HIV This Week

Turner AN, Morrison CS, Padian NS, Kaufman JS, Salata RA, Chipato T, Mmiro FA, Mugerwa RD, Behets FM, Miller WC. Men’s circumcision status and women’s risk of HIV acquisition in Zimbabwe and Uganda. AIDS 2007;21:1779-89.

Turner and colleagues aimed to assess whether male circumcision of the primary sex partner was associated with women’s risk of HIV. Data were analyzed from 4417 Ugandan and Zimbabwean women participating in a prospective study of hormonal contraception and HIV acquisition. Most were recruited from family planning clinics; some in Uganda were referred from higher-risk settings such as sexually transmitted disease clinics. Using Cox proportional hazards models, time to HIV acquisition was compared for women with circumcised or uncircumcised primary partners. Possible misclassification of male circumcision was assessed using sensitivity analysis. At baseline, 74% reported uncircumcised primary partners, 22% had circumcised partners, and 4% had partners of unknown circumcision status. Median follow-up was 23 months, during which 210 women acquired HIV (167, 34, and 9 women whose primary partners were uncircumcised, circumcised, or of unknown circumcision status, respectively). Although unadjusted analyses indicated that women with circumcised partners had lower HIV risk than those with uncircumcised partners, the protective effect disappeared after adjustment for other risk factors [hazard ratio (HR), 1.03; 95% confidence interval (CI), 0.69-1.53]. Subgroup analyses suggested a non-significant protective effect of male circumcision on HIV acquisition among Ugandan women referred from higher-risk settings: adjusted HR 0.16 (95% CI, 0.02-1.25) but little effect in Ugandans (HR, 1.33; 95% CI, 0.72-2.47) or Zimbabweans (HR, 1.12; 95% CI, 0.65-1.91) from family planning clinics. In conclusion, after adjustment, male circumcision was not significantly associated with women’s HIV risk. The potential protection offered by male circumcision for women recruited from high-risk settings warrants further investigation.

Editors’ note: Although an earlier Uganda study demonstrated that HIV-positive men who were circumcised were less likely to transmit HIV to their regular partners, this study found no such effect. It attempted to look at HIV acquisition in women enrolled in a hormonal contraceptive study by circumcision status of partners (as reported by the women). That the serostatus of male partners was not always known (the paper does not report the % of women who knew their partners’ HIV status), that circumcision status was not confirmed by visual inspection, and that the study was not designed to answer this question in the first place should be noted. Finding out whether male circumcision, which reduces the risk of HIV acquisition in men by 60%, has HIV-related benefits for women is a burning question. Women whose partners are circumcised are less likely to develop cancer of the cervix, a major killer in low-and-middle-income countries, but learning whether there are additional benefits, beyond the eventual drop in HIV prevalence among males, remains a key research challenge.

Fankem SL, Wiysonge CS, Hankins CA. Male circumcision and the risk of HIV infection in men who have sex with men. Int J Epidemiol 2007 Oct 19; Epub ahead of print.

Fankem and colleagues undertook a systematic review to describe the association between male circumcision and HIV acquisition in men who have sex with men. The findings were consistent between the two studies which met the inclusion criteria, with a pooled odds ratio of 0.49 (95% CI 0.32-0.73), suggesting a strong association between male circumcision and lower HIV among men who have sex with men. The observational nature of the studies included in this systematic review raised the possibility that the observed effect might be due to confounding factors not measured (and therefore not controlled for) in the studies, rather than being the result of a biological effect of male circumcision. In addition, ascertainment bias can be a problem in any study of male circumcision based on self-report because in some settings self-report has been found to have poor sensitivity and specificity for ascertaining real circumcision status. There is need for randomized controlled trials to find out if circumcised men who have sex with men are both at lower risk of HIV acquisition themselves and, if infected, less likely to transmit HIV than uncircumcised men who have sex with men.

Editors’ note: If there is a direct benefit for male circumcision among men who have sex with men, it will likely be for the insertive partner, if we extrapolate from the results of randomized controlled trials among heterosexual men. Finding men who have sex with men who are exclusively insertive during sex may be a challenge in some settings. A recent study in South America found that as much as 40% of men who have sex with men were both exclusively insertive and interested in participating in a clinical trial evaluating male circumcision for HIV risk reduction.