At a glance

Also known as

Trich, TV

Why get tested?

Trichomonas vaginalis is a pathogenic, single celled microorganism that infects the urogenital tract. It causes vaginal infections in women and urethritis in some men. An infection with Trichmonas vaginiais is called Trichomoniasis and is a sexually transmitted disease (STD).


Image 1: Diagram of Trichomonas vaginalis (Source: Veralovic et al 10th Edition of Clinical Microbiology, 2011)
 

When to get tested?

If  a woman shows symptoms of infection, such as a strong-smelling vaginal discharge, genital itching, and/or pain during urination then testing should occur.  A man may display symptoms of the frequent urge to urinate and/or a discharge from the urethra.
 

Sample required?

For  women, a vaginal or endocervical swab is collected.    For men, a urethral swab is required. Alternatively, both males and females can provide a first pass urine sample in a sterile container.
 

Frequency of testing

As symptoms warrant or if a sexual partners test positive.

What is being tested?

The test is looking for the presence of   Trichomonas vaginalis.
 

How is the sample collected for testing?

In women, a swab of the secretions inside the vagina is collected. In men, a thin swab is inserted into the urethra of the penis. Alternatively, the first portion of urine is collected for testing.

Is any test preparation needed to ensure the quality of the sample?

None

The Test

How is it used?

In some laboratories, the swab  is placed onto a slide and  examined under a microscope to visually see the presence or absence of Trichomonas.  However, the preferred method is   using nucleic acid amplification testing (NAAT)   to detect the DNA of Trichomonas vaginalis in urine and other samples. This method is more sensitive than microscopic examination.
 

When is it requested?

Your doctor may request the test if you show signs  of symptoms, such as vaginal discharge or pain on urination. Co-infection with other sexually transmitted diseases is likely. If you have an infection with another sexually transmitted disease, your doctor might test for Trichomonas vaginalis as well. Likewise, if you are positive for Trichomonasis your doctor may test you for other STDs such as Chlamydia and Gonorrhoea. Testing may also be performed if your partner has tested positive for a STD. Re-testing may also occur to ensure that the infection has been eradicated as reinfection from an untreated partner is common.
 

What does the test result mean?

A positive result means an infection of Trichomonasis. This   requires treatment with a course of antibiotics, usually Metronidazole. All sexual partners of a positive infected person should also be tested. Infection, especially in men, can often be asymptomatic (no obvious symptoms).

A negative test means either there is no infection with T. vaginalis and symptoms are due to another cause or Trichomonas was not able to be detected in the sample using the test method performed. If Trichomoniasis is still suspected, a different testing method may be used or a repeat sample may be taken to confirm the result.
 

Is there anything else I should know?

Trichomonasis is one of the most prevalent, treatable non-viral STDs, mostly affecting women. It  is more common in Aboriginal populations especially in rural and remote communities.
An infected person is at greater risk of getting other STDs , so the doctor may want to test for these other infections also.
Trichomonas infection can affect pregnancy, contributing to premature birth and low birth weight. You should inform your doctor if you think you might be pregnant. The doctor may medically manage a woman who is infected and in her first three months of pregnancy differently.

Common Questions

What are the symptoms of a trichomonas infection?

In women, vaginal discharge is typically described as copious, liquid, greenish, frothy and foul smelling. Symptoms, such as intense vaginal discharge, are often sudden and frequently noted to occur during or after menstruation. Itching or redness in and around the vagina may also be experienced. Other symptoms can include pain during sexual intercourse, discomfort or swelling in the lower abdomen or groin, and the frequent urge to urinate, often with pain and burning. However, at least 10% of women with Trichomonas vaginalis infections are asymptomatic.

Most infected men have no symptoms but when they do, symptoms include discharge from the urethra, a frequent urge to urinate, and a burning sensation on urination.

How is trichomonas transmitted?

The organism  is transmitted via  sexual contact. Female to female and neonatal transmission from mother to child during birth are rare but  have also been reported.
 

How is it treated?

It is usually treated with an antibiotic called Metronidazole. All current sexual partners should be notified and  treated at the same time or the patient is likely to become re-infected.
 

How can it be prevented?

  • Abstain from sexual intercourse during treatment until the infection is cleared and the course of antibiotics complete; or
  • Use a latex condom properly, every time you have sexual intercourse, with all  partners
  • Limit your sexual partners. The more sex partners you have, the greater your risk of encountering someone who has this or other STDs.
  • If you are infected, your sexual partner(s) should be treated. This will prevent you from getting reinfected.

Last Review Date: June 18, 2019