Mycoplasma genitalium

M. genitalium | M. gen |


  • Our understanding of M. genitalium is rapidly evolving and so some recommendations are practical and likely to change as more evidence emerges
  • Established cause of urethritis, cervicitis and PID and associated with preterm delivery and miscarriage(1, 2)
  • Azithromycin (macrolide) resistance is common, particularly in MSM(3)
  • More laboratories now offer testing and some tests report macrolide resistance
  • Asymptomatic anorectal infection in MSM is common but the significance is unknown and asymptomatic screening is not currently recommended.


Mycoplasma genitalium

Clinical presentation

Male Female
Often asymptomatic but associated with similar symptoms to chlamydia Often asymptomatic
Dysuria Vaginal discharge
Urethral discharge Pelvic pain
Possibly Proctitis Intermenstrual bleeding
  Post-coital bleeding
  Possibly dysuria
Significance in Epididymo-orchitis is unknown

pelvic inflammatory disease (PID), infertility and ectopic pregnancy

Possible role in tubal factor infertility

Further studies continuing to elucidate role in disease causation.


Diagnosis in males
NAAT* FPU  n/a
NAAT – Nucleic Acid Amplification Test 
FPU – First pass urine


Diagnosis in females
NAAT Endocervical swab  
NAAT  Vaginal swab (clinician or self-collected)  
NAAT FPU Not as sensitive as vaginal swab
*NAAT – Nucleic Acid Amplification Test - some also detect macrolide resistance which will guide choice of therapy.
FPU – First pass urine

Specimen collection

Clinician collected |


  • Throat swabs are not recommended as pharyngeal infection is uncommon.
  • NAAT testing for Mycoplasma genitalium is available in reference laboratories and in some private laboratories. Some tests can detect macrolide resistance mutations which can guide choice of therapy.

Special considerations

Screening asymptomatic people for M. genitalium is not recommended. Only test those with symptoms and their contacts.



Treating a macrolide-susceptible M. genitalium infection with azithromycin will result in treatment failure and macrolide resistance in about 10% of infections.

Macrolide resistance is likely to be present in at least half of infections in Australian cities, based on studies from the eastern states. At one centre resistance was present in 50% of infections in heterosexuals and 80% in MSM. Resistance to fluoroquinolones is present in 10 – 15% of infections.

Doxycycline is ineffective in two-thirds of infections but will lower bacterial load in most cases, increasing the likelihood of cure with a subsequent antibiotic.

Pre-treating M. genitalium infections with doxycycline 100mg bd for one week and then treating susceptible infections with azithromycin and macrolide-resistant infections with a fluoroquinolone eradicated >90% of infections.(4)

Without access to resistance testing, it is reasonable to assume macrolide resistance in infections persisting after failure of azithromycin and in MSM.(3)

Principal Treatment Options
M. genitalium infection known or suspected to be macrolide-susceptible


Doxycycline 100mg bd for 7 days

followed by

Azithromycin 1g stat then 500mg daily for three days (total 2.5g)*

Doxycycline 100mg bd for 7 days

followed by

Azithromycin 1g single dose*
M. genitalium infection known or suspected to be macrolide-resistant

Doxycycline 100mg bd for 7 days

followed by

Moxifloxacin 400mg daily for 7 days

Pelvic inflammatory disease due to M.genitalium Moxifloxacin 400mg daily for 14 days**  

 *It is not known to what extent the improved outcomes resulting from the use of doxycycline followed by 2.5g azithromycin are due to this dose of azithromycin, rather than simply the pre-treatment with doxycycline. The higher dose of azithromycin requires a private prescription.

**M. genitalium results are often received about a week after PID treatment has begun. After a good response to treatment it may be reasonable to shorten the course of moxifloxacin to ten days, due to the cost and potential toxicity of this drug, however this has not been studied.

Moxifloxacin requires a private prescription, cannot be used in pregnancy, and is expensive and is associated with diarrhoea, occasional tendinopathy and rare neurological and cardiac events.


Other immediate management

  • Advise no condomless sex until tested for cure (14 days after completion of treatment).
  • Advise no sex with untested previous sexual partners.
  • Provide patient with factsheet
  • M. genitalium is not a notifiable condition.


Special treatment situations

Special considerations

If moxifloxacin fails or cannot be used, seek specialist advice.

Contact tracing

  • In heterosexuals the risk of PID  and reproductive complications suggests a greater need to trace, test and treat infected contacts. The time period for contact tracing is unknown.
  • Asymptomatic infection and macrolide resistance are more common in MSM  and there is only limited evidence that this is harmful. As moxifloxacin will probably be required for treatment, contact tracing may be best confined to continuing partners of a symptomatic person.

See Australasian Contract Tracing Manual - Mycoplasma genitalium for more information.

Follow up

Test of Cure (TOC)

TOC by NAAT should be done at least 2 weeks after treatment is completed ie 4 weeks after commencing therapy.


  1. Jensen JS, Bradshaw C. Management of Mycoplasma genitalium infections - can we hit a moving target? BMC infectious diseases. 2015;15:343.
  2. Lis R, Rowhani-Rahbar A, Manhart LE. Mycoplasma genitalium infection and female reproductive tract disease: a meta-analysis. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 2015;61(3):418-26.
  3. Read TRH F, CK, Tabrizi S, Bissessor M, Vodstrcil L, Chow EPF, Grant M, Danielewski J, Garland SM, Hocking JS, Chen MY, Bradshaw CS. Azithromycin 1.5g over five days compared to 1g single dose in urethral Mycoplasma genitalium: impact on treatment outcome and resistance Clinical Infectious Diseases. 2016.
  4. Read TRH, Fairley CK, JS J, Murray GL, Worthington K, Doyle M, et al. Improved outcomes following resistance-guided treatment of Mycoplasma genitalium infection. International Society for Sexually Transmitted Diseases Research; Rio de Janiero2017.


Last Updated: Wednesday, 11 July 2018