Association between male circumcision and prevalent HIV infections in Rio de Janeiro, Brazil

Estimation of country-specific and global prevalence of male circumcision

BACKGROUND

Male circumcision (MC) status and genital infection risk are interlinked and MC is now part of HIV prevention programs worldwide. Current MC prevalence is not known for all countries globally. Our aim was to provide estimates for country-specific and global MC prevalence.

METHODS

MC prevalence data were obtained by searches in PubMed, Demographic and Health Surveys, AIDS Indicator Surveys, and Behavioural Surveillance Surveys. Male age was ≥15 years in most surveys. Where no data were available, the population proportion whose religious faith or culture requires MC was used. The total number of circumcised males in each country and territory was calculated using figures for total males from (i) 2015 US Central Intelligence Agency (CIA) data for sex ratio and total population in all 237 countries and territories globally and (ii) 2015 United Nations (UN) figures for males aged 15-64 years.

RESULTS

The estimated percentage of circumcised males in each country and territory varies considerably. Based on (i) and (ii) above, global MC prevalence was 38.7 % (95 % confidence interval [CI]: 33.4, 43.9) and 36.7 % (95 % CI: 31.4, 42.0). Approximately half of circumcisions were for religious and cultural reasons. For countries lacking data we assumed 99.9 % of Muslims and Jews were circumcised. If actual prevalence in religious groups was lower, then MC prevalence in those countries would be lower. On the other hand, we assumed a minimum prevalence of 0.1 % related to MC for medical reasons. This may be too low, thereby underestimating MC prevalence in some countries.

CONCLUSIONS

The present study provides the most accurate estimate to date of MC prevalence in each country and territory in the world. We estimate that 37-39 % of men globally are circumcised. Considering the health benefits of MC, these data may help guide efforts aimed at the use of voluntary, safe medical MC in disease prevention programs in various countries.

Male circumcision for prevention of homosexual acquisition of HIV in men

BACKGROUND

Previous systematic reviews found inconsistent effects of male circumcision on HIV acquisition in men who have sex with men (MSM). However, a number of new studies have become available in the three years since the last systematic review.

OBJECTIVES

To assess the effects of male circumcision for preventing HIV acquisition by men through sex with men.

SEARCH STRATEGY

In June 2010 we electronically searched the Cochrane Central Register of Controlled Trials, PubMed, EMBASE, AIDS Education Global Information System, ClinicalTrials.gov, and WHO International Clinical Trials Registry Platform; hand-searched reference lists of relevant articles; and contacted relevant organisations and experts. We updated the search in March 2011.

SELECTION CRITERIA

We looked for randomised controlled trials (RCTs) and observational studies that assessed the effects of male circumcision on HIV acquisition in MSM.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility and methodological quality, and extracted data. We expressed study results as odds ratios (OR) with 95% confidence intervals (CI), and conducted random-effects meta-analysis.

MAIN RESULTS

We found no completed RCT and included 21 observational studies with 71,693 participants. The only eligible RCT is currently ongoing among MSM in China. The pooled effect estimate for HIV acquisition was not statistically significant (20 studies; 65,784 participants; OR 0.86, 95% CI 0.70 to 1.06) and showed significant heterogeneity (I²=53%). In a subgroup analysis, the results were statistically significant in studies of men reporting an insertive role (7 studies, 3465 participants; OR 0.27, 95% CI 0.17 to 0.44; I²=0%) but not in studies of men reporting a receptive role (3 studies, 1792 participants; OR 1.20, 95% CI 0.63 to 2.29; I² = 0%). There was no significant association between male circumcision and syphilis (8 studies; 34,999 participants: OR 0.96, 95% CI 0.82 to 1.13; I² = 0%), herpes simplex virus 1 (2 studies, 2740 participants; OR 0.90, 95% CI 0.53 to 1.52; I²=0%), or herpes simplex virus 2 (5 studies;10,285 participants; OR 0.86, 95% CI 0.62 to 1.21; I²=0%). The overall GRADE quality of evidence was low. None of the included studies assessed adverse effects associated with male circumcision.

AUTHORS' CONCLUSIONS

Current evidence suggests that male circumcision may be protective among MSM who practice primarily insertive anal sex, but the role of male circumcision overall in the prevention of HIV and other sexually transmitted infections among MSM remains to be determined. Therefore, there is not enough evidence to recommend male circumcision for HIV prevention among MSM at present. Further research should be of high quality and further explore interaction with the predominant sexual role.

Egocentric network data provide additional information for characterizing an individual's HIV risk profile

OBJECTIVE

We investigated the hypothesis that partner-specific characteristics are important to improve an individual's risk characterization.

DESIGN

It has been shown that the egocentric network structure is important to establish a person's risk for infection.

METHODS

The study was cross-sectional in its design and enrolled 1231 volunteers at one HIV testing site in Rio de Janeiro, Brazil, and applied an adapted ego-network questionnaire. Each individual was interviewed about their own risk factors and those related to up to 10 sex partners. We used the dyadic data analysis method in which each relationship forms a record. Two receiver operator characteristic curves were generated, and the ability to correctly predict volunteers' HIV serostatus based on a model with characteristics of volunteers and sex partners and another with only volunteers' characteristics was evaluated.

RESULTS

Partner-related variables were associated with HIV serostatus both for men and women. The model with volunteer/sex partners' characteristics performed better in discriminating between HIV-positive and negative volunteers only for men but not for women. The c statistic for men volunteers was 0.82 [95% confidence interval (CI) 0.77-0.87] for the volunteer alone model and 0.88 (95% CI 0.86-0.91) for the combined model (P = 0.03). The values for women were 0.75 (95% CI 0.65-0.86) and 0.78 (95% CI 0.71-0.85), respectively (P = 0.71).

CONCLUSION

Ego-network theory-based approaches provide additional information for characterizing risk for HIV infection among men.