One of the first fully-scientific studies to examine the link between circumcision and AIDS is calling male circumcision a potential tool that can be used to control HIV infection.

Preliminary results of a two-year study involving 4,996 HIV-negative Ugandan men (between the ages of 15 and 49) who offered to be circumcised show that the practice is a major step towards HIV prevention in Africa and rest of the world.

Researchers found that men who are circumcised cut their chances of acquiring HIV infection, the retrovirus that causes AIDS, by over 50 per cent. Projections show that the procedure could save three million lives over the next 20 years.

Researches say the male foreskin is made up of cells that absorb HIV and are extremely vulnerable to HIV infection. The foreskin is also vulnerable to tearing and ulcers that act as entry points for HIV.

Once a male undergoes circumcision and the surgical scar is healed, researchers say the new skin is covered with a protective lining called keratin that is less vulnerable to HIV infections and other sexually transmitted diseases.

Researcher Dr. Maria Wawer of the Rakai Health Sciences Program in Uganda says this is one of the first fully scientific studies to look at AIDS and circumcision.

"Previous studies on circumcision suggested circumcision could be effective in reducing HIV, but they couldn't prove it. This is the proof," she told Â鶹´«Ã½ in Rakai District in south central Uganda.

Study volunteer Frank Mukasa told Â鶹´«Ã½ that although circumcision is not the custom in his tribe, he was proud to undergo the procedure as part of a study on fighting AIDS.

However, researchers found cultural barriers that could prevent others from undergoing the simple, potentially life-saving procedure.

For instance, while many Muslim men in the Rakai District seemed to be more open to the practice of circumcision, researchers found that many of the Christian men were not.

But they also noticed that some men, realizing their lives are at stake, became flexible with their customs.

"The question was asked, will Christians feel they are becoming Muslims if they get circumcised?" said Wawer. "And one guy just looked us in the face and said, 'What's the problem? Jesus was circumcised'."

The study authors warned, however, that male circumcision is far from a "cure-all" and men who have unsafe sex are at high risk of HIV whether or not they are circumcised.

Researches say men who become circumcised must continue to use condoms and point out that the procedure offers no protection from HIV acquired through anal sex or injection drug use.

Still, AIDS specialists are encouraged at the latest results.

A link between male circumcision and HIV prevention was noted as long ago as the late 1980s. The first major clinical trial, of 3,000 men in South Africa, found in 2005 that circumcision cut the HIV risk by 60 per cent.

"The next step will be convincing African governments to begin routine circumcision of men and boys," said CTV's Africa correspondent Murray Oliver, "and that also means convincing western aid donors to help fund this new attack on a deadly epidemic."

With a report from CTV's Africa correspondent Murray Oliver in Rakai District, Uganda