The prevalence of urethral and rectal Mycoplasma genitalium among men who have sex with men in China, a cross-sectional study.

Background: Although Mycoplasma genitalium (MG) is a common sexually transmitted infection (STI), very little information regarding the prevalence of MG among MSM (men who have sex with men) is available in China. The objective of this study was to determine the prevalence of MG among MSM in the city of Shenzhen, Guangdong Province, China, and to identify the potential risk factors associated with MG infection in this population.
Methods: Between January and May 2010, a total of 409 MSM were recruited in Shenzhen, Guangdong Province, China. An anonymous questionnaire was used to collect information regarding their sociological and sexual behaviors. In addition, their first-void urine (FVU) samples and rectal swabs were collected for PCR-based MG testing.
Results: Among the 406 FVU and 405 rectal swab samples were collected from 409 MSM, the overall MG prevalence was 8.1% (33/406, 95% CI 5.7%-10.6%), with a FVU positivity of 3.4% (95% CI 1.7%-5.4%) and a rectal positivity of 5.4% (95% CI 3.5%-7.7%). Using both univariate and multivariable logistic regression analyses, urethral MG infection was significantly associated with having more heterosexual behaviors (AOR 7.16, 95% CI 1.89-27.13), and with having unprotected anal intercourse in the past six months (AOR 4.80, 95% CI 1.40-16.47). Rectal MG infection was significantly associated with HIV infection based on univariate logistic regression analysis (OR = 4.49, 95% CI 1.18-17.12).
Conclusions: In this study, we investigated the prevalence of MG infection in the population of interest, as determined from both urethral and rectal specimen. We showed that MG was more prevalent in MSM who had bisexual behaviors compared to those who engaged only in homosexual behaviors. Further work is needed to establish the mode of MG transmission and to identify its role in HIV transmission. Meanwhile, more attention should be paid to MG infection among MSMs, and especially bisexual MSMs, which might have critical implications for effective HIV/STD control in China.