Trichomoniasis: symptoms, testing and treatment

The NHS says the main symptoms are a yellow-green discharge from the vagina that may smell like fish, and pain when peeing. Symptoms can start 5 to 28 days after being infected, but sometimes you may not get them until much later. Many people get no symptoms at all, so it is important to get tested if you think you might have it.

The NHS says trichomoniasis is treated with antibiotics, usually metronidazole. You take it either twice a day for 7 days or as a one-off dose. If you have symptoms, they should start to get better within a few days of starting the antibiotics. It is important to finish the course even if you start to feel better.

If your symptoms do not go away, the NHS says you may be given another course of antibiotics.

Because the infection passes back and forth, partners matter. The NHS says your current and any recent sexual partners will also need to be treated, and that the GP or sexual health clinic can advise you about contacting them, which can be done without naming you. Do not have sex until at least 1 week after you and any sexual partners have finished treatment.

• Take the medicine exactly as prescribed, and finish the course.

• Do not have sex until at least 1 week after you and any partners have finished treatment.

• Let current and recent partners know, or ask the clinic to do it without naming you.

• Ask your pharmacist or the prescriber about anything else you take, and about alcohol, before starting a course.

Trichomoniasis is an STI. The NHS says you can get or pass it on from vaginal sex without a condom, skin-to-skin contact of the genital area and sharing sex toys. You can still pass it on if you do not have symptoms, and you can get it again if you have had it before.

It can affect people with a vagina and people with a penis, but symptoms differ and are often absent, which is why testing matters if you have had unprotected sex with a new partner.

The NHS lists a short set of steps to lower the risk of catching or spreading trichomoniasis.

• Use external (male) or internal (female) condoms when you have sex.

• Get tested once a year, or if you have a new sexual partner.

• Do not share sex toys, and wash them between uses and cover them with a new condom each time.

The NHS says a doctor or nurse will ask about your symptoms and sexual partners and may check your penis or vagina for signs of trichomoniasis. When you make your appointment you can ask for a chaperone.

They may use a swab, like a large cotton bud, to take a sample of fluid from your penis or vagina, and you may be able to do the swab yourself. You might also be asked to give a pee sample. You can ask to be tested even if you do not have symptoms, and you may also have tests for other STIs at the same time.

NICE Clinical Knowledge Summaries (CKS) says women at increased risk of an STI should be offered testing for chlamydia, gonorrhoea, trichomoniasis, HIV and syphilis. It says testing is ideally done in a genito-urinary medicine (GUM) clinic to facilitate treatment and partner notification, but can be done in primary care if a woman is unwilling or unable to attend one.

The NHS says to go to a sexual health clinic or see a GP if you or a partner have symptoms of trichomoniasis, if you have recently had sex without a condom with a new partner or with someone who has trichomoniasis or another STI, if you or a partner have had sex without a condom with other partners, or if you are pregnant or planning to get pregnant and think you might have it.

NICE CKS says referral to a GUM clinic should be arranged if vaginal discharge is persistent or recurrent or there is doubt about the cause.

The NHS says trichomoniasis in pregnancy can cause your baby to be born early or with a low birthweight. You can also pass it on to your baby when they are born, and there is a higher chance you could get sepsis after you give birth.

If you are pregnant or planning to get pregnant and think you might have trichomoniasis, the NHS says to go to a sexual health clinic or see a GP.

The NHS lists the complications of trichomoniasis that is not treated, summarised below.

• A higher chance of getting or passing on HIV.

• A higher chance of getting bacterial vaginosis.

• Pelvic inflammatory disease (PID), which can lead to pelvic pain, ectopic pregnancy or infertility.

• Inflammation of the prostate gland (prostatitis).

Not every abnormal discharge is trichomoniasis. NICE CKS says abnormal vaginal discharge can be due to infective or non-infective causes, and that a detailed history and often an examination are needed to tell them apart.

NHS sexual health clinics and GPs offer testing and treatment, and the NHS says you can ask to be tested even without symptoms. A clinic or GP can also help with contacting partners without naming you.

Some people choose a private STI screen or private doctor for convenience or speed. In general terms the medicine is the same. The practical questions are how partners will be informed, whether results and treatment are recorded with your GP, and who will arrange a repeat test if symptoms continue.