Circumcision Stops HIV

19 July 2018

Circumcision is preventing tens of thousands of cases of HIV infection, a new study from Zimbabwe has confirmed this week.

In 2007, trials first began to show that men who had been circumcised are significantly less likely to contract HIV. Compared with uncircumcised individuals, the HIV infection rate was up to 80% lower in the individuals who had had their foreskins removed.

This level of protection is sufficient for the precedure to be regarded as a form of surgical vaccine, and led to the roll-out of a range of internationally-funded initiatives aiming to increase circumcision rates, by 2015, to at least 80% of sexually-active men living in 14 countries. These were areas with traditionally low-levels of circumcision previously and a high prevalence of HIV infection.

One of these geographies is Zimbabwe where, in the 1990s, about one third of the population was HIV infected; today, it is about 14%.

To establish the impact, if any, of circumcision within communities in Zimbabwe, Imperial College scientist Jessica McGillen and her colleagues have now constructed a series of mathematical models, which they have calibrated using household survey data on prevalence and risk behaviours, as well as circumcision coverage data. The results are published in PLoS ONE.

Overall, more than one million men have undergone circumcision in the country, preventing, co-author John Stover suggests, in the region of 80,000 cases of HIV so far. This number, he predicts, will scale to over half a million cases of HIV prevented over the next 15 years since many of the participants in the voluntary medical male circumcision programme were not yet sexually active.

The uptake of circumcision was initially slightly slower than expected owing, the team speculate, to uncertainty around the procedure. Consequently, the date to reach the 80% target has been pushed back to 2021.

But, Stover explains, if 80-90% of the male population can be accessed by the programme,  "the benefits will be huge". And there is also an added return: "The cost of the programme is offset by the money saved on anti-retroviral drugs."

What will the strategy be once the target level is achieved though? Will the focus shift from targeting teenagers and men in their early twenties to promoting circumcision of newborns? "That's being debated at the moment," says Stover. "Circumcision is simpler and cheaper, with fewer side effects, when done in the neonatal period. But the system is very much set up around reaching out to  older age groups, and to switch targets might undermine the success of the initiative."

The impact of HIV means that studies like the present one are important in determining whether policies like voluntary medical male circumcision are effective and therefore whether the funding is being well invested.

Overall, the importance of effective anti-AIDS interventions cannot be overstated. Every day thousands of people die from an HIV-related infection and an equivalent number become newly infected with the virus, 80% of them in sub-Saharan Africa. Alongside education and safe sex messages, and until an effective vaccine is produced, circumcision remains the most effective tool we have in combating one of the worst pandemics to afflict the human race.

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