Trichomoniasis is diagnosed through a lab test on a vaginal swab, urethral swab, or urine sample. The most accurate option is a nucleic acid amplification test (NAAT), which detects the parasite’s genetic material and can return results in about an hour. Several other methods exist, ranging from a quick microscope exam done during your visit to rapid antigen tests and at-home collection kits.
The Most Accurate Test: NAAT
NAATs are the preferred diagnostic method for trichomoniasis because they catch infections that other tests miss. These tests work by amplifying tiny amounts of the parasite’s DNA in a sample, making even low-level infections detectable. One widely used NAAT, the GeneXpert TV assay, can produce results in under an hour when run on-site at a clinic or hospital lab.
For women, the sample is typically a vaginal or cervical swab. For men, a urethral swab or urine sample is used. NAATs are the only testing method that reliably detects trichomoniasis in men, where the parasite is often present in lower numbers and harder to find with less sensitive techniques.
Wet-Mount Microscopy
A wet mount is the simplest and oldest method. A clinician places a drop of vaginal fluid on a glass slide, adds a small amount of saline, and looks under a microscope for the moving, pear-shaped parasites. When positive, you can get an answer within minutes during your appointment.
The catch is that wet mounts miss a lot of infections. The sensitivity drops sharply over time: if the slide isn’t examined immediately after collection, detection rates fall to around 20% within one hour. Even under ideal conditions, wet mounts are significantly less sensitive than NAATs. A negative result on a wet mount does not rule out trichomoniasis, and many clinicians will follow up with a NAAT if symptoms are suggestive but the slide looks clear.
Rapid Tests
Rapid point-of-care tests sit between wet mounts and NAATs in both speed and accuracy. Two are commonly available:
- OSOM Trichomonas Rapid Test: A dipstick-style antigen test that produces results in about 10 to 15 minutes. Studies show its specificity is excellent (around 99%), meaning a positive result is almost certainly correct. Sensitivity is lower, roughly 77% on average, so it still misses about one in four infections.
- Solana Trichomonas Assay: A molecular-based rapid test that delivers results in under 40 minutes, with higher sensitivity than the dipstick approach.
Rapid tests are useful when a NAAT isn’t available or when same-day results are needed to start treatment. If a rapid test comes back negative but you have symptoms like unusual discharge, itching, or burning during urination, a follow-up NAAT is a reasonable next step.
At-Home Collection Kits
You can order at-home STI kits that include trichomoniasis testing. These kits have you collect a urine sample or vaginal swab at home, then mail it to a lab. The lab typically runs a NAAT on your sample, so the accuracy is comparable to what you’d get at a clinic. Results usually come back within a few days, depending on the company and shipping time. If the result is positive, many services connect you with a provider who can prescribe treatment remotely.
What the Sample Collection Involves
For women, a vaginal swab is the preferred sample. This can be collected by a clinician during a pelvic exam, or in many settings you can do a self-collected vaginal swab, which is just as accurate and more comfortable for most people. Urine can also be tested, though vaginal swabs tend to perform better.
For men, the standard sample is a urethral swab or a first-catch urine sample (the initial stream when you start urinating). Trichomoniasis in men often causes no symptoms and clears on its own, but infected men can pass the parasite to partners. Because the organism is harder to detect in men, NAAT is especially important rather than relying on microscopy or rapid tests.
Who Should Get Tested
Testing is straightforward if you have symptoms: unusual vaginal discharge (often yellow-green and frothy), genital itching or irritation, or discomfort during urination or sex. But trichomoniasis is frequently asymptomatic, particularly in men and in up to 30% of women.
The CDC recommends considering screening for women in high-prevalence settings such as STI clinics and correctional facilities, as well as women with multiple sexual partners, a history of other STIs, or those who use drugs. Women living with HIV should be screened at entry to care and at least once a year after that. There are no routine screening recommendations for men outside of specific clinical situations.
Why the Test Method Matters
Trichomoniasis is the most common curable STI worldwide, yet it’s frequently missed because many clinics still rely on wet-mount microscopy as a first-line test. If you’re told your wet mount was negative but your symptoms persist, asking for a NAAT can make the difference between a missed diagnosis and getting treated. Treatment itself is simple, typically a single oral dose of an antibiotic, but it only works if the infection is identified in the first place. Sexual partners need treatment at the same time to prevent reinfection, which is another reason accurate testing matters.