Comments from Expert Advisory Group

  1. Trichomoniasis is caused by the flagellated protozoan, Trichomonas vaginalis. It can infect the vagina, urethra and para urethral glands.
  2. In women trichomoniasis usually presents with a vaginal discharge which may be offensive with an associated vulvitis/vaginitis. Symptoms in women include frothy yellow-green discharge, offensive odour, dyspareunia/dysuria, vulval itch/discomfort. Signs include vulvitis, vaginitis, a frothy vaginal discharge and strawberry cervix.
  3. Men usually present as sexual contacts of women with infection. They may present with symptoms of urethritis including dysuria and urethral discharge. Men with persistent urethritis should be referred to a dedicated GUM clinic.
  4. Complications of trichomoniasis in women include perinatal complications, infertility and pelvic inflammatory disease. Complications in men include prostatitis and infertility.
  5. Diagnostic testing for trichomoniasis should be undertaken in patients complaining of vaginal discharge or vulvitis, male contacts of female cases and considered in men with persistent symptoms/signs of urethritis. Asymptomatic testing is not routinely indicated.
  6. Diagnosis can be made on a wet prep of vaginal secretions (in GUM clinics), culture or PCR. In general practice, PCR testing in men is on a first void urine specimen and in women on a vulvovaginal swab.
  7. Trichomonas testing can be performed on the same platform (Hologic Aptima) as the chlamydia and gonorrhoea testing, and can be performed on the same sample. Trichomonas should be specifically requested on the testing form. The Aptima specimen collection kits are available through the NVRL 'swab shop' on the NVRL website.
  8. Individuals diagnosed with trichomoniasis should be offered testing for other STIs including HIV, Hepatitis B, chlamydia, gonorrhoea and syphilis.
  9. Hepatitis C testing (HCV) should be considered part of routine sexual health screening in the following circumstances: gay, bisexual or other men who have sex with men (gbMSM), people living with HIV; commercial sex workers; people who inject drugs (PWID). Partners of the above should also be considered for HCV testing.
  10. Testing and treatment of sexual partners within the four weeks prior to presentation is important to prevent reinfection and onward transmission and patients should be encouraged to inform their sexual partners. Sexual partners in the two week window period after last sexual contact may have a false negative result and should be empirically treated for trichomoniasis.
  11. Advise patients to avoid sexual contact with their partner for at least one week and until they and their partner have completed treatment and follow-up. Further information on partner notification is available in the useful resources section.
  12. Test of cure is recommended only if the patient remains symptomatic following treatment or if asymptomatic when tested. Optimal timing for test of cure is 4 weeks after start of treatment. A positive test of cure with no risk of re-infection requires a referral to a specialist.
  13. For persistent or recurrent trichomoniasis, consider reviewing adherence to therapy, reinfection or resistance.
  14. Trichomoniasis is a notifiable disease. Notification process is usually initiated by the testing laboratory.


Drug Dose Duration Notes
1st choice option
Metronidazole 400 mg every 12 hours 7 days

Avoid alcohol during metronidazole treatment and for 48 hours afterwards (disulfiram reaction).

Avoid 2g dose metronidazole in pregnancy, breastfeeding and elderly.



2nd choice option

Can be considered where there is a concern regarding adherence, but there is a higher risk of treatment failure compared to the 7 day regime.

Metronidazole 2 g Single dose

Patient Information

Safe Prescribing

Visit the safe prescribing page

Reviewed May 2024

antibiotics banner