Trichomonase
Revu par Dr Rosalyn Adleman, MRCGPDernière mise à jour par Dr Rachel Hudson, MRCGPDernière mise à jour 26 avr. 2023
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Dans cette série :Infections sexuellement transmissiblesVerrues génitalesHerpès génitalGonorrhéeUrétrite chez les hommesMycoplasma genitalium
La trichomonase est une infection sexuellement transmissible (IST) causée par un tout petit germe appelé trichomonas vaginalis. Elle peut provoquer des douleurs et des écoulements du vagin ou du pénis, mais elle ne cause souvent aucun symptôme. Cela signifie que vous pouvez la transmettre sans le savoir.
En un coup d'œil
Trichomoniasis is a common curable sexually transmitted infection (STI) caused by a tiny germ.
Symptoms in women can include a green-yellow, frothy, smelly vaginal discharge, itching, and painful sex.
Most men with trichomoniasis have no symptoms, but some may have penile discharge or pain when urinating.
The infection is typically passed on through sexual contact, even if there are no symptoms.
It is diagnosed by testing a swab from discharge, or sometimes urine in men.
Treatment is usually an antibiotic called metronidazole, and sexual partners also need treatment.
Untreated trichomoniasis can lead to complications such as increased risk of HIV and infertility.
What is trichomoniasis?
How do you get trichomoniasis?
Trichomonas vaginalis is a protozoan, which is a tiny germ, similar to bacteria. It can infect your genital area. That is, the vagina and urethra in women, and the urethra and sometimes the prostate gland in men.
This infection is passed on to other people by having sex (intercourse). This infection does not usually go further into your body and so does not tend to be as serious as some other infections sexuellement transmissibles (IST).It can also be completely cured, unlike some other STIs.
STIs are passed between sexually active partners - any sexual contact may enable this, not necessarily penetrative sex. Sharing sex toys between partners can also pass it on.
How common is trichomoniasis?
In England in 2016, there were 7,075 new diagnoses of trichomoniasis, compared to 202,546 of chlamydia, 36,244 for gonorrhoea and 31,860 for genital herpes.
As with most STIs, it is most common in younger people under the age of 25. In England, there are ten times as many cases of trichomoniasis in black ethnic minority populations as there are in the general population. Other than in this group of the population, trichomoniasis is uncommon in the UK.
Trichomoniasis symptoms
Symptômes chez les femmes
Des sécrétions vaginales is common. This is typically greeny-yellow and may be 'frothy'. The discharge usually has an unpleasant or fishy smell.
Your vagina and vulva may be itchy and uncomfortable. The irritation may extend into your groin. Sex may be painful.
You may have pain in the lower part of your tummy (abdomen).
It may be sore when you pass urine.
No symptoms occur in some women. However, you can still pass on the infection even if you have no symptoms.
Symptômes chez les hommes
Discharge from the penis is common.
It may be sore when you pass urine.
You may pass urine frequently (due to irritation inside the penis).
No symptoms occur in most infected men. However, you can still pass on the infection even if you have no symptoms.
How do you get trichomoniasis?
Trichomoniasis is usually passed on by having sexual contact (vaginal, oral or anal sex) with an infected person. As no symptoms may occur in both men and women who are infected, you can pass on the infection without realising it.
Trichomoniasis is the most common non-viral sexually transmitted infection (STI) in the world. It is less common in the UK. However, it is thought that many cases are still not recognised and are not diagnosed. It can be cured with antibiotic treatment.
How to test for trichomoniasis
You can be tested for trichomoniasis at your GP or by visiting a genitourinary medicine (GUM) clinic. It is important to obtain the correct diagnosis, as the same symptoms can be caused by a number of different infections:
A sample (swab) of the discharge from your vagina or penis is sent to the laboratory to be tested. This may be taken by a healthcare professional, or they may show you how to take one yourself.
Trichomoniasis is sometimes seen by chance when a smear test is done in women.
A sample of urine from men may also show the infection.
Trichomoniasis treatment
Une médicament antibiotique called metronidazole is the common treatment. You and your partner should be given treatment at the same time and you should avoid having sex (intercourse) for at least one week after receiving your treatment.
Tinidazole is an alternative antibiotic medicine that is sometimes used.
Does my sexual partner need treating?
Yes. Partners should also be treated even if they do not have symptoms of trichomoniasis. You and your partner should be treated at the same time. Anybody you have been sexually active with in the four weeks before your symptoms started should be treated.
Some other points about trichomoniasis
After you are treated, you may get the infection back if your sexual partner was not treated, or if you have sex with a new partner who has this infection.
Other STIs are more common in people with trichomoniasis. You (and your partner) may be advised to be tested for other infections.
What are the complications with trichomoniasis?
Grossesse
If you have untreated trichomoniasis during pregnancy, you have an increased risk of having an early labour and a baby with a low birth weight. You are also more at risk of septicémie after your baby is born.
In women
It may go on to cause une maladie inflammatoire pelvienne, and you are more likely to develop another infection called bacterial vaginosis.
In men
Trichomoniasis can, rarely, cause an unpleasant infection of the prostate gland (called prostatite).
VIH
If you have untreated trichomoniasis, you have an increased risk of developing infection par le VIH if you have sex (intercourse) with someone who is infected with HIV.
Infertilité
In both men and women, trichomoniasis can result in reduced fertility.
How to prevent trichomoniasis
As trichomoniasis is passed on through sexual intercourse, abstinence is the most effective way to prevent it. Otherwise, using a condom is the best way. Use a condom for vaginal or anal sex. For oral sex with a man, use a condom on the penis. For female oral sex, and for women who have genital to genital contact, use a dam (a latex or polyurethane sheet. These are available online).
Limiting the number of sexual partners you have will reduce the chance of contracting it.
Do not douche (actively wash the vulva/vagina with water or soap/other cleansers) - this gets rid of the normal bacteria in this area and may increase the risk of developing infections, including STIs.
Wash sex toys between uses and cover them with a condom before using.
Do not abuse alcohol or drugs - these increase risky behaviours and put you more at risk of contracting an STI.
Have regular STI tests via your local sexual health clinic, particularly before having sex with a new partner - both partners should be tested.
If you are pregnant and have trichomoniasis, or think you might do, get tested and treated to reduce the risk of a premature birth or low-birth-weight baby.
Sélections des patients pour Infections sexuellement transmissibles

Santé sexuelle
Chlamydia
Environ 3 à 7 jeunes sexuellement actifs sur 100 au Royaume-Uni sont infectés par la chlamydia. Elle est plus fréquente chez les moins de 25 ans.
par Dr Hayley Willacy, FRCGP

Santé sexuelle
Herpès génital
L'herpès génital est une infection virale. Au moins 8 personnes sur 10 porteuses du virus de l'herpès génital ignorent qu'elles sont infectées. Elle se transmet par contact intime (généralement sexuel) avec une personne porteuse du virus. Entre les épisodes, le virus reste dans le système nerveux et peut se réactiver de temps en temps pour provoquer des symptômes.
par Dr Philippa Vincent, MRCGP
Questions fréquemment posées
Can I get trichomoniasis from sharing sex toys?
Yes, sharing sex toys between partners can pass on the infection.
Does trichomoniasis usually cause severe health problems?
This infection does not usually spread deeper into your body, so it tends not to be as serious as some other sexually transmitted infections (STIs). It can also be completely cured, unlike some other STIs.
If I'm infected but have no symptoms, can I still pass trichomoniasis to someone else?
Yes, both men and women can pass on the infection even if they experience no symptoms themselves.
Are there any specific situations where trichomoniasis is more common in the UK?
Yes, in England, trichomoniasis is ten times more common in black ethnic minority populations than in the general population. Other than this group, it is uncommon in the UK.
Why is it important to avoid douching to prevent trichomoniasis?
Douching, which involves actively washing the vulva/vagina with water or cleansers, removes the normal bacteria in this area. This can increase the risk of developing infections, including STIs like trichomoniasis.
If I am pregnant and suspect I have trichomoniasis, what should I do?
If you are pregnant and have trichomoniasis, or think you might, you should get tested and treated to reduce the risk of a premature birth or having a low-birth-weight baby.
Lectures complémentaires et références
- Infections Sexuellement Transmissibles en Soins Primaires; Collège Royal des Médecins Généralistes et Association Britannique pour la Santé Sexuelle et le VIH (avr. 2013)
- Sexually transmitted infections (STIs): surveillance, data, screening and management; UK Health Security Agency (Last updated February 2020)
- Poole DN, McClelland RS; Global epidemiology of Trichomonas vaginalis. Sex Transm Infect. 2013 Sep;89(6):418-22. doi: 10.1136/sextrans-2013-051075. Epub 2013 Jun 6.
- Menezes CB, Frasson AP, Tasca T; Trichomoniasis - are we giving the deserved attention to the most common non-viral sexually transmitted disease worldwide? Microb Cell. 2016 Jun 27;3(9):404-419. doi: 10.15698/mic2016.09.526.
- Gulmezoglu AM, Azhar M; Interventions for trichomoniasis in pregnancy. Cochrane Database Syst Rev. 2011 May 11;(5):CD000220. doi: 10.1002/14651858.CD000220.pub2.
- Trichomonase; NICE CKS, mai 2020 (accès réservé au Royaume-Uni)
- United Kingdom national guideline on the management of Trichomonas vaginalis; British Association for Sexual Health and HIV - BASHH (2021)
À propos de l'auteurVoir la biographie complète

Dr Rachel Hudson, MRCGP
Médecin généraliste et auteur médical
MBChB, MRCGP (2008), BSc (Medical Science), DFSRH, DRCOG, DCH
Dr Rachel Hudson est médecin généraliste du NHS travaillant dans le nord-ouest de l'Angleterre.
À propos du critiqueVoir la biographie complète

Dr Rosalyn Adleman, MRCGP
MRCGP
Dr Rosalyn Adleman est médecin généraliste du NHS travaillant dans le nord de Londres.
Historique de l'article
Les informations sur cette page sont rédigées et examinées par des cliniciens qualifiés.
Article également disponible en Anglais, Allemand, Espagnol, Français, Italien, Portugais, Hindi, Hébreu, Arabe, and Suédois.
Prochaine révision prévue : 24 avr. 2028
26 avr. 2023 | Dernière version

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