Trichomoniasis Vaginalis


Trichomoniasis in women typically causes a frothy, yellow-green vaginal discharge. It can cause cervical inflammation: “strawberry cervix”. It is an uncommon cause of symptomatic urethritis in men. 
Infection can be asymptomatic. Trichomonas is uncommon among men and women in Australian cities but is common in many countries and should be considered in women who present with vaginal discharge and men who present with urethritis, particularly if they have had sex overseas. Prevalence of trichomonas is high in some remote Aboriginal and Torres Strait Islander communities.

  1. Wet preparation and microscopy (only 60-70% sensitive) from vaginal swab in women or urethral swab in men  
  2. Culture from vaginal swab in women or urethral swab in men – less sensitive than PCR
  3. PCR of vaginal swab in women or first void urine from men

First line treatment

  • Metronidazole 2g as a single dose
  • Tinidazole 2g as a single dose

Alcohol should be avoided when taking nitroimidazole antibiotics

For persistence following single dose treatment

  • Exclude non-compliance 
  • Ensure concomitant partner treatment 
  • Metronidazole 400mg twice daily for 7 days OR
  • Metronidazole or tinidazole 2g daily for 5 days 

If trichomonas persists despite the above measures please discuss the case with a sexual health physician as metronidazole resistance may be possible.

Trichomonas in pregnancy
Trichomonas has been associated with adverse pregnancy outcomes, particularly premature rupture of membranes, preterm birth and low birthweight.

  • If symptomatic, manage as for nonpregnant women. Metronidazole (category B) can be used in all trimesters. 
  • If asymptomatic, consult with sexual health physician. Some trials suggest the possibility of increased prematurity or low birthweight after metronidazole therapy, however, limitations of the studies prevent definitive conclusions regarding risks of treatment.

Trichomoniasis in HIV positive women
There is evidence that metronidazole 400mg twice daily for 7 days is superior to single dose therapy in HIV infected women with lower rates of treatment failure. 


Partner notification should be discussed with patients diagnosed with trichomonas as sex with untreated trichomonas infected partners can result in repeat infection. Consider referring patients to the Let Them Know website (   which is designed to support patients to undertake partner notification and which facilitates sending of SMS and email messages to partners. Partners should be contacted, tested and treated for trichomonas without waiting for their test results. Individuals should abstain from sex with their partners until 7 days after both have received treatment.


Test of cure is not necessary if symptoms resolve with standard treatment. Consider test of cure if there is uncertainty about partner treatment or if metronidazole resistance is suspected. Repeat testing for trichomonas should be performed 3 months after treatment.

The content of these treatment guidelines is for information purposes only. The treatment guidelines are generic in character and should be applied to individuals only as deemed appropriate by the treating practitioner on a case by case basis. Alfred Health, through MSHC, does not accept liability to any person for the information or advice (or the use of such information or advice) which is provided through these treatment guidelines. The information contained within these treatment guidelines is provided on the basis that all persons accessing the treatment guidelines undertake responsibility for assessing the relevance and accuracy of the content and its suitability for a particular patient. Responsible use of these guidelines requires that the prescriber is familiar with contraindications and precautions relevant to the various pharmaceutical agents recommended herein.

Last Updated October 2014