Mycoplasma genitalium is associated with symptomatic and asymptomatic non-gonococcal urethritis in men.

Objectives: To examine the prevalence of Mycoplasma genitalium in a large number of male patients attending a sexually transmitted infections (STI) clinic and to determine if there is an association with objective non-gonococcal urethritis (NGU) in patients with and without clinical symptoms.

Methods: Patients were tested for both M genitalium and Chlamydia trachomatis if they had symptoms or microscopic signs of NGU or if they were perceived to be at high-risk of exposure to a STI (n = 8468). Urethral smears were examined for polymorphic mononuclear leucocytes.

Results: We found that M genitalium infection was associated with symptoms of non-chlamydial NGU (discharge and dysuria; OR 4.3; 95% CI 3.4 to 5.5). We also found that M genitalium infection was associated with signs of non-chlamydial NGU independently with or without symptoms of NGU (with symptoms: OR 4.7; 95% CI 3.2 to 6.7; without symptoms: OR 3.1; 95% CI 2.0 to 4.6). Prevalence of M genitalium was also associated with severity of urethritis as quantified by microscopic examination of urethral smears.

Conclusions: These data add further evidence to the association of M genitalium infection with NGU and should allow better risk analysis of recent recommendations of not performing urethral smears in asymptomatic men attending STI clinics.