Trichomoniasis
Introduction
Trichomoniasis is a common sexually transmitted infection (STI) caused by a tiny parasite called trichomonas vaginalis.
Trichomoniasis can be difficult to diagnose because there may not be any symptoms, and when there are symptoms, they can be similar to those of other conditions and STIs
Women are more likely to have symptoms than men. They may have soreness and itching around the vagina and a change in vaginal discharge, while men may experience pain after urination and ejaculation (see Symptoms for further information).
How it is caught
Trichomoniasis is usually spread through unprotected sexual intercourse (without using a condom). However, you do not have to have lots of sexual partners to catch trichomoniasis. Anyone who is sexually active can catch the infection, and then pass it on (see causes for more information).
Outlook
Trichomoniasis is unlikely to go away without treatment. Most men and women are treated with an antibiotic called metronidazole, which is very effective. Trichomoniasis rarely causes complications.
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Symptoms
Trichomoniasis is believed to be very common, but many infected men and women will not have any symptoms. Women are more likely to have symptoms of trichomoniasis than men.
The symptoms of trichomoniasis are similar to those of other sexually transmitted infections or conditions (see below). They tend to appear 5 to 28 days after exposure to the infection.
If you develop any of the below symptoms, visit your GP to confirm the diagnosis.
Symptoms in women
Trichomoniasis affects the vagina and urethra (tube through which urine passes), causing any of the following symptoms:
- Soreness, inflammation and itching around the vagina. Sometimes your inner thighs also become itchy.
- Change in vaginal discharge. Your discharge may appear thicker, thinner, frothy or yellow or green in colour. You may also notice you are producing more discharge than normal, and it may also have an unpleasant, fishy smell.
- Pain or discomfort when passing urine.
- Discomfort during sexual intercourse.
- Pain in your lower abdomen.
Symptoms in men
Trichomoniasis affects the urethra (tube through which urine passes) and occasionally the prostate gland (a gland at the neck of the bladder that helps produce semen), causing any of the following symptoms:
- pain after urination and ejaculation,
- thin white discharge from the penis, and
- discomfort during sexual intercourse.
Rarely, a man may also notice that his foreskin is inflamed.
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Causes
Trichomoniasis is caused by a tiny single-celled parasite called Trichomonas vaginalis.
The germ is usually spread by having unprotected sex (without using a condom).
If you get trichomoniasis while you are pregnant, you may be at risk of passing the infection on to your baby.
In rare cases, the infection can also be spread by sharing sex toys. However, if you use a condom to cover your sex toy and make sure that you wash your sex toys after each time you use them, you will not spread the infection.
Myths
Trichomoniasis cannot be passed on through oral or anal sex, kissing, hugging, sharing cups, plates or cutlery, toilet seats or towels.
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Diagnosis
Trichomoniasis can sometimes be difficult to diagnose straight away because there are a lot of conditions and sexually transmitted infections that can produce similar symptoms.
If you do not want to visit your GP, go to your local genitourinary medicine (GUM) clinic, where they will be able to test and treat your infection. Find your nearest sexual health clinic.
Examination
If your GP or nurse suspects you have trichomoniasis, they will usually carry out an examination of your genital area.
In a woman, trichomoniasis may cause red blotches on the walls of your vagina and on the cervix (the neck of the womb).
If you are a man with suspected trichomoniasis, your GP will examine your penis to check for any signs of inflammation.
Laboratory testing
After carrying out your physical examination, your GP or nurse may need to take a swab from either the vagina or penis so that it can be tested for the trichomoniasis infection. The swab will be sent for analysis at a laboratory. It may take several days for the results to come back.
If your GP or nurse strongly suspects that you have trichomoniasis, you may be able to begin a course of treatment before your results come back. This will ensure that your infection is treated as soon as possible and reduces the risk of the infection spreading.
Sometimes, the result of a routine smear test may report that 'organisms consistent with trichomonas vaginalis have been seen'. This does not necessarily mean that you have trichomoniasis, so do not assume that you have an STI until further tests have been done.
In men, a urine sample can also be tested for trichomoniasis.
Partner notification
If the test shows that you have trichomoniasis, it is very important that your current sexual partner and any other recent partners are also tested and treated. The staff at the clinic or general practice can discuss with you which of your sexual partners may need to be tested.
You may be given a contact slip to send or give to your partner or partners or, with your permission, the clinic can do this for you. The slip explains that they may have been exposed to an STI and suggests that they go for a check-up. It may or may not say what the infection is. It will not have your name on it, so your confidentiality is protected.
This is called partner notification. You are strongly advised to tell your partner(s), but it is not compulsory.
If you have had trichomoniasis and been cured, there is no need to tell any future partners that you had it.
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Treatment
If there is a high chance you have trichomoniasis and you are showing very obvious symptoms, treatment may be started before the results of the test are back.
Trichomoniasis is unlikely to go away without treatment. In some rare cases, the infection may cure itself, but if you do not get treated, you risk passing the infection on to someone else.
Antibiotics and antifungals
Trichomoniasis is usually treated quickly and easily. Most cases will be treated using an antibiotic known as metronidazole, which if taken correctly, is very effective. You will usually have to take metronidazole twice a day, for five to seven days.
Sometimes this antibiotic can be prescribed in a single concentrated dose. However, this single dose is not suitable for pregnant or breastfeeding women.
Metronidazole can cause nausea, vomiting and a slight metallic taste in your mouth. If you develop side effects like these, contact your GP, as the treatment will not be effective if you are suffering from vomiting.
You must not drink alcohol whilst taking metronidazole or for at least 48 hours after finishing the course of antibiotics. Drinking alcohol whilst taking this medicine can cause more severe side effects.
If you cannot tolerate metronidazole, your GP may prescribe a single dose of another antibiotic called tinidazole.
Contraception
The antibiotics used to treat trichomoniasis can affect the reliability of some forms of contraception.
If you are taking a contraceptive pill which contains both estrogen and progestogen (such as the combined pill), your antibiotics may stop it from working properly.You may also be affected if you are using the contraceptive patch or the contraceptive ring (NuvaRing).
It is therefore advisable that you use another form of contraception, such as a condom, while you are being treated for trichomoniasis. Your GP, or family planning clinic nurse, will be able to advise you.
Follow-up tests
If you take your antibiotic treatment correctly, you will not normally require any follow-up tests, or examinations, for trichomoniasis.
However, if your symptoms remain after treatment, or if your original laboratory test produced a negative result for trichomoniasis, you may require further testing to see whether your symptoms are being caused by a different sexually transmitted infection.
If you have unprotected sex before your treatment is finished, you need to return to your GP surgery, or sexual health clinic, because you may have become re-infected. You must also return if you:
- did not complete your course of antibiotics,
- did not take your antibiotics correctly (according to the instructions), or
- if you vomited shortly after taking your antibiotics.
Pregnant women
Pregnant women can safely take metronidazole.
However, pregnant women who experience side effects when taking metronidazole or who do not wish to take the medicine may be prescribed clotrimazole. A clotrimazole pessary is a type of antifungal medicine that is inserted into the vagina. It is very safe for pregnant women to use and will help relieve symptoms of trichomoniasis. However, it is far less effective than antibiotics and is unlikely to cure the infection. Your GP will have to monitor your condition and may need to carry out further tests to check the infection has cleared.
Sexual partners
Don't have sexual intercourse while you are being treated for trichomoniasis, otherwise you may become re-infected.
If you were prescribed a single, 'one day' dose of antibiotics, you need to abstain from sexual intercourse for seven days after you have taken the medication.
It is also important that your partner is tested for the infection, as they too must be treated. If your sexual partner is not treated, then this again increases the risk of re-infection.
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Complications
Complications are rare with trichomoniasis.
The infection can sometimes weaken the barrier of mucus in the cervix (the neck of the womb). This mucus barrier helps protect women from developing infection in their reproductive organs. If the mucus is weakened, this increases your risk of developing HIV.
It is therefore very important that you practice safe sex, by always using a condom.
Pregnancy
If you develop trichomoniasis whilst you are pregnant your baby may be at risk of developing complications. Trichomoniasis may cause your baby to be born prematurely, or be a low birth weight.
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Prevention
Like any sexually transmitted infection (STI), the best way to prevent trichomoniasis is to practise safe sex. This means always using a condom.
The following measures will help protect you from trichomoniasis and most other STIs, including HIV, chlamydia and gonorrhoea. They will also help prevent you passing it on to your partner:
- Use condoms (male or female) every time you have vaginal or anal sex.
- If you have oral sex, cover the penis with a condom or the female genitals with a latex or polyurethane square (a dam).
- If you are a woman and rub your vulva against your female partner’s vulva, one of you should cover your genitals with a dam.
- If you are not sure how to use condoms correctly read the FPA leaflet.
- Avoid sharing sex toys. If you do share them, wash them or cover them with a new condom before anyone else uses them.
If you are sexually active, go for regular sexual health check-ups. You can get an appointment by visiting your local genitourinary medicine (GUM) clinic. Find your local sexual health clinic.
If you notice any signs or symptoms of an STI, stop having sex and visit your GP or GUM clinic as soon as possible.
If you have been diagnosed with trichomoniasis, make sure that any sex toys you have used are cleaned. You should also avoid sharing them, to make sure the infection does not spread.
Further help and advice
Call the Sexual Health Helpline on 0800 567123 for confidential advice and support 24 hours a day, seven days a week. Alternatively, call Sexual Health Direct, run by the FPA, on 0845 122 8690.
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