The evidence continues to mount that circumcision by itself is a remarkably effective way to prevent the spread of AIDS.
A new study reported today in the British journal The Lancet followed the AIDS infection rates of nearly 2,300 originally uninfected young men in India. After roughly a decade worth of observation, the Indian and American researchers involved in the study report that the uncircumcised men had between six to seven times the infection rates of circumcised men.
While lower rates of AIDS infection have been reported among circumcised men in Africa as far back as the late 1980s, there have always been questions about whether one was looking at a behavioural rather than a biological phenomena. Perhaps the most unique feature of the new study is that there was no difference in the rates of other sexually transmitted diseases such as syphilis, gonorrhea and herpes. This suggests that the sexual behaviours of the men were much the same.
"What this study suggests to us is that there is something specific about the contact of HIV with the foreskin," says Robert Bollinger of Johns Hopkins University, and one of the authors of the new study. Laboratory studies have suggested that foreskins are full of certain cells "which are essentially a magnet for HIV infection," he added.
What the new study does not do is resolve a contentious public-health issue which arose soon after the first reports of a substantial circumcision/non-circumcision differential appeared. Should men in high-risk places like Africa be circumcised in a public-health measure some have likened to a surgical vaccination?
A clear answer to that question awaits the results in perhaps two to three years of three separate AIDS circumcision trials now going on in Africa. One, in Kenya, is part of a University of Manitoba AIDS in Africa research study that has been under way since the 1980s. In that study, 2,800 young men will be recruited. Half will be men who, after explanations of the risks and potential benefits, will agree to be circumcised.
What is known as a randomized clinical study will address a number of issues that doctors believe must be dealt with before circumcision can be recommended on a wide-scale basis. The first is to make sure that circumcision itself, and not some difference in sexual behaviour among circumcised men, is the true preventative agent.
Another issue is the complication rates of the surgery. "There are risks which are associated with circumcision, some of which can be severe. You need to be able to quantify any benefit you get from circumcision, if there is benefit," Stephen Moses, the U of M microbiologist who is a principal investigator for the Kenyan study.
The Kenyan and other studies will also see if the circumcised men change their sexual behaviour after surgery, specifically if they stop other safe-sex practices because they believe losing their foreskins has made them invulnerable to AIDS. "That could be quite dangerous, because we know that circumcision, even if it is protective, is not 100 per cent protective," Prof. Moses said.
The new studies may also spur debate on the kind of generalized nervousness about circumcision as a medical practice. There has been considerable recent debate in countries like Canada about whether routine infant circumcision -- something which now takes place in an estimated 20 to 25 per cent of Canadian newborns -- can ever be medically justified.
"In circumcision, the bar has to be very high. You are dealing with a surgical procedure. You are removing a part of somebody's body, and there are a lot of people who think that is sort of a priori unacceptable. So the evidence has to be quite good before this can be recommended as a widespread medical intervention," Prof. Moses said.
However, with upward of 40 per cent of people in some African countries infected with AIDS, and with various studies already suggesting anywhere from two to eight times more uncircumcised men get AIDS than circumcised men, positive results may present medical circumcision in a different light in Africa.