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 penile urethra (urethral swab less sensitive) or, high vaginal swab (cervical swab slightly less sensitive and first pass urine least sensitive). A rectal swab should be collected in individuals 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 penile urethral discharge, urethral discomfort/irritation or dysuria.

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 women and MSM (cis and trans) (rectal site more often infected than urethral site), and 30% in heterosexual men[4].

*Note: the gendered language is that used in the research and repeated here.

Protective effect of condoms Likely high
Transmission by oral sex

Low as pharyngeal infection is uncommon (<1%).[3]

Duration of potential infectivity Uncertain; however, persistent infection is common: 25% of untreated cervical infections persist >12 months  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.

Limited evidence to suggest a possible role in sexually acquired reactive arthritis and epididymo-orchitis

Direct benefit of detection and treatment of contacts Cure/prevent transmission
Usual management of contacts

Counselling, clinical examination, testing of ongoing sexual partners.

Treat based on test results according to STI guidelines 

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


  1. Read TRH, Murray GL, Danielewski JA, Fairley CK, Doyle M, Worthington K, Su J, Mokany E, Tan LT, Lee D, Vodstrcil LA, Chow EPF, Garland SM, Chen MY, Bradshaw CS.Symptoms, Sites, and Significance of Mycoplasma genitalium in Men Who Have Sex with Men. Emerg Infect Dis. 2019 Apr;25(4):719-727.DOI: 10.3201/eid2504.181258
  2. Latimer RL, Shilling HS, Vodstrcil LA, Machalek DA, Fairley CK, Chow EPF, Read TR, Bradshaw CS. 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. 
  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


Page last updated September 2022