[sci.med.aids] F->M HIV transfer

DOUG%YSUB.BITNET@oac.ucla.edu (Doug Sewell) (11/17/89)

How vulnerable is a male to contracting the HIV virus from a female
sexual partner ?  Is circumcision (or lack thereof) a factor ?  Is
there a feel for the percentage of cases where females transferred
the HIV virus to their male partners ?

Doug

rwright@gatech.edu (Ronald K. Wright) (11/19/89)

DOUG%YSUB.BITNET@oac.ucla.edu (Doug Sewell) writes:

>How vulnerable is a male to contracting the HIV virus from a female
>sexual partner ? 

All of the above questions are subject to great dispute for several
reashons.  First, this is a sexually transmitted disease and people
are less than candid about their sex practices.  Also they exaggerate
in both directions, depending on whim and to whom they are conveying
the informtion.  Second, this is a disease with an average
"incubation" period of 10 years but which can appear in as little as
two.  Thus you have to deal with asking people who they have had sex
with for a period of 10 or 15 years before 1987, covering say 77
through 87.  
Direct experimentation is not ethical.  There is no good animal model.
There is great importance, I think, of infection by Herpes, Yaws,
syphlis and maybe gonnorhea.  
In third world countries F>M appears very high.  In US and Europe only
amongst drug users.

>Is circumcision (or lack thereof) a factor ? 

In my view, too early to tell from data available.  You have to adjust
for socio-economic status.  Not doing so would say circumscision is
important.  I doubt it though.

>Is there a feel for the percentage of cases where females transferred
>the HIV virus to their male partners ?

See answer one.  Also, most collectors allow only one risk group.
The following questions are for a male.
Question one, have you had sex with a man since 1985?  If the answer
is yes that is all of the questions, usually.  The male is then 
homosexual/bisexual.
Question two, have you used illegal drugs?  (most inquiries seem to 
ignore route of administration)  If the answer to that is yes then
the person is "drug user" or more commonly "IV drug user"

With data collected this way, I am highly skeptical that we can find
much out about the transmission from it.

-- 
R. K. Wright MD JD                     | office: medexam!rkw
Chief Medical Examiner, Broward County | nova:   novavax!rwright
Associate Professor Pathology          | home:   medexam!love1!rkw
University of Miami School of Medicine | fax:    305 765 5193

chet@retix.retix.COM (Chet Mazur) (11/22/89)

The risk from M->F x'fer seems to be the same as for F->M. This is
based on research in Africa, where the majority of PWA's are
heterosexual and you don't see a disproportionate amount of females
infected (implying M->F is riskier) or vis-versa.

As for being uncircumcised, this does put you at greater risk (again
based on African research).... The reason is not known (yet) but it is
suspected that the unretracted foreskin provides a great place for the
virus to live (warm, dark, moist). Also the "un-cut" penis is much
more sensitive and therefore subject to abrasion; with this allowing
transmission.