What is the recommended treatment for Mycoplasma (M.) genitalium sexually transmitted disease (STD)?

Treatment of Mycoplasma genitalium Sexually Transmitted Disease

The recommended first-line treatment for Mycoplasma genitalium infection is azithromycin 1g orally in a single dose, with doxycycline 100mg orally twice daily for 7 days as an alternative option, though treatment failures are increasingly common due to antimicrobial resistance.

Diagnosis and Clinical Presentation

M. genitalium is a common cause of non-gonococcal urethritis (NGU) in men and can cause cervicitis, pelvic inflammatory disease (PID), and potentially infertility in women 1. Clinical presentation includes:

• In men: Urethral discharge, dysuria, or asymptomatic infection
• In women: Cervicitis, abnormal vaginal discharge, PID, or asymptomatic infection

Laboratory testing should include nucleic acid amplification tests (NAATs) for M. genitalium, as this organism cannot be cultured using standard methods.

Treatment Algorithm

First-line Treatment:

• Azithromycin 1g orally in a single dose 2, 3
  • Advantages: Single-dose therapy improves adherence
  • Higher efficacy than doxycycline for M. genitalium specifically

Alternative Regimens (if azithromycin unavailable or contraindicated):

• Doxycycline 100mg orally twice daily for 7 days 2, 3
  • Note: While effective for chlamydia, doxycycline has lower efficacy against M. genitalium

For Treatment Failures (suspected antimicrobial resistance):

1. Moxifloxacin 400mg orally once daily for 7-14 days 4

   • Currently the most reliable option for azithromycin-resistant infections

2. For multi-drug resistant infections:

   • High-dose tinidazole 2g daily for 7 days may be considered 5

Antimicrobial Resistance Considerations

Antimicrobial resistance in M. genitalium is an increasing concern:

• Macrolide resistance (affecting azithromycin) has been reported on three continents 4
• Up to 41% of M. genitalium infections may carry macrolide resistance markers 6
• Fluoroquinolone resistance (affecting moxifloxacin) is also emerging 6

When available, antimicrobial resistance testing should guide therapy selection. In settings with high macrolide resistance, consider initial treatment with moxifloxacin rather than azithromycin.

Partner Management

• All sexual partners from the preceding 60 days should be evaluated, tested, and treated 3
• Partners should receive the same treatment regimen as the index case
• Patients and partners should abstain from sexual intercourse until 7 days after completing single-dose therapy or until completion of a multi-day regimen 3

Follow-up

• Test-of-cure is recommended 3-4 weeks after treatment completion due to high treatment failure rates
• Patients with persistent symptoms after treatment should be re-evaluated for:
  • Reinfection from untreated partner
  • Antimicrobial resistance
  • Alternative diagnoses

Special Considerations

• Pregnancy: Doxycycline and fluoroquinolones are contraindicated; azithromycin is preferred 3
• HIV infection: Same treatment regimens are recommended for HIV-positive and HIV-negative patients 3
• Co-infections: Test for other STIs including chlamydia and gonorrhea, as co-infections are common 3

Clinical Pitfalls to Avoid

1. Failing to consider M. genitalium in persistent/recurrent NGU: Up to 16.7% of NGU cases may be caused by M. genitalium 6
2. Using doxycycline as first-line therapy: While effective for chlamydia, it has lower efficacy against M. genitalium
3. Not testing for antimicrobial resistance: When available, resistance testing should guide therapy
4. Inadequate partner treatment: Untreated partners lead to reinfection
5. Overlooking the possibility of PID in women: M. genitalium has been associated with PID and potential reproductive sequelae 7

The increasing prevalence of antimicrobial resistance in M. genitalium highlights the importance of appropriate diagnostic testing and targeted therapy to improve clinical outcomes and prevent further development of resistance.