Saturday, March 10, 2007

His And Her HIV Risk Reduction

First, the good news. Circumcised men are 51-60 percent less likely to contract HIV (I haven't read the study yet, but, if the article is accurate, this sounds promising):

LONDON - Scientists say conclusive data shows there is no question circumcision reduces men's chances of catching HIV by up to 60 percent — a finding experts are hailing as a major breakthrough in the fight against AIDS. The question now is how to put that fact to work to combat AIDS across Africa.

The findings first were announced in December, when initial results from two major trials — in Kenya and Uganda — showed promising links between circumcision and HIV transmission. However, those trials were deemed so definitive that the tests were halted early.


"This is an extraordinary development," said Dr. Kevin de Cock, director of the
World Health Organization's AIDS department. "Circumcision is the most potent intervention in HIV prevention that has been described."

Circumcision has long been suspected of reducing men's susceptibility to HIV infection because the cells in the foreskin of the penis are especially vulnerable to the virus.


But experts warn that solid evidence is not justification for mass circumcisions, noting that African health systems are already overburdened, and circumcision requires more planning than, for example, an immunization campaign.


In the Kenyan study, 1,391 circumcised men were compared to 1,393 who were not. And in Uganda, 2,474 circumcised men were compared to 2,522 men who were not. Scientists tracked the men for two years and found that those who were circumcised were 51-60 percent less likely to contract HIV.

[The initial Yahoo story I linked/quoted is gone, so I updated link to similar article.]

Second, the disappointing news. Cellulose sulfate (a microbicide) does not protect women from HIV infection:

A Phase III study of the candidate microbicide* cellulose sulfate to prevent HIV transmission in women has been stopped prematurely because of a higher number of HIV infections in the active compared with the placebo group. The study was sponsored by CONRAD and conducted in Benin, India, South Africa and Uganda. A second study on the same product sponsored by Family Health International conducted in Nigeria has also been stopped because of the safety concerns in the first trial. This is a disappointing and unexpected setback in the search for a safe and effective microbicide that can be used by women to protect themselves against HIV infection. Cellulose sulfate was one of four compounds being evaluated in large-scale studies of effectiveness among women at high risk of HIV infection.

Currently there are three other Phase III microbicide studies under way. The Carraguard study (sponsored by the Population Council and conducted in three sites in South Africa) is nearing completion and results are expected by the end of 2007. Another product, PRO 2000, is being tested in one study in five sites in South Africa, Tanzania and Uganda (results expected in 2009) as well as in a second study in seven sites in Malawi, South Africa, Zambia and Zimbabwe (results expected in 2008). In this second study a further compound, BufferGel, (a vaginal defence enhancer) is being tested. All the other compounds mentioned are products that block HIV infection – known as HIV entry inhibitors – and have a similar presumed mechanism of action.

To refresh your memory: A microbicide is designed to kill microbes (like the HIV virus). A spermicide kills (inactivates) sperm. Now, and this is important, if a substance is able to kill microbes it does not follow that it can also kill sperm. And vice versa.

Of course, when it comes to birth control, the ideal substance would prevent pregnancy while fighting infection. It would be both spermicidal and microbicidal. [We're still looking for such a substance.]

For more on spermicides and microbicides go here. [still working on the post; will link when done]


At 4:48 PM, Anonymous Anonymous said...

I would be interested to see who they managed to prove that the circumsized men had the same sexual habits as the uncircumsized (and vice-versa). This has been a myth floating around since circumcision began, I'd need to see actual evidence before I recommend cutting bits off of people (did they find that female circumcision had a similar decrease in infection rate? if so, would any of us recommend that?).

At 7:14 PM, Blogger Joshua said...

Somehow I don't think you are that interested in how they established similar sexual habits between circumcised men and the uncircumcised otherwise you would have read the full text of the studies before commenting. But seeing you know this to be a 'myth' why not explain how this is so?

At 9:20 PM, Anonymous Anonymous said...

um, okay. Do you have a link to the full study? I didn't see one above (there's a link to a TIME article in this post; the article linked to indicates that the procedure "has long been suspected", sorry if "myth" is stronger than "suspected"). I've no problem accepting that circumcision prevents AIDS. I'd simply like to see the evidence. That's kinda why I asked for it. If you have a link, Joshua, please let me know.


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