Posted on 04/20/2005 8:50:02 AM PDT by Boundless
An outbreak of the killer Marburg virus beyond
northern Angola is being successfully controlled thanks
to a combination of frontline assistance by international
health agencies and "social mobilization," says
Angola's top health official. ...
... the disease has been mainly confined to the
northern province of Uige, where 277 people have died, ...
(Excerpt) Read more at allafrica.com ...
277 have died!!?? That the ....?
If the the new death count is 277, it is hardly "contained".
Anyone know what the geometric progression chart looks like? What part of the curve are we on?
Seems like quite a jump 235 on Friday to 277 today.
ping
That 235 figure was old then.........I wonder how old this "new" 277 is?
I just went to the source link and read the rest of the article. What a whitewash job this one is. Nothing to see here, move along, and please - whistle this tune while walking past the graveyard.
As of late, figures from WHO and/or CDC are administratively "cooked" - evidently the coverup continues.
That is a growth rate of 2.8% per day.
That is equivalent to an exponential growth time constant of 36 days. If the ratio of deaths to cumulative cases remains .92, then this is consistent with the middle growth curve and a patient lifetime of just over 3 days. The total number of cases should be about 301.
See plot at: Marburg Growth Plot
What is disturbing is that nowhere that I can remember did they ever indicate there were even 277 active cases.
Marburg ping!
> It was 255 on the 17th. So it is 277 three days later.
No. Almost certainly more.
Parse the Clintonish language:
"... the northern province of Uige, where 277 people have died ..."
That 277 may be just in Uige.
Who knows what's happening in the slums of Luanda,
and elsewhere.
Wow!
Excellent point.
Well, one way or another, we are back on an exponential growth curve of something between 9 and 36 days.
Indeed, many of us hypothesized that the data were being "administratively" modified. However, ultimately, they cannot "administratively" change the data forever. Eventually, if this thing is not contained, it is going to grow to a level that they cannot conceal.
I'm still stuck on the observation '...children died 3-5 week, now they're dying 3-5 day..' (paraphrased). There's a number 7 in there somewhere.
Canadian Press
TORONTO — The alarm now sounds with increasing frequency and urgency: the world could be on the brink of an influenza pandemic sparked by the highly virulent avian flu strain ravaging poultry stocks in Southeast Asia, experts fear.
But can that strain -- known as H5N1 -- actually acquire the ability to spread easily to and among people? And if it can, how likely is that dreaded event to occur?
Early in the new year, U.S. scientists will begin experiments that should provide some answers to those questions. In the process, they hope to learn more about why a virus that nature designed to infect migratory water birds has the astonishing capacity to kill mammal species ranging from house cats to tigers to humans.
The work won't indicate how soon a pandemic might start. And the findings can't be taken as a guarantee the virus will evolve as the science predicts.
"Like a lot of science, it's an imitation of nature,'' explains Dr. Frank Plummer, scientific director of Canada's National Microbiology Laboratory.
"It doesn't replicate exactly what happens. But I think it gives you an idea of the propensity of the H5N1 virus to do this thing.''
The researchers, from the influenza branch of the Centers for Disease Control in Atlanta, will mate H5N1 and human flu viruses in a process known as reassortment. Viable offspring will be tested in animals thought to be good surrogates for humans, to see if the viruses can infect, can be transmitted easily from infected animals to healthy ones and to note the severity of disease each provokes.
In other words, the CDC researchers will be deliberately engineering viruses of pandemic potential. It's high-risk but crucial work, the influenza community insists.
"It's a dangerous experiment,'' admits Dr. Robert Webster, a world-renowned expert on influenza based at St. Jude Children's Research Hospital in Memphis, Tenn.
Still, Webster has no doubt the work needs doing. Science must gain a better understanding of the menacing H5N1 virus.
"These experiments are fully justified, knowing what we know,'' he stresses, using a scatological adjective to describe how scared influenza experts are of H5N1.
"This is the worst virus I've ever met in my long career.''
The World Health Organization has been pleading for months for qualified research facilities -- of which there are few -- to undertake this work.
The Geneva-based agency would like to be able to put some kind of odds on how likely H5N1 is to become a pandemic strain and how deadly -- or not -- H5N1 reassortment viruses might be in humans.
If none of the hybrids cause severe disease, the organization might feel comfortable with stepping down its current high level of alert, explains Dr. Klaus Stohr, director of the WHO's global influenza program.
On the other hand, if CDC researchers easily produce highly transmissible and lethal hybrids, "that would certainly add to our concern.''
It's about quantifying risk.
"Currently we do risk-speculation, but we want to do risk-assessment. And that will give us scientific evidence on the possible outcome on the emergence of a pandemic virus,'' Stohr says.
"It will give us an opportunity to predict the probability because we will have an understanding on the number of reassortment viruses which are viable, the percentage of those that are viable which are then transmissible -- and also on the percentage of those which are viable, transmissible and pathogenic. And how pathogenic they are.''
The CDC researchers will work in high containment level 3-enhanced labs, says Dr. Nancy Cox, the leading influenza authority who heads the agency's flu branch. The labs have special features designed to protect both the health of the workers and the world against a viral escape.
"It's not typical level 3,'' Cox says, adding the lab workers are "extremely cognizant of the danger of the H5 viruses.''
"And of course we know we can autoclave these viruses,'' she adds, referring to a process that kills using high pressure and heat. "So if you find something that is particularly worrisome, you can get rid of it.''
Still, lab accidents happen. Since SARS was contained in mid-2003, four lab workers in Asia have infected themselves with the potentially deadly disease and one spread it beyond the walls of the laboratory. Earlier this year, a Russian lab worker died after accidentally infecting herself with Ebola virus.
Given that reality, some groups have raised concern that work like this should not be done. But a top virologist from the Netherlands insists it must be, expressing confidence in the CDC's ability to do the job safely.
"If it's being done by CDC, then the good thing about that is that safety measures will properly be in place,'' said Dr. Albert Osterhaus, of the Erasmus Medical Centre in Rotterdam.
The CDC researchers will mix genes from H5N1 with genes from circulating strains of human flu to see which combinations produce viruses that grow and infect. Cox says H3N2 -- the strain that has been responsible for most human flu in recent years -- will be the first priority.
However, Southeast Asia has recently seen activity with H1N1, the mild modern descendant of the strain that caused the Spanish flu of 1918. So the CDC has been sequencing H1N1 viruses recently isolated in Thailand to be able to work with it as well.
"We're really keeping our minds open. But as long as H3N2 viruses continue to predominate, that will be our first target,'' Cox says.
Reassortment studies can be performed two ways, she explains. Scientists can use reverse genetics, a procedure that allows them to custom tailor a virus with a predetermined constellation of genes from each parent virus.
The other alternative is what Cox describes as the classical way -- simultaneously infecting tissue culture with H5N1 and H3N2 viruses and seeing what results. That approach is more time-consuming and laborious, but more closely mimics evolution of influenza viruses in nature.
"We will probably be using a combination of the two different methods. I think there are advantages and disadvantages to each,'' says Cox, who believes her team may have some preliminary results within a couple of months of beginning the work.
Some skeptics have pointed to the fact H5N1 hasn't yet reassorted to argue it may not be able to do so outside of the artificial confines of a laboratory.
Webster thinks that optimism is misplaced. He calls H5N1 "one of the most promiscuous viruses that we've ever seen. It would amaze me if it wouldn't mate with a human virus, given the opportunity.''
CDC researchers have already made hybrid viruses with H5N1, using versions of the virus isolated after it first caused human infections in 1997 in Hong Kong.
"Some gene combinations could be produced and others were not,'' is all Cox will reveal of that as-yet unpublished work.
Even if, in this new round of experiments, CDC's researchers fail to produce a single viable hybrid virus, that doesn't prove H5N1 won't reassort in nature, experts say.
For one thing, flu viruses are constantly evolving. The viruses that the CDC will work with now -- isolated in 2004 -- are not identical to those from the 1997 outbreak. A combination that fails with the 1997 virus might work with a 2004 virus -- or a 2005 version.
"Things in nature can happen that you can't replicate in the lab necessarily,'' stresses Plummer, whose lab is working on producing reassortments of H7N3, the strain behind last spring's avian flu outbreak in British Columbia.
"Can you be sure that all possible virus reassortments have occurred? No. And fairly minor changes in viruses can make really huge differences in their biologic properties.''
Wow ... I can't remember seeing more political correct words and phrases in one place at the same time ... I think the only thing they missed was "empowered" ... I didn't see anyone getting "empowered".
Perhaps I just missed it.
The numbers seemed to have slowed down considerably since they "administratively" "re-classified" a lot of things.
But no worries now.
It's over. Right ... pats on the back all round.
LOL.
That is too funny.
Given the seriousness of this, I don't know whether to laugh or cry.
That story makes me nervous.
I know we were at 237 yesterday, with 500+ under observation...when did it jump to 277!
We know their hiding people and numbers, how does that affect the curve? 40 more people died or 40 more people were finally accounted for?
We know their hiding people and numbers, how does that affect the curve? 40 more people died or 40 more people were finally accounted for?
See the posted article. It was reported as 277 effective today.
As to your second question... I don't know, but we can all speculate. I suspect that they have been hiding the numbers, however, they cannot effectively hide the number of deaths. So, they "administratively re-classify" the data and it looks like the growth has stopped. But eventually, the death rate catches up with them and it continues to grow.
To me, the significant aspect of this posted article is the data that are missing, namely the number of cumulative cases. It should nominally be well over 300 now, considering the .92 factor and also that the 277 deaths was in Uigi exclusively.
IMHO, the way to do the analysis now is to use the available data and model to bound the possible solutions for the growth curve. Namely, the growth is exponential, but not as fast as a 9 day e-folding time, but faster than the 108 day efolding time. As the data continue, we will be able to tighten the bounding values toward a reasonable answer.
OK, I have re-run the data using your correction.
It was 237 deaths in Uigi 3 days ago and 277 today. (If I have that wrong still, someone correct me).
That corresponds to exponential growth and an e-folding time of 19 days.
We are seeing data that range from 9 days to 108 days.
However, we can conclude the following:
1. It is still growing exponentially.
2. It is obviously not contained.
3. The exponential time constant is probably not as fast as 9 days, nor as slow as 100, and is beginning to converge to a nominal number of roughly 20 days.
The approximate growth (I'll wait before I replot) is:
May 1: 550 cumulative cases
June 1: 2,605 cumulative cases
July 1: 12,272 cumulative cases
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