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Trichomonas Vaginalis

Trichomonas Vaginalis - the basics 
Trichomonas vaginalis, or ‘TV’ is a sexually transmitted infection (STI) caused by a protozoan (sp). Protozoa are tiny germs similar to bacteria. TV is usually easy to treat and cure.

Testing is available at any specialised sexual health or Genitourinary Medicine (GUM) clinic and in some GP surgeries and contraceptive services. If you have TV we recommend that you have tests for other STIs including chlamydia, gonorrhoea, syphilis and HIV. 

How do you get TV? 
During sex, the protozoan usually spreads from a penis to a vagina, or from a vagina to a penis. It can also spread from a vagina to another vagina and through sharing sex toys. It is unclear why some people with the infection get symptoms while others do not. Infected people without symptoms can still pass the infection on to others.

TV is not a known issue for people with a neovagina following gender reassignment surgery.

TV cannot be caught from hugging, sharing baths or towels, swimming pools or toilet seats. 

What would I notice if I had TV? 
About 70% of people with the infection do not have any symptoms. When TV does cause symptoms, they can range from mild irritation to severe inflammation. Some people with symptoms get them within 5 to 28 days after being infected. Others do not develop symptoms until much later. Symptoms can come and go. Without treatment, the infection can last for months or even years.

People with a vagina may notice one or more of the following: 
•	increased vaginal discharge 
•	an unpleasant vaginal smell 
•	‘cystitis’ or burning pain when passing urine 
•	vulval itching or soreness 
•	pain in the vagina during sex 

Most people with a penis will not feel anything wrong but they can still pass TV on to their sexual partner. Some may notice one or more of the following: 
•	discharge from the tip of the penis 
•	burning pain when they pass urine 
•	wanting to pass urine more often than normal 
•	soreness around the foreskin 

How do I get tested for TV? 
In people with a vagina
It is not a routine test in all clinics if you have no symptoms but is usually done if you have symptoms that could be TV or have risk factors. 

If you do have symptoms, it is likely a swab will be taken from your vagina by a doctor or nurse during an internal examination. Some clinics can test for TV on a swab you take yourself from your vagina or on a urine sample. 

In people with a penis: 
In most clinics it is not routine for people with a penis to be tested for TV. You may be offered a TV test because your sexual partner has tested positive for TV. A swab is taken from the tip of the penis. Some clinics can test for TV on a urine sample. If this test is planned you should not have passed urine for an hour. Some of the tests for TV do not work very well in people with a penis and this explains why some people with a penis with TV infection will test negative. 

Some TV test results may be available during your first visit to clinic (by looking at the samples under a microscope). You will be informed about how you will receive your final results before leaving the clinic. 

How is TV treated? 
•	TV can be treated with antibiotics (metronidazole). These pills are taken by mouth. Occasionally a second course is needed if your symptoms don’t go away. 
•	If you still have symptoms after treatment, go back to see your doctor.
•	All treatments from sexual health clinics are free and are given to you in the clinic.

Important information about your treatment 
•	The antibiotics are highly effective if taken correctly. 
•	The antibiotics don’t interfere with your contraception. 
•	You will be advised not to drink any alcohol while taking your antibiotics and for at least 48 hours after finishing treatment. This is because alcohol may cause the antibiotics to give you a severe headache and feeling of sickness. The antibiotics would still work if you get this reaction. 
•	If you are pregnant, the benefit of treating TV with metronidazole outweighs any risk to the baby so long as high doses are avoided. 
•	If you are breastfeeding, you can continue with breastfeeding whilst taking Metronidazole as long as high doses are avoided. Metronidazole enters the breast milk and may affect the taste of the milk.

What about my partner? 
As TV is an STI it is important that your partner is tested for TV as well as other STIs. The TV test used in most clinics is not good at finding TV in a people with a penis, even if they have the infection. This is the reason why your partner will almost certainly be offered antibiotics, even if their TV test is negative. 

When can I have sex again?
You should not have sex (even with a condom) until one week after both you and your partner have finished your treatment and any follow-up visit to the clinic. 

What happens if my TV is left untreated? 
•	Your symptoms may not go away.
•	You can re-infect your partner or pass TV to your partner.
•	In rare cases, TV may infect the prostate gland causing prostatitis (inflammation or swelling of the prostate) and symptoms such as pain in the genital region, pain on ejaculation and problems in passing urine. 

Can I get TV again? 
Yes, you can. You can get it from an untreated sexual partner or from a new sexual partner. To prevent this make sure your partner(s) has been treated before having sex with them again. 
Protect yourself with new partners by ensuring a condom is used for all vaginal, anal and oral sex. Sex toys can be covered with a new condom each time they are used and should be washed with soap and water between sessions. 

TV in pregnancy 
If TV in pregnancy is not treated, there is an increased risk of labour starting early and the baby being delivered prematurely, or the baby having a low birth weight. At the moment we do not know if treating TV during pregnancy will stop these complications from happening. 
The tests and treatment are the same in pregnancy. Your doctor will discuss things in more detail with you. 

How common is TV? 
In 2019 just over 9,500 cases were diagnosed in England. However, only 30% of people with TV develop symptoms so many are not tested. In contrast, more than 229,000 cases of chlamydia were reported in the same year. Over 90% of TV cases are diagnosed in women.

This leaflet was produced by the Clinical Effectiveness Group of the British Association for Sexual Health and HIV (BASHH). The information in the leaflet is based on the ‘United Kingdom BASHH national guideline for the management of Trichomonas Vaginalis 2021’ published by BASHH. More information: BASHH: The leaflet was developed following The Information Standard principles developed by NHS England. More information:

If you would like to comment on this leaflet, e-mail us at: [email protected]. Please type ‘TV PIL’ in the subject box.

Copyright BASHH 2022. This leaflet was first published in 2014 and updated in October 2022. Review date 2026.