
Ebola: learn from the past - etiam
http://www.nature.com/news/ebola-learn-from-the-past-1.16117
======
7Figures2Commas
Past performance may not be indicative of future results.

Obviously, we should heed the lessons of the past, but a virus like Ebola is
not a static phenomenon and it's concerning that so many seem to have
developed strongly-held assumptions. The number of medical personnel infected
in this current outbreak is particularly worrisome and we don't yet understand
the exact causes of this.

We do know that the strain in the current outbreak is different from those
seen before, and that it's mutating[1]. Filoviruses have a rapid rate of
mutation, and the longer the outbreak lasts, the more opportunity the virus
has to mutate into a form that makes it harder to defeat. The speed with which
Ebola kills those it infects is actually disadvantageous to the virus. Natural
selection would logically favor a strain of the virus that didn't kill its
hosts so quickly.

While a lot of speculation revolves around the possibility that the virus
could become more easily transmissible, it would be just as worrisome if there
were mutations that affected incubation time or the onset symptoms. These
types of mutations could significantly complicate some the strategies we're
relying on today, if not render them useless.

[1] [http://www.washingtonpost.com/national/health-
science/ebola-...](http://www.washingtonpost.com/national/health-
science/ebola-virus-has-mutated-during-course-of-
outbreak/2014/08/28/98235aaa-2ecb-11e4-bb9b-997ae96fad33_story.html)

~~~
danieltillett
There are three large differences with this outbreak than all previous
outbreaks

1\. The size and the number of people infected.

2\. The geographical scale. No outbreak has ever been anything other than
localised.

3\. It is spreading in urban areas. All previous outbreaks of Ebola have been
rural.

If any of these differences are important then we can’t really look to past
outbreaks to know what is going to happen.

------
danieltillett
If we want to learn from the past maybe we should look at the Plague of Athens
[1]. These were the symptoms:

"As a rule, however, there was no ostensible cause; but people in good health
were all of a sudden attacked by violent heats in the head, and redness and
inflammation in the eyes, the inward parts, such as the throat or tongue,
becoming bloody and emitting an unnatural and fetid breath. These symptoms
were followed by sneezing and hoarseness, after which the pain soon reached
the chest, and produced a hard cough. When it fixed in the stomach, it upset
it; and discharges of bile of every kind named by physicians ensued,
accompanied by very great distress. In most cases also an ineffectual retching
followed, producing violent spasms, which in some cases ceased soon after, in
others much later.”

I wonder what this sounds like? The good news was it only killed between 1/3
and 2/3rds of the population.

[1]
[http://en.wikipedia.org/wiki/Plague_of_Athens](http://en.wikipedia.org/wiki/Plague_of_Athens)

------
bra-ket
Ebola evolves. Each outbreak carries a number of distinct genetic changes [1]
and there is a risk of a mutation (or a chain of mutations) that would
accelerate transmission in unpredictable ways by interacting with new hosts.

This happened in the past with Yersinia Pestis that wiped out half of the
world population through fleas.

I'm not sure sure why there is no centralized effort to accelerate research
but rather top virologists focus on logistics of moving dead bodies.

[1]
[http://www.sciencemag.org/content/345/6202/1369.full](http://www.sciencemag.org/content/345/6202/1369.full)

~~~
danieltillett
>I'm not sure sure why there is no centralized effort to accelerate research

Your answer is right at the bottom of the science article.

"In memoriam: Tragically, five co-authors, who contributed greatly to public
health and research efforts in Sierra Leone, contracted EVD and lost their
battle with the disease before this manuscript could be published: Mohamed
Fullah, Mbalu Fonnie, Alex Moigboi, Alice Kovoma, and S. Humarr Khan. We wish
to honor their memory."

------
vpeters25
I wonder why governments haven't dictated a 21+ day quarantine on any
population center where someone is positive for Ebola. That should stop
propagation on its tracks.

~~~
danieltillett
The reason why is the countries where the outbreak has occurred do not have
the policing or military capacity to do this. A couple of the countries tried
to enforce 3 days quarantines to slow down the spread but the population just
ignored it, either through lack of care or lack of ability (when you are
living day to day you don’t have much choice about working or not - don’t
work, don’t eat).

------
joeguilmette
I hope the author isn't being naive in assuming that this outbreak will pass.

~~~
nathannecro
For whatever people say, Ebola is still a fairly difficult disease to spread.
True, it has jumped borders (even oceans).

However, patient's don't become infectious until they start showing visible
symptoms. Not only that, the symptoms are pretty obvious. Compounding all of
that, the vector by which the virus travels is one of the "slowest" routes
available.

What I think this outbreak does show however, is that we as a global peoples,
need to really rethink how we treat and handle the spread of disease.

~~~
steven2012
Why do people keep saying it's a fairly difficult disease to spread, when a
health worker in the US contracted Ebola, even while wearing protective gear.

If a health worker with protective gear can contract Ebola, imagine how easy
it is for someone infected with Ebola to transmit the disease on an airplane
or a restaurant. If they start vomiting around people, and splatter the people
around them, will those people not get infected? Will the workers who try to
clean up the mess not get exposed as well?

The symptoms are obvious, but they are obvious symptoms for much more
innocuous diseases as well, so it's easy to miss.

~~~
limpon
Ebola is fairly difficult to spread, it is not very contagious, no matter what
you might believe based on news reports. If you want to look at a contagious
disease, look at flu. The 2009 flu pandemic lead to hospitalization of
~200,000 people in the US alone within a few weeks [1]. Talking about the flu,
you can somewhat guess the number of infected people to be much much higher.
The current Ebola outbreak lead to ~8,000 infected persons since its outbreak
more than half a year ago in March. As you see, Ebola is not very contagious
when compared to the flu. Yet flu pandemics are usually restricted fairly well
once they take off and people are aware.

I'm constantly reading people being afraid of Ebola mutating to make people
survive longer so the virus can spread better. Influenza (Flu) is very good
with that, yet not even the very contagious flu was able to cause a
significant thread to mankind in the recent history.

Ebola is the cause for a humanitarian crisis in West Africa and we should put
all our efforts to helping the people who are affected by it, rather than
worrying about ourselves for no good reason.

1)
[https://en.wikipedia.org/wiki/2009_flu_pandemic](https://en.wikipedia.org/wiki/2009_flu_pandemic)

~~~
steven2012
Just because something's growth rate does reach the flu's growth rate doesn't
mean that it's not contagious. The flu just happens to be extremely
contagious. Ebola is still growing at an exponential rate, the rate just so
happens to not be as steep as the flu's.

Even the CDC has predicted 1.4M people infected with Ebola in West Africa
alone, at its current rate of increase. Who knows what the infection rate will
be outside of West Africa. That doesn't sounds like something that is 'not
very contagious'.

~~~
limpon
1\. Ebola's rate of infection is ~1.5 - 2 new infections per infected persons
[1] Even though this is an exponential rate, it does nowhere get near the
rates of many other viruses. As such it is easier to restrict further
infections than it is for most other infectious diseases.

2\. The 1.4M people prediction from the CDS assumed no intervention or help
from other countries and a collapse of the local healthcare systems. That's
why I am saying that we should focus our efforts on helping the healthcare
workers in West Africa.

> Who knows what the infection rate will be outside of West Africa Way lower
> than the rate in West Africa, that is for sure. Ebola doesn't spread through
> the air, you have to get in direct contact with body fluids. You don't get
> infected by sitting in a bus or plane with someone, who is infected. Most of
> the infected people are healthworkers in a setting without protective
> clothing, even gloves are rare to come by. Others are direct relatives who
> don't know much about ebola and who have burial rituals that are very
> different to the ones most of us are used to. It is very common in West
> Africa to wash out the mouth of dead persons and to kiss them goodbye. I am
> pretty sure this would not happen in the US or Europe, especially not if the
> deceased person died by bleeding out of all body openings.

A very large majority of ebola infected people in West Africa can't go to a
hospital - there are no free beds at the moment. So they go back home to their
families. THIS is how ebola spreads.

That's why we have to act, but not by panicking, but rather by sending well
trained medical staff to help.

[1]
[http://www.nejm.org/doi/full/10.1056/NEJMoa1411100#t=article](http://www.nejm.org/doi/full/10.1056/NEJMoa1411100#t=article)

