Mycoplasma Genitalium (MG)

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Mycoplasma genitalium (MG) is an STI caused by bacteria. Transmission can occur if you have unprotected sex with someone who already has the infection. MG is a bacteria that can exist in the urethra, cervix and anus. It is often asymptomatic but can cause health problems such as pelvic inflammatory disease, endometriosis, and some serious pregnancy complications. Time between infection and when (if) symptoms appear vary between 2 and 60 days.

Signs & Symptoms

Visible symptoms may or may not be present. Most people are likely to show no visible symptoms, and it is more likely for people with vaginas to be asymptomatic. If symptoms are showing, they are likely to be: 


  • Bleeding between menstrual cycles
  • Bleeding after penetrative sex
  • Pelvic pain
  • Pain during penetrative sex
  • Discharge


  • Mild irritation or stinging when passing urine
  • Watery discharge
  • Irritation around urethral opening on penis


  • Inflammation around the rectum and anus


  • Throat infection is rare (1%)


  • Unprotected vaginal or anal sex
  • Docking or nudging without condoms


Routine STI testing will not detect this infection. It must be requested from your sexual health clinic. Testing is recommended for HIV positive people, and for people with symptoms who test negative for chlamydia, gonorrhoea and herpes. It is not recommended to test asymptomatic people unless there is a contact of known infection.

Testing is with an anal and vaginal swab, as well as a urine sample.


Treatment for MG is with antibiotics. In many instances, MG can be resistant to some antibiotics, so a further test at three weeks after treatment must be performed to ensure the prescribed treatment has worked. Reinfection by having sex with unsuccessfully treated or untreated partners may increase the likelihood of developing treatment resistance. 

After treatment it is advised to avoid sexual contact for 7 days, and avoid unprotected sex until after the follow up test comes back negative. It is also advised to avoid sexual contact with partners from the last 6 months, until 7 days after the partners have also been tested and treated. 


Use condoms during sexual activity. When withdrawing, hold the base of the condom so semen doesn’t spill out.