Trichomonas vaginalis

Trichomonas vaginalis, or Trich./TV for short, is a common sexually transmitted infection. Trichomoniasis is the name given to symptoms it produces.

Although not very well known in the UK, Trichomonas vaginalis is the most common non-viral STI in the world. It is less common in the UK, and is most commonly seen in patients from black and ethnic backgrounds and after sexual contact abroad. 

The behaviour of this infection can be best described as ‘men spread, women suffer’. Men often do not get symptoms or develop minimal symptoms, but once they have passed the infection to their female partners who get very distinct and clear symptoms.


  • In England, there are 10x as many cases of Trichomoniasis in black ethnic minority populations than any other group.
  • There are geographic pockets of high prevalence in the UK (Wolverhampton, London).
  • Over 90% of diagnosed Trichomoniasis cases occur in women, but this may be due to men not having access to tests.
  • In 2016, WHO estimated 376 million new infections with 1 of 4 curable STIs: chlamydia (127 million), gonorrhoea (87 million), syphilis (6.3 million) and trichomoniasis (156 million).
  • One is more likely to get exposed to TV compared to chlamydia or gonorrhoea after a sexual contact abroad, or a partner from abroad.


What are the symptoms of Trichomoniasis?

Women may experience:

  • Abnormal vaginal discharge: Foul, fishy or strong smelling 
  • Discharge may be green/yellow in colour
  • Discharge may be thick, thin or frothy
  • Producing more discharge than normal
  • Soreness, swelling or itching around the vagina
  • Less commonly, the inner thighs may become itchy
  • Pain during sexual intercourse
  • Pain upon urination
  • Bacterial vaginosis (BV): Underlying TV should be excluded in patients with BV and recurrent BV.

Men may experience:

  • Pain when urinating
  • Pain during ejaculation
  • Frequently needing to urinate 
  • Thin white discharge from the penis
  • Irritation in the water pipe (not feeling right)
  • Soreness, swelling, redness around head of penis and foreskin (balanoposthitis)
  • Non-Specific Urethritis (TV is one of top 4 causes on NSU)

When do symptoms of Trichomoniasis typically occur?

Symptoms occur within 4-28 days after exposure to the infection. Infection generally persists for fewer than 10 days in males but for much longer duration in women.

    Can I have Trichomoniasis without any symptoms?

    Yes. Some people may have Trichomoniasis without experiencing any symptoms, but are still able to spread the infection to other partners.

    Are symptoms of Trichomoniasis the same as other STIs or infections?

    Itchiness in combination with fishy odour is a classical presentation of Trichomoniasis in women. However many patients do not have any specific symptoms, and other symptoms can be produced by other STIs including Chlamydia and Gonorrhoea, and in fact sometimes in combination.

    Bacterial vaginosis in women, and Non-specific urethritis (NSU) and anaerobic balanitis in men can also be a sign of underlying TV infection.


    Though complications are rare, it may cause premature birth or a baby with a low birth weight in pregnant women. Genital inflammation caused by Trichomonas vaginalis may also increase the risk of contracting or transmitting HIV, as well as other sexually transmitted infections.

    If you are experiencing symptoms of Trichomonas vaginalis, we would recommend getting tested and begin treatment without delay.


    These illustrations show the anatomical sites where the symptoms of Trichomonas vaginalis are experienced.


    How do I get Trichomonas vaginalis?

    • Unprotected vaginal sex
    • Sharing of unclean sex toys (with/without a condom)
    • Genital contact

    There is no evidence that Trichomonas vaginalis can be spread from:

    • Close contact (e.g. kissing and/or hugging)
    • Sharing showers, towels, swimming pools
    • Toilet seats
    • Cutlery
    • It is not thought to be spread through anal or oral sex

    What can increase my chances of getting Trichomonas vaginalis?

    • If you have a greater number of sexual partners
    • Having a partner who has Trichomonas vaginalis
    • You have another sexually transmitted infection
    • If you have unprotected sex

    How can I prevent getting Trichomonas vaginalis?

    • Have protected vaginal, anal and oral sex
    • Use a condom, femidom and/or dental dam with a new partner
    • Only use sex toys that you know are clean
    • You and your new partner get tested before having sex

    Can I pass Trichomonas vaginalis to my child?

    It is very rare to pass Trichomonas vaginalis onto your child by giving birth. Having Trichomonas vaginalis may cause other problems, such as premature birth or low birth weight in infants.


    This is a RT-PCR test which means that the smallest amount of Trichomonas vaginalis DNA can be found in a good quality sample.  


    Window Period

    5 days after exposure

    Sample required for men

    For men: urine sample (please don’t urinate 1-2 hours before your appointment)

    For women: (self-taken) high vaginal swab

    Time for test results

    Express: within 3 hours (Birmingham only)

    Standard: within 4 working days

    Cost of test

    £130 (or £80 if taken with another test)

    Do I need a Trichomonas vaginalis test?

    • you or your partner have any symptoms of Trichomoniasis
    • you’ve had unprotected sex with a new partner
    • a condom splits while you’re having sex
    • you or your partner have had unprotected sex with other people
    • you think you could have a sexually transmitted infection (STI)
    • a sexual partner tells you they have an STI
    • you’re pregnant or planning a pregnancy

    Does it require a physical examination?

    A physical examination is recommended if you are experiencing symptoms, but we will only carry out physical examinations with your informed consent.

    What happens if my Trichomonas vaginalis test is positive?

    If you are tested positive for Trichomonas vaginalis (i.e. Trichomonas vaginalis is DETECTED) then we will discuss what it means for you, provide medication to treat the condition and ensure you don’t pass it on to your partner.

    Do I have to tell my partner, if I test positive for Trichomonas vaginalis?

    Yes. We will give you all the necessary support in conveying your diagnosis to your partner and get them tested. We will discuss the risk of passing on the infection and any tests and/or treatment your partner may need.


    Method of treatment

    Oral antibiotics


    Length of Treatment:

    Single dose to 5 days


    Further actions:

    1. Abstain from sexual intercourse for 7 days, after beginning treatment
    2. Test & treat your partner(s)
    3. Re-test for Trichomonas vaginalis in 2 weeks

    Cost of treatment

    £60 (Consultation fee of £50 applies if tested elsewhere)

    Can Trichomonas vaginalis be cured?

    Yes. Trichomonas vaginalis is easily treated and cured in most cases. However, the first line of antibiotics can fail to eradicate the infection in 5-15% of the patients, requiring further antibiotics to treat the infection. A complete cure is finally achievable in all patients.

    We can also offer antibiotics in the form of rectal suppositories which has a high effectiveness and fewer side effects compared to the oral route.

    How long does the treatment take to work?

    The medication usually starts to show an improvement in symptoms within a couple of days of taking the medications. It can take up to a week for symptoms to go away completely in most patients.

    Are there any side effects?

    Antibiotics used to treat Trichomonas Vaginalis are very safe but can give side effects in many patients. The most common side effects are:

    • Nausea (feeling sick)
    • A metallic (odd) taste in the mouth
    • Abdominal discomfort
    • Diarrhoea
    • Headaches

    Fortunately side effects are mild in most cases, allowing you to get on with your normal life. Side effects improve soon after finishing the course of antibiotics.

    Can I take this with other medications?

    Antibiotics to treat Trichomonas Vaginalis can be taken safely with most commonly used medications. However, doctors will be able to advise if any extra precautions are needed in your specific circumstances to reduce the side effects.

    Can I drink alcohol whilst taking Trichomonas vaginalis treatment?

    No. Antibiotics used to treat Trichomonas Vaginalis produce lots of serious side effects when alcohol is consumed at the same time. That is why it is advised to avoid any alcohol for 72 hours after the last dose of your medication.

    How effective is the treatment for Trichomonas vaginalis?

    The antibiotics used to treat Trichomonas vaginalis infection are effective in 80-95% of patients.

    What are the causes of treatment failure?

    Common causes of treatment failure in Trichomonas vaginalis, seen in 5-15% of patients receiving their first line treatment, are:

    • if you are not able to take the antibiotics as prescribed (miss one or more tablets)
    • if you vomit or have a loose motion soon after taking the antibiotics (this can reduce the level of antibiotics in your blood and tissues to ineffective levels)
    • inadequate dose of antibiotics
    • if you have sexual contact with your infected partner before their infection has been properly treated
    • if you have got infection with a resistant type of Trichomonas Vaginalis
    • if you develop antibiotic resistance while taking the antibiotics

    Does my partner need treatment?

    Trichomonas vaginalis is a very easy infection to share so we strongly advise that you inform your current partner(s) to be tested and treated. Often this infection is without symptoms, more so in men than women, and symptoms can appear months later.

    It is also advised that you inform any other sexual partner(s) from the last 4 weeks that you have the infection, so that these people can get tested and treated. This breaks the chain of infection. Based on your specific circumstances, this look back period can be much longer.

    Can I begin treatment before receiving my test results?

    Yes. However, it is really important to have appropriate specimens taken before any treatment is commenced. This helps in confirming the diagnosis, detect other infections that may require separate treatment, and serve as a baseline for repeat tests 2 weeks later to check for a cure.

    How long do I have to wait before having sex again?

    Ideally, you should avoid any sexual contact until your test of cure for Trichomonas vaginalis 2 weeks later is negative. This prevents transmission of infection to the partner if your infection is not yet cleared (treatment failure rate can be 5-15%).

    If 2 weeks is a too long a period to abstain for you, then you must certainly avoid any sexual contact for at least 7 days from the start of your treatment. This is to ensure that your infection is properly treated and you do not get re-infected in this period. If your partner has received treatment after you, then it must be 7 days after their treatment has started.

    Do I have to get re-tested?

    A test of cure is routinely recommended 2 weeks after starting the course of antibiotics, that is 14 days after a single dose therapy or 7 days after completing a 7 day course of the antibiotics.

    Can I get the infection again?

    Yes. Getting Trichomonas vaginalis infection does not produce an immunity, and therefore does not offer a protection from getting re-infected.

    What happens if I don’t get treated?

    If you do not have symptoms at the time of diagnosis, you may develop symptoms in the following weeks, sometimes as late as 6 months from diagnosis.

    Women often develop vaginal discharge, fishy smell and irritation of vulva, and can rarely cause genital ulcers and presence of blood in the vaginal discharge.

    Men typically remain asymptomatic, but can suffer from urethral discharge, dysuria, urethritis, epididymitis and prostatitis.

    If you have symptoms, they can persist or get worse and you will continue to be a risk of infection to your partner.

    Duration of potential infectivity
    Sometimes the infection may resolve by itself in due course in absence of any treatment.

    Trichomonas Vaginalis in women is thought to be longstanding, up to 3-5 years, whereas infection among men may spontaneously resolve lasting up to 4 months.

    Increased risk of getting HIV
    Presence of having an untreated STI, including Trichomoniasis, increases the risk of acquiring HIV.

    Complications in pregnancy
    Untreated in pregnancy, there is some evidence that this can cause preterm birth and low birth weight babies. Risk of transmission to newborn is about 5% (perinatal transmission).

    Page reviewed by Dr. Manoj Malu (Clinical Director)

    Last reviewed date: 3 March 2020
    Next review due: 3 March 2023

    Whilst this content is written and reviewed by sexual health specialists, it is for general guidance only. It is not intended to replace the advice of your clinician.

    If you think you may have Trichomonas vaginalis

    It is important to refer to a healthcare provider as soon as possible. Our experience combined with timely detection can help put you on the right track without delay and avoid complications in the future.

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