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From: rds@cbnewsj.att.com
Newsgroups: sci.med.aids
Subject: Re: (2775) a question
Summary: another question based on that question?
Message-ID: <1990Dec4.221753.18559@cs.ucla.edu>
Date: 4 Dec 90 18:49:45 GMT
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In article <1990Dec2.232631.3753@cs.ucla.edu>, ST602662%BROWNVM.BITNET@oac.ucla.edu (Bill Jesdale) writes:
> In answer to the question of how dangerous are various exposures
> to bodily fluids of HIV infected persons:
> 
> First, we do not know.
> Some estimates are given by two recent articles in the Annals
> of Internal Medecine (15 Nov 90).
> 
> Article 1) Infection with HIV-1 among Recipients of Antibody
>            Positive Blood Donations.
>   This study found 133 recipients of blood which was later found to
> test positive for antibodies to HIV. After excluding 9 with other
> high risks, they found that 111 out of 124 blood product recipients
> without other high risks themselves tested positive to antibodies.
>   So, for a direct innoculation of a large amount of HIV+
> blood directly into the blood stream, they estimate that the risk
> of subsequent infection is around 90%.
> 
> Bill Jesdale, ST602662@BROWNVM             I need a job.
> Box 5342, Brown U, Prov RI 02912. Ph: 401/863.4402

This posting makes me submit these questions again for the third time.
No one has taken a stab at them yet. The question being why certain
people who have been exposed to tainted blood don't get Aids.

The relavent lines from the previous posting: 

>  The moral of the story:  where it goes is more important than where
>it is.  Direct blood to blood or semen to blood contact is required.
>VERY large inocculum doses are required.  You are not at risk in 
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>any way from even intimate contact.  Only a very few activities 
>can transmit HIV.  HIV is very very hard to get for most people.
 
This is the third time I've seen this notion of quantum referred to 
in sci.med with regard to HIV transmission.
The first time was by Craig Werner in an informative
article concerning the improbability of AIDS transmission by mosquitos.
At that time I simply accepted the explanation without any feel 
as to the details of what makes it true. Now I'd like a feel for it.

I assume its theoretically possible for a single piece of
infectious HIV to eventually infect a person, given ideal 
conditions. But this "large dose requirement" suggests it unlikely.
I assume the "quantum threshold" varies between individuals.

Is it simply a matter of probability, as in the case of the number of
sperm required to fertilize an egg? If so what pitfalls might HIV
encounter? 
Does the "quantum model" require that some HIV DNA naturally break-
down due to age/entropy?
Perhaps the virus needs to adjust, to say, certain body chemistries?
Are there any attack mechanisms in the body that are actually successful
at first, perhaps taking a toll on the virus initially but then, I guess,
gets overwhelmed? 
Is the probability low because the space between cells is large as in the
model of atoms where valence shells are relatively far?

Maybe these questions can be answered in a few sentences (general virus 
rules?). But if there are 
a multitude of reasons, and someone has the knowledge and inclination, 
can a simple model be looked at to assign weight to the various factors.

Lets say 100 pieces (or 10^3,4,...n) of infectious HIV has entered a host's
blood stream and are now looking for host cells. Assume this level is below
the minimum required level that make quantum notions valid.
Now whittle down the numbers to 0 by proportionally assigning probable
HIV losses attributed to each hostile factor.

ANY VIROLOGISTS OUT THERE????

                              Sincere Thanks
                               Bob Sudano