What is trichomoniasis?
Trichomoniasis is a sexually transmitted infection (STI) caused by the protozoal organism, Trichomonas vaginalis.

How common is trichomoniasis?
It is the most common non-viral sexually transmitted infection in the US, affecting about 3.7million people. Women over forty years of age are more likely than younger women to be infected and black women are more likely than white or Hispanic women to be infected.1

How is trichomoniasis spread?
Trichomoniasis is usually spread through vaginal intercourse.

Does trichomoniasis cause symptoms?
About 70% of people with trichomoniasis do not recognize or report symptoms.2

What are the symptoms of trichomoniasis?
The most common symptom is vaginal discharge. Some infected females experience genital itching, frothy vaginal discharge, painful urination, and painful intercourse. Some infected males experience painful urination, discharge, itching and irritation of the urethra and tip of the penis.

Are there any available treatments for trichomoniasis?
Trichomoniasis can be treated with oral medications, often with only one dose. However, many people never seek treatment because they do not experience any symptoms of the infection. Without treatment of both partners, the infection continues to be spread between sexual partners.

What complications can result from trichomoniasis?
In many circumstances, Trichomoniasis does not cause as many serious long-term complications as several other STIs do. But there are notable exceptions, especially as it involves pregnant women and the spread of HIV.
If a mother has trichomoniasis during pregnancy, the baby is more likely to be born early and to have a low birth weight. The infection can also be passed to the baby during childbirth.3
Trichomoniasis also increases a person’s chances of acquiring HIV (see below.)

Does trichomoniasis affect the spread of HIV?
Yes. Like many other STIs, trichomoniasis can increase the risk of getting HIV from an infected sexual partner by about 50%.4,5 This is very important, because trichomoniasis is such a common infection.
If a woman is HIV positive, she is also susceptible to developing Pelvic Inflammatory Disease from a trichomoniasis infection.6

Can trichomoniasis be prevented?
Yes; refraining from sexual activity until a person is within a lifelong, mutually monogamous relationship with an uninfected partner can prevent the sexual transmission of trichomoniasis.


This image shows what Trichomonas vaginalis looks like under a microscope.


This image demonstrates the discharge from the cervix associated with trichomoniasis

1. Centers for Disease Control and Prevention, “2015 STD Treatment Guidelines,” accessed July 2015 at:
2. Centers for Disease Control and Prevention. Trichomoniasis – CDC Fact Sheet.
Available at:
Accessed July 2015
3. Secor WE, Meites E, Starr MC & Workowski A, “Neglected Parasistic Infections in the United States: Trichomoniasis,” Am J Trop Med Hyg 2014 vol. 90 no 5 800-804
4. McClelland RS, Sangare L, Hassan WM, et al, “Infection with Trichomonas vaginalis Increases the Risk of HIV-1 Acquisition,” The Journal of Infectious Diseases 2007; 195: 698-702
5. Van Der Pol B, Kwok C,Pierre-Louis B, et al. Trichomonas vaginalis infection
and human immunodeficiency virus acquisition in African women. J Infect Dis
6. Moodley P, Wilkinson D, Connolly C, et al, “Trichomonas Vaginalis is Associated with Pelvic Inflammatory Disease in Women Infected with Human Immunodeficiency Virus,” Clinical Infect Dis 2002; 34:5 19-22.

Updated: July 2015