Mycoplasma genitalium infection

Mycoplasma genitalium (Mgen) infection is a sexually transmitted infection. It is frequently asymptomatic but may cause urethritis or cervicitis. In patients who do not respond to antimicrobial therapy for these conditions, Mgen infection should be suspected. If available, macrolide resistance testing should also be performed because infection with macrolide-resistant strains of Mgen is common. Treatment requires a combination of antibiotics, usually doxycycline followed by either azithromycin or moxifloxacin.

• M. genitalium is detected in the genital tract in 1–6.4% of the general population. ^[1]
• In individuals with male genitalia, M. genitalium is detected in
  • 15–20% of patients with nongonococcal urethritis ^[2]
  • 40% of patients with refractory or recurrent urethritis ^[2]
• In individuals with female genitalia, M. genitalium is detected in 10–30% of patients with cervicitis ^[2]

Epidemiological data refers to the US, unless otherwise specified.

• Pathogen ^[3]
  • M. genitalium
  • Small, flask-shaped bacteria
  • No cell wall ^[4]
  • Incubation period: unknown ^[5]
• Transmission: sexual ^[2]

• Frequently asymptomatic
• Patients may present with:
  • Urethritis
    • Dysuria
    • Urethral discharge
    • Irritation of the urethral meatus
  • Cervicitis
    • Vaginal discharge
    • Postcoital and intermenstrual bleeding
• There may be an association with pelvic inflammatory disease (PID).

Consider Mgen infection in patients whose symptoms do not respond to antimicrobial treatment for urethritis or cervicitis. ^[2]

• Indications ^[2]
  • Urethritis or cervicitis refractory to antimicrobial therapy
  • Recurrent urethritis or cervicitis
  • Consider for patients with PID
• Methods ^[2]
  • NAAT of urine or urethral, penile, endocervical, or vaginal swabs
  • Molecular test for macrolide resistance: Perform when available.
  • Bacterial culture: not recommended

Testing for extragenital Mgen infection is not currently recommended. ^[2][6]

• Initiate antibiotic therapy.
  • Patients with urethritis or cervicitis: tailor treatment based on macrolide susceptibility, if known. ^[7]
    • Macrolide sensitive: doxycycline followed by azithromycin (total duration of therapy: 10 days) ^[2][7]
    • Macrolide resistant or resistance unknown: doxycycline followed by moxifloxacin (total duration of therapy: 14 days) ^[2][7]
  • Patients with PID and confirmed Mgen infection: treat with empiric antibiotic therapy for PID PLUS moxifloxacin. ^[2]
• Follow-up after treatment.
  • Symptoms resolved: Test of cure is not recommended. ^[2]
  • Suspected treatment failure: Consult infectious diseases.
• Offer testing and treatment to sexual partners. ^[2]
• Screen for other STIs, if not already performed.

The treatment of Mgen infection may be complex, as macrolide resistance is common, fluoroquinolone resistance is increasing, and beta-lactams, including cephalosporins, cannot be used as M. genitalium lacks a cell wall. ^[1][2]

Symptomatic Mgen infection may be associated with: ^[2]

• Pregnancy complications (e.g., preterm labor, spontaneous abortion)
• Infertility

We list the most important complications. The selection is not exhaustive.

• Screening asymptomatic individuals for Mgen infection is not recommended. ^[2]
• See “STI prevention.”