Dr. Maria Wawer of Johns Hopkins and her Uganda colleagues stopped their most recent male circumcision trial because it proved ineffective at preventing the spread of HIV from men to their female partners.
Wawer's earlier studies of male circumcision in Uganda — like other studies in Kenya — showed unequivocally that male circumcision could reduce female-to-male transmission rates. As nearly 3 decades of dealing with HIV-AIDS as an international public health crisis has shown, simply educating people about barrier contraception and making contraception more readily and inexpensively available — both difficult endeavors in developing countries, for a variety of reasons — are simply not having the same effect in some countries on reducing HIV transmission rates that developed countries like the U.S. experienced (let alone that such efforts seem to plateau when the perception of immediate danger declines and rates go up again). It's entirely possible (and somewhat unsurprising) that education and contraception access simply don't trump human sexual urges, culture and tradition, which is why scientists think adult male circumcision programs could provide a necessary addition to the HIV-AIDS reduction arsenal.
Wawer and her team were hopeful that male circumcision could reduce male-to-female transmission rates as well, given that in many places, women don't have access to barrier contraception or the power in sexual relationships to demand its use even if their partner's HIV status is known. Unfortunately, their hypothesis was incorrect.
Wawer's team recruited 922 uncircumcised, HIV-infected, men aged 15 to 49 years. Some were immediately circumcised and some had the procedure delayed for two years.
The researchers also followed 163 wives or female sex partners of these men.
"Circumcision of HIV-infected men did not reduce HIV transmission to female partners over 24 months; longer-term effects could not be assessed," Wawer's team wrote.
"Condom use after male circumcision is essential for HIV prevention."
Wawer and her colleagues do point to one positive benefit of a widescale adult male circumcision program, though.
"However, the efficacy of male circumcision for prevention of HIV in uninfected men is clear, and reductions in male acquisition of HIV attributable to circumcision are likely to reduce women's exposure to HIV-infected men. Male circumcision programs are thus likely to confer an overall benefit to women," the researchers concluded.
Unfortunately, this is one of at least 3 promising studies conducted in Africa over the last decade — the other two being with carageenan and nonoxynol-9 — that attempted to find a method for women to protect themselves against HIV transmission when they couldn't implement ongoing, external protection themselves. Luckily, scientists plan to keep trying.
Related: Male Circumcision For HIV Prevention In Men In Rakai, Uganda: A Randomised Trial. [NIH]
Male Circumcision For HIV Prevention In Young Men In Kisumu, Kenya: A Randomised Controlled Trial. [NIH]
HIV Transmission Rates in the United States [CDC]
HIV Transmission Rate Declines in United States, Study Finds [Johns Hopkins]
Experimental Microbicide Carraguard Does Not Provide Protection Against HIV, Study Finds [Kaiser Network]
Nonoxynol-9 For Preventing Vaginal Acquisition Of HIV Infection By Women From Men [WHO]