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Author Topic: Why does Ebola often kill its host?  (Read 1811 times)

Offline thedoc

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Why does Ebola often kill its host?
« on: 08/01/2015 15:30:01 »
Nick Kendall asked the Naked Scientists:
   
Why does ebola kill its host? Not in its interest surely?

Naked scientists you're great I love science!
What do you think?
« Last Edit: 08/01/2015 15:30:01 by _system »


 

Offline Bored chemist

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Re: Why does Ebola often kill its host?
« Reply #1 on: 08/01/2015 17:29:41 »
I understand the the "real" host for it is a bat and we are just unlucky.
Since it doesn't kill the bats, it's just fine from an evolutionary point of view.
 

Offline evan_au

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Re: Why does Ebola often kill its host?
« Reply #2 on: 08/01/2015 18:39:00 »
There are different strains of Ebola which have different lethality ratios.

Studies of Ebola exposure have shown that perhaps 10% of the West African population have Ebola antibodies, which is far greater than the number of patients counted in official statistics of hospital admissions. So it is possible that there are many non-lethal exposures.

The course of Ebola disease is a race between the immune system and virus replication. It takes days to weeks to create an effective immune response. But Ebola can kill in weeks. Ebola attacks white blood cells directly, and causes infected cells to produce chemicals which inhibit some parts of the immune response. The remaining parts of the immune system go into overdrive, and do considerable damage to the whole body.

Ebola also attacks the lining of blood vessels and lymphatic vessels, causing them to become leaky. Together with vomiting and diarrhea, this causes a lethal loss of bodily fluids. It does not help that Ebola also inhibits blood clotting. Part of the treatment regimen is to keep the patient hydrated.

Other contributors are lack of communications & health care infrastructure in countries that have been ravaged by war, and mistrust of the government & aid agencies. The remoteness of the outbreak areas hinders treatment, but increased mobility of the population assists long-distance transmission.

As a viral disease, it does not respond to antibiotics, and we don't have a proven vaccine at this time.
See: http://en.wikipedia.org/wiki/Ebola_virus_disease#Pathophysiology
 

Offline RD

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Re: Why does Ebola often kill its host?
« Reply #3 on: 08/01/2015 20:13:48 »
Why does ebola kill its host? Not in its interest surely?

There could be a net-gain for the virus : lose one host, but potentially be transmitted to several new hosts via the blood loss*.

[ * Ebola is haemorrhagic ... http://en.wikipedia.org/wiki/Viral_hemorrhagic_fever#Signs_and_symptoms ].
« Last Edit: 08/01/2015 20:17:35 by RD »
 

Offline CliffordK

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Re: Why does Ebola often kill its host?
« Reply #4 on: 10/01/2015 22:53:45 »
If the virus remains viable in the dead carcass for some time, then there is also a chance to spread to scavengers.
 

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Re: Why does Ebola often kill its host?
« Reply #4 on: 10/01/2015 22:53:45 »

 

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