Ok, so the CDC has confirmed..and other things!

[Giovanni Maga]

In article
<Pine.A32.3.91.950513184141.54432E-100000 at freenet3.freenet.ufl.edu>,
Vampire Junction <vampires at freenet.ufl.edu> wrote:


'You have a virus that over a 20 year period of time has 
> remained relatively intact' said CDC spokesman Bob Howard.    That in 
> itself is puzzling, because viruses such as Ebola are highly unstable and 
> prone to mutate. 

I don't see why Ebola should be *in principle* so highly prone to
mutate...they have just one round of RNA transcription by a viral RNA
polymerase to produce (+) strand and an additional round to produce new
genomic (-) strand. No retrotranscription/integration/excision events which
could contribute to mutation. Has the mutation rate already been tested? It
is not carrying segmented genomes, just one (-) strand, so recombination is
also unlikely (am I wrong?) Nevertheless, the 1989 Reston strain was
similar to the 1976 Sudan strain (source: J.Clin.Path., 43:813), indicating
that even viruses with a different host specificity are similar, thus not
mutating so fast.

Has the Yambuku virus been biding its time for 
> nearly 20 years, incubating in living creatures such as mosquitoes or 
> pigs, only to erupt once again now in humans?"

It is possible (I think very likely) that some natural reservoir allowed
the virus to persist during this period and then a new occasional contact
of this vector (maybe related to changes in the enviroment like climate,
humidity, food, competitors that pushed these vectors away from their
natural area to try to colonize a new one) with humans spread a new
infection. The dynamic and ecology of Ebola infections are not known, so we
can only speculate about this long lag time between infections.

 Anyway, what i want to know, is if this epidemic is getting under contral 
> like the CDC says, why did they have to put a quarantine zone *120 miles* 
> around Kitwit.  Isn't that a little much for a disease that they say 
> hasn't killed very many people, and isn't *that* contagious?  They didn't 
> put up that big a quarantine last year in India during the Bubonic Plague 
> outbreak.  

the pneumonic plague was caused by  bacteria (Yersinia sp. I guess) which
means that it could be efficently controlled by antibiotics. If such an
outbreak have occurred in developed countries, there would have been no
epidemic at all. In India the available antibiotics were the limiting
factor, thus there was no need for an extensive quarantine, just for a
widespread prophylaxis. 


What's the deal here, are we being screwed by the CDC and 
> WHO?  Why do I have the feeling that half the know poulation of the world 
> would have to die before they'd admit something was wrong?  I'm sorry, 
> but I just don't buy what they're trying to feed us.
> ---Candy


I sincerely hope to be in the second half, in that case...stop bullshitting
such paranoid theories please, CDC and WHO are not trying to bribe us (I
would recall you that MDs and Biologists out there are putting their lives
at risk in order to face the infection for YOU also).
maga at vetbio.unizh.ch