South African women whose most recent sexual partner was
circumcised are less likely to have HIV, suggesting that the voluntary medical
male circumcision programmes have benefits for women too, according to a study
presented to the 9th
International AIDS Society Conference on HIV Science (IAS 2017) in
Paris yesterday.
It is well established that circumcision protects men
against HIV infection, but until now there has been little evidence of benefit
for women. Almost a decade ago, a
meta-analysis found no evidence to suggest that circumcision directly
reduced the risk of women acquiring HIV.
Studies have shown a reduced risk of human papillomavirus,
genital ulcers, herpes simplex virus type 2, syphilis, bacterial vaginosis,
and T vaginalis in women whose partners are circumcised. This
is likely due to changes in the male partner’s anatomy, making transmission of
an infection less likely.
However, in the case of HIV, it is more likely that male
circumcision can benefit women by reducing the prevalence of HIV in men who
have been circumcised.
Carlos Toledo and colleagues from the Centers for Disease
Control and Prevention analysed data from the HIV Incidence Provincial
Surveillance System, a longitudinal cohort drawn from a representative
sample of households in two sub-districts of KwaZulu Natal, South Africa. There
is an extremely high prevalence of HIV and other sexually transmitted
infections (STIs) in KwaZulu Natal.
Among 3540 male participants in the survey, the proportions
who had been medically circumcised were higher among the younger men,
reflecting the recent introduction of the procedure. For example, 51% of men aged
15 to 19 were circumcised, 45% of men aged 20 to 24 and 28% of men aged 25 to 29, while
in all age groups over 35, fewer than 20% were circumcised. KwaZulu Natal
is predominantly Zulu and circumcision does not play an important role in Zulu
customs; only 10% of men had had a traditional (rather than a medical)
circumcision.
As could be expected, circumcised men were less likely to
have HIV and other STIs. This could be due to both
the protective effect of circumcision and the younger age of circumcised men.
The main analysis concerned 4766 female members of the
cohort, aged 15 to 49, who provided information on the circumcision status of
their most recent sexual partner. Participants were tested for HIV and a series
of STIs, as well as being asked about STI symptoms
and diagnoses.
There were a number of differences between the 35% of women
whose partner was circumcised and the 65% of women whose partner was not. Women
with circumcised partners were younger and had lower incomes, larger households,
more education, fewer pregnancies and slightly fewer total partners.
Women whose most recent partner was circumcised also had
lower rates of HIV (42%) than women whose partner was not circumcised
(54%).
In a multivariable analysis, which attempted to control for
the skewing effect of the other differences between the two groups of women,
women with circumcised partners had a 30% lower likelihood of having HIV
(adjusted odds ratio 0.71, 95% confidence interval 0.59-0.86). They were also
less likely to have herpes simplex virus type 2 (adjusted odds ratio 0.78, 95%
confidence interval 0.66-0.92).
Carlos Toledo acknowledged some limitations with these cross-sectional
data – some of the women may have said that their partner was circumcised when
in fact he had had a ‘traditional’ circumcision that did not involve the
complete removal of the foreskin. Such a circumcision would provide much less protection
than a medical circumcision. The analysis only took into account the
circumcision status of the woman’s most recent partner, whereas she has
probably had other partners too. Future analyses will attempt to
more fully capture this history. Finally, when a man accesses voluntary male
medical circumcision services, he receives a package of services including
screening and treatment for STIs and HIV. The
reduced prevalence of infections in women could be partly due to these
interventions.
But Toledo said that the findings support the idea that male
circumcision provides some community-level protection against HIV. The impact
of the scale up of male circumcision has implications for women’s health and
there could be synergies between circumcision and women’s health programmes, he
said.