What is the recommended treatment for Mycoplasma hominis infections?

Management of Mycoplasma hominis Infections

Mycoplasma hominis infections should be treated with tetracyclines (doxycycline) as first-line therapy, with fluoroquinolones (moxifloxacin) as effective alternatives, especially in cases of tetracycline resistance or treatment failure.

Antimicrobial Options for M. hominis

First-Line Treatment

• Doxycycline: 100 mg twice daily for 7-14 days
  • Most effective first-line option for uncomplicated infections
  • Treatment duration depends on infection site and severity

Alternative Treatments

• Fluoroquinolones:

  • Moxifloxacin: 400 mg once daily for 7-14 days 1
  • Ciprofloxacin: 400 mg IV or 500-750 mg oral twice daily 2
  • Particularly useful for invasive infections or treatment failures

• Clindamycin: Can be considered in cases of tetracycline resistance or in pregnant women

Treatment Considerations by Infection Site

Genital Infections

• Uncomplicated urethritis/cervicitis:
  • Doxycycline 100 mg twice daily for 7 days 1
  • Test for concomitant infections (C. trachomatis, N. gonorrhoeae)

Invasive Infections

• Septic arthritis/ventriculitis/other invasive infections:
  • Initial IV therapy with fluoroquinolones (moxifloxacin or ciprofloxacin) 2
  • Consider combination therapy for severe infections
  • Longer treatment duration (minimum 14 days)

Neonatal Infections

• Meningitis in infants:
  • Moxifloxacin has been successfully used in neonates with M. hominis meningitis 1
  • Careful monitoring required due to limited data on fluoroquinolone use in neonates

Diagnostic Approach

1. Specimen collection:

   • Urethral/cervical swabs for genital infections
   • Synovial fluid for septic arthritis
   • CSF for suspected CNS infections

2. Testing methods:

   • PCR testing is most sensitive and specific
   • Culture requires special media (not routine bacterial culture)
   • M. hominis lacks a cell wall and won't be visible on Gram stain

Treatment Challenges

• Diagnostic delays: M. hominis grows slowly or not at all on routine culture media 3
• Intrinsic resistance: Naturally resistant to macrolides (azithromycin, erythromycin) due to genetic characteristics
• Treatment failures: Monitor for clinical improvement; consider resistance testing if available

Special Populations

Immunocompromised Patients

• May require longer treatment courses
• Consider consultation with infectious disease specialists
• Close monitoring for treatment response

Pregnant Women

• Clindamycin preferred over tetracyclines and fluoroquinolones
• Individualize treatment based on infection severity and trimester

Follow-up

• Clinical reassessment after completion of therapy
• Test of cure recommended for persistent symptoms
• Partner notification and treatment for genital infections

Key Pitfalls to Avoid

1. Using macrolides: M. hominis is intrinsically resistant to macrolides like azithromycin
2. Inadequate treatment duration: Especially for invasive infections
3. Delayed diagnosis: Consider M. hominis in culture-negative infections, particularly after genitourinary procedures
4. Missing concomitant infections: Test for other sexually transmitted infections in genital cases

Remember that M. hominis infections can range from asymptomatic colonization to severe invasive disease, with treatment approach determined by clinical presentation, infection site, and patient factors.