JOHANNESBURG, April 27 — For well over a decade, southern Africans have battled the spread of H.I.V. with everything from condoms and abstinence campaigns to doses of antiretroviral drugs for pregnant women — and yet the epidemic continues unabated.
Now a growing number of clinicians and policy makers in the region are pointing to a simple and possibly potent weapon against new infections: circumcision for men.
Armed with new studies suggesting that male circumcision can reduce the chance of H.I.V. infection in men, and perhaps in women, health workers in two southern African nations are pressing to make circumcisions broadly available to meet what they call a burgeoning demand.
The validity of the approach is still being tested. But in Lusaka, the capital of Zambia, surgeons at the University Teaching Hospital began offering circumcisions for about $3 some 18 months ago and are urging the government to expand the service nationwide. Dr. Kasonde Bowa, a urologist at the hospital, says about 400 patients a month request the procedure — eight times as many as the surgeons can accommodate.
"One reason we decided to set up this service was the increasing evidence in the research in relation to reducing H.I.V.," thevirus that causes AIDS, he said. "The evidence is very strong."
In Swaziland, the Health Ministry backed a workshop in January to train 60 doctors in circumcision, responding to what it called a surge in demand. Studies indicate that circumcision may protect against H.I.V., the ministry said, adding that the service should be more available.
"I've lost a cousin and an aunt," Nokuthula Sibandze said as she waited nervously with her 16-year-old son and 10-year-old nephew at a Swazi clinic offering free circumcisions in February. "I am trying to do the best for my children, and I have heard that if a male is circumcised there is less risk of infection."
Other policy makers in the region are holding back, waiting for direction from the World Health Organization. Officials there say the evidence so far, while intriguing, is not definitive enough to call for a shift in strategy on H.I.V. prevention.
The most striking studies suggest that men can lower their own risk of infection by roughly two-thirds, and that infected men can reduce the odds of transmitting the virus to their partners by about 30 percent, simply by undergoing circumcision. Research suggests that the cells on the underside of the foreskin are prime targets for the virus and that tears and abrasions in the foreskin can invite the infection.
But World Health Organization experts say it would be premature to recommend circumcision until results come in from two randomized controlled trials involving nearly 8,000 people in Kenya and Uganda. Preliminary results could be released by late June.
Data from earlier studies is "excitingly tantalizing, and the potential effectiveness looks pretty good," said Kevin O'Reilly, who is in charge of H.I.V. prevention for the health organization. But it must be confirmed, he said, "before we officially declare that circumcision is a policy that should be adopted by countries."
"We don't want to steer countries wrong," he said.
So far, southern Africa's H.I.V. infection rate, the world's highest, has resisted efforts to lower it. Only three sub-Saharan countries — Kenya, Uganda and Zimbabwe — have shown declines in the prevalence of the virus among adults, according to Unaids, the United Nations agency devoted to curbing the epidemic.
Of the nearly 5 million people worldwide who became infected last year, 3.2 million live in sub-Saharan Africa, the agency said.
Daniel Halperin, an epidemiologist and H.I.V. specialist in Africa for the United States Agency for International Development, argues that low rates of circumcision and high rates of multiple, concurrent sexual partners are the main reasons that the AIDS epidemic has raged in southern Africa but left western Africa mostly unscathed.
According to a study Mr. Halperin published in 1999, seven southern African countries, where fewer than one in five men were circumcised, had H.I.V. prevalence rates in adults of 14 percent to 26 percent in 1998. In nine western African countries, where more than four in five men were circumcised, H.I.V. prevalence rates were below 5 percent.
Researchers have suspected since the 1980's that such patterns are more than coincidence, and while the topic has long been a controversial one, many experts say the bulk of studies suggest that circumcision has at least some protective effect.
An analysis of data in 2002 cited by the Agency for International Development found that 38 studies, mostly in Africa, appeared to show that uncircumcised men were more than twice as likely to be infected than circumcised men.
Perhaps the most compelling evidence came last year from a study financed by the French government of 3,274 men outside Johannesburg. Half of them underwent circumcision; the others were uncircumcised.
After 17 months, 49 of the uncircumcised men became infected with H.I.V., while only 20 of the circumcised men caught the virus. The study was called to a halt in March 2005 when a review board decided that it would be unethical to withhold circumcision from the control group. Researchers estimated that the procedure reduced the risk of contracting H.I.V. by roughly two-thirds.
One study in February of the medical records of more than 300 Ugandan couples suggested that male circumcision also benefited women. In it, researchers estimated that circumcised men infected with H.I.V. were about 30 percent less likely to transmit it to their female partners.
Dr. Diana Dickinson, who has battled H.I.V. for years from her private health clinic in Gaborone, Botswana, is one of many clinicians in a quandary over how to react to such studies. On the one hand, she said, she wants her patients to be protected as much as possible. On the other, she worries that if circumcision is oversold, circumcised men may think they are free to engage in risky sex.
"I really worry about mixed messages," she said. World Health Organization officials warn that even if studies now under way confirm the benefits of circumcision, it must be viewed as part of a broader prevention strategy to promote testing, condom use, reduction in the number of sexual partners and abstinence.
"There never has been a magic bullet," said Mr. O'Reilly of the W.H.O., "and there never will be."
Other H.I.V. specialists are concerned that the studies may encourage unsafe circumcisions by traditional healers. Every year, the authorities in Eastern Cape Province in South Africa report deaths and amputations from botched circumcisions of young boys.
While many Western doctors routinely encourage circumcision of newborns, surgeons in government hospitals and clinics in southern Africa typically schedule circumcisions only if medically necessary. At Chris Hani Baragwanath Hospital in Soweto, South Africa, the waiting list runs six to nine months.
To offer it more broadly, "you can imagine what kind of resources would have to be made available," said Dr. Martin Smith, head of the hospital's surgery department.
Although circumcision is not a custom among most ethnic groups in the region, studies in Botswana and elsewhere suggest that more than half of men would accept circumcision if it were free and done safely. Most say they think circumcision improves hygiene and sexual pleasure.
The few programs that offer free or low-cost circumcision have been swamped with applicants. Officials of the Family Life Association, a nonprofit organization in Swaziland, expected a few dozen volunteers when they offered free circumcisions in January. But about 140 men and boys showed up at its clinic in the Swazi capital, Mbabane. Doctors worked until 8 p.m. to circumcise 54 patients and told the rest to come back later.
About 10 men and boys returned in February, including a 28-year-old laboratory technician, a 19-year-old student and a 31-year-old unemployed father of four. Dennis Mkhonta, 44, a married government meteorologist, said he wanted to be circumcised for hygienic reasons. But he wants his 21-yearold son to do so because he is afraid of H.I.V.
"There is nobody who is not," Mr. Mkhonta said. "I tell my sons: protect yourselves."
Thulani Shongwe, 29, a health club attendant at a Swazi hotel, missed the Family Life Association's one-day advertisement and appears to be out of luck. For four years, he said, he has gone repeatedly to the government hospital to be circumcised, only to be told to try again another day. He said that "they give the impression they don't care much about it."
But he does. "It reduces the risk of H.I.V.," he said. Besides, he added, "my girlfriend wants me to do it."