circumcision may reduce AIDS risk

will be interesting to see if this is borne out. correlation != causation, etc.


Circumcision may offer Africa AIDS hope
Procedure linked to much lower rate of new HIV infections

Sabin Russell, Chronicle Medical Writer

Wednesday, July 6, 2005

French and South African AIDS researchers have called an early halt to a study of adult male circumcision to reduce HIV infection after initial results reportedly showed that men who had the procedure dramatically lowered their risk of contracting the virus.

The study's preliminary results, disclosed Tuesday by the Wall Street Journal, showed that circumcision reduced the risk of contracting HIV by 70 percent -- a level of protection far better than the 30 percent risk reduction set as a target for an AIDS vaccine.

According to the newspaper account, the study under way in Orange Farm township, South Africa, was stopped because the results were so favorable. It was deemed unethical to continue the trial after an early peek at data showed that the uncircumcised men were so much more likely to become infected.
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The hope is that, lacking a vaccine, the nearly 5 million new HIV infections occurring each year could be slowed by circumcision, the surgical removal of the foreskin -- a simple, low-cost and permanent medical intervention that is a common but controversial cultural practice in much of the world. In Africa, about 70 percent of men are circumcised at birth or during rite-of-passage ceremonies in early puberty.

Medical anthropologists began noticing as early as 1989 that the highest rates of HIV infection in Africa were occurring in regions of the continent where the predominant tribal or religious cultures did not practice circumcision. Adult HIV infection rates above 30 percent are found in Zimbabwe, Botswana, Swaziland and eastern South Africa, where circumcision is not practiced; yet HIV infection rates remain below 5 percent in West Africa and other parts of the continent where circumcision is commonplace.

Laboratory studies have found that the foreskin is rich in white blood cells, which are favored targets of HIV, the virus that causes AIDS. So the theory is that men who are uncircumcised are much more likely to contract the virus during sex with an infected woman, and that the epidemic spreads when these newly infected men have sex with other women within their network of sexual partners.
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"I would be thrilled if it works, but we will also need the results of other trials,'' said Johns Hopkins University epidemiologist Ronald Gray, who is conducting, in Uganda, one of two other controlled clinical trials of male circumcision.
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Although the apparent protective effect of circumcision has been noted for more than 20 years, doubts linger as to whether circumcision itself is protective, or whether the lower risk may be the result of cultural practices among those who circumcise. HIV rates are low in Muslim communities, for example, which practice male circumcision but also engage in ritual washing before sex and frown on promiscuity.

E-mail Sabin Russell at srussell@sfchronicle.com.