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Circumcision May Be Potent AIDS Weapon Studies reveal pattern in African epidemic Sabin Russell, Chronicle Staff Writer |
Tuesday, July 11, 2000
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Male circumcision, a surgery so ancient it was first written onto the stone tomb walls of Egyptian pharaohs, is gaining urgent new attention here among doctors battling a modern- day African plague. A growing body of evidence sug- gests that surgical removal of the foreskin, a common rite of passage in western Africa but rarer in the AIDS-stricken southern and eastern African nations, could significantly reduce the odds that a boy will one day pick up HIV, the virus that causes AIDS. At the 13th International AIDS Conference yesterday, researchers compared notes and, for the first time at the highly influential meeting, debated the merits of adding male circumcision to the list of HIV prevention measures. Scientists presented conflicting but intriguing data. Several studies suggest that male circumcision might cut the risk of HIV infection in half --an extraordinary result that is comparable to the benefits expected from some future vaccines. Scientists who are more skeptical believe the benefits attributed to circumcision, which is a ritual of the Muslim and Jewish faiths, actually may be the result of other cultural and behavioral factors, such as Muslim traditions of abstinence from alcohol and genital washing before regular prayers.
But many top scientists are becoming convinced that the evidence of a protective effect is compelling. Dr. Anthony Fauci, director of the U.S. National Institute of Allergies and Infectious Diseases, said in an interview that he believes the link between male circumcision and lower HIV infection rates is now ``an absolute fact.''
The link might never have come up but for the work of a determined band of specialists who call themselves medical anthropologists. Unlike laboratory bench scientists, they study human behavior and cultural practices in the field. In 1989, anthropologist Priscilla Reining drew up a map of African cities, marking those where the male population is circumcised and those where it is not. She placed atop it another map of HIV infection rates. The results were startling: Almost everywhere that AIDS rates were spiraling out of control, the men were uncircumcised. ``The foreskin itself provides a route for transmission of the virus,'' said Reining, 77, of Washington, D.C., now retired from the American Association for the Advancement of Science. ``If it's gone, the route is gone.'' Other studies seem to support that conclusion. In November, University of California at San Francisco anthropologist Daniel Halperin and Robert Bailey of the University of Illinois published an article in the influential British journal The Lancet demanding that scientists pay attention to 10 years of data that had been quietly accumulating on circumcision and HIV. Twenty-seven of 38 studies had found ``significant associations'' between the lack of male circumcision and HIV infection. Only one study found the reverse effect. Bailey calculated that in cultures where circumcision rates are low, up to 55 percent of HIV infections could be attributed to lack of circumcision. ``If you can have a public health measure that reduces infection or illness by 25 percent to 30 percent, that is considered to be a very successful intervention,'' Bailey said. ``We're talking about a 50 percent reduction. That is huge by public health standards.'' The renewed interest in circumcision for AIDS prevention, however, comes at a time when American baby boomers are abandoning the procedure for their own children. Support for the medical benefits has been eroding for decades. In 1971, the American Academy of Pediatrics declared there were ``no valid medical indications'' for infant circumcision. The push to promote circumcision as an AIDS prevention measure in developing countries has outraged anti-circumcision advocates, including NOCIRC, a San Anselmo group that maintains that circumcision is a brutal procedure justified in America by sloppy science. ``The scare tactics are always consistent with the dreaded disease of the times,'' said Marilyn Milos, founder of NOCIRC. ``There was a penile cancer scare in the '30s; a cervical cancer scare in the '50s; and the sexually transmitted disease scare of the '60s.'' Author David Gollaher, who dubbed circumcision ``the world's most controversial surgery'' in his medical history of the procedure, said the case for an HIV link is simply not strong enough. ``This whole argument has surfaced in America, a nation with one of the highest circumcision rates, and also the highest HIV rate in the industrialized world,'' he said. Gollaher noted that circumcision rates are low in Europe, and so are HIV infection rates. But Halperin notes there are also biological reasons that suggest the foreskin is particularly vulnerable to HIV. The thin, fragile tissue of the foreskin can tear and bleed during sex, providing a point of entry for the virus. The most significant link may be that the foreskin is particularly rich in a kind of white blood cell, known as Langerhans' cells, which serve as sentries in the body's immune system. Recent research confirms that they lodge in great numbers in the soft mucous-covered tissue of the foreskin, vagina and cervix. But HIV has been found to have a special affinity for Langerhans' cells. Instead of protecting, Langerhans' cells become a gateway for HIV infection. Men who become infected in a sexual encounter with a prostitute or girlfriend will subsequently infect their wives. In this fashion, researchers believe, noncircumcising cultures may become especially vulnerable to a heterosexual HIV epidemic. If that is the case, it is especially grim news for noncircumcising societies such as India and China, which may be at the start of an African-style heterosexual epidemic. The most convincing evidence to date comes from a Johns Hopkins University study in the Rakai district of southern Uganda, where couples who were serodiscordant -- meaning that one partner was infected by HIV and the other was not -- were monitored during a 2 1/2-year period. One arm of the study looked at men who were HIV-negative, but whose wives or girlfriends were already infected. At the end of the study period, 40 of the 137 uncircumcised men whose sexual partners were HIV positive also became infected with the virus. But among a group of 50 men who were circumcised, not one contracted the virus. Proponents seized on the Rakai study results, which were presented here yesterday, as evidence of circumcision's protective effect, but the investigators themselves remained skeptical. Dr. Ronald Gray presented data yesterday suggesting that the behavior factors associated with Islam -- most of the circumcised men in the study were Muslim -- may account for about half the protective effect. The protective effect among the non-Muslim circumcised men did not reach statistical significance. ``It is not wise to promote circumcision in the absence of evidence from randomized trials,'' he said. Still, for circumcision proponents, the newfound attention is welcome. For years, they say, evidence of a link between the lack of male circumcision and skyrocketing HIV rates has been routinely ducked, dismissed or ignored.
``It's fascinating that the one intervention that is simple, apparently effective, cheap and lifelong is the one most violently opposed by men in this field,'' said Brian Williams, a South African AIDS researcher who is studying the disease in the mining communities west of Johannesburg. ``There is a strange reluctance even to discuss it.''
Even if the link between circumcision and lower HIV rates were well established, public health officials would still face significant cultural and social challenges promoting it in places where it is not practiced, people on both sides of the debate agree. UC San Francisco anthropologist Halperin, a forceful advocate for circumcision for HIV prevention, said the procedure makes some people uncomfortable because it stirs up images of religious and tribal identity, topics that frighten people in politically unstable regions. ``Circumcision is too human a solution,'' he said. ``It's funky. It's tribal. It's not modern medicine. It is not coming in with a pill.'' Jane Chege, a researcher for the Population Council in Kenya, said she has been accused of ``tribal imperialism'' for advocating circumcision among the Luo tribe in Kisumu, a city in the western part of the nation hardest hit by AIDS. But Chege, a member of the majority Kikuyu tribe, believes the findings about the link between circumcision and HIV rates among the Luo are too important to overlook. ``This is a big issue. It is not something you can just ignore,'' she said. ``Even a 5 percent difference in HIV rates is significant, because we are talking about a killer.''
CIRCUMCISION AND HIV RATES IN SUB-SAHARAN AFRICAInfection rates are much lower in western African nations, where circumcision is common, than in south and eastern African nations, where circumcision is more rare. Rates of HIV infection are shown in percent, in nations where: Less than 20% of males are circumsised More than 80% of males are circumsised Source: The Lancet *Without the largely non-circumsising Kisumu region, with an HIV rate of 34.9%, the national rate for Kenya would be about 8%. |
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