Trichomoniasis is a sexually transmitted disease caused by a small parasite called Trichomonas vaginalis. World wide it is one of the most common sexually transmitted diseases (STD’s) but in New Zealand it is uncommon. The infection is most common amongst sexually active females between 16 – 35 years. It is caught during sexual contact with an infected person. Trichomonas can be called ‘Trich” for short (sounds like trike).


Symptoms usually develop 1-4 weeks after contact. In about 15 percent of cases there are no symptoms. In women symptoms include vaginal discharge which is copious, greenish, frothy and watery with an unpleasant ‘fishy’ smell. The skin around the vagina and vulva is uncomfortable, hot, swollen with redness and inflammation that can extend onto the upper thighs. This can lead to discomfort when walking. Itching or pain when urinating can also occur. In males it can cause non-specific urethritis which causes a discharge from the penis and discomfort when urinating. Sometimes it produces an inflammation of the head of the penis (balanitis). Men usually don’t have symptoms and can act as carriers.


Examination of the vagina is required and a swab of the vaginal fluid can be sent to a laboratory where the organism can be detected by culture or other methods. A common way of detecting trichomonas is on a cervical (pap) smear. Trichomonas in males is very difficult to identify. Male partners are always treated. It is important to check for other sexually transmitted diseases during the examination as several STD’s are often found together.


Antibiotic tablets have about a 90 percent cure rate.

This page was last updated at 12:00PM on February 18, 2019.