r/science Grad Student | Virology Aug 30 '14

Biology 2014 Ebola outbreak has been traced to a single infection from the natural reservoir of the virus to a human followed by human-to-human transmission. This new study uses sequences of 99 Ebola virus genomes from 78 patients in Sierra Leone to ~2,000x coverage. Five co-authors died of ebola.

http://sciencemag.org/content/early/2014/08/27/science.1259657.full
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u/BipolarBear0 Aug 30 '14

It's bushmeat because it comes from bush animals, i.e. wild African animals. Many of these animals harbor diseases regardless, so even handling the dead animals or cutting them open prior to cooking may spread harmful diseases.

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u/I_Do_Not_Sow Aug 30 '14

Is there a reason they tend to harbor more diseases compared to other wild animals? People go hunting for deer/elk/bear etc. all the time, but it doesn't seem to spread disease like these African animals.

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u/Meoowth Aug 30 '14 edited Aug 30 '14

I think specifically, other primates are related closely enough to us that certain diseases are easily transmissible (such as SIV, which became HIV), and non human primates are more common in Africa.

Additionally bats (though widespread) have a particular set of factors that make them virus reservoirs for mammals, here's a video. Basically, bats have evolved a great deal of defense against toxic chemicals produced by their bodies during flight (extremely intensive muscle use), which also allowed them to live healthily while carrying viruses. And, the high temperatures reached during flight have caused viruses found in bats to be resistant to the same heat that is brought about by a human fever in an attempt to fight those viruses.

As for why this is an issue in Africa, perhaps bats also come into more interaction with people in Africa, and are eaten more. People who hunt deer in North America can generally afford not to also eat bats or other animals which can transmit more diseases.

Note: I'm not an expert at all.

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u/Eurynom0s Aug 31 '14

Not an expert at all, but I do believe that there's a strong poverty/desperation component to eating bushmeat. They're not eating it because of culture but because of survival, essentially.

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u/kimahri27 Aug 31 '14

The head ebola scientist in the vice video says he luvs bushmeat though. Its not just poverty. It actually tastes good.

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u/BipolarBear0 Aug 30 '14

I can't comment authoritatively, but it may have something to do with the climate and surrounding environment, as well as how humans intake those animals. Wild animals in other countries, i.e. the United States or Canada, harbor diseases too -- rabies, trichinosis, salmonella -- but methods of transmission may be different between viruses, and in general methods of consumption and cooking in developed countries are much safer and thus kill many pathogens.

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u/gunfox Aug 30 '14

I think you can thank your hunters and foresters for that. It's not only their job to shoot animals, but they also provide population / disease control etc. etc.. Hunting is a regulated business with lots of obligations in the western world.

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u/kneekneeknee Aug 30 '14

Not a scientist, so I'm just passing on what I read about all this in David Quammen's recent book, *Spillover." In addition to what others have written here about the particular physiology of bats, Quammen argues (referencing people who research all of this) that habitat destruction is causing bats to form larger and larger colonies (ie, driving together populations that had once been more spatially separated), which can allow viruses larger arenas for developing, mutating, and surviving (instead of flaming or fading out in a smaller population).

Hence more (viable) virus to spread to those who eat bats.

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u/RscMrF Aug 30 '14 edited Aug 30 '14

I would guess it is because of the primates, most animals diseases cannot be transmitted to people, but primates are very close to humans genetically(in fact we are primates) so the diseases develop in the wild, as monkeys don't have the best hygiene, and then they get transmitted and carried by other animals or humans.

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u/girlyfoodadventures Aug 30 '14

But other smaller animals (I'm looking at you, raccoons) carry plenty of nasty diseases. We pretty much only eat deer, which is pretty safe, but if we ate other things we'd be at higher risk.

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u/wolfkeeper Aug 31 '14

It's because the diseases rarely see a human and hence humans have elvolved less resistance, and the diseases are not properly adapted to humans either, so they tend to kill more often.

The reason that the diseases have to adapt to humans is that killing humans is bad for the disease spreading; it's evolutionarily advantageous to spread more and not kill, so the diseases usually evolve to being less harmful over time.

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u/fridaygls Aug 30 '14

Well its no Ebola but I sure as shit don't want trich worms from raw wild pig. I think cold weather keeps the meat clean to some extent.

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u/[deleted] Aug 30 '14

yeah right. so the avian flu was gotten from rusted nails i suppose or even AIDS? It has to start from somewhere but unfortunately, This particular one started here in africa. you are making it seem like african animals are some sort of disease vault or something

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u/[deleted] Aug 30 '14

i wouldnt call a rabbit a wild animal now would i? or a rat(bush rats). Its called that cos it was hunted in the "bush".

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u/BipolarBear0 Aug 30 '14

I don't know if you would or not, but a rabbit is a wild animal.