Mycoplasma genitalium Infection in Men

Abstract

Mycoplasmagenitalium is one of the major causes of nongonococcal urethritis (NGU) worldwide but an uncommon sexually transmitted infection (STI) in the general population. The risk of sexual transmission is probably lower than for Chlamydia trachomatis. Infection in men is usually asymptomatic and it is likely that most men resolve infection without developing disease. The incubation period for NGU caused by Mycoplasma genitalium is probably longer than for NGU caused by C. trachomatis. The clinical characteristics of symptomatic NGU have not been shown to identify the pathogen specific etiology. Effective treatment of men and their sexual partner(s) is complicated as macrolide antimicrobial resistance is now common in many countries, conceivably due to the widespread use of azithromycin 1 g to treat STIs and the limited availability of diagnostic tests for M. genitalium. Improved outcomes in men with NGU and better antimicrobial stewardship are likely to arise from the introduction of diagnostic M. genitalium nucleic acid amplification testing including antimicrobial resistance testing in men with symptoms of NGU as well as in their current sexual partner(s). The cost effectiveness of these approaches needs further evaluation. The evidence that M. genitalium causes epididymo-orchitis, proctitis, and reactive arthritis and facilitates human immunodeficiency virus transmission in men is weak, although biologically plausible. In the absence of randomized controlled trials demonstrating cost effectiveness, screening of asymptomatic men cannot be recommended.

Keywords: Mycoplasma genitalium; antimicrobial resistance; men; nongonococcal urethritis; nucleic acid amplification test.

Figure 1.

Hypothetical frequency distribution of urinary leukocyte counts for Mycoplasma genitalium and no infection in high-risk men presenting to a genitourinary medicine department who were tested for Chlamydia trachomatis and Neisseria gonorrhoeae. Line A correlates with the urethral smear cutoff of 5 polymorphonuclear leukocytes per high-power field for nongonococcal urethritis, and line B demonstrates the effect on sexually transmitted infection detection if the cutoff is decreased. Adapted from Wiggins et al [45].