| Causative organism |
Trichomonas vaginalis A protozoan which infects the vagina, urethra and paraurethral glands. |
| Incubation period | 5-28 days |
| How far trace back | There is insufficient data to provide a definitive period, but current contact tracing and concurrent treatment is recommended to prevent reinfection. |
| Usual testing method | Nucleic acid amplification tests (NAATs) are the most sensitive tests available to detect Trichomonas vaginalis. Wet preparation microscopy and culture are less sensitive |
| Common symptoms |
10–50% of people are asymptomatic. Vaginal symptoms: vaginal itch, vaginal discharge typically profuse malodorous (fishy odour) and frothy, and cervicitis. Penile symptoms: are uncommon, but urethral discharge and dysuria occasionally occur |
| Likelihood of transmission per act of unprotected intercourse |
Unknown, likely moderate to high Perinatal transmission 5% |
| Likelihood of long-term sexual partner being infected | Up to 70% of insertive partners in penis-in-vagina sex and 60-100% of receptive partners in penis-in-vagina sex |
| Protective effect of condoms | High |
| Transmission by oral sex | Extragenital infections (oral, anal) are uncommon |
| Duration of potential infectivity | Trichomonas vaginalis in vaginal infections is thought to be longstanding, up to 3-5 years, whereas penile infections may spontaneously resolve lasting up to 4 months. |
| Important sequelae |
Preterm delivery and low birth weight; Increased transmission of HIV |
| Direct benefit of detection and treatment of contacts | Cure |
| Usual management of contacts | Counselling, clinical examination and testing. Treat sexual partners presumptively |
| Contact tracing priority | Medium. |
| Notification |
Only notifiable in the Northern Territory in Australia. Not notifiable in New Zealand |
Page last updated September 2022