Circumcision may somehow protect men from sexual transmission of the AIDS virus, researchers said on Sunday, but they admitted they do not have a clue why.
A study in Uganda aimed at examining how couples infect one another found two things seemed to protect people - being older and being circumcised.
"Acquisition of HIV did not occur in any of the circumcised men," Dr. Thomas Quinn of Johns Hopkins University in Baltimore, who led the study, told the 7th Conference on Retroviruses and Opportunistic Infections, a meeting of AIDS researchers.
"Age, independent of viral load, appeared to have a protective effect," Quinn added. The highest transmission rate was in people 15 to 29 years old.
Quinn's team, working with 15,000 people in the Rakai district of Uganda, also found that people did not pass on the virus to their partners if they had a naturally low level of HIV in the blood - in this case, 1,500 copies according to standard measures.
He found that the more virus people had in their blood, the more likely they were to pass it on. There were no differences in women infecting men or men infecting women.
Quinn said his team was one of the first to actually go out and test the idea where HIV is raging the worst. More than 23 million people in sub-Saharan Africa are infected with HIV.
The findings might suggest ways of stemming the epidemic.
Telling people to abstain from sex or use condoms has not worked, and the drugs that keep the virus at bay in some patients in rich countries are not available in the poor countries hardest hit by the epidemic.
But the study suggests that using drugs to keep the virus at lower levels, or a vaccine that might do the same without quite curing a patient, might help.
Quinn said he was at a loss to explain why circumcision might affect a man's risk of being infected by a woman.
Circumcision hailed as way to curb Aids
Bryan Appleyard
The Sunday Times, UK
http://www.sunday-times.co.uk
NEW evidence suggests that circumcision of all male babies could help to halt the global Aids epidemic. With 50m living cases and more than 16m deaths, the disease is now the worst human health disaster since the Black Death.
The thesis - laid out in a scientific paper to be published soon - seems likely to create huge controversy as it represents a complete change in accepted ideas about the transmission of Aids.
One of the paper's authors, Roger Short, professor of obstetrics at Melbourne University and a respected scientist with long experience of Aids-ravaged areas, has been told he cannot address the subject at a forthcoming international conference.
Short and his co-author, Dr Robert Szabo, are convinced that a high level of receptors - sites to which invading organisms attach themselves - on the inside of the foreskin make it responsible for transmission.
Short and Szabo noted a sharp difference in the prevalence of HIV infection in the "Aids belt" countries in sub-Saharan Africa. In some areas the infection rates are as high as 25%, in others as low as 1%. The lower infection rates were clearly associated with the practice of male circumcision.
"The presence of an intact foreskin," says the Short-Szabo paper, "has consistently been shown to be the single most significant factor associated with the much higher prevalence of HIV in countries of the Aids belt."
The link is stronger than with more familiar indicators such as promiscuity, other sexually transmitted diseases and multiple marriage.
Even more startling evidence came from a recent study in Uganda, reported in February. This showed that among a large group of "discordant couples" - where one is infected and one not - no circumcised males became infected over 30 months, even though their wives were HIV-positive. Short describes these results as "staggeringly significant".
Outside Africa there is the same pattern. Countries with low circumcision rates, such as Thailand, India and Cambodia, have between 10 and 50 times the rates of infection compared with countries with high circumcision rates, such as the Philippines, Bangladesh and Indonesia.
Once they get ethical clearance in Australia, Short and Szabo intend to test their conclusions by applying live HIV virus to newly removed foreskins to check its rate of uptake. They could have definite results within weeks.
If experimentally confirmed, the implications are radical. Short and Szabo believe that about 80% of male HIV infections in the world happen through the foreskin.
Short is not advocating adult circumcision, a painful and potentially dangerous operation. But future generations could be saved if mass circumcision began now.
Short believes his findings should be spread globally, as rapidly as possible.
"There has been insufficient focus on prevention," he said, "and too much emphasis on the search for a vaccine." Despite the billions poured into research, there is still no sign of an Aids vaccine.
The crisis in sub-Saharan Africa - where life expectancy rates at birth as a result of Aids have dropped from 59 to 44 - is out of control.
"The whole of my life's prejudice has been anti-circumcision," said Short.
"I've written papers against it. I didn't believe the benefits outweighed the costs. If God had made us the way we were, why remove a sound organ? But I have been totally converted."
This is the biggest load of nonsense. The vast majority of transmissions are from male to female or male to male. Female to male is the least common method, and newer studies have shown that circumcised men actually are MORE likely to transmit HIV to uninfected female partners.
http://news.bbc.co.uk/2/hi/health/8154134.stm
So, when circumcised men contract HIV, they are actually going to spread it at higher rates. This doesn't look like prevention to me.
Thanks.