Causes
Trichomonas, also known as trichomoniasis, is caused by a protozoan parasite Trichomonas vaginalis.
Trichomonas is not common among people in Australian cities but is more common in many countries and in remote Aboriginal and Torres Strait Islander communities.
Trichomonas should be considered in women who present with vaginal discharge and men who present with urethritis, particularly if they have had sex in higher risk areas.
Clinical presentation
Trichomonas in women may be asymptomatic or present as a frothy, yellow-green vaginal discharge with vulvar itch and or dysuria.
Trichomonas can cause cervical inflammation, where the cervix has a spotted strawberry like appearance, so called “strawberry cervix”.
Men are usually asymptomatic but may present with dysuria.
In women infection typically involves multiple sites: most vaginal infections also involve the urethra, Skene's and Bartholin's glands, and endocervix. Intravaginal treatments alone are not recommended.
Diagnosis
| Test | Site/ specimen | Comments |
|---|---|---|
| Wet preparation | Vaginal or urethral swab | Only 60-70% sensitive from vaginal swab in women or urethral swab in men. |
| PCR |
Vaginal swab or First void urine (men or women) |
Culture is only available in a few specialised labs. |
Management
The 5-nitroimidazoles, which include metronidazole (MTZ) and tinidazole (TDZ), are the only class of drug known to be effective against Trichomonas vaginalis.
Index patient
| Condition | Recommended | Comments | |
|---|---|---|---|
|
Trichomonas in women
|
Exclude reinfection / non-compliance. Repeat Metronidazole 400 mg BD one week. |
Alcohol should be avoided when taking metronidazole. |
|
| Trichomonas in men | Metronidazole 2 g PO, stat | There are no studies comparing single dose metronidazole to multi-dose metronidazole in men. | |
| Trichomonas in pregnancy | If symptomatic, manage as for nonpregnant women. Metronidazole (category B) can be used in all trimesters. |
Trichomonas has been associated with adverse pregnancy outcomes, particularly premature rupture of membranes, preterm birth and low birthweight. If asymptomatic, consult with a sexual health physician. Some studies suggest the possibility of increased prematurity or low birthweight after metronidazole therapy. However, limitations of the studies prevent definitive conclusions regarding risks of treatment. |
|
|
Complicated cases:
|
High dose metronidazole: 2 g orally daily for 7 days |
Treatment should be discussed with a sexual health physician. Alternatives to consider include:
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Patients should be advised to abstain from intercourse until they and their sexual partners have been adequately treated and any symptoms have resolved.
Contact tracing & partner management
Sexual partners should be notified, tested and treated for trichomonas.
Partner notification should be discussed with patients. Sex with untreated, infected partners can result in reinfection. Consider referring patients to Let Them Know where patients can SMS and email partners about their diagnosis.
Test of Cure
This is only recommended if symptoms remain, and should be performed three weeks after completing antibiotics
Clinical education: Vaginal discharge
This presentation on vaginal discharges includes discussion on clinical presentations and case studies, laboratory confirmation and treatment options.
Disclaimer
We recognise that gender identity is fluid. In our treatment guidelines, the words and language we use to describe genitals and gender are based on the sex assigned at birth.
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.