What is Trichomoniasis?

Trichomoniasis is an infection caused by the single-celled parasite Trichomonas vaginalis. It is spread by unprotected sexual contact and it is one of the most common sexually transmitted infections in the United States. While it affects both men and women, the two genders usually experience it in different ways. Women will notice an infection of the urethra, vagina, or both. In men, it only occurs in the urethra.

Trichomoniasis cannot be spread through normal physical contact like kissing, sitting on the toilet seat, or hugging. Additionally, it cannot be passed to other people through sexual contact not involving the genitals.

Certain factors can increase a person’s chance of contracting the parasite. These include previous trichomoniasis infections, the history of other sexually transmitted diseases, unprotected sexual contact, and having multiple sexual partners.

What are the Symptoms of Trichomoniasis?

Due to the nature of trichomoniasis, men who have become infected typically do not exhibit any symptoms. Likewise, some women may not notice anything amiss, either.

Symptoms include:

  • Genital itching
  • Foul-smelling or discolored discharge
  • Painful urination
  • Abdominal pain
  • Pain during sexual intercourse
  • Inflammation of the cervix
  • Vaginal irritation and inflammation
  • Inflammation of the vulva
  • Spotting or bleeding
  • Pain after ejaculation in men

Because many of these symptoms are similar to those presented by other sexually transmitted infections, it is necessary to have a medical professional perform a physical exam as well as laboratory tests to determine whether trichomoniasis is indeed the cause.

Trichomoniasis Causes

Trichomoniasis (often called “trich”) is a sexually transmitted disease that is typically passed on through genital to genital contact via unprotected sexual activity. It is very rare to have it transmitted by mouth, hand, or anus.

The disease often occurs in patients who exhibit no symptoms and transmit it to others unknowingly. It can be passed from penis to vagina, vagina to penis or vagina to vagina. It is not transmitted by non-sexual activity such as drinking after someone, casual contact or inhalation. The protozoan parasite that causes Trichomoniasis is Trichomonas vaginalis.

How is a Trichomoniasis Treated?

Trichomoniasis can usually be prevented by ensuring proper condom use during sexual intercourse. Additionally, both partners should be treated to minimize the chances of spreading the infection to one another.

Since the condition is caused by a parasite, doctors will prescribe an oral anti-parasitic drug. This is usually given as a single large dose of metronidazole that will clear it up within a week. Without treatment, the infection will likely continue.

Trichomoniasis Prevention

As with any sexually transmitted disease, the surest way to prevent infection is complete sexual abstinence. Trich is generally innocuous and seldom causes long-term damage; however, it is one of the most prevalent sexually transmitted diseases because it often manifests no symptoms and so it is spread unknowingly. Estimates put the number of infected persons in the United States at somewhere around 3.5 million.

Trich is not specific to any region of the country, so the risk exists everywhere. It occurs equally in men and women, although the more serious side effects typically occur in women. Besides abstinence, consistent and appropriate use of latex condoms is the most efficacious way to prevent contracting Trichomoniasis. However, the parasite can exist in areas not covered by the condom, so it is not completely effective.

A long-term, monogamous relationship with a sexual partner who is free of STDs is another way to avoid the infection. For patients who have frequent, unprotected sexual activity, regular testing for any sexually transmitted disease, including Trich, is recommended. Multiple partners are another risk factor that would indicate frequent testing.

Last Reviewed:
October 11, 2016
Last Updated:
September 10, 2017