- In Australia, trichomonas is more common in older women and women from regional and remote areas, especially Aboriginal & Torres Strait Islander women
- Uncommon cause of vaginal discharge or male urethritis in urban settings
- Long natural history (years) if not treated in women
- Without treatment, the infection is cleared more quickly in men than women.
Trichomonas vaginalis, a protozoan which infects the vagina, urethra and paraurethral glands.
|Usually asymptomatic. See chlamydia for more information||Malodourous vaginal discharge - typically profuse and frothy|
|Urethral discharge (uncommon)||Vulval itch/soreness|
|Associated with prostatitis||Associated with premature rupture of membranes, pre-term delivery and low birth weight|
- Up to 50% of infected women are asymptomatic, men are usually asymptomatic.
- May enhance HIV transmission.
- Seek specialist advice
- Testing is not routinely recommended for men with urethritis
- Treat male contacts presumptively.
|Diagnosis in males|
||FPU||Available in major laboratories in each state|
|NAAT – Nucleic Acid Amplification Test
FPU – First pass urine
|Diagnosis in females|
||High vaginal swab or FPU
||High vaginal swab can be self-collected or clinician collected Clinician collected|
||High vaginal swab||
Clinician collected from posterior fornix or self collected
Normal vaginal pH = 4.5. pH >4.5 suggestive of trichomoniasis or bacterial vaginosis
NAAT – Nucleic Acid Amplification Test
Specimen collectionUrine Collection | Swab Collection
- NAAT testing for Trichomonas vaginalis is currently available through some private pathology companies and the following laboratories:
- NSW: SydPath, St Vincent’s PathologyDarlinghurst & Pathology West – ICPMR, Westmead Hospital, Westmead
- QLD: QML Pathology, Brisbane & Queensland Pathology
- SA: SA Pathology, Adelaide
- VIC: Core Laboratory, The Royal Women’s Hospital, Melbourne
- WA: PathWest Laboratory, Queen Elizabeth II Medical Centre, Perth
- Cervical screening (Pap smear) and urine or high vaginal samples may report trichomonas but these results must be confirmed by NAAT before initiating treatment
- Cervical screening alone is not diagnostic of trichmonas
|Principal Treatment Options|
Metronidazole 2g PO with food, stat.
|Metronidazole 400mg PO with food, BD for 5 days.|
- Reinfection and poor adherence should be ruled out in persistent or recurrent infection
- Treatment failures with single-dose metronidazole should trial single dose tinidazole or extended metronidazole therapy
- High-level metronidazole resistance has been reported, although incidence is believed to be low. Reports indicate successful treatment with extended doses of oral or intra vagina tinidazole for these patients – discuss with local sexual health clinic
- Avoid alcohol with metronidazole and tinidazole treatment and for 24 hours thereafter.
Other immediate management
- Advise no sexual contact for 7 days after treatment is administered and their current sexual partner is treated
- Contact tracing
- Provide patient with factsheet
- Trichomoniasis is only a notifiable condition in the NT.
Special treatment situations
- Single-dose treatments are advised.
- Consider seeking specialist advice before treating any complicated presentation.
|Pregnant women||Due to conflicting outcomes of treating in pregnancy, seek specialist advice|
|Breastfeeding||Consider intravaginal treatment. Metronidazole may affect taste of breast milk; avoid high doses in breastfeeding.|
|Allergy to principal treatment choice||There is no effective alternative to 5 nitroimidazole compounds.
Metronidazole desensitisation has been described
|People who are HIV positive||Reports indicate single-dose metronidazole is less effective than extended metronidazole.|
- For all sexual partners
- There is currently insufficient data to provide a definitive period for this, partner treatment encouraged presumptively.
See Australasian Contact Tracing Manual - Trichomoniasis for more information.
Review in 1 week provides an opportunity to:
- Confirm patient adherence with treatment and assess for symptom resolution
- Confirm contact tracing procedures have been undertaken or offer more contact tracing support
- Provide further sexual health education and prevention counselling.
Test of Cure (TOC)
- For patients who remain symptomatic or where partner treatment remains uncertain, retesting should be performed after 4 weeks
- This also provides the opportunity to retest, post the window period, for other STIs.
100% of women diagnosed are treated with recommended principle treatment option.
- Dize, Laura. Agreda, Patricia. Quinn, Nicole. Barnes, Mathilda R. Hsieh, Yu-Hsiang. Gaydos, Charlotte A. Comparison of self-obtained penile-meatal swabs to urine for the detection of C. trachomatis, N. gonorrhoeae and T. vaginalis. Sexually Transmitted Infections. 89(4):305-7, 2013 Jun.
- Lusk, Josephine. Naing, Zin. Rayner, Ben. Rismanto, Nikolas. McIver, Christopher. Cumming, Robert. McGeechan, Kevin. Rawlinson, William. Konecny, Pam. Trichomonas vaginalis: underdiagnosis in urban Australia could facilitate re-emergence. Sex Transm Infections. 86:227-230, 2010.