Thursday, March 16, 2017

On Being a Cassandra: Pandemic

C’est les microbes qui auront le dernier mot.
Louis Pasteur

Previous Cassandra Posts: A.I.Global WarmingAntibiotics

Continuing on my public health kick on the heels of my antibiotics-themed Cassandra post, I’d like to talk about another terrifying future threat:
Probably not
Now, apologies if I start shamelessly channeling Richard Preston, but it’s important to remember that diseases are one of the built-in controls on population growth. In many ways, disease acts on animal populations the same way predators do.

The point to keep in mind is that diseases are natural. And as the population density increases, so does the density of diseases, and the higher the chance for the disease to spread. Obviously humans are not the only animal whose numbers are similarly controlled, Hoof and Mouth disease in bovids comes to mind. I’m sure epidemiologists know more.

I’m assuming everyone is at least somewhat familiar with the history of the bubonic plague, aka “The Black Death”, but on the off chance that you’re not: in the mid 1300s, the plague spread throughout Asia and Europe, killing anywhere from 75 to 200 million people. Records are inconsistent both because it was 700 years ago, causes of death were harder to ascertain (or deliberately misrepresented to avoid quarantine), and the fact that over one third of the population was killed off (with some estimates as high as 60%).
There's a lot of bad-ass Black Death imagery to choose from
This is a staggering statistic to imagine, and really makes the people who thought the plague was god’s wrath and/or the end of the world seem a lot more reasonable.

The other important thing to remember is that disease and plague were a fact of life. If it wasn’t the black death, it was smallpox, and if it wasn’t smallpox, it was cholera. Or a hemorrhagic fever. Or any number of things. The black death was not the first and although the peak was in the mid to late 1300s, outbreaks (of varying sizes) continued to occur in Europe until the late 1800s, and still occur in many places around the world.

Obviously, the death tolls are not what they once were, even the worst modern outbreaks tend not to claim more than a few hundred lives at a time. Mainly because we’re better at quarantine, killing the fleas and rats that carry it, and we have various treatments for curing and preventing it. (Though, tying back into “On Being a Cassandra: Antibiotics”, there is serious public health concern about the possible spreading of an antibiotic-resistant bubonic plague. Luckily, at present only a few antibiotic-resistant strains have been observed.)

But while exotic tropical diseases like Dengue and Ebola are certainly exciting, from an epidemiology standpoint, they’re not the plague you should be most worried about. What you should be worried about is influenza.
JPEG artifacts are not a symptom of influenza
Now, there’s usually quite a bit of a fuss each year about bird flu, or swine flu, which I imagine is fairly puzzling to people who associate the flu with spending a few days feeling shitty in bed. So, let’s talk about the 1918 flu pandemic

In the span of a year, 500 million people were infected, and somewhere between 10 and 20 percent of them died. This amounted to about a 3-4% reduction in the worldwide population, and was at least three times the number of people who died in WWI.

Obviously, most flu strains are nowhere near as virulent as that one, and the flu is “incentivized” not to be that dangerous, as killing the host makes transmission more difficult. But, there is no reason why this year’s flu was not as dangerous, other than the fact that most flus aren’t that dangerous. That’s why the public health officials get so spooked when the latest H1N1 strain appears and kills a few thousand people, because a sufficiently virulent strain could do much worse damage. Also to note, the flu vaccine is not particularly effective against these pandemic flus, as they tend to be new and unaccounted for mutations.

Regardless of which disease you choose to concern yourself with, the simple fact is that our society is massively overdue for a pandemic. Our population is incredibly high, and incredibly dense in most places, with a shocking amount of interconnectedness (due to people traveling around via trains and planes). Not only is our society due for a pandemic, we are drastically unprepared for it. This is more than simple alarmism, according to the report I just linked: “the commission's own modeling suggests that we are more likely than not to see at least one pandemic over the next 100 years, and there is at least a 20 percent chance of seeing four or more.”

Nor are natural pandemics the only concern, just recently Bill Gates addressed the Munich Security Conference, warning of the risk posed by bio-terrorism. But whether natural or unnatural, if you’re looking for more things to worry about, don’t hesitate to add pandemics to your list.

P.S. Quarantine may be ineffective with certain dangerous diseases, as they are capable of drastically altering human behavior. See this study for more information.

1 comment:

  1. I am currently reading "I contain Multitudes". Ed Yong, the Science writer ,says the Microbes in our gut will save us !