Trichonomas is caused by a tiny parasite which lives in the vagina and urethra.


The parasite can be passed on through unprotected vaginal, anal or oral sex and from parent to baby during birth.


As with most STIs, symptoms of trichonomas infection don’t always happen or can be easy to miss, especially if you have a penis. If there are symptoms, they may include any of the following:

  • Increased discharge from the vagina, which may be thin or frothy, yellow / green in colour and have a musty or fishy smell (similar to bacterial vaginosis)
  • Pain when having vaginal sex
  • Itching, soreness and inflammation around the vagina
  • Vaginal or penile Pain when urinating 
  • Thin whitish discharge from the tip of the penis, which can stain underwear.


Treatment is simple and effective and involves a single dose of antibiotics. This is followed by a second test a month later to make sure the infection has gone.  If it hasn’t, another dose of antibiotics may be needed. It is important to avoid having sex until you get the ‘all clear’. Otherwise, as well as passing on the infection to people you have sex with, you’ll also keep on re-infecting yourself.

It’s also important for your sexual partners to get checked too. If you’re a bit embarrassed about doing this or are finding it difficult to get in touch with your partners, the clinic where you get tested can help. They can contact people on your behalf and let them know without giving your name.

How to avoid it

Using condoms and dental dams for oral sex and rimming, and condoms with lots of water-based lubricant for anal and vaginal sex, can help stop the infection from being passed on.