Ebola virus outbreak

ProfessorPlum · 09-10-2014 10:37PM

realweirdo wrote: »

And as Miss No Stars explained to you, it's irrelevant without the time frame.

See my post. Comparing to measles. Temporally similar.

miss no stars wrote: »

But you haven't considered the precautions against transmission. A spanish nurse allegedly provided with and correctly using BSL2 protective equipment contracted Ebola in a hospital environment.

I'm not saying the R number isn't useful, I'm saying that comparing apples with oranges isn't useful. Comparing the R number for Ebola (dead and gone in about 3-4 weeks) with the R number for HIV (alive after decades with modern medicine and no need for BSL4 protective equipment) is a false comparison.

I never did compare to HIV. I compared to measles, just for you. Not a false comparison at all.

ProfessorPlum · 09-10-2014 10:38PM

realweirdo wrote: »

2 in a week.

So let's imagine someone gets infected with HIV today. How many people do you think they will have infected by this time next week? 4?

I do give up.

Explain your problem with R numbers with reference to measles please.

realweirdo · 09-10-2014 10:41PM

ProfessorPlum wrote: »

See my post. Comparing to measles. Temporally similar.

I never did compare to HIV. I compared to measles, just for you. Not a false comparison at all.

And measles is an even worse comparision. How many measles cases are fatal, given that 50% of ebola cases are fatal.

In all seriousness you might as well quote the R value for headlice.

miss no stars · 09-10-2014 10:42PM

ProfessorPlum wrote: »

See my post. Comparing to measles. Temporally similar.

I never did compare to HIV. I compared to measles, just for you. Not a false comparison at all.

What on earth is your problem? I responded saying that those claiming Ebola is anything short of a massive public health risk because HIV has an R number twice as high are talking absolute crap.

I addressed your point about measles. When assessing risk you assess:

Likelihood of occurrence (a factor of inherent contagiousness AND the speed at which new infections occur)
AND
the consequence of occurrence

Ebola is still coming out way up there.

I never said it was the most contagious disease in the world. I said it's highly contagious when you factor in the time it takes to spread and the fact that despite massive precautions against transmission, new infections still occur.

I said that when you add that in to the 50% mortality rate it's a highly dangerous disease.

ProfessorPlum · 09-10-2014 10:43PM

realweirdo wrote: »

And measles is an even worse comparision. How many measles cases are fatal, given that 50% of ebola cases are fatal.

In all seriousness you might as well quote the R value for headlice.

Ok, in all seriousness, WTF does fatality got to do with R numbers. And you might well quote the number for head lice if you want to quantify how contagious it is, and move on to the CFR if you want to quantify how deadly it is.

realweirdo · 09-10-2014 10:43PM

I'd much rather get measles than ebola! In fact I'm pretty sure most Irish people had measles at one stage or another.

WakeUp · 09-10-2014 10:46PM

ProfessorPlum wrote: »

Your link is to a crank conspiracy theory type website, and the link in that to the peer reviewed medical paper is to a blog.

However, one thing a medical student learns early on (as most of the exams are negative marking MCQ's) if there's a choice of an 'always' or 'never' answer in medicine, the right answer is probably not that one.

the link does take you a blog which is signed of at the end by this guy...

The German physicians, led by Dr. Timm H. Westhoff of the Department of Nephrology at the Carité Campus Benjamin Franklin in Berlin, noted in a virology blog published Feb. 12, 2009, that acute viral infections such as Ebola hemorrhagic fever may cause little or no clinical symptoms in a so-called “inapparent infection” yet may be contagious.

“A well-known example is poliovirus: over 90% are without infections,” Westhoff and his colleagues continued. “During an inapparent infection, sufficient virus replication occurs in the host to induce antiviral antibodies, but not enough to cause disease. Such infections are important for the spread of infection, because they are not easily detected.”

10.1093/ndt/gfn693 - this is is also at the end of the blog which redirects you to the oxford journal though it appears to be just the abstract synopsis with a list of other articles citing the research.

in the original wnd article - The German physicians published in 2008 the fundamental medical research that formed the basis for their blog comments - this sentence is hyperlinked and again redirects you to the oxford journal - full.

ProfessorPlum · 09-10-2014 10:47PM

miss no stars wrote: »

What on earth is your problem? I responded saying that those claiming Ebola is anything short of a massive public health risk because HIV has an R number twice as high are talking absolute crap.

I addressed your point about measles. When assessing risk you assess:

Likelihood of occurrence (a factor of inherent contagiousness AND the speed at which new infections occur)
AND
the consequence of occurrence

Ebola is still coming out way up there.

I never said it was the most contagious disease in the world. I said it's highly contagious when you factor in the time it takes to spread and the fact that despite massive precautions against transmission, new infections still occur.

I said that when you add that in to the 50% mortality rate it's a highly dangerous disease.

Ohh hold on there - major shifting of goal posts!

You said that R number was useless when talking about how contagious a disease was, and despite it's R number of 2, that Ebola was a highly contagious disease. Which it's not.
Now you're bringing in mortality, which has nothing what so ever to do with contagiousness. Nothing.
And assessing risk - nope, you hadn't mentioned that either.

Nobody is saying Ebola isn't a highly dangerous disease - that just wasn't your argument in the first place.

ProfessorPlum · 09-10-2014 10:48PM

realweirdo wrote: »

I'd much rather get measles than ebola! In fact I'm pretty sure most Irish people had measles at one stage or another.

Seriously, not the point. Where is the brick wall.:(

ProfessorPlum · 09-10-2014 10:49PM

WakeUp wrote: »

the link does take you a blog which is signed of at the end by this guy...

The German physicians, led by Dr. Timm H. Westhoff of the Department of Nephrology at the Carité Campus Benjamin Franklin in Berlin, noted in a virology blog published Feb. 12, 2009, that acute viral infections such as Ebola hemorrhagic fever may cause little or no clinical symptoms in a so-called “inapparent infection” yet may be contagious.

“A well-known example is poliovirus: over 90% are without infections,” Westhoff and his colleagues continued. “During an inapparent infection, sufficient virus replication occurs in the host to induce antiviral antibodies, but not enough to cause disease. Such infections are important for the spread of infection, because they are not easily detected.”

10.1093/ndt/gfn693 - this is is also at the end of the blog which redirects you to the oxford journal though it appears to be just the abstract synopsis with a list of other articles citing the research.

in the original wnd article - The German physicians published in 2008 the fundamental medical research that formed the basis for their blog comments - this sentence is hyperlinked and again redirects you to the oxford journal - full.

A lot of maybes there, but like I said, always and never are dirty words in medicine!

realweirdo · 09-10-2014 10:49PM

I think miss no stars has explained this amply. Its the temporal issue that is key along with the fatality rate and the life expectancy of infected patients.

I am sure miss no stars will also concur that the fact that fatality rate is relatively low for this outbreak of ebola makes it even more serious than previous outbreaks. It possibly has a longer encupation period as well.

Here's an interesting comparison with the spanish flu of the early 20th century. I think there are some similarities.

http://www.rense.com/general63/ebola.htm

ProfessorPlum · 09-10-2014 10:50PM

realweirdo wrote: »

I think miss no stars has explained this amply. Its the temporal issue that is key along with the fatality rate and the life expectancy of infected patients.

I am sure miss no stars will also concur that the fact that fatality rate is relatively low for this outbreak of ebola makes it even more serious than previous outbreaks. It possibly has a longer encupation period as well.

Here's an interesting comparison with the spanish flu of the early 20th century. I think there are some similarities.

http://www.rense.com/general63/ebola.htm

Yada yada. It's just not the point the two of you were arguing though. Was it?

miss no stars · 09-10-2014 10:51PM

ProfessorPlum wrote: »

Ohh hold on there - major shifting of goal posts!

You said that R number was useless when talking about how contagious a disease was, and despite it's R number of 2, that Ebola was a highly contagious disease. Which it's not.
Now you're bringing in mortality, which has nothing what so ever to do with contagiousness. Nothing.
And assessing risk - nope, you hadn't mentioned that either.

Nobody is saying Ebola isn't a highly dangerous disease - that just wasn't your argument in the first place.

No, I said it was useless when you refuse to consider time spans.

ProfessorPlum · 09-10-2014 10:55PM

miss no stars wrote: »

No, I said it was useless when you refuse to consider time spans.

So please explain your assertion that it is highly contagious, given it's R number of 2 vis a vis Measles, which has an R number of 18, and is infectious in a similar time frame.

realweirdo · 09-10-2014 10:57PM

ProfessorPlum wrote: »

Seriously, not the point. Where is the brick wall.:(

To put it bluntly, yes ebola, particularly this version is highly contagious. The temporal issue is still the key, but somehow I doubt you will ever grasp this concept and I'm wasting my time explaining it to you.

As for measles, its not in the same ballpark as ebola, it too is irrelevant. SARs might be a better comparision, but my understanding the fatality rate with SARs was something like 10%.

Another point is, people have an assumption that unless something is airborne such as via a sneeze or cough, its not highly contagious.

The only good way to look at ebola is that people don't really become contagious until they are at a late stage. And when they are at a late stage, most people have the sense not to go near them. However all indications are it is still spreading exponentially in Africa.

WakeUp · 09-10-2014 10:59PM

ProfessorPlum wrote: »

A lot of maybes there, but like I said, always and never are dirty words in medicine!

perhaps they are. though Im just pointing out the fact that the blog article is signed off by Westhoff and his research published in the oxford journal. lest there be any confusion about "conspiracies" or things like that. if you want to argue against his findings please feel free to do so. I for one would be genuinely interested in reading your hypothesis.

ProfessorPlum · 09-10-2014 11:02PM

WakeUp wrote: »

perhaps they are. though Im just pointing out the fact that the blog article is signed off by Westhoff and his research published in the oxford journal. lest there be any confusion about "conspiracies" or things like that. if you want to argue against his findings please feel free to do so. I for one would be genuinely interested in reading your hypothesis.

God, I'd have to have a good trawl thru the paper. Busy trying to get through to these two about the difference between contagiousness and risk, or seriousness or something. I'm sure there's some merit in the research, but generally research that can't (or hasn't) been replicated doesn't get much attention. Maybe it'll get a bit more of a look in now we have this latest outbreak.

Rightwing · 09-10-2014 11:04PM

I know 1 thing about ebola. No one knows f*ck all about it.

Spring Onion · 09-10-2014 11:05PM

Ebola is not highly contagious.

charlie_says · 09-10-2014 11:06PM

This isn't likely to be the end of the world. Ebola is not very infections according to it's R0 value, it's at the lower end of the scale.

If it was airbonrne then we'd be fecked though.

realweirdo · 09-10-2014 11:06PM

ProfessorPlum wrote: »

God, I'd have to have a good trawl thru the paper. Busy trying to get through to these two about the difference between contagiousness and risk, or seriousness or something. I'm sure there's some merit in the research, but generally research that can't (or hasn't) been replicated doesn't get much attention. Maybe it'll get a bit more of a look in now we have this latest outbreak.

I read a bit about R value just now and it was stated that its pretty irrelevant in the actual field, as its based on mathematical models as opposed to real life observations.

A better way of measuring contagiousness is the speed of spread.

A HIV person might infect 1 new person every ten years on average. An ebola victim might infect 2 new people in a week.

In other words ebola (unchecked) always spreads more rapidly than HIV.

Do you at least agree with this statement?

ProfessorPlum · 09-10-2014 11:12PM

realweirdo wrote: »

To put it bluntly, yes ebola, particularly this version is highly contagious. The temporal issue is still the key, but somehow I doubt you will ever grasp this concept and I'm wasting my time explaining it to you.

As for measles, its not in the same ballpark as ebola, it too is irrelevant. SARs might be a better comparision, but my understanding the fatality rate with SARs was something like 10%.

Another point is, people have an assumption that unless something is airborne such as via a sneeze or cough, its not highly contagious.

The only good way to look at ebola is that people don't really become contagious until they are at a late stage. And when they are at a late stage, most people have the sense not to go near them. However all indications are it is still spreading exponentially in Africa.

To put it bluntly, you're clearly confusing yourself.

realweirdo wrote: »

I read a bit about R value just now and it was stated that its pretty irrelevant in the actual field, as its based on mathematical models as opposed to real life observations.

A better way of measuring contagiousness is the speed of spread.

A HIV person might infect 1 new person every ten years on average. An ebola victim might infect 2 new people in a week.

In other words ebola (unchecked) always spreads more rapidly than HIV.

Do you at least agree with this statement?

Statistics generally have little relevance in the field. I still don't know why you're latched on to HIV. Yes I agree ebola spreads faster than HIV.
But it's still not a highly contagious disease!!!!
If it wasn't for the fact that it was so deadly, it wouldn't be a Level 4 agent, and nobody would be bothering with hazmat suits. But that has nothing to do with its level of contagiousness.

ProfessorPlum · 09-10-2014 11:12PM

charlie_says wrote: »

This isn't likely to be the end of the world. Ebola is not very infections according to it's R0 value, it's at the lower end of the scale.

If it was airbonrne then we'd be fecked though.

Oh God, don't do it. Leave now while you can:eek:

realweirdo · 09-10-2014 11:17PM

ProfessorPlum wrote: »

To put it bluntly, you're clearly confusing yourself.

Statistics generally have little relevance in the field. I still don't know why you're latched on to HIV. Yes I agree ebola spreads faster than HIV.
But it's still not a highly contagious disease!!!!
If it wasn't for the fact that it was so deadly, it wouldn't be a Level 4 agent, and nobody would be bothering with hazmat suits. But that has nothing to do with its level of contagiousness.

Ok you know what this is just contradictory! Would you treat an ebola victim without a hazmat suit? Of course you wouldn't! You've just underlined how contagious it is. Good night!

ProfessorPlum · 09-10-2014 11:20PM

realweirdo wrote: »

Ok you know what this is just contradictory! Would you treat an ebola victim without a hazmat suit? Of course you wouldn't! You've just underlined how contagious it is. Good night!

No, I've just underlined how deadly it is (where is that brick wall again:( )

GreeBo · 09-10-2014 11:31PM

realweirdo wrote: »

Ok you know what this is just contradictory! Would you treat an ebola victim without a hazmat suit? Of course you wouldn't! You've just underlined how contagious it is. Good night!

Yawning is contagious
Cancer is deadly

The two are unrelated

If you get a contagious, deadly thing it's a problem.

ceadaoin. · 10-10-2014 12:01AM

Here is an interesting illustration detailing the measures needed to stop the epidemic in west Africa

http://apps.washingtonpost.com/g/page/national/ebola-by-the-numbers/1366/

It's going to be a long road by the looks of things.

Meglamonia · 10-10-2014 12:20AM

What are the chances of it mutating and becoming airborne?

WakeUp · 10-10-2014 12:22AM

the_monkey wrote: »

Can everyone who thinks the world is about to end please read this :

http://www.theguardian.com/commentisfree/2014/oct/09/ebola-highly-contagious-virus-myths-outbreak-epidemic

Now go back to worrying about those men in white vans driving around the country trying to abduct our kids ...

I dont think the world is going to end but I wonder how long this James Ball chap has been studying the virus. he looks about 12. and from what I can see has no medical qualifications. he isnt qualified to be making such statements. in August he declared the outbreak to be linear, among other things, and not exponential. he got that wrong. and you dont need to be a virologist nor an epidemiologist to know and spot an exponential curve. Im sure he had a look at some charts. or maybe he didnt. didnt matter anyway.

__________________________________________________________________

If I may interject into the "r" discussion. they are based on mathematical models as people have pointed out. for them to be "accurate" you need accurate information on the ground. and I dont think we have that at the moment. this might be of interest to some.

As increasing numbers of outbreak generations were used, best fit R0 estimates and estimates of d declined (Figure 1). We identified no abrupt surges in d that simulations suggest are indicative of multi-wave outbreaks 1 . There was a range of combinations of R0 and d that provided approximate fits to observed case counts, but RMSD was lowest, by an order of magnitude, for R0 values close to 1.8, and d values close to 0.01 (Figure 2). Our best fit model identified Ro as 1.78, and d as 0.009. Cumulative model case counts were projected to be 2435 as compared to 2473 observed cases (Figure 3).

Based on these parameter values, and in the absence of increase in d as a result of intervention, the outbreak would be projected to have caused over 25,000 infections by the end of 2014. A peak in the epidemic would not occur until April 2015, and continue until mid-2016, with a final size greater than 140,000 cases. However, epidemic size and duration are projected to be extremely sensitive to incremental increases in the size of d. For example, a September 2014 increase in d by 0.005 (to 0.014 rather than 0.009) would diminish the projected epidemic size to < 10,000 cases, with incidence steadily diminishing rather than increasing in the coming months.

Using a simple, two-parameter mathematical model, we find that the initial growth characteristics of the 2014 West African Ebola epidemic to be similar to those associated with prior Ebola outbreaks. Concerning is the lack of control evident, with epidemic processes growing in an essentially uncontrolled exponential manner, particularly in Liberia. While further data will permit model validation or re-calibration in the coming months, our findings indicate that this epidemic represents a public health emergency which has the potential to grow to extraordinarily destructive dimensions. We hope our model will add support to those voices already calling for an extraordinary international cooperative effort to control this epidemic.

http://currents.plos.org/outbreaks/article/obk-14-0036-early-epidemic-dynamics-of-the-west-african-2014-ebola-outbreak-estimates-derived-with-a-simple-two-parameter-model/

until we start getting accurate information on the ground its hard to fully know what is going on or which way its going to go.

DarkyHughes · 10-10-2014 12:29AM

The Republican party of America say they have a plan to defeat Ebola. They say we should bomb west Africa & then send large troop numbers in after to police the situation & do some airstrikes around the rest of Africa to stop Ebola from spreading.

Ebola virus outbreak

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