Overview

Trichomoniasis is a sexually transmitted infection (STI) caused by a tiny parasite called Trichomonas vaginalis (TV).

Symptoms of trichomoniasis usually develop within a month of infection, although up to half of all infected men and women have no symptoms.

The symptoms of trichomoniasis are similar to those of many other sexually transmitted infections (STIs) so it can sometimes be difficult to diagnose.

Title
Trichomoniasis

Symptoms

Symptoms in women

Trichomoniasis in women can cause any of the following symptoms:

  • abnormal vaginal discharge that may be thick, thin or frothy and yellow-green in colour
  • producing more discharge than normal, which may also have an unpleasant fishy smell
  • soreness, inflammation (swelling) and itching around the vagina – sometimes the inner thighs also become itchy
  • pain or discomfort when passing urine or having sex

Symptoms in men

Trichomoniasis in men can cause any of the following symptoms:

  • pain during urination or ejaculation
  • needing to urinate more frequently than usual
  • thin white discharge from the penis
  • soreness, swelling and redness around the head of the penis (balanitis) or foreskin (balano-posthitis)

 

Diagnosis

Trichomoniasis can sometimes be difficult to diagnose because symptoms are similar to those of other sexually transmitted infections (STIs).

If you think you may have trichomoniasis, you should visit your GP or your local genitourinary medicine (GUM) clinic.

Some GP surgeries offer an enhanced sexual health service for diagnosing and treating STIs. It may be better to visit a GUM clinic instead because these clinics can carry out accurate tests more quickly.

Examination

If your doctor or nurse suspects you have trichomoniasis, they'll usually carry out an examination of your genital area.

In women, trichomoniasis may cause abnormal vaginal discharge or red blotches on the walls of the vagina and on the cervix (the neck of the womb).

If you are a man with suspected trichomoniasis, your doctor or nurse will examine your penis for signs of inflammation or discharge.

Laboratory testing

After a physical examination, your doctor or nurse may need to take a swab from either the vagina or penis. The swab will be analysed in a laboratory to check for signs of the trichomoniasis infection. It may take several days for the results to come back.

In men, a urine sample can also be tested for trichomoniasis.

If your doctor or nurse strongly suspects you have trichomoniasis, you may be advised to begin a course of treatment before your results come back. This ensures your infection is treated as soon as possible and reduces the risk of the infection spreading.

Notifying sexual partners

If the test shows you have trichomoniasis, it's very important that your current sexual partner and any other recent partners are also tested and treated. The staff at the clinic or GP surgery can discuss with you which of your sexual partners may need to be tested.

If possible, tell your sexual partner and any ex-partners so they can get tested and treated as well. If you don't want to do this, the clinic can usually do it for you (it's called partner notification and the clinic won't reveal who you are).

If you've had trichomoniasis and have been cured, there's no need to tell any future partners.

Treatment

Trichomoniasis is unlikely to go away without treatment. The infection may cure itself in rare cases, but you risk passing the infection on to someone else if you're not treated.

Antibiotics

Trichomoniasis is usually treated quickly and easily with antibiotics.

Most people are prescribed an antibiotic called metronidazole which is very effective if taken correctly. You'll usually have to take metronidazole twice a day, for five to seven days.

Sometimes this antibiotic can be prescribed in a single, larger dose. However, this may have a higher risk of side effects and it's not recommended for pregnant or breastfeeding women as a precaution.

Metronidazole can cause nausea, vomiting and a slight metallic taste in your mouth. It's best to take it after eating food. Contact your doctor for advice if you start vomiting, because the treatment won't be effective if you're unable to swallow the tablets.

Don't drink alcohol while taking metronidazole and for at least three days after finishing the course of antibiotics. Drinking alcohol while taking this medicine can cause more severe side effects, including:

  • a fast heartbeat or heart palpitations
  • skin flushing
  • nausea and vomiting

A specialist can recommend alternative treatments if metronidazole is unsuitable for you (for example, if you're allergic to it).

Follow-up

If you take your antibiotics correctly, you won't normally need any follow-up tests or examinations for trichomoniasis.

However, you may require further testing to see whether your symptoms are being caused by a different sexually transmitted infection (STI) if your symptoms remain or recur after treatment.

If you have unprotected sex before your treatment is finished, you need to return to your GP surgery or sexual health clinic. You may have become reinfected. You must also return if you:

  • didn't complete your course of antibiotics
  • didn't take your antibiotics correctly (according to the instructions)
  • vomited shortly after taking your antibiotics

You may need more antibiotics or a different form of treatment.

Sexual partners

You should avoid having sex while you're being treated for trichomoniasis, as you may become reinfected.

If you were prescribed a single dose of antibiotics, you need to avoid having sex for seven days after taking the medication.

It's very important that your current sexual partner and any other recent partners are also tested and treated. If your sexual partner isn't treated, this increases the risk of reinfection.

Prevention

If you've had trichomoniasis and it's been treated, you won't be immune to the infection and could get it again.

Like any sexually transmitted infection (STI), the best way to prevent trichomoniasis is to have safe sex. This means always using a condom.

The following measures will help protect you from trichomoniasis and most other STIs, including chlamydia and gonorrhoea. They'll 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're a woman and rub your vulva against your female partner's vulva, one of you should cover your genitals with a dam.
  • Avoid sharing sex toys. If you do share them, wash them or cover them with a new condom before anyone else uses them.