Trichomonas

What is being tested?
The test looks for infection with Trichomonas vaginalis, a sexually transmitted microscopic parasite that causes vaginal infections and urethritis.

According to the US Centers for Disease Control and Prevention, trichomoniasis is the most common curable sexually transmitted disease (STD) in young, sexually active women. In the USA, an estimated 7.4 million new cases occur every year in women and men, with the highest rate in women aged 16 to 35.

Trichomonas vaginalis is one of the most common causes of vaginitis in women. Symptoms include:

• vaginal swelling
• itching, irritation, inflammation
• burning sensation
• frothy, yellow-green vaginal discharge
• unpleasant odour
• frequent urge to urinate
• possible presence of blood

 

These symptoms develop over a few days or weeks; treatment with antibiotics is, however, easy. All sexual activity should stop during treatment, and partners should be treated at the same time to avoid reinfection.

A long-term untreated infection can cause changes in the tissues of the cervix in women, which can be seen on a Pap test. Having trichomoniasis during pregnancy can cause complications and may contribute to premature birth or a low-birth-weight baby.

How is the sample collected for testing?
For women, a swab of vaginal secretions is collected. For men, a swab is inserted into the urethra. Urine samples can sometimes also be used

 

How is it used?
When is it requested?
What does the test result mean?
Is there anything else I should know?

How is it used?
The test is used to diagnose Trichomonas vaginalis infection. In women, small red sores may be visible on the walls of the vagina or cervix during a pelvic examination. Secretions from the vagina or urethra collected on a swab can be examined under the microscope (a “wet prep”), cultured, or tested with molecular methods to detect the parasite.

The “wet prep” examination determines by direct observation whether the symptoms are caused by trichomonas infection. The parasite can be seen under the microscope. This method is simple and quick, but the parasite may be missed because of sampling error.
A more sensitive test is to culture the sample, but it takes up to 7 days for the culture to grow enough to identify the parasite. Other available methods include the direct fluorescent antibody (DFA) test and a test that detects trichomonas antigens.

Molecular tests using direct DNA probes or PCR (polymerase chain reaction) technology offer the most sensitive and fastest detection (usually within 24 hours). Samples can be taken during a routine gynaecological examination that includes a Pap test.

When is it requested?
The doctor may request the test if you have symptoms such as foul-smelling vaginal discharge or pain when urinating. If you have an infection with another sexually transmitted disease, the doctor may also ask you to have a trichomonas test. Similarly, if the results confirm trichomonas infection, you may also be tested for chlamydia and gonorrhoea, as these sexually transmitted diseases often occur together.

What does the test result mean?
A positive test indicates an active infection that requires treatment with specific medicines.
If you are infected, your partner should also be tested and treated if necessary.

Is there anything else I should know?
An infected person is at greater risk of other sexually transmitted diseases. In particular, the genital inflammation that occurs with trichomonas can increase a woman’s susceptibility to HIV if she is exposed to the virus.

Neonatal trichomoniasis, although rare, can also occur and cause complications for the newborn.

Faecal contamination of the sample may show a non-pathogenic organism (Pentatrichomonas hominis, officially named Trichomonas hominis) that looks similar and can therefore be confused with T. vaginalis on direct observation. The presence of this organism does not require any treatment