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Miscellaneous thoughts and ramblings
Friday, April 29, 2005
Heterosexual HIV Transmission
A good friend of miine, who is a doctor (wink wink), told me years ago that HIV transmission from straight sex was exceedingly rare, if nonexistant. The lack of a widespread epidemic in the non-needle-using, non-hemopheliac, heterosexual community in the Western World, despite promises of such an epidemic for the past 20 years, has been something which I felt confirmed his words.

Yet we're told that, in Africa, the massive epidemic which DOES exist is largely the result of transmission through straight sex. This has just never sat well with me on a common sense basis. I dug up this article, which broaches the subject:

Michael Fumento: The African heterosexual AIDS myth


The chief reason it’s so hard to spread HIV vaginally is that, as biopsies of vaginal and cervical tissue show, the virus is unable to penetrate or infect healthy vaginal or cervical tissue. Various sexually transmitted diseases facilitate vaginal HIV infection, but even those appear to increase the risk only slightly.


Yet almost certainly greater – and more controllable – contributors to the African epidemic are “contaminated punctures from such sources as medical injections, dental injections, surgical procedures, drawing as well as injecting blood, and rehydration through IV tubes,” says Brody.

There are many indicators that punctures play a huge role in the spread of African HIV/AIDS. For example, during the 1990s HIV increased dramatically in Zimbabwe, even as condom use increased and sexually transmitted infections rapidly fell.

Or consider that in a review of nine African studies, HIV prevalence in inpatient children ranged from 8.2% to 63% – as many as three times the prevalence in women who’d given birth. If the kids didn’t get the virus from their mothers, whence its origin?


I'm curious is the our resident physician has any further thoughts on the issue, gleaned from his years in practice (and attending medical conventions). Bean, feel free to add any important thoughts to this post, as opposed to in the comments section.
The majority of HIV cases are from heterosexual transmission.

See here.

It's much more of a contributer outside the US. Personally, the majority of cases I see are from homosexual or IV drug transmission, but I do see the occasional spouse.
The numbers you just directed me to don't appear to support your conclusion.

I'm looking at a table which is linked to from the study you just linked to, and I'm getting:

36K HIV diagnoses through heterosexual transmission versus 66K diagnoses through nonheterosexual transmission. Ballpark then is 2/3 of all HIV diagnoses were not from heterosexual transmission.

Given the large discrepancy in numbers between the population sizes, hugely larger heterosexual non-IV-drug-using population, this would indicate that the means of transmission via non-heterosexual contact is vastly more efficient.

With sex being sex, I'm not understanding how heterosexual sex would become so much more efficient in Africa than it apparently is in the United States.
Sorry, I meant the majority worldwide.
Of course, given the high number of AIDS cases in Africa, if the transmission there is being misunderstood, it would skew the worldwide numbers.

Viruses aren't very opinionated. They behave fairly predictably. I have yet to hear an adequate explanation for why HIV would be transmitted one way in an African population, but orders of magnitude differently in an American one.

One could theorize that condom use among American heterosexuals (but oddly not homosexuals??) could account for some of the difference. An interesting test of that theory would be comparing the rates of other STDs traditionally transmitted by vaginal sex between the African and the American populations. Not that I have the time to do that now, but I'm throwing it out there.
My understanding of the transmission of HIV in the US has evolved. There was always a little heterosexual transmission in the US but almost always from man to woman, almost never the other way around. I used to tell patients that in the US to contract HIV you had to belong to one of these groups:
1. men who have ever had sex with men
2. men or women who have ever injected drugs or had a blood transfusion in th 80s
3. women who have had sex with men in groups 1 & 2 (here's the heterosexual transmission)
4. babies born to women in groups 2 & 3
The point is that this list does NOT include men who have had sex with infected women.

I used to say that there were more men diagnosed with breast cancer than men who acquire HIV from sex with a woman. I can't say that anymore. In the last several years, the number of cases acquired heterosexually has been increasing, particularly among minorities. The CDC statistics that Psychotoddler links to (thanks!) are helpful. About a third of new infections are considered to have been transmitted heterosexually and a third of those (or 1 in 9 of all new cases) are men who acquired it through sex with women. It's certainly a small number but not nonexistant. I have to think that the numbers for heterosexual transmission are inflated, though, since they partially depend on self-reported behavior and since they are highest in minorities in whose communities' anti-gay stigma is greatest.

I see a lot of patients who are at very low risk for HIV who have been scared by the media hype. I try to put the risk in perspective but always tell them that there are a lot of other good reasons to use condoms (pregnancy, herpes, syphillis...).

The numbers in Africa seem to tell a similar story. The Fumento article that you link to doesn't argue that there is NO heterosexual transmission. It argues that the fraction of cases transmitted heterosexually is at most a third (similar to US figures), not 99%.

(the end)
Nomad: Once I wrote my reply it was so long that I thought it was better in the comments after all. Worse still, the length of my comment exceeded my Treo's clipboard limit, so I had to post it as 3 comments. Sorry.
One side effect of all of this is, of course, that when you go to give blood they ask questions that make you giggle.
I was looking at your posts about cancer stomach and found a good article about the same cancer stomach info too...

God luck with it : )
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