Trichomonas vaginalis

Causes of trichomonas vaginalis

Trichomonas vaginalis is also called trichomoniasis or shortened to TV. It's a common sexually transmitted infection caused by a tiny protozoan parasite.

TV is almost always passed from one person to another during sex. In women, the infection can live inside the cells of the vagina and in the urethra. In men, it can be found in the urethra. The infection can spread if you have vaginal sex or possibly by sharing sex toys. It's possible for a pregnant woman to pass the infection to her baby at birth.

Symptoms of trichomonas vaginalis

Up to half of infected women and men will have no symptoms. Signs and symptoms can show up three to 21 days after coming into contact with TV.

Women may notice:

• an unusual vaginal discharge - this may be thin, frothy and have a musty or fishy smell
• soreness, inflammation and itching in and around the vagina
• pain when passing urine
• pain when having sex
• lower abdominal tenderness

Men may notice:

• a discharge from the penis - this may be thin and whitish
• pain, or a burning sensation, when passing urine
• inflammation of the glands or foreskin (less common)

Testing for trichomonas vaginalis

You can have a test as soon as you think you have been in contact with TV. Testing is free on the NHS from general practice, genitourinary medicine (GUM) clinics or sexual health clinics.

Testing will involve using a swab (like a cotton bud) to take a sample of cells from the vagina, the genital area and the urethra. Sometimes TV will be found during a routine cervical screening test.

Treatments for trichomonas vaginalis

Treatment is simple and involves taking antibiotic tablets, usually metronidazole, either as a single dose or a longer course (up to a week).

Some antibiotics used to treat TV interact with the combined oral contraceptive pill or contraceptive patch making them less effective, so check with your doctor or nurse. Also tell them if you are you pregnant, or think you might be, or if you are breastfeeding. This might affect the type of antibiotic you are given.

To avoid reinfection, any sexual partners should be treated too.

For most people, trichomonas vaginalis won't go away without treatment, so the symptoms will remain.

Advice and support

You can go to your general practice, a GUM medicine clinic or a sexual health clinic. All services are confidential.

You can call the FPA helpline on 0845 122 8690 or the NHS Sexual Health Helpline on 0800 567123.

How to avoid STIs

• Male and female condoms, when used correctly, can help protect against STIs
• Before you have sex, talk to your partner about using condoms
• Use condoms every time you have vaginal or anal sex
• If you have oral sex, use a dam