[sci.med.aids] life cycle, methods of infection

gregs@uunet.UU.NET (Greg Strockbine) (05/22/91)

I have a couple of questions:
	* can someone tell me the life cycle of a virus in general,
	  does it also apply to the aids virus?

	* regarding methods of infection, is it safe to perform fellatio
	  up to the point of ejaculation?  In particular, there is a
	  clear, sticky fluid that comes out of the penis before ejaculation,
	  could this also carry the aids virus? 

	* does stomach acid kill the aids virus?  This might sound
	  silly but I have a friend who is an occasional prostitute
	  and makes this claim.

	* regarding my friend, her clients are exclusively well to do
	  men she is referred to thru friends, she sees them about 
	  once or twice a week.  Obviously she is not in the same risk
	  category as a woman who works the street, but can we say
	  anything about her risks?

	* is it easier for a man or a woman to contact aids?

I appreciate any feed back anyone can give me on these questions.
	thanks, greg s.

bwoodman@magnus.acs.ohio-state.edu (Robert H Woodman) (05/23/91)

In article <1991May22.110023.27019@cs.ucla.edu> decwrl!well.sf.ca.us!well!gregs@uunet.UU.NET (Greg Strockbine) writes:

>I have a couple of questions:
>    * can someone tell me the life cycle of a virus in general,
>      does it also apply to the aids virus?

     The AIDS virus (HIV) is a retrovirus.  Its genetic information is stored
by RNA rather than (the normal) DNA.  DNA viruses have the following,
generalized life cycle:

(1)  Attachment to the cell.

(2)  Injection of the viral DNA into the cell.

(3a) Takeover of cellular functions by the virus to begin producing massive 
     numbers of viral particles.  Cell death quite often results from this.

(3b) Integration of the viral DNA into the genome of the cell.  The virus
     enters a quiescent phase, and may stay this way for a long time, but
     shock to the cell can trigger (3a).  An example of this is the herpes
     virus, such as causes fever blisters.

(4)  Release of virus particles into the environment around the cell, where
     new rounds of infection may then occur.

     With HIV, steps (1) and (2) are the same, except that "DNA" is changed
to "RNA" for HIV.  With infected T4 cells, the attachment point is the CD4
antigen on the T4 surface.  Between steps (2) and [(3a) or (3b)], a step must
be introduced in which transcription and translation of the HIV genome occurs. 
The reverse transcriptase of HIV then converts the HIV RNA to DNA, thus
allowing either integration of the DNA into the genome or production of many
new viral particles.  Recent research has shown that, with HIV, step (3a)
occurs for awhile, until many cells are affected, and then the virus enters a
quiescent phase for a period of time.  It re-emerges later with devastating
effect.

     Please note that, though I am a molecular biologist, I am not a
virologist, so I am presenting only a generalized picture, and not the
specialized view held by people who work with this all of the time.

>    * regarding methods of infection, is it safe to perform fellatio
>      up to the point of ejaculation?  

     No.

>      In particular, there is a
>      clear, sticky fluid that comes out of the penis before ejaculation,
>      could this also carry the aids virus? 

     Yes.

>    * does stomach acid kill the aids virus?  This might sound
>      silly but I have a friend who is an occasional prostitute
>      and makes this claim.

     Yes, stomach acid can kill HIV, but the efficacy varies, and relying on
this is damn stupid.

>    * regarding my friend, her clients are exclusively well to do
>      men she is referred to thru friends, she sees them about 
>      once or twice a week.  Obviously she is not in the same risk
>      category as a woman who works the street, but can we say
>      anything about her risks?

     She is high risk.  Period.

>    * is it easier for a man or a woman to contact aids?

     Male-to-male transmission and male-to-female transmission has been shown
to occur quite readily, while female-to-male transmission *does* occur, as has
been convincingly shown, but is much less easy than m-m or m-f transmission.

>I appreciate any feed back anyone can give me on these questions.
>    thanks, greg s.

You're welcome.

Bob Woodman

-- 
*********************************************************************
*Robert H. "Bob" Woodman, PhD * "A job not worth doing well is not  *
*INTERNET:  woodman.1@osu.edu *  worth doing."--Salvador Luria      *
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cc_s470@kingston.ac.uk (Chris Eborn) (05/29/91)

In article <1991May22.110023.27019@cs.ucla.edu> decwrl!well.sf.ca.us!well!gregs@uunet.UU.NET (Greg Strockbine) writes:
[stuff deleted]
>	* regarding methods of infection, is it safe to perform fellatio
>	  up to the point of ejaculation?  In particular, there is a
>	  clear, sticky fluid that comes out of the penis before ejaculation,
>	  could this also carry the aids virus? 
[stuff deleted]

	I know that there have been several replies to this posting
already, however, several of these referred to *oral sex*. Is the risk
the same for fellatio and cunnilingus? Does the risk increase
significantly for cunnilingus during mmenstruation (or, to rephrase the question,
what are the risk factors associated with the various bodily fluids)?
The (government) agencies in England seem to class oral sex as `low
risk', I cannot remember hearing about the risk factors associated
with rimming.

-chris
-cc_s470@king.ac.uk