics

post by Stuart_Armstrong · 2012-12-06T13:44:22.443Z · score: 3 (6 votes) · LW · GW · Legacy · 21 comments

Contents

  Pandemics
None
21 comments

The FHI's mini advent calendar: counting down through the big five existential risks. The fourth one is an ancient risk, still with us today: pandemics and plagues.

 

Pandemics

Current understanding: high
Most worrying aspect: the past evidence points to a risky future

The deathrates from infectious diseases follow a power law with a very low exponent. In layman’s terms: there is a reasonable possibility for a plague with an absolutely huge casualty rate. We’ve had close calls in the past: the black death killed around half the population of Europe, while Spanish Influenza infected 27% of all humans and killed one in ten of those, mostly healthy young adults. All the characteristics of an ultimately deadly infection already exist in the wild: anything that combined the deadliness and incubation period of AIDS with the transmissibility of the common cold.

Moreover, we know that we are going to be seeing new diseases and new infections in the future: the only question is how deadly they will be. With modern global travel and transport, these diseases will spread far and wide. Against this, we have better communication and better trans-national institutions and cooperation – but these institutions could easily be overwhelmed, and countries aren’t nearly as well prepared as they need to be.

 

21 comments

Comments sorted by top scores.

comment by CarlShulman · 2012-12-06T15:42:51.216Z · score: 11 (11 votes) · LW · GW

The deathrates from infectious diseases follow a power law with a very low exponent. In layman’s terms: there is a reasonable possibility for a plague with an absolutely huge casualty rate.

Have you taken into account the cutting criticisms from Cosma on the bogosity of many power-law claims?

Do you have any examples of a species rendered extinct by a plague in nature? As far as I know, there are no known natural evolutionary paths to produce a super-plague like this:

anything that combined the deadliness and incubation period of AIDS with the transmissibility of the common cold.

Some people are genetically immune to AIDS, such transmission would rapidly select for that resistance in humans, while selection on the virus would reduce lethality (losing hosts). Also, HIV has a long incubation period because it is not replicating and killing cells at the rapid rate of the common cold, the tradeoffs here are real.

We’ve had close calls in the past: the black death killed around half the population of Europe, while Spanish Influenza infected 27% of all humans and killed one in ten of those, mostly healthy young adults.

People were suffering from malnutrition, poor sanitation, lack of broad-spectrum antibiotics and antivirals, lack of vaccination tech (to deal with both the flu and simultaneous or opportunistic infections). The Spanish Flu did its damage disproportionately to poor countries, while rich countries got by with a small fraction of the fatality rate.

Today the world is much richer, better fed, and otherwise protected than in 1918-1919.

The FHI survey of global catastrophic risks conference attendees assigned a median probability of 0.05% to a natural pandemic killing off humanity. I would assign a higher existential risk than direct extinction risk, on the basis that social collapse might be irrecoverable, but this is a small x-risk compared to artificial diseases.

comment by gwern · 2012-12-06T20:57:29.524Z · score: 2 (2 votes) · LW · GW

Do you have any examples of a species rendered extinct by a plague in nature?

How would we know? A pandemic should kill in a generation or two, leaving essentially no fossils (and if there were fossils, would we notice unless it was some sort of weird bone-distorting disease? or even then...), so the deep historical record would not help much. The human historical record is very sketchy since germ theory is so new and so many anciently-recorded species are of uncertain identification (think of all the plants and insects in the Bible we don't know what they actually are), and when humans are competent to record data about wild diseases and plagues, it's generally because they're part of the problem: Tasmanian Devils are being killed off by a nasty communicable cancer (population cut by 70% since 1996, Wikipedia says), but maybe their vulnerability is just due to human-caused stress or something.

comment by CarlShulman · 2012-12-06T21:03:13.711Z · score: 4 (4 votes) · LW · GW

Recent observations, not fossil record or ancient history. And extirpation of a connected population from its (substantial) range is an OK proxy.

comment by [deleted] · 2012-12-06T22:18:40.746Z · score: 5 (5 votes) · LW · GW

Do you have any examples of a species rendered extinct by a plague in nature?

Recent observations, not fossil record or ancient history. And extirpation of a connected population from its (substantial) range is an OK proxy.

My first thought, off the top of my head, is Dutch Elm Disease, which developed in Asia, where the trees grew tolerant of it, but then spread to other areas, where the trees had no resistance. Non-Asiatic elms aren't extinct yet, but I think the two options are either: 1) Saved via human intervention, genetic modification, etc., or 2) The susceptible breeds will eventually go extinct as it spreads.

comment by Desrtopa · 2012-12-09T03:49:26.399Z · score: 1 (1 votes) · LW · GW

The American Chestnut is not completely extinct either, but has been mostly eradicated by chestnut blight.

comment by gwern · 2012-12-06T21:41:41.315Z · score: 3 (3 votes) · LW · GW

And extirpation of a connected population from its (substantial) range is an OK proxy.

I'm not a paleontologist, but don't we see species suddenly vanish from their ranges all the time even excluding the mass extinction events? How do we know that some of these extirpations are not pandemics?

comment by JoshuaZ · 2012-12-07T14:22:56.542Z · score: 0 (0 votes) · LW · GW

Well, the time period then is quite small. Moreover, we're currently inadvertently killing so many species, that a handful being killed by disease could just get lost in the noise. I suspect there aren't any, but it isn't clear how to test that.

comment by Stuart_Armstrong · 2012-12-06T18:39:53.050Z · score: 2 (2 votes) · LW · GW

Have you taken into account the cutting criticisms from Cosma on the bogosity of many power-law claims?

No, thanks for pointing that out. He didn't look directly at epidemics or any natural disasters, but his general critiques may be worth looking into.

I would assign a higher existential risk than direct extinction risk, on the basis that social collapse might be irrecoverable, but this is a small x-risk compared to artificial diseases.

Still makes the top five in our current estimation.

comment by CarlShulman · 2012-12-06T18:46:25.461Z · score: 2 (2 votes) · LW · GW

You said survivor-killing drones were a risk factor from Drexlerian nanotech, but those could be created separately. Also, permanent nasty totalitarianism is on the x-risk list. I'd say that should be higher than natural pandemics.

comment by shminux · 2012-12-07T00:57:00.421Z · score: 0 (0 votes) · LW · GW

Do you have any examples of a species rendered extinct by a plague in nature?

We might be observing one right now.

comment by FiftyTwo · 2012-12-06T16:32:12.170Z · score: 7 (7 votes) · LW · GW

All the characteristics of an ultimately deadly infection already exist in the wild: anything that combined the deadliness and incubation period of AIDS with the transmissibility of the common cold.

Correct me if I'm wrong, but aren't there very good reasons why those qualities don't overlap? Analogously it would be literally true to say that we'd be at great risk if threaten by an animal with the killing abilities of a tiger and the reproduction speed and numbers of ants, but such a thing isn't biologically possible.

comment by GeraldMonroe · 2012-12-06T20:52:14.507Z · score: 4 (4 votes) · LW · GW

The theory goes : plagues that are especially deadly must spread through the body extremely quickly. Otherwise, they give the immune system time for the B cells to formulate an antibody. Yet, if the plague spreads quickly, it has a short incubation period, and it means that hosts will die before spreading it. Ebola is thought to fit in this part of the ecology, and this is one reason why the virus is rare.

A virus that spread itself like the flu but also killed like ebola would be pushed by evolution away from these properties because it would kill off it's hosts too quickly.

Another factor is that some of the better viruses for evading the immune system (HIV) depend on being able to randomly recombine and change the pattern for their outer shells.

If you designed a virus that had a tough outer coating, targeted cells and receptors designed to kill the host, and had some kind of sophisticated clock mechanism to force a long incubation period, you would be forced to give it genes that would code for complex error correcting proteins so that each new generation of the virus would have a low chance of containing a mutation. This would in turn prevent it from evolving, allowing the immune system (and synthetic antibodies) to target it easily.

So, you'd have to deliberately make it able to adjust it's own outer coat randomly, but not any other components.

Such a virus is not something evolution is likely to ever create (because for one, it would extinct it's hosts, and for another, evolution doesn't work like this. Evolution as an algorithm finds the highest point on the NEAREST hill in the solution space, not the peak of a theoretical mountain that towers over the solution space)

Net result : with very sophisticated bioscience, such a person killer that had overlapping qualities could be created. However, you are correct that there is a reason you don't see them in nature.

comment by Alicorn · 2012-12-07T00:38:57.008Z · score: 2 (2 votes) · LW · GW

Such a virus is not something evolution is likely to ever create (because for one, it would extinct it's hosts

This is a reason we would not expect to see many of them around at any given time. But a virus that can extinguish its hosts has no pressure to avoid evolving that way in the first place. Neither viruses nor evolution can predict the future, at all.

comment by GeraldMonroe · 2012-12-07T01:21:47.771Z · score: 4 (4 votes) · LW · GW

This isn't true. Viruses are subject to evolutionary pressure even inside a single patient. They don't replicate perfectly (partly because they have to be small and simple, and don't have very good control of the cellular environment they are inside, being invaders and all) and so variants of the particle compete with one another. Because of this, features that might be desired in a bioweapon but are not needed in order for the virus to replicate can get lost.

For instance, a bioweapon virus might contain genes for botulism toxin in order to kill the host. However, copying this gene every generation would diminish the particles ability to replicate, and so variants of the particle that are missing the gene would have a small evolutionary advantage. After just a few patients, the wild version of the virus might have lost this feature.

comment by FiftyTwo · 2012-12-07T00:19:00.233Z · score: 0 (0 votes) · LW · GW

Very interesting, thanks for taking the time to give a detailed reply.

with very sophisticated bioscience, such a person killer that had overlapping qualities could be created.

How sophisticated are we talking? Is this something conceivable for sufficiently motivated modern day humans with access to up to date knowledge, or theoretically possible but extremely difficult?

comment by GeraldMonroe · 2012-12-07T01:12:42.821Z · score: 2 (2 votes) · LW · GW

The latter. I've read of limited successes in other fields of research (no one is publicly trying to make something like this) that indicate it's just barely possible, maybe, with some luck.

One nasty thing is that the virus doesn't have to be safe. It just has to work, and it's not a problem if it permanently damages the people it doesn't kill. So, creating a weapon like this is fundamentally much easier than trying to create, say, a treatment for cancer using similar methods.

comment by turchin · 2012-12-06T14:37:16.393Z · score: 2 (2 votes) · LW · GW

Also worth to mention that humans created ideal bioreactor for creating new viruses - and that is pigs. Pigs could ill human, avian and animal flu viruses and recombinate them. Population of pigs is growing with economic growth and now is around one billion.

Another "bioreactor" is widespread use of antibiotics which lead to creating of new superbags.

Growing human population is also contribute to the chances of appearance of new superbug.

But in fact I a little bit dissapointed by this 4th risks as it seems similar to biohazards mentioned earlier. It could be not easy to distingush natural pandemic and bioweapon usage.

comment by vi21maobk9vp · 2012-12-09T17:34:54.919Z · score: 0 (0 votes) · LW · GW

Well, it does look that killing a big species is like freezing a body to absolute zero.

I am ready to buy that 0%-10% killers are distributed according to the promised power law, if you buy that reducing human population from X to kX costs -log k. Note that this doesn't alter your observed power law at all.

Why this? Because you have to be stronger than random resistances (due to genetics, lifestyle, health conditions etc.) present in different slices in populations.

Also, any virus will evolve while it infects a billion humans; there is a pressure to spread better and leave host alive.

And long incubation period cuts both ways — either you are stealth for years, or you are spread by air next week.

comment by devas · 2012-12-06T16:08:58.531Z · score: 0 (0 votes) · LW · GW

I agree with most of what was said here, except that, well.... I don't think it has the potential to actually cause humans to go extinct, or even to simply collapse civilization :-/ Even if a pandemic killed off 75 % of all humans, I have an unprovable feeling civilization would be able to soldier on. This is substantiated by a couple of observations; nearly all human knowledge has multiple backups (pandemics don't kill libraries), so we wouldn't have to reinvent science from scratch. Plus,remaining population would have access to all the material goods of the dead (including canned goods, long lasting food, etc. Which wouldn't be nearly enough to sustain human population for more than a month, but which would give time for people to pick up a book on farming or some such).

On the other hand, it is virtually guaranteed that a pandemic WILL happen (I define pandemic as something that shows up on the news a lot and causes some panic. Kill ratios depend on a case by case basis), given our interconnectedness which is frankly unprecedented in human history (i.e. Microbes, viruses and germs never had airplanes before 1902)

comment by Eugine_Nier · 2012-12-07T03:37:27.361Z · score: 1 (1 votes) · LW · GW

On the other hand, it is virtually guaranteed that a pandemic WILL happen (I define pandemic as something that shows up on the news a lot and causes some panic. Kill ratios depend on a case by case basis)

Given how easy it is to get the media into headless chicken mode, I don't think this is the best standard.

comment by devas · 2012-12-07T10:31:29.477Z · score: 0 (0 votes) · LW · GW

it isn't, actually.

Although it was fun to watch the panic over the pig flu become increasingly silly