How Trichomoniasis Is Diagnosed

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Trichomoniasis is caused by the parasite Trichomonas vaginalis. For many years, the primary way of diagnosing trichomoniasis was to use a microscope to look for the parasite in a vaginal swab. However, STD testing technology has improved greatly in the last few years. Now, trichomoniasis is more often looked for using DNA amplification or rapid testing techniques. Such techniques can find the parasites even when very few are present in a urine or other sample.

Testing for trichomoniasis is important because many infected people have no symptoms. That means that you can't rely on the presence or absence of symptoms to know if you have this (or other) STDs.

Many people can remain asymptomatic for trichomoniasis for years. However, even when no symptoms are present, trichomoniasis can still cause health problems or infect a partner.

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At-Home Testing

Several companies have begun to offer online or at-home testing for various STDs, including trichomoniasis. The best of these tests are the same tests that would be provided in your healthcare provider's office. The only difference is that for a home test, you are the one who takes the sample rather than your healthcare provider.

Samples for at-home trichomoniasis tests can include urine and vaginal swabs. These samples are then mailed to or dropped off at, a lab for testing.

At-home trichomoniasis testing can be a good option for people who are uncomfortable talking to their healthcare providers about STDs. However, at-home tests are not for everyone. At-home tests are not covered by insurance, and they can be quite expensive. In addition, some people aren't comfortable taking their own samples or preparing them to send to a lab.

If you do think an at-home test is a right choice for you, make certain the samples are sent to be processed at a certified testing laboratory such as Quest or LabCorp. This information should be available wherever you purchase your test.  

Note: There are no "instant" home tests for trichomoniasis.

Labs and Tests 

Microscope Analysis

In women, the most common way to diagnose trichomoniasis is to use a microscope to examine a vaginal sample. The Trichomonas parasite is very distinctive looking, and it is easy to identify.

However, there are problems with this type of testing. It is much less sensitive than other types of tests. How well the tests work is also very dependent on how samples are collected and treated. On the other hand, microscopic examination of a vaginal sample is very cheap and can be done in the office setting. 

Culture Analysis

Another way to test for trichomoniasis is to use culture techniques. These techniques attempt to grow trichomonas from collected samples. For culture to be successful, it is very important to collect samples properly and avoid the risk of contamination.

Culture is up to 95% sensitive and more sensitive than microscopy. It can be used if there is high clinical suspicion but no parasite has been found on microscopy and when molecular testing is not available.

Trichomoniasis Doctor Discussion Guide

Get our printable guide for your next healthcare provider's appointment to help you ask the right questions.

Doctor Discussion Guide Woman

Molecular Testing

These days, molecular tests are far more likely to be used to detect trichomoniasis than microscopes. Molecular tests for trichomoniasis work in several different ways. There are several types of these tests.

Perhaps the most common are nucleic amplification tests. These look for small amounts of T. vaginalis DNA in urine, vaginal, urethral, or rectal samples. They are more sensitive than many other molecular tests because they are designed to amplify the signal of even small amounts of DNA.

Other molecular tests exist as well. Rapid tests can use antibodies to detect the presence of trichomonas in various samples.

These tests are more expensive than options like culture or microscopy, but they are also much easier. They often don't require special handling of samples, and results can be available quite quickly.

There are additional specialized tests that look for trichomonas DNA but do not amplify it. These tests are less sensitive than amplification tests. However, they are faster and less expensive.

Differential Diagnoses

Many STDs have similar symptoms or no symptoms at all. As such, it's very difficult to diagnose these conditions without diagnostic testing.

That's why, in general, if you're going to be tested for one STD, you'll be tested for multiple STDs. In particular, the symptoms of trichomoniasis, chlamydia, and gonorrhea are similar enough that you will usually be tested for all three conditions at once.

Another reason that people are generally tested for multiple STDs at once is that these conditions often occur in groups. In communities where STDs are common, it is not unusual for people to be infected with multiple diseases.

As treatments are different for each of the STDs, it's very important to use testing to identify precisely what infections are present. Only then can appropriate treatment be prescribed.

In general, when you are tested for trichomonas you will simply receive a positive or negative result. It is possible, however, for the tests to be incorrect. Therefore, if you have symptoms that cannot be explained by another positive test, your healthcare provider may recommend a second round of testing. If symptoms recur after you've been treated, additional testing may also be indicated.

Frequently Asked Questions

  • Is trichomoniasis included in STD testing?

    Typically yes, although you should specifically ask your healthcare provider to test you for trichomoniasis if you suspect you have been exposed.

  • Can I test for trichomoniasis at home?

    Yes. At-home trichomoniasis test kits are available online and at drug stores. There is no rapid test for trichomoniasis. You collect a sample—either a swab or urine sample depending on the test—then send it to a lab to be tested. Results are typically available through a secure website. 

  • How long does it take for trichomoniasis to show up on a test?

    Symptoms of trichomoniasis can appear between three days to a month after infection. If you have symptoms, lab tests may be able to detect the parasites. However, research shows the tests aren’t very sensitive and can miss more than half of positive cases. 

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Meites E. Trichomoniasis: the "neglected" sexually transmitted disease. Infect Dis Clin North Am. 2013;27(4):755-64. doi:10.1016/j.idc.2013.06.003

  2. Shih SL, Graseck AS, Secura GM, Peipert JF. Screening for sexually transmitted infections at home or in the clinic?. Curr Opin Infect Dis. 2011;24(1):78-84. doi:10.1097/QCO.0b013e32834204a8

  3. Van der pol B, Williams JA, Fuller D, Taylor SN, Hook EW. Combined Testing for Chlamydia, Gonorrhea, and Trichomonas by Use of the BD Max CT/GC/TV Assay with Genitourinary Specimen Types. J Clin Microbiol. 2017;55(1):155-164. doi:10.1128/JCM.01766-16

  4. Planned Parenthood. What are the symptoms of trichomoniasis?

  5. Van Der Pol B. Clinical and laboratory testing for trichomonas vaginalis Infection. J Clin Microbiol. 2016;54(1):7-12. doi:10.1128/JCM.02025-15

Additional Reading

By Elizabeth Boskey, PhD
Elizabeth Boskey, PhD, MPH, CHES, is a social worker, adjunct lecturer, and expert writer in the field of sexually transmitted diseases.