24 December 2007

Circumcision and HIV prevention: Manitoba researchers make a medical breakthrough


An HIV study led by the University of Manitoba's Dr. Stephen Moses has been named the year's top medical breakthrough by Time magazine. Dr. Moses was one of the principal investigators in research that found male circumcision can reduce the risk of HIV infection in men who have heterosexual sex.

Collaborating with researchers from universities in the U.S. and Nairobi, Dr. Moses conducted clinical trials in Kenya and Uganda, following thousands of HIV-negative men over a number of years to determine what effect circumcision would have on the spread of HIV. Their results show that circumcised men were roughly 50 per cent less likely than uncircumcised men to acquire HIV during sex with women. The trials were halted a year ago after early data showed high levels of success, and the results were published in the The Lancet earlier this year.

"It’s nice that the issue has got this kind of recognition in the popular press," Dr. Moses told the Winnipeg Free Press. The notion that circumcision can protect against HIV transmission has been accepted in the scientific community, and increasingly in the world health community. Dr. Moses predicts that "circumcision is going to start to be taken up more widely as a public-health measure to protect against HIV." While circumcision is no magic bullet against HIV, it can help reduce the spread of infection along with safer-sex practices and improved screening and treatment of sexually transmitted infections.

Dr. Moses is now working with the government of India and state governments to try to mitigate the impact of HIV in India, and prevent the spread of the virus. His work is largely based in the southern state of Karnataka, where the aim is to enhance care for people living with HIV.

Time.com currently lists the HIV study as the biggest breakthrough of 2007, followed by the development of a test for metastatic breast cancer and a human vaccine against avian flu.

Does circumcision help men who have sex with men?
Dr. Allan Ronald, an infectious disease specialist in Winnipeg who has also done important work in African HIV research, added some perspective in an interview with CBC Radio One last week. He stated that, although the results of Dr. Moses' research are convincing, they are not likely to have the same relevance for North America. Referring to recent research, Dr. Ronald cautioned that circumcision is not as effective in reducing the rate of HIV infection among men who have sex with men (MSM). He was referring to an article by researchers with the Centers for Disease Control in Atlanta, which was published in PLoS Medicine this month [4], which reported: "Most sexual transmission of HIV in the US [and Canada] occurs through male–male sex, most often infecting the receptive partner in penile–anal intercourse. The results from the African trials demonstrated that circumcision was protective for men who were the insertive partner in vaginal intercourse, suggesting that the utility of male circumcision in preventing HIV transmission among MSM may be limited." Another study published this month reinforces this statement, concluding that "there was no evidence that being circumcised was protective against HIV infection among black MSM or Latino MSM" in the United States [1].

Circumcision certainly has a role in the prevention of HIV transmission. However, because of the many differences between the underlying HIV epidemics in Africa and the developed world, differences in the prevalence of male circumcision, and the considerable gaps in knowledge that exist regarding the potential impact of circumcision on HIV transmission by male–male sex, the extent of this role on a population basis is unknown.The PLoS article calls for more discussion of the benefits and risks of circumcision before any recommendations are drafted. Among the issues to be considered are gaps in the research (for example, differences in shedding of HIV by rectal versus vaginal mucosa), barriers and facilitators to acceptance of adult male circumcision, buy-in from the at-risk communities, cultural and ethical questions, cost benefits, and insurance.

A contentious issue
Male circumcision is a contentious issue still. It has its vocal opponents and strong defenders on the web, while the published literature is generally favourable [2,3,4,6]. Canadian statistics show fewer infant sons being circumcised. Infant circumcision rates dropped to 9.2% in 2005. The rate of male circumcision in the United States is high by comparison: about 57% nationwide. Roughly 3% of male children in the UK are being circumcised. Owing to the sometimes intensely partisan positions taken by opponents of circumcision, librarians and researchers should be cautious when searching the web for information.

Non-heterosexual and injection drug HIV transmission must be considered
Although circumcision is a very important issue, it should not be forgotten that, for example, it is estimated that just under half of all people living with HIV in China in 2006 were infected while injecting drugs with contaminated equipment, and drug use remains the main mode (66%) of HIV transmission in the Russian Federation [5]. In the United States 18% of HIV infections occurred among injecting drug users, and more than half of all newly diagnosed HIV infections (53%) in 2005 were among men who have sex with men [5]. Canadian statistics are similar: 19% injection drug users and 43.2% MSM. Circumcision must always be regarded as one more method to reduce the HIV infection rate. In those parts of the world where heterosexually acquired infections account for the largest proportion of new HIV diagnoses, circumcision will be effective as part of a comprehensive prevention program.

Condoms first
Condoms are still the most effective means of HIV prevention. Because high rates of sexually transmitted infections (STIs) are an important contributing factor to the spread of HIV, it is also vital that STIs be controlled [3]. Free STI testing would be an extremely useful weapon in the anti-HIV arsenal. Taking into account regional variations and the special needs of affected populations, health authorities and community-based organizations should promote a global expansion of STI treatment and male circumcision programs as vital components in the prevention of HIV infection.


References:

1. Millett GA, Ding H, Lauby J, Flores S, Stueve A, Bingham T, Carballo-Dieguez A, Murrill C, Liu KL, Wheeler D, Liau A, Marks G. Circumcision Status and HIV Infection Among Black and Latino Men Who Have Sex With Men in 3 US Cities. J Acquir Immune Defic Syndr. 2007 Dec 15;46(5):643-650.

2. Morris BJ. Why circumcision is a biomedical imperative for the 21st century. Bioessays. 2007 Nov;29(11):1147-58.

3. Sahasrabuddhe VV, Vermund SH. The future of HIV prevention: control of sexually transmitted infections and circumcision interventions. Infect Dis Clin North Am. 2007 Mar;21(1):241-57, xi.

4. Sullivan PS, Kilmarx PH, Peterman TA, Taylor AW, Nakashima AK, Kamb ML, Warner L, Mastro TD. Male circumcision for prevention of HIV transmission: what the new data mean for HIV prevention in the United States. PLoS Med. 2007 Jul 24;4(7):e223.

5. UNAIDS. AIDS epidemic update : December 2007 [Internet]. “UNAIDS/07.27E / JC1322E”. Geneva: UNAIDS; 2007. [cited 2007 Dec 24]. 50 p. Available from: http://data.unaids.org/pub/EPISlides/2007/2007_epiupdate_en.pdf

6. Vardi Y, Sadeghi-Nejad H, Pollack S, Aisuodionoe-Shadrach OI, Sharlip ID. Male circumcision and HIV prevention. J Sex Med. 2007 Jul;4(4 Pt 1):838-43.

4 comments:

Hugh7 said...

I would have expected a librarian at St Boniface's to be more cautious in his endorsement of circumcision. It was at St Boniface's in 2005 that two babies were switched and the wrong baby was circumcised, resulting in the hospital's decision to do no more neonatal circumcisions. But they may also have been influenced by the memory of David Reimer, who (as Bruce) was to be circumcised at St Boniface's along with his twin brother Brian in 1966 but instead had his penis burnt off and he was unsuccessfully raised as a girl. Brian's circumcision was called off and he recovered without treatment, underlining that his circumcision was unnecessary, as most are.

Not only did the Millett et al. study show no protective effect against HIV at all of circumcision on men who have sex with men (not just "not as effective"), the Mor et al. study showed no effect on heterosexual US men either. There are many problems and unanswered questions about the three non-blinded randomised clinical trials in Africa, and Dr Stephen Moses is right to pick up on the role of the media in promoting circumcision way beyond what has been proved. (64 circumcised men reportedly contracted HIV, but another 340 dropped out of the trials, their HIV status unknown. The studies assumed all HIV transmission was sexual, but there is evidence that in Africa much is by other means, such as dirty needles.) It is very questionable whether circumcision can be successfully promoted without undermining more effective safe-sex campaigns.

Your illustration of the circumcision of Christ underlines the multifacetted nature of this extraordinary subject. (Would you have illustrated an article on brain surgery with a picture of someone having his skull opened to let out evil spirits? And in passing, Gal 5 2 says "If you are circumcised, Christ shall profit you nothing.")

Rachel said...

Wasn't there a recent study that circumcision wouldn't help HIV prevention in the US/similar environments?

The Shelver said...

In reply to Hugh7 I would say first that his use of the opposite of an "argumentum ad verecundiam," implying guilt by association, is unhelpful. What on earth does an instance or two of botched circumcision at this or any other hospital have to do with the issue at hand? Secondly, I make it quite clear in my post that the evidence is not yet in on the preventive efficacy of male circumcision in North America, where male-to-male sex and injection drug use figure substantially in HIV transmission.

Contrary to what Hugh7 says, the Mor, et al. study states the following: "Based on the data from the three African clinical trials, it is likely that circumcision will decrease the probability of a man acquiring HIV via penile–vaginal sex with an HIV-infected woman in the US." (Mor Z, Kent CK, Kohn RP, Klausner JD. Declining rates in male circumcision amidst increasing evidence of its public health benefit. PLoS ONE. 2007 Sep 12;2(9):e861.)

The whole point of Mor, et al. is to recommend further research because the benefits of male circumcision in the U.S. are becoming more evident. "Given recent studies suggesting the public health benefits of male circumcision, a reconsideration of national male circumcision policy is needed to respond to current trends" (Abstract).

I would agree to some extent with Hugh7's questioning whether circumcision can be successfully promoted without undermining more effective safe-sex campaigns. I don't have easy answers about the place of circumcision in HIV prevention in the North American context. As I state in my post, condoms are still the most effective means of HIV prevention — period. Next come harm reduction programs, like needle exchange and safe injection sites, free STI testing and treatment, pyschosocial and economic support for people with HIV, addiction treatment and prevention, education programs in schools, etc. The list goes on and on.

However, what is clear is that the research of Stephen Moses and others points clearly to the general benefits of male circumcision for the prevention of heterosexual HIV infection. Obviously, more research is needed on the epidemiology of male circumcision on this continent to satisfy skeptics like hugh7.

To answer Rachel's question, I am not aware of a study that demonstrates the ineffectiveness of male circumcision for HIV prevention in the U.S.

Sullivan, et al. are cautious in their approach. (Sullivan PS, Kilmarx PH, Peterman TA, Taylor AW, Nakashima AK, Kamb ML, Warner L, Mastro TD. Male circumcision for prevention of HIV transmission: what the new data mean for HIV prevention in the United States. PLoS Med. 2007 Jul 24;4(7):e223.)

Circumcision MAY have a role for the prevention of HIV transmission in the US, but the extent of this role on a population basis is unknown. Further, the already high prevalence of circumcision among US men suggests some limitations in the potential impact of circumcision at a population level. Sullivan, et al. conclude that it is not yet clear whether male circumcision can be efficacious for men in reducing their risk of HIV acquisition through sex with women in the U.S.

The experts are waiting for further evidence but have not shut the door to circumcision, as Hugh7 has done.

Hugh7 said...

I am certainly not guilty of argumentum ad verecundium (appeal to authority) or its opposite. You would have better accused me of ignoratio elenchi (irrelevant refutation) but that too fails, because circumcision is not cost-free or risk free, and the two famous cases at St Boniface's are only the tip of the iceberg of botches and complications. (The cutters are very fond of saying "Properly performed, circumcision is safe and harmless" so that they can throw any damaged baby to the wolves by blaming the practitioner.)

I know that the Mor et al. study extrapolated from the three RCTs in Africa to the US - anybody can do that - but their own study itself failed to find any significant association between HIV and circumcision in the US, though if you didn't read it carefully you might think it had. Mor et al. themselves did some of the further research. Some evidence is in, and it points to a verdict of "Foreskin is not guilty." What do you bet they and others will do more research until they find some association, and that will be widely touted as "proof" that US babies should be circumcised to prevent HIV, while the real outcome of this study is forgotten?

"However, what is clear is that the research of Stephen Moses and others" - yes, those same few others, Bailey, Halperin and the rest, again and again - "points clearly to the general benefits of male circumcision for the prevention of heterosexual HIV infection." No, as I pointed out, not so clearly at all. Though you have to work it out yourself, their studies show a Number Needed to Treat of 30-55 circumcisions to prevent one female-male HIV transmission per year. Transmission in the other direction is much easier, and as Bill Clinton and Bill Gates pointed out, women need to be empowered to resist men's demands for unprotected sex. "I'm circumcised, I'm safe" is going to have the reverse effect.

"Obviously, more research is needed on the epidemiology of male circumcision on this continent to satisfy skeptics like hugh7." You seem to have decided already what the outcome of that research is going to be. If proper research is ever done, it wouldn't surprise me if it turns out that circumcised men are indeed slightly less likely to get HIV, just because they have less surface area, but that still wouldn't of itself justify cutting part of the genitals off any babies. (Two studies have found women who have been "circumcised" are less likely to contract HIV. Calls for a "rollout" of FGM have not followed...)