To: virology@net.bio.net
From: maga@vetbio.unizh.ch (Giovanni Maga)
Subject: EBOLA-READ ME-FAQ-SERVER

Dear posters,
													in an attempt to reduce the OVERLOAD of basic informations
(and misinformations) about Ebola that is currently limiting the use of
this list for its original pourpose (I want to recall that it is a bionet
group, thus primarly devoted to the exchange of scientifc informations
between professionals virologists) I would like to point ALL OF YOU THAT
ARE INTERESTED IN GENERAL INFORMATION ABOUT EBOLA AS WELL AS ABOUT THE 1995
OUTBREAK IN ZAIRE to an excellent www server reachable by http maintained
by Stephen Spencer at the National Institute for Molecular Virology. The
addres is:

HTTP://WWW.BOCKLABS.WISC.EDU for general info and
HTTP://WWW.BOCKLABS.WISC.EDU/OUTBREAK.HTML for 1995 Zaire outbreak daily
updates

While there, I would suggest to have a look to the many SCIENTIFIC
informations therein, which are very useful for both professionals and not.
Thanks to everyone who will try to reduce the misuse of this group by
looking for alternative and more appropriate sources of informations.
G.Maga
maga@vetbio.unizh.ch


To: virology@net.bio.net
From: maga@vetbio.unizh.ch (Giovanni Maga)
Subject: Re: Mosquitoes, etc. as infection vectors?

In article <3p38dl$2dl@portal.gmu.edu>, tvalesky@site.gmu.edu (Tom Valesky
(CS 555)) wrote:

> Question from a layman:
> 
> Malaria spreads through mosquitos. Sleeping sickness spreads through
> tsetse fly bites. Why haven't mosquitoes, biting flies, etc., become
> infection vectors for viral diseases like Ebola and AIDS?
> 

The ability of a virus to survive in an intermediate host depends on many
factors. Basically, if the virus/host relationship is satisfactory (i.e.
allows infection, replication and spreading of the virus) without the
intervention of an intermediate host (the so-called vector), thus there
will be no selection for viruses able to survive in the vectors.
Enviromental changes as well as fluctuation of the host population could in
principle create those conditions which favour the selection of a virus
able to propagate itself through a vector. The fact that HIV does not have
this route of transmission means that in the natural hystory of the virus
it was never an advantage to spread through vectors. Possibly, all the
putative vectors with whom HIV was in contact (e.g. blood-sucking
mosquitos) were not permissive for HIV survival. BTW, being HIV infected
people long-survivors to the infection, they are the best vectors for the
virus, since they have more than enough time to spread it to other people.
There are anyway many examples of viruses passed to men by animals (not
necessarly bugs). Ebola itself could be considered a zoonotic infection,
since the virus seems only occasionally infecting humans, which are not its
natural hosts. The existence of a vector (kind of unkown) for Ebola
transmission to humans in my hopinion is very likely.
Regards, G.Maga
maga@vetbio.unizh.ch


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