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The Mathematics of Ebola Trigger Stark Warnings

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Re: The Mathematics of Ebola Trigger Stark Warnings

#71

Post by learc83 »

privong wrote: post #59
philsnow wrote: post #58

Earlier quoted context omitted.

Antibodies generally last a very long time [citation needed], but would they be useful against such a rapidly-changing pathogen ?

> but would they be useful against such a rapidly-changing pathogen ? Does that explain why people are not immune from the flu after having it once – the version they have antibodies to is not the same as the mutated version which circulates later?

>Does that explain why people are not immune from the flu after having it once

Yes. There are many strains of Influenza, immunity to one strain doesn't necessarily confer any immunity to another strain.

However, Ebola mutates much less rapidly that Influenza.

Re: The Mathematics of Ebola Trigger Stark Warnings

#72

Post by dreamcompiler »

learc83 wrote: post #69
philsnow wrote: post #58

Earlier quoted context omitted.

Antibodies generally last a very long time [citation needed], but would they be useful against such a rapidly-changing pathogen ?

Ebola isn't rapidly changing. At least in comparison to a virus that does mutate rapidly like influenza.

That used to be true. But TFA points out it's not true now. Ebola used to be too lethal to be efficient: It killed its host so quickly it didn't have time to spread. But because this outbreak is in urban areas, it does have the ability to spread. Which means it has many more opportunities to evolve.

Re: The Mathematics of Ebola Trigger Stark Warnings

#73

Post by gbhn »

joe_the_user wrote: post #68
joesmo wrote: post #61

Earlier quoted context omitted.

I think you bring up some good points and I don't mean to discount the moral dilemma here, but in reality such moral considerations are hardly ever considered. I don't think the article is suggesting invasion, but if that was the best solution, I don't see a problem with it if it prevents an epidemic or worse, a world wide pandemic(especially if it mutates into airborne transmission). After all, the US has invaded ma…

It's just ugly to see an eagerness to think about invasions when not even simple supplies are not coming through. Liberian President, Ellen Johnson Sirleaf to Barack Obama: "I am being honest with you when I say that at this rate, we will never break the transmission chain and the virus will overwhelm us" "The dilemma" of invasion and whatnot is beside the point. The Liberian state is desperate. Johnson Sirleaf also…

Agreed. There's no 'invasion' when you're being invited in on a humanitarian mission. People need help.

Re: The Mathematics of Ebola Trigger Stark Warnings

#74

Post by techdragon »

joe_the_user wrote: post #68
joesmo wrote: post #61

Earlier quoted context omitted.

I think you bring up some good points and I don't mean to discount the moral dilemma here, but in reality such moral considerations are hardly ever considered. I don't think the article is suggesting invasion, but if that was the best solution, I don't see a problem with it if it prevents an epidemic or worse, a world wide pandemic(especially if it mutates into airborne transmission). After all, the US has invaded ma…

It's just ugly to see an eagerness to think about invasions when not even simple supplies are not coming through. Liberian President, Ellen Johnson Sirleaf to Barack Obama: "I am being honest with you when I say that at this rate, we will never break the transmission chain and the virus will overwhelm us" "The dilemma" of invasion and whatnot is beside the point. The Liberian state is desperate. Johnson Sirleaf also…

This is more than just a supply issue.

http://reliefweb.int/report/democratic-republic-congo/update...

  "One of the patients hospitalised at the HGR Boende had managed to escape before being recovered by the services deployed to the field."
That is why if this situation escalates we will need people with guns, both medical and security personal with full Biological Warfare training and equipment. We are staring at a disease where scared infected people, are trying to ESCAPE and become extremely dangerous disease vectors, risking the spread of the disease to anywhere from dozens to hundreds, to thousands. When that is what is going on, I don't think the word we should use is "invasion", its something other than that. Best I've got to describe it, is a martial law quarantine, enforced by UN armed forces and medical personnel provided by the nations who have the capable personnel and equipment.

Re: The Mathematics of Ebola Trigger Stark Warnings

#75

Post by narrator »

ChuckMcM wrote: post #23

Going 'meta' for a moment, this is a tragedy of huge proportions, the question I have been considering is whether or not it is even possible to avoid? Updates from MSF which highlight the level of mistrust and superstition amongst the infected population, where people hide their sick relatives from isolation wards and take them back to their village. We cannot exactly put a giant fence around the place (and not that…

The American perspective is to solve every problem with the military or money. We believe that violence and more money are the only effective solutions to every single problem the world faces. Original thinking just doesn't happen.

A creative solution would be to temporarily halt all regulations on anti-ebola drug development and let them experiment on any willing person in Liberia who wishes to receive treatment. The example of Banting and Best in the 20s is a great example of the enormous progress that can be accomplished if there is no regulation on medicine. These guys came up with the idea for extracting insulin from animals and injecting it into humans. They tested it out on willing patients, the first being a 14 year old, released the invention for use by the public and won the Nobel prize in the span of 3 years (1921-1923). That speed of drug development and testing is impossible today.

A good analogy of the present situation would be this. Someone is drowning in the river. You can use the military to prevent him from knocking any nearby bathers into the river as he floats down stream but don't you dare throw him something handy like a branch or a quickly improvised flotation device because that might help him float and it may not work and there would be lawsuits or regulatory violations! You can pay someone to swim after him and try and save him, but the stream is really rushing fast and they might drown too, but that's seemingly a-ok.

Re: The Mathematics of Ebola Trigger Stark Warnings

#76

Post by techdragon »

nostromo wrote: post #44
aaron695 wrote: post #17

I find it interesting that people worry about Ebola going airborne but not something like AIDS. I guess there's a biological reason....

Because Ebola has already been shown to be transmissible via the air, but only in other species. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3498927/ > Piglets [with Ebola] were transferred to the room housing macaques in an open inaccessible cage system. All macaques became infected.

Dont overstate this particular study, the team did nothing to eliminate the possibility that there was transmission via droplets flung off the animal, and did not fully eliminate the possibility of particulate cross contamination which could have lead to transmission via infectious fluids piggybacking to the macaques on the particulate cross contamination.

Yes there is a risk of mutation to transmit via air, but we have not yet seen it. We have merely proven that 'shit happens' and 'ebola is dangerous'.

Re: The Mathematics of Ebola Trigger Stark Warnings

#77

Post by tstactplsignore »

rdtsc wrote: post #65
tokenadult wrote: post #14

The author of the article kindly submitted here, which I found quite interesting and informative, notes that she used to write for the Center for Infectious Disease Research and Policy (CIDRAP) based at my alma mater university. Sure enough, CIDRAP has its own current write-up on ebola[1] that is a good supplement to the information in the Wired article we are discussing here. "The possibility of an airborne-transmis…

How hard is it to predict (if possible at all) the mutation based on the virus type and particular strain (maybe somehow computationally simulate or mutate it) ? In general do mutations follow probability distributions that are known? And then let's say someone wanted to cause mutations that would make it airborne. Could they do it?

>In general do mutations follow probability distributions that are known?

In some ways, yes. Substitution matrices[0] describe how likely it is for an amino acid to mutate into another amino acid. However, they are generalized descriptors. At the same time, PWMs[1] describe how the probability of any given variant (mutation) is in a specific sequence, and are created by analyzing all known homologs (similar sequences) of that sequence.

However, the number of mutations required for a virus which is incapable of becoming airborne is probably large and definitely unknown. I'm not an expert in virology, but I believe that there are two requirements for a pathogen to become airborne:

A. It must infect and replicate in an area of the body capable of generating aerosols (generally, the respiratory system, like Influenza and Tuberculosis).

B. It must be good at surviving in aerosols- I believe this requires specific environmental adaptations and the right surface proteins and sugars.

I believe that Ebola meets neither requirement (especially the first), and you could see how meeting both would require not just large physical adaptation, but also a complete change in the virus' life cycle in the host.

>And then let's say someone wanted to cause mutations that would make it airborne. Could they do it?

I think in general it would be easier to start with an airborne virus, and make it deadlier. I'm not an expert but this BBC article[2] quotes that a deadly virus has never been observed to change their vector of infection.

0. http://en.wikipedia.org/wiki/Substitution_matrix

1. http://en.wikipedia.org/wiki/Position_weight_matrix

2. http://www.bbc.com/news/blogs-echochambers-29168905

Re: The Mathematics of Ebola Trigger Stark Warnings

#78

Post by joe_the_user »

techdragon wrote: post #74
joe_the_user wrote: post #68

Earlier quoted context omitted.

It's just ugly to see an eagerness to think about invasions when not even simple supplies are not coming through. Liberian President, Ellen Johnson Sirleaf to Barack Obama: "I am being honest with you when I say that at this rate, we will never break the transmission chain and the virus will overwhelm us" "The dilemma" of invasion and whatnot is beside the point. The Liberian state is desperate. Johnson Sirleaf also…

This is more than just a supply issue. http://reliefweb.int/report/democratic-republic-congo/update... "One of the patients hospitalised at the HGR Boende had managed to escape before being recovered by the services deployed to the field." That is why if this situation escalates we will need people with guns, both medical and security personal with full Biological Warfare training and equipment. We are staring at a d…

Uh, that's exactly the supply issue. I have read a number of reports of that incident.

The guy escape because he was starving - he went immediately to the market to buy food. If he had food in the isolation ward, that wouldn't have happened (or would be a good deal less likely).

And uh, the idea of shooting people infected with Ebola shouldn't be first or second resort considering you would be straying their infected blood over a significant area. Not to mention guaranteeing no else would want to be treated, etc.

Re: The Mathematics of Ebola Trigger Stark Warnings

#80

Post by rdtsc »

tstactplsignore wrote: post #77
rdtsc wrote: post #65

Earlier quoted context omitted.

How hard is it to predict (if possible at all) the mutation based on the virus type and particular strain (maybe somehow computationally simulate or mutate it) ? In general do mutations follow probability distributions that are known? And then let's say someone wanted to cause mutations that would make it airborne. Could they do it?

>In general do mutations follow probability distributions that are known? In some ways, yes. Substitution matrices[0] describe how likely it is for an amino acid to mutate into another amino acid. However, they are generalized descriptors. At the same time, PWMs[1] describe how the probability of any given variant (mutation) is in a specific sequence, and are created by analyzing all known homologs (similar sequences…

That made sense. Thank you for explaining.
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