Flutterby™! : partner count and HIV rate 2007-09-16 21:37:42.678545+00

partner count and HIV rate

2007-09-16 21:37:42.678545+00 by Dan Lyke 7 comments

Number of partners doesn't explain gay HIV rate:

In fact, two surveys found that most gay men have a similar rate of sex with unprotected partners compared to straight men or women.

So it's likely unprotected anal sex that's largely the culprit. (via)

Having not read the original, it is impossible to know what has been lost between the research and the translation into the news media. But as background, this has been well known since the late '80s.

Heterosexual penile-vaginal sex has an extremely low rate of HIV transmission. Early estimates of heterosexual transmission were made in married couples where the male was infected by HIV tainted blood products for the control of hemophilia. At that time, the guesstimate for positive male to female transmission was 1 in 500 acts of unprotected acts of vanilla intercourse. Female to male transmission is much more unlikely. The risk for transmission in unprotected homosexual anal intercourse is believed to be about 1 in 9 for the anal receptive, if the penetrating partner is positive.

I have no knowledge of what the risk would be for unprotected male/female anal sex. Even that might very well be different than for gay men. Gay men have a very different immunological profile than heterosexuals because of the overall infection path provided by anal intercourse.

I have seen a couple of papers that hypothesized an ability to determine if a man was actively homosexual just by the diseases which he had. Examples would include CMV (cytomegalo virus) and the Hepatitis viruses A through G, the HPVs, Epstein-Barr, etc. These, and many other disease are much more likely to occur in those who practice unprotected anal sex, or have other types of sex with those who practice unprotected anal sex with high risk individuals. HIV transmission is believed to be enhanced in those who are syphilitic. While there are specific reasons why syphilis would enhance transmission, it is probably reasonable to expect that other diseases would also increase the likelihood of transmission and/or cause infection.

One way of quantifying the infectivity and contagiousness of any disease is to look at the length of the infection chain in a population or a subpopulation. The length of the chain has been estimated at about 0.40 for heterosexuals. That is that every case of HIV that occurs in a heterosexual is likely to give rise to 0.4 additional cases. Normally the chain dies with the first victim or two. In order for a disease to become epidemic in any population, the length of the infection chain must be greater than 1.

HIV has been epidemic in Africa for a variety of cultural and biological reasons. Heterosexual anal intercourse is believed to be more prevalent because female genital mutilation often causes penile-vaginal intercourse to be painful. Multiple use of syringes and needles occurs because they are relatively rare and expensive, and there is a cultural attitude in many parts of Africa that only injectable medications are effective. The disease load faced by the average African brings about what immunologists call "sticky serum", which may be much more subject to infection by the HIV virus. There are any number of other cultural and political issues as well. Poverty, war, separation of families, starvation, and other issues also make this contagion environment very different from what is found in industrialized countries.

Nice analysis. I also wonder if there are more cultural differences about lubrication, even in the U.S. between heterosexual and homosexual practices of anal sex, and those differences might also apply to vaginal sex. I know that I've mocked a product that claimed "Decreases Vaginal Moisture Increases Sexual Satisfaction!" (the original web site no longer exists), but if that's really a trait that people are going out of their way for, it seems like that'd be a route to disease transmission.

Don't even take the rest of this comment seriously, however just as a point of conversation...

There was an incident a few years ago where there were a handful of porn actors who tested positive for HIV. One of the largest concerns of the actors, their unions, and the few articles that I read was talking about the fears of HIV and anal sex. The reasoning that was given, and I have nothing to back this up but mere memory of an article, was that during anal sex there is usually trauma of the tissue which could give a better path for the HIV virus to enter the body since any fluid that was in that area would sit against traumatized tissue for a number of hours until the next natural cycle of things cleared the area of the alien fluids.

I vaguely remember something about not enough lubrication was normally used coupled with people wanting to be "rougher" for the camera, which is why it was more dangerous for the actors than the average couple trying anal sex at home.

While anal stimulation may provide significant sexual pleasure both physiologically and psychologically for both genders, this orifice is not really evolved for the purpose of intercourse. The walls of the anus and rectum are much more fragile than than those of the vagina. They will frequently tear and abrade no matter how much lubrication is used. It is these insults to the lining, which are the most likely route of infectious materials, believed to be either intact HIV virus and/or infected white cells.

As to the product you describe, it is most like alum based. Alum douches and powders have been used for "improving" vaginal friction and compression through dryness for centuries. They have also been used for the simulation of virginity. Sometimes they work so well that penetration becomes impossible without severe damage to the female genitals, as would be found in a forceful rape.

JT, I'm as "first amendemnt" as anyone, but I've recently run across a lot of porn that I can't watch because the health practices make me shudder; potential for anal to vaginal transmission that just completely squick me. So I could completely buy that mainstream porn performers fall into that high risk sex category, and only the rest of the health precautions taken keep that pool from having serious issues.

m, my guess at the time was that it was corn starch, but even that notion wigged me out a little bit. Alum... well... yikes. But I'm a "lots of lubricious slippery goodness" person, so any step down the 'more dryness' path makes me shudder. Ouch.

#Comment Re: Slippery goodness made: 2007-09-17 16:13:00.229663+00 by: m

I have to agree about that. One lover was a voluminous squirter/ejaculator at each of her orgasms. Eventually the mucous secreted by the vagina would be washed away, and the remaining fluid while quite wet had little in the way of lubricating qualities. With the slipperies gone, there was a tremendous reduction in pleasure -- hers and mine, even though compression increased significantly. This is probably about the closest one could come to a controlled test environment in the demonstration of the value of the slipperies.