Male circumcision may not protect against some STDs

Circumcision may not reduce the risk of contracting certain nonulcerative sexually transmitted infections, according to results of a study conducted in Kisumu, Kenya.

Researchers randomly assigned 1,318 men aged 18-24 years to undergo circumcision to prevent HIV and 1,337 men of the same age to be in the control group.

The primary outcome was the first incidence of a nonulcerative sexually transmitted infection during a two-year follow-up period. Laboratory-detected Neisseria gonorrhoeae, Chlamydia trachomatis and Trichomonas vaginalis were the infections examined.

Results demonstrated that there were 342 incident infections among 2,655 men. The rate of infection for N. gonorrhoeae was 3.48 cases per 100 person-years. The rate for C. trachomatis was 4.55 cases per 100 years and for T. vaginalis, 1.32 cases per 100 years.

The combined incidence rate for N. gonorrhoeae and C. trachomatis was 7.26 cases per 100 person years (95% CI, 6.49-8.13 cases per 100 person-years).

The incidences of the studied infections did not vary regarding circumcision status, either as a time-dependent variable or a fixed variable based on assignment. This held true for analyses of the individual infections and for combined rates.

Multivariate analysis results demonstrated that having a sexually transmitted infection at enrollment, multiple sex partners within the past 30 days and sexual intercourse during menses in the previous six months were independent risk factors for incident infection. The researchers observed a protective effect of condom use.

Mehta SD et al. J Infect Dis. 2009;200:370-378.