Marburg Surveillance Project

Various ^ | May 4, 2005 | Vanity

[Judith Anne]

Welcome to the Marburg Surveillance Project.

This thread will be used for all of the latest Marburg Outbreak News and comments. This is the place to post all comments about the Marburg outbreak, all articles and links to articles about the Marburg outbreak.

We're going to use just one thread instead of having to go from article to article as we have in the past. We'll use this thread as long as we can.

[Doctor Stochastic]

Have the Angola government explained what they mean by "administrative reclassification"? Do they mean that someone died but they now don't think it was due to Marburg? Are they just trying to keep the toursts from panicking?

[Oorang]

Thank you for taking the time to post the information and your thoughts. Your efforts are appreciated.

[Judith Anne]

No, no official explanation has been given. If I recall correctly, the administrative reclassification removed cases outside of Uige province and cases which had not been laboratory proven to be Marburg.

It was done to keep business contacts and whatever tourism there is from abandoning the country, in my opinion.

History has taught Africans to believe the dangerous fallacy that Marburg "burns itself out" because it's too hot a virus. Clearly, when it erupted in small rural communities and killed everyone quickly, that was true.

However, this time Marburg has arisen in a city. No way to burn itself out, the fire has too much fuel, so to speak.

[Doctor Stochastic]

The epidemiology doesn't indicate fleas, or mosquitos, or dogs or such does it? I would think that most of the usual patterns were well known and Marburg just doesn't follow one. Randomly generated-year locusts?

[Dog Gone]

Very few people vacation in Angola, although they do have a tourism industry.

If they're protecting anything, it's the oil industry. The offshore drilling and production activity is far bigger than you may realize and it's the lifeblood of the government.

Unfortunately, it's mostly run out of Houston, Texas.

If this virus gets loose in Luanda, all hell will break loose on several fronts.

[Judith Anne]

The reservoir and initial vectors are unknowns. CIDRAP, if I recall correctly, said that insect transmission is possible, but at present is an unknown. They mentioned arthropods, mosquitos and flies.

Ticks, fleas and mosquitos and flies potentially could carry Marburg. Also, microscopic aerosolization is possible. Again according to CIDRAP, it takes 5-10 virions to cause infection when inhaled deep into the lungs--literally an infinitesimally small amount.

[Judith Anne]

Two direct round-trip flights to Houston from Luanda each week, as another poster informed us.

[EBH]

Bookmark

[Judith Anne]

Apparently, most US oil workers rarely spend any time actually in country, except for the airport, if I am correct.

Angola exports to the US 4% of our oil. Doesn't seem like much till you think about it...it is by far Angola's largest industry, with diamonds a distant second.

[xVIer]

Thank you for all the effort that obviously went into that piece!
I will have to reread it again to take it all in, however I find what you said to be alarming because you seem to be one of the more skeptical among us!
Thanks again for your valuable perspective.

[blam]

"Containment is not working. We are at the 3rd or 4th chessboard square."

This is seriously troubling. Thanks for all you work...you're one sharp guy.

[Doctor Stochastic]

Am I correct in assuming that your computations in this post are for a single infected person?

A similar result would hold for a population but the geographical variation in food-density (people) would add complications. Even a virus outbreak such as Marbug may die out by killing all its infectees. This justifies quarantine.

Of course, treatment (of a single individual assuming your results) could consist in (if possible) slowing the virus growth, increasing the immune response, changing the "environment" so that the definition of fittest changes. Maybe this isn't possible in practice.

[Dog Gone]

Actually, I was that other poster.

Technically, they are charter flights and you have to be an oil company employee or consultant to book a seat.

An infected Angolan with no connection to the industry can't simply book a direct flight to Houston. An infected American oil employee certainly can and probably would.

It's probably a moot point. There are plenty of flights from Angola to South Africa with connections to the US. If Marburg arrives at a US airport, though, the passenger will have come from Luanda.

[Steelerfan]

For obvious reasons, I hope you are wrong but thank you for the analysis.

[Dog Gone]

Apparently, most US oil workers rarely spend any time actually in country, except for the airport, if I am correct.

That's the case for nearly all of the passengers on those flights, but the oil companies do have offices in Luanda with permanent staff who occasionally travel back to Houston.

[Doctor Stochastic]

The reason that the total number (current) doesn't matter is that the main growth is in the future. Cutting the current number of infections (or the number at any time) by 1/e gives only a 40 or 93 day delay to total annihilation of the human race. Of course, if the rates are really half-lives, we get another month to live

[infominer]

I agree with 2ndreconmarine - " I'd like to suggest that we run this current topic to ground before we move to the next thread."

2dnreconmarine,

I understand the basis of your analysis and your pretext for assumptions on the RNA mutations. This process brings me back to a question I posed to Kelly_2000 sometime back (on post 1322) about the VP40 matrix protein. It appears there is a lot of research going on about how the VP40 matrix protein for Marburg (and Ebola) are causing (allowing) the virus to more effectively penetrate the host cell walls and replicate. From the research I have read, it seems that this is a continuing processes in the evolution of Marburg that is increasing its virility.

As a side note, one of the the hemagglutinin proteins of the H5N1 virus is mutating in with a similar mutation causing (allowing) the virus to more effectively penetrate the host cell walls. This is one of the things that appears to have the epidemiologists on edge.

Now I know that this outbreak is Marburg but, as Kelly_2000 pointed out to redoglum in post 1217, in part, "...it is Marburg and something entirely new." In this frame of reference then retreating back to the original report of the outbreak it was children under 5 with the first lab confirmed cases of Marburg.

Fast forward to the frame of reference as to the probability of containment. Since the first signs of the outbreak occurred in October 2004 how many cases infected others before knowing it was Marburg? This is, essentially, a rhetorical question. However, if I understand your modeling correctly it appears to fit your modeling represented by Figure D.

[Doctor Stochastic]

Thanks. It seems that if one knows nothing, reclassification doesn't help.

[2ndreconmarine]

Am I correct in assuming that your computations in this post are for a single infected person?

Yes. However, it also indicates the nature of the population distribution for the next infected person.

A similar result would hold for a population but the geographical variation in food-density (people) would add complications. Even a virus outbreak such as Marbug may die out by killing all its infectees. This justifies quarantine.

Absolutely yes!!!!!

Of course, treatment (of a single individual assuming your results) could consist in (if possible) slowing the virus growth, increasing the immune response, changing the "environment" so that the definition of fittest changes. Maybe this isn't possible in practice.

First two might be possible, I don't know. You would need to ask Kelly_2000 or someone with that expertise. I don't believe the third one is possible: growth rate and survivability is the definition of "fittest".

[Judith Anne]

Actually, I was that other poster.

LOL! I knew it was somebody I knew! ;-D

Thanks for the recap, I appreciate it. My scenario for Marburg's arrival in the US was the diplomatic route to the UN, by an infected Angolan...