This is a sexually transmitted disease cause by a parasite called trichomonas. It usually presents as an unpleasant, foul-smelling yellow-green discharge from the vagina. It can also cause vaginal itching or discomfort during sex.
However nearly 50% of cases are detected during routine STI screening i.e. the patient has no symptoms. This infection is usually treated with an antibiotic taken orally called metronidazole (flagyl). Male partners should also be treated with similar medication.