Ebola outbreak, and other potential epidemics

biffvernon · Post by **biffvernon** » 07 Sep 2014, 08:50

Counting accurately can't be too easy in a place without path labs and where gut diseases and death from the resulting dehydration are pretty common. The numbers are still trivial compared to malaria but I wonder if it would be better to compare with HIV/AIDs, which has killed a lot of people in Africa but has turned out to be containable and even curable. It took a royal princess's hand-hold before people started being sensible. There do seem to be a number of potential medical treatments being pursued and the quicker they are worked on the better. Given good care ebola seems far from 100% fatal.

The perennial challenge is to get people to allow science to trump religion, superstition and fear, and to ensure that the interests of all humanity trump those of western capitalism.

snow hope · Post by **snow hope** » 08 Sep 2014, 09:35

biffvernon wrote: The perennial challenge is to get people to allow science to trump religion, superstition and fear, and to ensure that the interests of all humanity trump those of western capitalism.

We are well and truly snookered on the first count as that won't happen in Africa! On the second count, as we have seen time and again over the last century, western capitalism will undoubtedly triumph over humanity to our obvious loss.

I really think we are well past the stage of containment. The question now is how fast will it spread in the developed world. That seems to be a function of the long gestation period (3-21 days which is terrible) and how infectious the virus becomes - will it mutate to become airborne?

At least there seems some hope with treatments and vaccinations.

PS_RalphW · Post by **PS_RalphW** » 08 Sep 2014, 11:35

I think there is a good chance of this disease becoming endemic in Africa, and over a period of years it will put a serious strain on life expectancy, but the exact impact will vary dramatically between countries, due to social and behavioural factors, as with HIV. The worst impact will be where risky practices are cultural and trust in Western medicine lowest. HIV was widely dismissed as an Imperial Oppression un some countries, leading to millions more dieing than necessary. Of course, capitalism made it worse too by preventing the production of effective drugs for years.

I suspect its impact on the developed world will be lass, as with HIV, because big money will be put into developing treatments and a vaccine, and much stronger medical controls.

Sooner or later the disease will either be brought under control, or will evolve into a less deadly strain.

I assume that survivors develop immunity from re-infection, so the prospect for vaccine development must be significant, and fear will force speed and safety shortcuts.

Little John · Post by **Little John** » 08 Sep 2014, 12:11

One upside, if it can be characterised as such, for those parts of Africa who either have limited access to modern medicines or have culturally rejected them, is that they will be the first human populations to develop a large degree of natural immunity. However, not before losing a significant portion of their existing populations. The truth is, modern medicines primarily serve to protect complex societies. They are not required to protect populations, at least not in the long run. Mr Darwin's process of natural selection is a far more suitable candidate for that job. Indeed, such modern medicines may even promote underlying, long-term vulnerabilities in populations as a price for the short term benefits they confer. Which just goes to serve as yet another example of complex, hydrocarbon-fuelled, industrial society's central delusion of there being such a thing as free lunch.

UndercoverElephant · Post by **UndercoverElephant** » 08 Sep 2014, 12:16

snow hope wrote: I really think we are well past the stage of containment. The question now is how fast will it spread in the developed world. That seems to be a function of the long gestation period (3-21 days which is terrible) and how infectious the virus becomes - will it mutate to become airborne?

That would seem rather unlikely. One of the key features of an airborne disease is that it irritates the lungs and throat - it makes you cough. Ebola doesn't do that - it's just not that sort of virus.

It would appear, though, that is already infectious enough to be uncontainable. If you look at the history of really nasty diseases, there's no particular transmission type that links them. The black death and malaria are spread by insect bites. Cholera and typhoid are waterborne. AIDS and syphilis are sexually transmitted.

Little John · Post by **Little John** » 08 Sep 2014, 12:28

UndercoverElephant wrote:
snow hope wrote: I really think we are well past the stage of containment. The question now is how fast will it spread in the developed world. That seems to be a function of the long gestation period (3-21 days which is terrible) and how infectious the virus becomes - will it mutate to become airborne?
That would seem rather unlikely. One of the key features of an airborne disease is that it irritates the lungs and throat - it makes you cough. Ebola doesn't do that - it's just not that sort of virus.

It would appear, though, that is already infectious enough to be uncontainable. If you look at the history of really nasty diseases, there's no particular transmission type that links them. The black death and malaria are spread by insect bites. Cholera and typhoid are waterborne. AIDS and syphilis are sexually transmitted.

Another thing to note is that as the disease infects more people, it is afforded ever growing opportunities to evolve different transmission methods, different degrees of infectiousness etc. In the end, if it doesn't burn itself out by being too good at killing people, it will become much more infectious and far less lethal. It's the bit in-between the journey from deadly to harmless is where the majority of people die. It seems that midpoint is what we are about to face.

UndercoverElephant · Post by **UndercoverElephant** » 08 Sep 2014, 15:01

I doubt it will end up "harmless." Cholera and typhoid have been around for a very long time, without becoming harmless.

Little John · Post by **Little John** » 08 Sep 2014, 15:44

UndercoverElephant wrote:I doubt it will end up "harmless." Cholera and typhoid have been around for a very long time, without becoming harmless.

Typhoid and cholera are bacterial infections as opposed to viral ones. Generally, mutation rates in bacteria are about one mutation per one hundred million genes per generation as opposed to about one mutation per one million genes per generation in viruses. Which, I'm guessing means viruses are far more prone to adhering to the epidemiological curve I mentioned. Though, of course, not always.

Post by **adam2** » 08 Sep 2014, 16:35

UK military to be sent to help.
http://www.bbc.co.uk/news/health-29113530

biffvernon · Post by **biffvernon** » 08 Sep 2014, 17:11

adam2 wrote:UK military to be sent to help.
http://www.bbc.co.uk/news/health-29113530

Gosh! Our government doing something sensible. The normal response to any local difficulty is to drop bombs on people. Wouldn't Britain be Great if it tried to be the world's nurse rather than the world's policeman.

snow hope · Post by **snow hope** » 08 Sep 2014, 17:43

Things looking grim in Liberia. "Liberia 'faces huge Ebola surge' - WHO"

http://www.bbc.co.uk/news/world-africa-29115298

fuzzy · Post by **fuzzy** » 08 Sep 2014, 18:00

I see no reason for the virus to mutate into a less lethal form if it has a safe pool in other mammals. Humans might eventually develop better ability to fight it as the weaker are culled.

Little John · Post by **Little John** » 08 Sep 2014, 18:26

fuzzy wrote:I see no reason for the virus to mutate into a less lethal form if it has a safe pool in other mammals. Humans might eventually develop better ability to fight it as the weaker are culled.

Viruses don't mutate with any agenda. They just mutate. The more organisms that are infected at any given time, the greater the frequency of mutations that will occur giving rise to many strains. Given that those strains will have initially arisen randomly and so will range from lethal to harmless and from highly infectious to hardly infectious, it simply turns out that the strain that becomes most prevalent is the one that is highly infectious and relatively harmless. The reason being that the lower lethality means that more people survive long enough to pass it to more other people and the high infectiousness means it spreads from person to person relatively more efficiently. This further speeds up the demise of the earlier, more lethal forms. The reason being that, as people survive the less lethal one and are left with an immune response, this immune response also protects them, to a significant, though not total extent, from infection from the remaining pools of the more lethal strains leaving the lethal strains with fewer and fewer potential hosts.

Don't misunderstand me, all of the above does not mean a lot of people are not going to die.

Standuble · Post by **Standuble** » 08 Sep 2014, 19:00

I can't see the lethal strains going into decline for as long as its easy for infected travellers to travel all across the globe. There are too many people who are too easy to infect for the lethality to become a detrimental trait any time soon. At best it would only co-exist with non-lethal strains for now.

I was going to comment about the Sierra Leone three-day lock down but it may have already been mentioned.

Addendum: I do have an outstanding question: What are the odds of a lethal ebola strain surviving in Europe or America via the native bat populations? Could they become endemic in the developed world as a result?

Little John · Post by **Little John** » 08 Sep 2014, 19:08

Standuble wrote:I can't see the lethal strains going into decline for as long as its easy for infected travellers to travel all across the globe. There are too many people who are too easy to infect for the lethality to become a detrimental trait any time soon. At best it would only co-exist with non-lethal strains for now.

I was going to comment about the Sierra Leone three-day lock down but it may have already been mentioned.

Oh yeah, don't misunderstand me, tens of millions could die across Africa before the more lethal strains become superseded by less lethal strains and, if it make significant headway into the rest of the world, that number could very easily become hundreds of millions. The thing is, though, compared to a population of over 7 billion, it's insignificant. My guess is, for really big numbers to die, it would take some kind of bacterial plague for reasons of lower mutation rate I mentioned earlier, though I'm just guessing. What I am trying to say is that the worst viral pathogen is worse than any bacterial pathogen I can think of. However, those kinds of deadly viruses live fast and die young. Bacterial pathogens, on the other hand, even really quite nasty ones, are in it for the long haul and so can be far more devastating to a population over the longer term.