Symptoms of Mycoplasma genitalium Infection
Mycoplasma genitalium infection is frequently asymptomatic in both men and women, but when symptomatic, it causes urethritis in men (with urethral discharge and dysuria) and cervicitis in women (with abnormal vaginal discharge, intermenstrual bleeding, and pelvic pain). 1, 2
Clinical Presentation in Men
Most men with M. genitalium infection are asymptomatic and likely clear the infection spontaneously without developing disease. 3
When symptomatic, men typically present with:
- Urethral discharge (purulent or mucopurulent) 4
- Dysuria (painful urination) 2
- Urethral discomfort or irritation 5
- Symptoms of non-gonococcal urethritis (NGU) that are clinically indistinguishable from chlamydial urethritis 3
Acute vs. Chronic Symptoms in Men
- Acute urethritis is the most common presentation (75.6% of symptomatic cases), characterized by urethral discharge and dysuria 4
- Chronic symptoms are associated with previous antibiotic use, history of STIs, and absence of visible urethral discharge 4
- The incubation period for M. genitalium urethritis is likely longer than for chlamydial urethritis 3
Clinical Presentation in Women
Women with M. genitalium may present with nonspecific symptoms or be completely asymptomatic. 2, 6
When symptomatic, women typically present with:
- Abnormal vaginal discharge (mucopurulent cervical discharge) 5
- Intermenstrual vaginal bleeding, particularly after sexual intercourse 5
- Pelvic pain 2
- Dysuria 2
- Signs of cervicitis including purulent endocervical exudate and sustained endocervical bleeding induced by gentle swabbing 5
Upper Genital Tract Complications in Women
M. genitalium can cause serious complications including:
- Pelvic inflammatory disease (PID) 5, 1, 2
- Endometritis 1, 7
- Potential infertility 6, 7
- Increased susceptibility to HIV 6
Important Clinical Considerations
The clinical characteristics of symptomatic infections do not reliably identify M. genitalium as the causative pathogen, as symptoms are indistinguishable from those caused by C. trachomatis or N. gonorrhoeae. 3
Co-infections Are Common
- M. genitalium frequently occurs as a co-infection with C. trachomatis (39.3%) and N. gonorrhoeae (21.3%) 4
- Co-infections are more prevalent in acute urethritis compared to chronic or asymptomatic cases 4
- Only 52.8% of M. genitalium cases present as mono-infections 4
Asymptomatic Infection
- M. genitalium can act as a "stealth pathogen" in the female reproductive tract, causing no symptoms despite active infection 6
- Asymptomatic infection is common in men, with most likely clearing infection spontaneously 3
- Prevalence ranges from 0.5-10% in the general population and 20-40% in women with STIs 6
Key Clinical Pitfalls
Do not rely on symptoms alone to diagnose or rule out M. genitalium infection, as the majority of infections are asymptomatic and symptomatic presentations are nonspecific. 6, 3 Testing requires nucleic acid amplification testing (NAAT), as standardized commercial diagnostic tests are not widely available. 5, 1