# How Likely is a Worldwide Ebola Outbreak **URL:** \ **Category:** Factual Questions\ **Created:** [March 25, 2014, 2:08pm UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523 "2014-03-25T14:08:51Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Biotop](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/biotop/32/321_2.png) [@Biotop](https://boards.straightdope.com/u/Biotop)\ **Post date:** [March 25, 2014, 2:08pm UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/1 "2014-03-25T14:08:51Z")
[The current Guinea ebola outbreak](http://www.cnn.com/2014/03/22/world/africa/fever-epidemic-guinea/index.html?hpt=hp_t3) may be crossing borders in Africa. Fortunately, [a suspected Canadian case appears not to be ebola after all](http://abcnews.go.com/International/wireStory/man-canadian-hospital-ebola-symptoms-23046001) (though the Canadian is still in isolation). Still, one has to wonder if such a horrible worldwide scenario is truly possible. Ebola kills its victims fast, limiting the spread. Ebola + one international airplane full of people heading in many directions… Could it really happen, or is a worldwide ebola outbreak simply an unrealistic frightening movie scenario? ---
**Author:** ![VunderBob](https://avatars.discourse-cdn.com/v4/letter/v/839c29/32.png) [@VunderBob](https://boards.straightdope.com/u/VunderBob)\ **Post date:** [March 25, 2014, 2:16pm UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/2 "2014-03-25T14:16:16Z")
From what I’ve read, Ebola is a rather fragile virus, and optimal conditions for it are humid tropical heat. I could see it being a problem worldwide around the Equator if it jumps the Atlantic or Indian Ocean, but arid areas or those with colder weather would limit it greatly. All bets are off if it combines with a hardier virus, either naturally or via laboratory intervention. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [March 25, 2014, 2:56pm UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/3 "2014-03-25T14:56:57Z")
> [@Biotop](#): > > Ebola kills its victims fast, limiting the spread. > > Ebola + one international airplane full of people heading in many directions… > > Could it really happen, or is a worldwide ebola outbreak simply an unrealistic frightening movie scenario? As you note, the fact that Ebola is so virulent limits its spread. It burns itself out before it can get very far. Its continued existence depends on it having a natural reservoir in wildlife, in which it is less virulent. It’s not impossible that you could have scattered outbreaks outside of Africa due to the scenario you mention. However, its unlikely that any single outbreak will spread far, especially in developed countries where any cases will be stringently quarantined as soon as the outbreak is detected. ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [March 25, 2014, 3:22pm UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/4 "2014-03-25T15:22:17Z")
Ebola appears to be a virus that mutates quickly and burns itself out. BTW, people who came down with Ebola after returning to an area where modern intensive-care medicine was available usually recover. It’s still a scary, horrible disease. ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [March 25, 2014, 3:24pm UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/5 "2014-03-25T15:24:26Z")
Plus, if it gets too bad, we can always hop in the time machine and prevent it before it spreads. ---
**Author:** ![Poysyn](https://avatars.discourse-cdn.com/v4/letter/p/f4b2a3/32.png) [@Poysyn](https://boards.straightdope.com/u/Poysyn)\ **Post date:** [March 25, 2014, 3:29pm UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/6 "2014-03-25T15:29:43Z")
Ebola is also not airborne (as of yet), so it spreads by contact with infected fluids. It’s very sad, but the medical facilities in many of the outbreak countries actually help spread the virus through poor sterilization and lack of protective/isolation areas. If I remember right, people suffering from it generally feel very badly VERY quickly, so are not up for international travel soon after infection. It is a very fragile virus, needing a host to survive. They have not determined it’s natural host, as far as I know. I remember reading about one rural tribe that helped eliminate spreading the virus by isolating the infected in their huts, leaving food for them and once they were better, they came out on their own. If they died, the hut was burned, thus eliminating the risk of infection, so even rudimentary procedures help. IANAD, but this virus was fascinating to me ever since I saw a report on Ebola Reston and have done a ton of research. I apologize if recent discoveries have shown otherwise. Oh! One point of interest, did you know Ebola shares many immunospressive motifs with Rabies? ---
**Author:** ![mandala](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mandala/32/95_2.png) [@mandala](https://boards.straightdope.com/u/mandala)\ **Post date:** [March 25, 2014, 3:31pm UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/7 "2014-03-25T15:31:23Z")
> [@nearwildheaven](#): > > Ebola appears to be a virus that mutates quickly and burns itself out. BTW, people who came down with Ebola after returning to an area where modern intensive-care medicine was available usually recover. > > It’s still a scary, horrible disease. Cite? I thought most victims died despite intervention, as Ebola kills in a matter of days. ---
**Author:** ![Biotop](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/biotop/32/321_2.png) [@Biotop](https://boards.straightdope.com/u/Biotop)\ **Post date:** [March 25, 2014, 3:34pm UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/8 "2014-03-25T15:34:18Z")
Interesting responses. We’ve had a relatively few major outbreaks of ebola. When it “burns out” does that mean that the ebola kills or infects the available supply of people and then dies, or does it somehow lesson its ability to transmit and reproduce? It seems we’ve been expecting the bird flu to mutate to a human to human transmission for years, but have been lucky so far as the current variety goes and its been strictly poultry to human transmission. How much scientific certainty do we have in these viral situations, and how much are we really dealing with the unknown? ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [March 25, 2014, 3:54pm UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/9 "2014-03-25T15:54:35Z")
> [@Biotop](#): > > We’ve had a relatively few major outbreaks of ebola. When it “burns out” does that mean that the ebola kills or infects the available supply of people and then dies, or does it somehow lesson its ability to transmit and reproduce? It kills off the available supply of people, or those who were infected recover. Outbreaks have often occurred in areas with poor roads and transportation, making it relatively easy to contain the spread. So far, Ebola is only known to be transmitted between humans through body fluids, not through the air. (There is evidence of some aerosol transmission in test animals.) I am not aware of any evidence that Ebola has changed its virulence or transmission in the course of an outbreak. Many human diseases evolve lower virulence over time, because those strains that are less virulent can spread and persist better. However, all Ebola outbreaks have apparently been due to transmission from a non-human host (which however has not yet been identified). Since each outbreak is from a different source, there is really little opportunity for Ebola to evolve lower virulence. ---
**Author:** ![Iggy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/iggy/32/3364_2.png) [@Iggy](https://boards.straightdope.com/u/Iggy)\ **Post date:** [March 25, 2014, 4:14pm UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/10 "2014-03-25T16:14:02Z")
The various Ebola strains have an incubation period during which the patient does not feel ill. The deadliest subtype, EBOV, Zaire, has [an incubation period](http://www.kcdc-phrp.org/article/S2210-9099%2811%2900002-6/abstract) of a mean 12.7 days standard deviation of 4.31 days. With worldwide travel almost anywhere within 48-72 hours it is quite conceivable that an infected patient could travel long distances from where he was infected. The Ebola Reston strain is already known to be spread airborne as observed in [an animal study](https://www.sciencenews.org/article/ebola-may-go-airborne). Fortunately it is not (yet) highly infectious to humans, though antibodies to the virus have been found in humans. Transmission of the Zaire, Sudan, and Ivory Coast subtypes does not appear to be dependent on airborne routes. However analysis of prior outbreaks was unable to link 13 patients to direct contact with other infected persons or suspect animals. Analysis of data from the most recently identified Bundibugyo subtype, from the Uganda 2012 outbreak, is still ongoing. ---
**Author:** ![Iggy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/iggy/32/3364_2.png) [@Iggy](https://boards.straightdope.com/u/Iggy)\ **Post date:** [March 25, 2014, 4:18pm UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/11 "2014-03-25T16:18:50Z")
oops double post ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [March 26, 2014, 1:33am UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/12 "2014-03-26T01:33:08Z")
The Ebola virus is believed to be carried by chimpanzees and gorillas, and bats too, although bats do not get sick from it. > **[Scientists find more signs of bats' role in Ebola](https://www.scidev.net/global/news/scientists-find-more-signs-of-bats-role-in-ebola/)** > > Tracing the origins of a massive Ebola outbreak, researchers have linked the deadly virus to a colony of migrating fruit bats. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [March 26, 2014, 2:03am UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/13 "2014-03-26T02:03:52Z")
> [@nearwildheaven](#): > > The Ebola virus is believed to be carried by chimpanzees and gorillas, and bats too, although bats do not get sick from it. It should be noted that although chimps and gorillas get Ebola, it is so virulent to them that they are probably not the natural reservoir for the disease. They probably get it from some other animal in which the disease is not virulent. ---
**Author:** ![Ranger\_Jeff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranger_jeff/32/2065_2.png) [@Ranger\_Jeff](https://boards.straightdope.com/u/Ranger_Jeff)\ **Post date:** [March 26, 2014, 3:49am UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/14 "2014-03-26T03:49:56Z")
Last I read said fruit bats are the carriers. They’ll grab a fruit, munch on it for a bit, pass on the ebola virus that’s in their saliva, and once they’ve had all they want, they’ll drop what’s left of it. They’re not very big eaters. So a passing human or simian will finish the fruit and become infected. Or a human will try to play with an infected simian and get bitten and infected. For the record, the idea of vacationing equatorial Africa has NO appeal to me. ---
**Author:** ![mandala](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mandala/32/95_2.png) [@mandala](https://boards.straightdope.com/u/mandala)\ **Post date:** [March 26, 2014, 4:10am UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/15 "2014-03-26T04:10:05Z")
Ebola virus is a BSL 4 agent and is a candidate for (bio)weaponization. The Zaire subtype has the [highest mortality rate]([Ebola - Wikipedia](http://en.wikipedia.org/wiki/Ebola_virus_disease#Zaire) ebolavirus (ZEBOV)) (90%) of any known human pathological agent. It might be possible to further artificially enhance its virulence for use as a bioweapon. Besides in 2012 Canadian scientists reported evidence for [sustained aerosol transmission]([Ebola - Wikipedia](http://en.wikipedia.org/wiki/Ebola_virus_disease#Recent) research)of the most pathogenic form of Ebola. A naturally-occuring outbreak will probably be self-limiting due to the extreme mortality and short course of illness. A [vaccine](http://en.wikipedia.org/wiki/Ebola_virus_disease#Prevention)for Ebola has been developed. Ebola also mutates far more slowly than does Influenza A, which gives the latter more pandemic potential. ---
**Author:** ![even\_sven](https://avatars.discourse-cdn.com/v4/letter/e/dfb087/32.png) [@even\_sven](https://boards.straightdope.com/u/even_sven)\ **Post date:** [March 26, 2014, 4:41am UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/16 "2014-03-26T04:41:53Z")
My understanding is that Ebola is not too hard to contain in a modern hospital, and any victims would likely be isolated (as well as those who had close contact with the victims) in a first-world outbreak. The African outbreaks spread the way they do in a large part due to the poor medical facilities in the area. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [March 26, 2014, 3:24pm UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/17 "2014-03-26T15:24:05Z")
> [@even\_sven](#): > > My understanding is that Ebola is not too hard to contain in a modern hospital, and any victims would likely be isolated (as well as those who had close contact with the victims) in a first-world outbreak. The African outbreaks spread the way they do in a large part due to the poor medical facilities in the area. In some cases the infection was actually spread by medical personnel _within_ a hospital due to failure to isolate patients and equipment used to treat them. ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [March 26, 2014, 10:53pm UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/18 "2014-03-26T22:53:03Z")
> [@Colibri](#): > > In some cases the infection was actually spread by medical personnel _within_ a hospital due to failure to isolate patients and equipment used to treat them. Yes. But the idea that Ebola can be contained is tautology with “There are no asymptomatic carriers”… eg some (small but non-zero) % of Europeans have the anti-viral mutation ( it grants HIV-immunity…its a big unknown as to the extend of its power.). It could be this mutation that creates the possibility of an asymptomatic carrier. That just means that Ebola spreading to a European population would then present a higher danger of epedemic Ebola. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [March 27, 2014, 3:21am UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/19 "2014-03-27T03:21:04Z")
> [@Isilder](#): > > Yes. But the idea that Ebola can be contained is tautology with “There are no asymptomatic carriers”… > > eg some (small but non-zero) % of Europeans have the anti-viral mutation ( it grants HIV-immunity…its a big unknown as to the extend of its power.). It could be this mutation that creates the possibility of an asymptomatic carrier. Do you have a cite for any of this? ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [March 27, 2014, 3:37am UTC](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523/20 "2014-03-27T03:37:24Z")
> [@Colibri](#): > > Do you have a cite for any of this? There are links galore about it. It appears to be the same gene that made some people immune to bubonic plague. People who have it can be HIV positive, indicating that they were exposed to the AIDS virus at some time, but they don’t get AIDS. [Next page](https://boards.straightdope.com/t/how-likely-is-a-worldwide-ebola-outbreak/684523.md?page=2)