C’est les microbes qui auront le dernier mot.
Louis
Pasteur
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 |
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.
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.
I am currently reading "I contain Multitudes". Ed Yong, the Science writer ,says the Microbes in our gut will save us !
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