

How plagues really work - gregd
http://aeon.co/magazine/health/the-next-pandemic-will-not-erupt-from-the-rainforest/

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timr
_" But the truth is that Ebola, murderous though it is, doesn’t have what it
takes to produce a pandemic, a worldwide outbreak of infectious disease. It
spreads only through intimate contact with infected body fluids; to avoid
Ebola, just refrain from touching sweat, blood or the bodies of the sick or
dead."_

Oh, is that all? Just _refrain from touching people?_ Because last time I
checked, we touch people _all the damned time_ , usually without being very
aware of it. Easy experiment that will warp your perspective: try to go
through an entire day without touching someone, or (harder still) touching
something that someone has recently touched. Then track the number of times
you accidentally touch something or someone, and later touch your face.

There's a somewhat alarming bit of Comforting Conventional Wisdom floating
around the western media that we're totally safe from this because our
hospitals are better than in western Africa (true, and yet hospital-acquired
infections are incredibly common), or because we have better public health
infrastructure (true, and yet we routinely have large outbreaks of rare
diseases _for which vaccines exist_ ) -- but it's absolutely delusional to
think that we're safe because a virus can only be contracted via human
contact. The flu is mostly spread by human contact, and it gets around just
fine.

The way this doesn't become a global plague is by stopping it before it breaks
out of the isolated corner of the world it's flourishing in right now.

~~~
cmrivers
I agree wholeheartedly with your last sentence - stopping transmission in West
Africa and improving health systems is key.

I don't agree with your other points though. Ebola patients are only
infectious while symptomatic, so accidentally bumping into someone on the
subway is not the kind of direct contact needed for transmission. And although
the virus can be present in sweat, it's mostly blood, fecal matter, etc. that
transmit.

If there were a case introduced in the United States, it's not entirely out of
the question that there would be a secondary case or two. Not probable, but
not impossible, either. However, I truly believe there would be no more than
one secondary generation (two at the absolute max). Western countries can
mobilize effective isolation, quarantine, and contact tracing in ways that
overburdened West African countries cannot.

~~~
timr
It spreads via saliva and survives on surfaces, and the "symptomatic" period
starts like a fever. It's not as if people go from being healthy to bleeding
from every orifice in 24 hours. It's a hard disease to stop because it
initially looks like a thousand other common illnesses.

Again, we're telling ourselves comforting bedtime stories when we pretend that
there's something innate to the virus that makes us safe. We've just never had
an outbreak in a city before, so we've had the advantage of geographical
isolation.

Take a few incipient cases and stick them in a tenement in New York or Paris,
and the epidemiology can become incredibly complicated before we even know we
have a problem.

~~~
cmrivers
But why have we never seen an outbreak in a city before? It's not just good
luck. We've had (at least) seven imported cases of Lassa hemorrhagic fever in
the US [0], and at least one imported case of Marburg [1]. Both have a similar
clinical presentation and epidemiology as Ebola, and both resulted in no
secondary transmission inside the US.

SARS was estimated to have a similar basic reproduction number as Ebola (~2),
and it was successfully contained globally.

[0] [http://www.cdc.gov/media/releases/2014/p0404-lassa-
fever.htm...](http://www.cdc.gov/media/releases/2014/p0404-lassa-fever.html)
[1]
[http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5849a2.htm](http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5849a2.htm)

~~~
timr
It's obviously a matter of probability -- not every case is going to lead to
epidemic. And as long as we're separated from the outbreak by geography, it's
relatively easy to say _" this person has a fever and was recently in West
Africa, therefore we should suspect Ebola."_ It's much harder when a disease
becomes endemic, and suddenly everybody with a fever in St. Paul has to add
Ebola to the differential diagnosis.

As for SARS: you're making my argument. It was stopped through a combination
of good luck and herculean global effort. This outbreak was ignored by the
West for way too long, and I don't think we do ourselves any favors by
diminishing the risks of it spreading.

~~~
XorNot
Yes but the point is that Ebola doesn't work like that. While it presents as a
fever, you're also not particularly infectious in the early stages. Viral
loading matters.

The West then benefits from the fact that all we have to do is push the alert
button, and even if we have inconsiderate actors with Ebola out there, people
will avoid contact and they will not be well enough to remain mobile for very
long.

The problem in Africa, if you've been following the news, is that there is a
paucity of education about disease response, hygiene and handling of the dead,
as well as a fair amount of "it's definitely America's fault and also it's not
real!" going on.

~~~
timr
_" While it presents as a fever, you're also not particularly infectious in
the early stages. Viral loading matters."_

I have seen nothing authoritative that backs up this assertion. Our estimates
of _everything_ about the epidemiology of this virus are based on rather
limited data. The disease isn't spreading like wildfire in Monrovia based on
"burial practices" alone; we're getting some new data on what happens when it
gets loose in a densely populated urban area.

As for your other point: you're right that rural Africa has problems with
education and fear, but it's foolish to think that we'd be substantially
better. Look at the response to the (perfectly safe) return of the two
infected people to Emory: people were _protesting_ this move, spreading
misinformation on social media, and otherwise being complete idiots. If we
_actually_ had Ebola circulating in the population of a major US city, I doubt
the collective response would be particularly educated or rational.

I hesitate to call these sorts of arguments _xenophobic_ , but there's
definitely an element of the _" ignorant other"_ at work in assumptions that
the people of Africa are responding in some fundamentally different way than
we'd see in any large population of fearful people. We have sophisticated
hospitals and high standards of medical care, but crowds are crowds around the
world.

------
Tycho
Article talks about 'disease factories.' Doesn't mention various modern
phenomena: music festivals, public transport, airports, stadiums...

