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Approach to trichomoniasis

Last updated 22 Mar 2026 · STIs & Sexual Health

Assessment of Trichomoniasis

Clinical Presentation

Trichomoniasis presents differently in males and females, with many infections being asymptomatic. Clinical assessment should consider both symptomatic and asymptomatic presentations, particularly in high-risk populations.

Female Presentation
  • Vaginal discharge (frothy, yellow-green, malodorous)
  • Vulvar irritation and pruritus
  • Dysuria and urinary frequency
  • Dyspareunia
  • Post-coital bleeding
  • Strawberry cervix (pathognomonic but uncommon)
  • Asymptomatic (up to 50% of cases)
Male Presentation
  • Urethral discharge (typically clear or mucopurulent)
  • Dysuria
  • Urinary frequency
  • Urethral irritation
  • Prostatitis (uncommon)
  • Epididymitis (rare)
  • Asymptomatic (up to 80% of cases)
⚠️
High-Risk Populations: Trichomoniasis prevalence is significantly higher in Aboriginal and Torres Strait Islander communities, particularly in remote areas. Consider screening even in asymptomatic patients from high-risk populations.

Risk Factors Assessment

1
Sexual History
New or multiple sexual partners, unprotected sexual contact, history of STIs
2
Demographics
Age >40 years, Aboriginal and Torres Strait Islander background, remote/rural location
3
Co-infections
HIV, other STIs, recurrent bacterial vaginosis, recurrent UTIs
4
Pregnancy Status
Increased risk of adverse pregnancy outcomes including preterm birth

Physical Examination

Female Examination

  • External genital examination for vulvar erythema, oedema, excoriation
  • Speculum examination to assess vaginal discharge characteristics
  • Cervical examination for friability, erythema, petechial lesions
  • Bimanual examination to assess for pelvic tenderness

Male Examination

  • Inspection of urethral meatus for discharge
  • Penile and scrotal examination
  • Prostate examination if indicated by symptoms
  • Inguinal lymph node palpation
💡
Clinical Pearl: The classic "strawberry cervix" appearance occurs in only 2-5% of infected women but is pathognomonic when present. Most trichomoniasis infections have non-specific or absent clinical signs.

Differential Diagnosis

Condition Key Differentiating Features Diagnostic Test
Bacterial Vaginosis Fishy odour, homogeneous grey discharge, pH >4.5, clue cells Amsel criteria, Gram stain
Vulvovaginal Candidiasis Thick cottage cheese-like discharge, intense pruritus, pH <4.5 KOH preparation, culture
Chlamydia/Gonorrhoea Often asymptomatic, mucopurulent discharge, younger age NAAT testing
Urinary Tract Infection Dysuria without discharge, urinary frequency/urgency Midstream urine culture
Non-specific Urethritis Urethral discharge, negative for GC/CT Urethral swab microscopy

Severity Assessment

Uncomplicated
Urogenital Infection
Standard vaginal/urethral infection without complications
Outpatient management
Complicated
Pregnancy-Associated
Infection during pregnancy with risk of adverse outcomes
Enhanced monitoring required
High-Risk
Co-infection Present
Co-existing HIV, multiple STIs, or treatment failure
Specialist consultation
🚨
Pregnancy Considerations: Trichomoniasis in pregnancy is associated with preterm birth, low birth weight, and premature rupture of membranes. All pregnant women with trichomoniasis should receive treatment and enhanced antenatal monitoring.

Documentation Requirements

  • Comprehensive sexual history including partner details
  • Clinical presentation and examination findings
  • Risk factor assessment and co-infection screening
  • Pregnancy status and contraceptive history
  • Previous STI history and treatment responses
  • Contact tracing requirements and partner notification

Treatment of Trichomoniasis

First-Line Treatment

Metronidazole remains the cornerstone of trichomoniasis treatment in Australia. Single-dose therapy is preferred for improved adherence and partner treatment.

💊
Metronidazole
Flagyl® · Generic · First-line
Adult Dose 2 g single dose (preferred)
Alternative 500 mg BD × 7 days
Route Oral
Frequency Single dose or twice daily
Duration Single dose or 7 days
Renal Adj. None required
Hepatic Adj. Reduce dose in severe impairment
PBS Status ✓ PBS General Benefit
⚠️
Alcohol Warning: Avoid alcohol during treatment and for 48 hours after completion due to disulfiram-like reaction.

Second-Line Treatment

For treatment failures or when metronidazole is contraindicated. Resistance rates remain low in Australia but are increasing.

💊
Tinidazole
Fasigyn® · Second-line
Adult Dose 2 g single dose
Alternative 500 mg BD × 5 days
Route Oral
Frequency Single dose or twice daily
Duration Single dose or 5 days
Renal Adj. None required
Hepatic Adj. Reduce dose in severe impairment
PBS Status ⚠ Authority Required

Treatment Failures

Suspect resistance if symptoms persist after appropriate treatment and reinfection excluded.

1
Confirm Failure
Repeat microscopy/PCR 1 week post-treatment. Rule out reinfection.
2
High-Dose Metronidazole
500 mg TDS × 7 days or 2 g daily × 3-5 days
3
Specialist Referral
Consider sexual health specialist for resistance testing and alternative regimens

Special Populations

🤰 Pregnancy
Metronidazole Safe in all trimesters. Preferred: 500 mg BD × 7 days
Single dose 2 g single dose acceptable if adherence concern
Tinidazole Avoid in first trimester; use if metronidazole fails
👶 Paediatrics
Metronidazole 15 mg/kg (max 500 mg) BD × 7 days
Single dose 30 mg/kg (max 2 g) single dose for adolescents ≥12 years
Investigation Consider sexual abuse investigation in prepubertal children
🫘 Renal Impairment
Metronidazole No dose adjustment required for CrCl >10 mL/min
Severe CKD Reduce dose by 50% if CrCl <10 mL/min or on dialysis
Hemodialysis Administer after dialysis session
🫀 Hepatic Impairment
Mild-Moderate Standard dosing appropriate
Severe Cirrhosis Reduce dose by 50% and extend intervals
Monitoring Monitor for CNS toxicity with prolonged use
🛡️ Immunocompromised
HIV Patients Standard dosing effective; may need longer courses
Resistance Risk Higher rates of treatment failure; consider 7-day regimens
Follow-up Test of cure recommended at 4 weeks

Partner Management

ℹ️
Simultaneous Treatment: All sexual partners from the last 4 weeks (or last partner if >4 weeks) must be treated simultaneously to prevent reinfection.
Partner Notification Options
  • Patient-delivered partner therapy (PDPT)
  • Provider-assisted referral
  • Anonymous partner notification services
  • Online partner notification platforms
Sexual Activity Guidelines
  • Abstain from sexual activity during treatment
  • Resume after completion if asymptomatic
  • Partners must complete treatment before resumption
  • Condom use recommended until partner treated

Treatment Monitoring

Day 1
Initiate Treatment: Counsel on alcohol avoidance, partner treatment, and sexual abstinence
Day 7-10
Symptom Review: Contact patient to ensure symptom resolution and adherence
4 weeks
Test of Cure: Only if symptoms persist, immunocompromised, or pregnancy
3 months
Reinfection Screening: Consider repeat testing given high reinfection rates
✅
Treatment Success: >95% cure rate with single-dose metronidazole when both partners treated simultaneously.

References

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    Kissinger P, Adamski A. Trichomoniasis and HIV interactions: a review. Sex Transm Infect. 2013;89:426-433. doi:10.1136/sextrans-2012-051005
  • 02
    Workowski KA, Bachmann LH, Chan PA, et al. Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR Recomm Rep. 2021;70(4):1-187. doi:10.15585/mmwr.rr7004a1
  • 03
    Hocking JS, Vodstrcil LA, Huston WM, et al. A cohort study of Chlamydia trachomatis treatment failure in women: a study protocol. BMC Infect Dis. 2013;13:379. doi:10.1186/1471-2334-13-379
  • 04
    Australian Government Department of Health. Fifth National Sexually Transmissible Infections Strategy 2018-2022. Canberra: Commonwealth of Australia; 2018.
  • 05
    Schwebke JR, Burgess D. Trichomoniasis. Clin Microbiol Rev. 2004;17(4):794-803. doi:10.1128/CMR.17.4.794-803.2004
  • 06
    Royal Australian College of General Practitioners. Guidelines for preventive activities in general practice. 9th edition. Melbourne: RACGP; 2016.
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    Secor WE, Meites E, Starr MC, Workowski KA. Neglected parasitic infections in the United States: trichomoniasis. Am J Trop Med Hyg. 2014;90(5):800-804. doi:10.4269/ajtmh.13-0723
  • 08
    Pharmaceutical Benefits Scheme. PBS Online. Canberra: Australian Government Department of Health; 2024. Available from: https://www.pbs.gov.au
  • 09
    Meites E, Gaydos CA, Hobbs MM, et al. A review of evidence-based care of symptomatic trichomoniasis and asymptomatic Trichomonas vaginalis infections. Clin Infect Dis. 2015;61(Suppl 8):S837-S848. doi:10.1093/cid/civ738
  • 10
    Silver BJ, Guy RJ, Kaldor JM, Jamil MS, Rumbold AR. Trichomonas vaginalis as a cause of perinatal morbidity: a systematic review and meta-analysis. Sex Transm Dis. 2014;41(6):369-376. doi:10.1097/OLQ.0000000000000134
  • 11
    Australian Institute of Health and Welfare. Aboriginal and Torres Strait Islander Health Performance Framework 2020 report. Canberra: AIHW; 2020. Cat. no. IHPF 2.
  • 12
    Muzii L, Muzii M, Spitz IM. The prognostic value of trichomoniasis in pregnancy. Obstet Gynecol Surv. 2000;55(10):648-656. doi:10.1097/00006254-200010000-00024
  • 13
    Australian Commission on Safety and Quality in Health Care. National Safety and Quality Health Service Standards. 2nd edition. Sydney: ACSQHC; 2017.
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    Soper D. Trichomoniasis: under control or undercontrolled? Am J Obstet Gynecol. 2004;190(1):281-290. doi:10.1016/j.ajog.2003.08.023
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    Guy RJ, Ward JS, Smith KS, et al. The impact of sexually transmissible infection programs in remote Aboriginal communities in Australia: a systematic review. Sex Health. 2012;9(3):205-212. doi:10.1071/SH11074