Causative organism Mycoplasma genitalium (Mg)
Incubation period Unknown but likely to be 60 days or longer
How far back to trace The time period for contact tracing is unknown. Contact tracing is recommended for ongoing sexual partners
Usual testing method Nucleic acid amplification testing on first pass urine in men (urethral swab less sensitive) and, high vaginal swab in women (cervical swab slightly less sensitive and first pass urine least sensitive). A rectal swab should be collected in MSM and females engaging in anal sex. A throat swab is not indicated.
Common symptoms

Often asymptomatic. Symptoms and signs when present are similar to those of chlamydia but less frequent.

If symptomatic, causes urethral discharge, urethral discomfort/irritation or dysuria in people with a penis.

In those with a vagina, M.genitalium has been associated with post-coital bleeding, cervicitis and pelvic inflammatory disease.

Symptoms of PID include abdominal and/or pelvic pain, dyspareunia [1-2] and may include fever.

Evidence suggests an association with proctitis in MSM (rectal pain, bleeding and tenesmus), although studies do not show a strong and consistent association

Likelihood of transmission per act of condomless intercourse


Although it is established that M. genitalium is sexually transmitted, it is not known how often this occurs per episode of condomless sexual intercourse [3]

Likelihood of long-term sexual partner being infected Infection rates in a study of sexual contacts, that predominantly represented long term partners, are in the order of 40–50% in those with a vagina and MSM (cis and trans) (rectal site more often infected than urethral site), and 30% in heterosexual people with a penis[4].
Protective effect of condoms Likely high
Transmission by oral sex

Low as pharyngeal infection is uncommon (<1%).

Studies are limited but indicate it is uncommonly detected in the pharynx[3]

Duration of potential infectivity Uncertain; however, persistent infection is common: 25% of untreated infections persist > 12 months in people with a vagina and infections up to 2-3 years have been reported. With rising antimicrobial resistance persistent infection due to treatment failure is also increasingly common.
Important sequelae PID, spontaneous abortion, post-abortal PID preterm delivery and possibly tubal factor infertility in women. Limited evidence to suggest a possible role in sexually acquired reactive arthritis and epididymo-orchitis
Direct benefit of detection and treatment of contacts Cure/prevention transmission
Usual management of contacts

Counselling, clinical examination, testing of ongoing sexual partners.

Treat based on test result according to STI guidelines 

Contact tracing priority Medium
Notification Not notifiable in Australia or New Zealand.


  1. Read TRH, Murray GL, Danielewski JA, et al. Symptoms, Sites, and Significance of Mycoplasma genitalium in Men Who Have Sex with Men. Emerg Infect Dis. 2019 Apr;25(4):719-727.
  2. Latimer RL, Shilling HS, Vodstrcil LA, et al. Prevalence of Mycoplasma genitalium by anatomical site in men who have sex with men: a systematic review and meta-analysis.Sex Transm Infect. 2020 Apr 27: sextrans-2019-054310. doi: 10.1136/sextrans-2019-054310. Online ahead of print
  3. Taylor-Robinson D, Jensen JS. Mycoplasma genitalium: from Chrysalis to multicolored butterfly. Clin Microbiol Rev. 2011 Jul;24(3):498-514. doi: 10.1128/CMR.00006-11. PMID: 21734246; PMCID: PMC3131060.
  4. Slifirski JB, Vodstrcil LA, Fairley CK, et al. Mycoplasma genitalium Infection in Adults Reporting Sexual Contact with Infected Partners, Australia, 2008-2016. Emerg Infect Dis. 2017 Nov;23(11):1826-1833. doi: 10.3201/eid2311.170998.


Page last updated April 2021