Most people infected with Trichomonas vaginalis do not have any symptoms and can be undetected for years. Symptoms experienced include pain, burning or itching in the penis, urethra (urethritis), or vagina (vaginitis). Discomfort for both sexes may increase during intercourse and urination. For women there may also be a yellow-green, itchy, frothy, foul-smelling ("fishy" smell) vaginal discharge. In rare cases, lower abdominal pain can occur. Symptoms usually appear within 5 to 28 days of exposure. Sometimes trichomoniasis can be confused with chlamydia because the symptoms are similar.
Bacterial vaginosis is an abnormal vaginal condition with signs and symptoms of vaginal discharge, vaginal odor, and vaginal pain. Bacterial vaginosis results from an overgrowth of normal bacteria in the vagina. Although it may cause some disturbing symptoms (discharge and odor), it is not dangerous and cannot be passed by sex. Diagnosis becomes important to exclude serious infections like gonorrhea and Chlamydia. Many treatment options are available such as oral antibiotics and vaginal gels.
There were about 58 million cases of trichomoniasis in 2013. It is more common in women (2.7%) than males (1.4%). It is the most common non-viral STI in the U.S., with an estimated 3.7 million prevalent cases and 1.1 million new cases per year. It is estimated that 3% of the general U.S. population is infected, and 7.5-32% of moderate-to-high risk (including incarcerated) populations.
^ Epstein, Aaron; Roy, Subir (2010). "Chapter 50: Vulvovaginitis". In Goodwin, T. Murphy (ed.). Management of Common Problems in Obstetrics and Gynecology (5th ed.). Wiley-Blackwell. p. 228. ISBN 978-1405169165. Archived from the original on 2017-02-15. In 80% of cases, the diagnosis of trichomoniasis is confirmed by microscopic examination of saline wet mount, with the observation of motile trichominondas; their shape is "football-like" with moving flagella.
Your sex partner(s) should be treated at the same time you are being treated. This increases the cure rate and reduces the possibility of further transmission or reinfection. Sexual intercourse should be avoided during treatment until symptoms are gone and until partners have been treated. It is best to avoid sex for 1 week after treatment with a single dose of metronidazole. Male partners may not have symptoms but still need treatment.