Three large studies in South Africa, Zimbabwe and Kenya have
found no evidence that men who have been circumcised have more sexual risk
behaviours than uncircumcised men. Two of the studies were reported last
week at the Conference on Retroviruses and Opportunistic Infections (CROI 2017)
in Seattle; the third was published in the February issue of the Journal of Acquired Immune Deficiency Syndromes.
Voluntary male medical circumcision reduces men's risk of acquiring HIV by 60%. However, ‘risk compensation’
or ‘behavioural disinhibition’ after circumcision could
mitigate or negate the protective effect of circumcision in reducing HIV
infection if people changed their sexual behaviour as a result of perceiving
themselves to be less at risk of infection.
Katrina Ortblad and colleagues examined longitudinal
demographic surveillance data from the Africa Health Research Institute’s
cohort in KwaZulu-Natal, South Africa. Almost 15,000 men contributed data from 2003
to 2014, including 13% who had been circumcised and 6% who were circumcised
whilst in the cohort.
‘Risk compensation’ was assessed by considering four aspects
of sexual behaviour: not using a condom the last time the man had sex, never
using condoms, the number of sexual partners, and the number of concurrent
sexual relationships. As well as simply comparing circumcised and uncircumcised
men, the researchers also compared behaviour before and after an individual’s
circumcision.
None of these comparisons showed any statistically
significant differences – the researchers found no evidence for risk
compensation following circumcision. If anything, men who were circumcised had
slightly decreased risk-taking behaviour, although the differences weren’t
statistically significant.
Daniel Montano and colleagues followed a cohort of 2379 men who
received an HIV-negative test result and were referred to Zimbabwe’s voluntary
male medical circumcision programme. Around half chose to accept the offer of circumcision,
while half did not. The researchers did not provide any risk reduction
counselling in addition to that routinely provided by the national programme.
Sexual behaviour was measured for up to two years following
circumcision. The researchers found no evidence that circumcised men had
greater increases in risk behaviour over time than uncircumcised men. There
were some increases in risk behaviour in both groups (for example, not using
condoms, partner numbers and concurrent relationships), which the researchers
suggest might be linked to the wider availability of HIV treatment in Zimbabwe
at the time.
Matthew Westercamp and colleagues conducted three cross-sectional
surveys of randomly sampled households in Kisumu, Kenya – the location for one
of the three pivotal randomised controlled trials of male circumcision for HIV
prevention. During a five year period, 7507 people took part in the three
surveys.
The prevalence of male circumcision increased steadily from
32% in 2009 to 49% in 2011 to 60% in 2013. This was associated with a fall in
sexually transmitted infections in the community, especially in circumcised
men. But there were no differences observed between circumcised and
uncircumcised men in sexual behaviour (including condom use and number of
sexual partners) or in knowledge about HIV or perception of HIV risk.
All three groups of researchers recommend that voluntary
male medical circumcision should continue to be scaled up.