Ebola

This has been discussed, although not very rationally, over in debates - I felt we could look at the problem more scientifically. My feeling is that this disease is a serious worry. It has a huge mortality rate - I've heard measles described as a real killer and the mortality rate is 0.3% [1] - this has a mortality rate of over 50%. I think it's been demonstrated that it is easily spread and the problems they've had in Texas and Spain show that first world medical services can be caught off guard and struggle with it.

One issue is what is the correct response to an affected region. Closing borders has made things worse. It has meant that aid workers cannot gain access, so the disease entrenches itself more. Also cross border trade collapsed in the affected countries driving food prices through the roof. There was an interesting article on the BBC website [2] about how mobile phone use data has given a picture of people's movement, giving the medical services information about where to intervene and control the potential transmission of the disease.

The big worry with this disease is that it evolves rather fast. They are RNA viruses which do not copy themselves very precisely. The nightmare scenario is that the virus could become airborne [3][4], at which point disease transmission will be very difficult to stop. From what I've read this is regarded as highly unlikely, there are no documented cases in any viral disease, but not impossible. Other bad scenarios include the disease reaching and becoming endemic within a mega-city like Lagos or Kinshasa.

I think there are two basic angles of attack. One is systems - had the WHO had the authority and funding to step in earlier the initial spread of the disease could have been prevented. The local hospitals seem to have quickly become overwhelmed, so possibly a better approach would be for temporary WHO hospitals to cope with ebola and the local medical services to do their usual work.

The other angle is medical technology, and a vaccine. There is an untested one, which is encouraging, but if there were a reliable one then the whole situation would be perfectly controllable. So the big question is should they try pre-emptive vaccination of the population in the affected regions - assuming there is enough vaccine. There are two dangers, one is that it is ineffective which is only a problem if it leads to complacency. The other, more serious problem is that the vaccine could come with adverse effects.

[1] http://en.wikipedia.org/wiki/Measles#Epidemiology
[2] http://www.bbc.co.uk/news/business-29617831
[3] http://edition.cnn.com/2014/09/12/health/ebola-airborne/
[4] http://blogs.reuters.com/great-debate/2014/10/13/read-this-to-get-a-better-understanding-of-how-ebola-spreads/
I recommend the reuters article. It explains what is meant by airborne and what the evidence is quite well without melodrama.

The post that was quoted here has been removed

Well yes, that was a major motivating factor in starting the thread here. The latest suggestion over in debates was to "hose them [ebola victims] down with bleach" ho hum...

Originally posted by DeepThought
My feeling is that this disease is a serious worry. It has a huge mortality rate - I've heard measles described as a real killer and the mortality rate is 0.3% [1] - this has a mortality rate of over 50%. I think it's been demonstrated that it is easily spread and the problems they've had in Texas and Spain show that first world medical services can be caught off guard and struggle with it.

I disagree. Unless it mutates and starts to spread more easily, it will not be much of a problem. It does not spread rapidly like the flu or measles, but rather requires fairly close contact.
Yes it is quite dangerous, but so are rabies, anthrax and any number of other diseases - none of which you typically worry too much about. My room mate at University lost some of his relatives to anthrax, and rabies is not uncommon in Livingstone. As far as I know both have mortality rates higher than ebola, and both can probably be transmitted in similar ways to ebola.

Originally posted by twhitehead
I disagree. Unless it mutates and starts to spread more easily, it will not be much of a problem. It does not spread rapidly like the flu or measles, but rather requires fairly close contact.
Yes it is quite dangerous, but so are rabies, anthrax and any number of other diseases - none of which you typically worry too much about. My room mate at Universit ...[text shortened]... ortality rates higher than ebola, and both can probably be transmitted in similar ways to ebola.

Unless it mutates

That's the only possibility that terrifies me; I don't think this would probably happen but, what if the abola mutates into a strain that can spread like the flue?
Then we would sure have something to worry about!
It often takes about 21 days from catching it to showing symptoms so what if it is not only infectious during that time but gets airborne? Then each infected person could pass it on to 100 others before showing symptoms!
Then, by the time it becomes apparent in your neighborhood, it is too late for you to take counter measures because you probably already got it!

Originally posted by twhitehead
I disagree. Unless it mutates and starts to spread more easily, it will not be much of a problem. It does not spread rapidly like the flu or measles, but rather requires fairly close contact.
Yes it is quite dangerous, but so are rabies, anthrax and any number of other diseases - none of which you typically worry too much about. My room mate at Universit ...[text shortened]... ortality rates higher than ebola, and both can probably be transmitted in similar ways to ebola.

Rabies is not very infectious, it requires a bite, and there is a vaccine which is effective - provided it is administered before symptoms develop. In the case of anthrax there are three types of infection: pulmonary, gastro-intestinal and cutaneous. The last case of anthrax in the UK was a drum maker inhaling spores on the surface of an imported animal skin in Hackney [1] when I was living there. People who are infected tend to be workers in industries such as wool packing (pulmonary), or people who ate meat from an infected animal (G.I.), cutaneous infection is typically via handling of infected meat. Human to human transmission is rare to non-existent. There is a vaccine and caught early it can be treated with antibiotics, caught late the fatality rate for the pulmonary variant is 97% independent of treatment [2].

Measles has a virtually identical transmission profile to Ebola [3], I suspect that the rates of transmission are identical. Can you provide some evidence to show that transmission rates of measles are higher than for Ebola?

The difference with the 'flu is that it is airborne. Measles and Ebola both require contact with bodily fluids, including aerosols. Influenza can survive outside a host without being in water. The worry is that if the disease is allowed to continue to spread then it will hit a mutation that allows it to become airborne, without needing to be in an aerosol. Then it will be as transmissible as influenza.

Frankly it's a major problem without that. Nigeria has almost certainly managed to contain its outbreak, but not without 20 cases and 8 fatalities, and they caught it early with good warning that it was an Ebola case that they were treating. In both the US and Spain small slip ups have lead to additional cases and in Spain fatalities.

Britain hasn't had rabies or anthrax for ages, so it is quite natural for me not to worry about them. If I were to go to an area where they are prevalent I'd be vaccinated and since I've been vaccinated against measles I'm not worried about that either. Most strains of the 'flu are only a real worry for the immuno-compromised.

[1] http://news.bbc.co.uk/1/hi/uk/7705328.stm
[2] http://en.wikipedia.org/wiki/Anthrax
[3] http://en.wikipedia.org/wiki/Measles

Originally posted by humy

Unless it mutates

That's the only possibility that terrifies me; I don't think this would probably happen but, what if the abola mutates into a strain that can spread like the flue?
Then we would sure have something to worry about!
It often takes about 21 days from catching it to showing symptoms so what if it is not onl ...[text shortened]... ighborhood, it is too late for you to take counter measures because you probably already got it!

People with Ebola do not become infectious until they are showing symptoms. For airborne transmission their bodies would have to be producing enough of the bug that I think that that wouldn't change. I don't know though, I'm guessing, this is one for a disease expert.

The post that was quoted here has been removed

That is a very good point and one that hasn't been raised elsewhere. Panicky responses in closing borders have caused food shortages and price rises as well.

When I was researching my response to twhitehead's post I found that in India there is a similar problem with rabies and people suspicious of conventional medicine consulting witch doctors:

Effective control and treatment of rabies in India is also hindered by a form of mass hysteria or group delusion known as puppy pregnancy syndrome (PPS). Dog bite victims with PPS (both male and female) become convinced that puppies are growing inside them, and often seek help from faith healers rather than from conventional medical services. In cases where the bite was from a rabid dog, this decision can prove fatal. Dr. Nitai Kishore Marik, former district medical officer of West Midnapur, states "I have seen scores of cases of rabies that reached our hospitals very late because of the intervention of faith healers. We could not save those lives."

Originally posted by DeepThought
Britain hasn't had rabies or anthrax for ages, so it is quite natural for me not to worry about them.

I doubt that Britain has had ebola recently either. The main reason you are worried about it is the news reports, not the actual characteristics of the disease.
Why is nobody here worrying about rabies or anthrax mutating?

Originally posted by DeepThought
Measles has a virtually identical transmission profile to Ebola [3], I suspect that the rates of transmission are identical. Can you provide some evidence to show that transmission rates of measles are higher than for Ebola?

I doubt that. I think measles survives because people can be carriers. Is that true for ebola?

http://en.wikipedia.org/wiki/Measles#Prevention

Measles is spread through respiration (contact with fluids from an infected person's nose and mouth, either directly or through aerosol transmission), and is highly contagious—90% of people without immunity sharing living space with an infected person will catch it.

http://en.wikipedia.org/wiki/Ebola_virus_disease

Human-to-human transmission occurs only via direct contact with blood or body fluid from an infected person (including embalming of an infected dead body), or by contact with objects contaminated by the virus, particularly needles and syringes.

Originally posted by DeepThought
People with Ebola do not become infectious until they are showing symptoms. For airborne transmission their bodies would have to be producing enough of the bug that I think that that wouldn't change. I don't know though, I'm guessing, this is one for a disease expert.

It can be contracted through fluids such as sweat and air born droplets (sneezing), and there is some evidence showing the virus can survive for several days under the right conditions, but contact with fluids seems to be the common denominator.

I've heard reports of percentages of deaths vs survival, so this appears to suggest that some people are able to fight off this disease. If so, then I would think one area to look into would be to study the people who have survived, and find out why they survived... for instance, do they have superior autoimmune systems?

But I'm wondering if I've heard correctly, that some people have survived and recovered from this disease. If the death rate from infection is not 100% and there is any survival rate (however small), then wouldn't it be prudent to find out why those people survived?

Originally posted by DeepThought
People with Ebola do not become infectious until they are showing symptoms. For airborne transmission their bodies would have to be producing enough of the bug that I think that that wouldn't change. I don't know though, I'm guessing, this is one for a disease expert.

People with Ebola do not become infectious until they are showing symptoms.

Might that might change if it mutates to become airborne?
But then I assume it would require coughing or sneezing to readily get airborne which, of course, is a symptom.

Anyone:

I am not sure if a virus necessarily requires coughing or sneezing or a specific symptom to become airborne.
Can anyone name a type of virus that readily gets airborne but not through coughing or sneezing or any other symptom and, if so, what is the mechanism that gets it airborne?

Originally posted by twhitehead
http://en.wikipedia.org/wiki/Measles#Prevention

Measles is spread through respiration (contact with fluids from an infected person's nose and mouth, either directly or through aerosol transmission), and is highly contagious—90% of people without immunity sharing living space with an infected person will catch it.

http://en.wikipedia.org ...[text shortened]... or by contact with objects contaminated by the virus, particularly needles and syringes.[/quote]

Aerosol transmission is contact with fluids from an infected person. At the bottom of the section on transmission there is this bit:

Airborne transmission has not been documented during EVD outbreaks. Transmission among rhesus monkeys via breathable 0.8–1.2 μm airborne droplets has been demonstrated in the laboratory.

So it depends on aerosol physics and the extent to which aerosols are produced.