Trichomoniasis Test: Purpose, Test Details & Results

Purpose of Trichomoniasis Test

Trichomoniasis is a common but often overlooked sexually transmitted infection (STI) that can affect anyone who is sexually active. While it is curable, undiagnosed and untreated trichomoniasis can lead to serious health complications, including increased risk of HIV transmission, adverse pregnancy outcomes, and long-term reproductive issues. Because many people with trichomoniasis are asymptomatic, testing is crucial to identify infections early, prevent complications, and reduce the spread of the disease. This section explores why testing for trichomoniasis is so important—both for individual health and broader public health.

Objective	Importance	Population Focus	Sources
Detect infection	Prevent complications	High-risk, pregnant, all	1,4,10,12
Reduce spread	Limit transmission	Sexually active individuals	1,4,10
Protect pregnancy	Prevent adverse outcomes	Pregnant individuals	4,12
Support treatment	Enable timely intervention	Symptomatic & asymptomatic	1,7,10

Table 1: Purposes and Importance of Trichomoniasis Testing

Why Testing Matters

Trichomoniasis is the most prevalent curable, non-viral STI worldwide, with tens of millions of new cases annually. Yet, its symptoms are often mild or absent, especially in women, making it easy to miss without testing 1,4. Untreated infections can lead to:

• Greater risk of acquiring or transmitting HIV and other STIs
• Adverse reproductive health outcomes, such as infertility or pelvic inflammatory disease (PID)
• Complications in pregnancy, such as preterm birth and low birth weight 4,12

Who Should Be Tested?

Testing is recommended for:

• Individuals with symptoms of vaginal or urethral infection (e.g., unusual discharge, itching, irritation)
• People with risk factors: multiple sexual partners, prior STI history, or partners with STIs
• Pregnant individuals in high-prevalence populations or with symptoms
• Those who have engaged in unprotected sex or are part of high-risk groups 1,12,13

Public Health Impact

Screening and timely treatment of trichomoniasis have a broader impact by:

• Reducing the likelihood of HIV shedding and transmission 10
• Lowering community prevalence rates, especially in disproportionately affected groups (e.g., Black women, adolescents) 1,13
• Improving sexual and reproductive health outcomes on a population level 4

Trichomoniasis Test Details

Getting tested for trichomoniasis is straightforward, but understanding the variety of test options, their accuracy, and practical aspects is key to making informed choices. Here, we break down the main testing methods, what they involve, and their strengths and limitations.

Test Type	Key Features	Sensitivity/Specificity	Sources
NAAT (e.g., Aptima)	Highly accurate; detects DNA/RNA	Sensitivity: 95–100%; Specificity: 99%+	1,7,12
Rapid Antigen	Point-of-care; results <30 min	Sensitivity: ~78–98%; Specificity: 99%	2,9,11
Wet Mount	Microscopy; immediate results	Sensitivity: 26–66%; Specificity: 99%+	1,5,6,12
Culture	Gold standard (historically); slow	Sensitivity: ~82–95%; Specificity: 100%	5,6,9
PCR/LAMP	Molecular; highly sensitive	Sensitivity: 80–100%; Specificity: 97%+	3,6,8
Pap Smear	Cytology; not recommended for T. vaginalis	Sensitivity: 57–61%; Specificity: 97%	5,8

Table 2: Trichomoniasis Testing Methods Overview

Overview of Test Types

Nucleic Acid Amplification Tests (NAATs)

NAATs, such as the Aptima Trichomonas vaginalis assay, are now considered the gold standard for diagnosis. They detect genetic material (DNA or RNA) of the parasite and are extremely accurate—even in asymptomatic cases or those with low parasite levels. NAATs can be performed on various samples, including vaginal swabs (self- or clinician-collected) and urine 1,7,12.

• Advantages: High sensitivity and specificity; can detect asymptomatic cases; works well with self-collected samples
• Limitations: May require laboratory facilities; results can take a day or more

Rapid Antigen Detection Tests

These point-of-care (POC) tests, like the OSOM® Trichomonas Rapid Test, detect proteins from the parasite. They deliver results in about 10–30 minutes, enabling treatment decisions in the same visit 2,9,11.

• Advantages: Fast, easy to use, can be self-performed, high specificity
• Limitations: Slightly less sensitive than NAATs, especially in low parasite loads

Wet Mount Microscopy

An immediate but less sensitive test, wet mount involves examining a sample of vaginal fluid under a microscope to look for live trichomonads 1,5,6,12.

• Advantages: Quick, inexpensive, available in most clinics
• Limitations: Misses many cases (especially asymptomatic), cannot rule out infection with a negative result

Culture

Culturing the organism from a vaginal or urethral swab is highly specific and was historically the reference method. However, it requires special media and several days for results 5,6,9.

• Advantages: Highly specific, can confirm diagnosis if other tests are inconclusive
• Limitations: Slower turnaround (2–7 days), more technically demanding

Molecular Amplification (PCR, LAMP)

Polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) are highly sensitive DNA-based tests. LAMP, in particular, is rapid and effective even at low resource settings 3,6,8.

• Advantages: Detects very low levels of parasite, highly accurate, rapid (LAMP)
• Limitations: Availability and cost may limit use in some settings

Pap Smear (Papanicolaou Test)

While trichomonads can sometimes be seen on Pap smears, this test lacks sensitivity and is not recommended as a primary diagnostic tool for trichomoniasis 5,8.

Sample Collection

Samples for trichomoniasis testing are usually collected via:

• Vaginal swabs (self- or clinician-collected)
• Endocervical swabs
• Urine (for NAATs)
• Urethral swabs (in men)

Self-collection of vaginal swabs for NAAT or rapid antigen testing is just as effective as clinician collection, helping reduce barriers to testing 1,9.

Special Considerations

• Asymptomatic Infection: Most cases are asymptomatic; sensitive tests (NAAT, rapid antigen, PCR) are preferred for screening 1,7,12.
• Pregnant Women: Testing is not universally recommended in pregnancy but is important in high-risk or symptomatic cases due to potential complications 12.
• At-Risk Populations: High-risk groups (adolescents, non-Hispanic Black women, those with previous STIs) should be prioritized for screening and retesting 1,12,13.

Trichomoniasis Test Results & Follow-Up

Once you’ve been tested for trichomoniasis, understanding your results and what to do next is crucial. This section explains what your results mean, the steps after diagnosis, and the importance of follow-up testing to prevent reinfection.

Result	Interpretation	Next Steps	Sources
Positive	Infection confirmed	Treat; notify partners; retest	10,12,13
Negative	Infection unlikely*	No treatment; retest if at risk	5,6,12
Indeterminate	Unclear result	Repeat or use another test	5,8

*Note: Negative results with low-sensitivity tests (e.g., wet mount) do not rule out infection.

Table 3: Trichomoniasis Test Results and Follow-Up Actions

How to Interpret Results

• Positive Test: This means trichomoniasis infection is present. Immediate treatment is recommended, usually with a single dose of oral metronidazole or tinidazole. Sexual partners should also be notified and treated to prevent reinfection 10,12,13.
• Negative Test: Likely no infection, but if you have symptoms or remain at risk, consider retesting with a more sensitive method or after a window period 5,6,12.
• Indeterminate or Borderline: Sometimes, results are unclear. In this case, repeat testing or a different method may be necessary 5,8.

What Happens After a Positive Result?

Treatment

• Medications: Standard treatment is a single dose of metronidazole or tinidazole, which is highly effective.
• Partner Notification: All recent sexual partners should be notified and treated, even if they have no symptoms, to prevent reinfection.
• Abstinence: Avoid sex until treatment is completed and symptoms resolve.

Retesting and Reinfection

• High Reinfection Rates: Up to 24–33% of women may test positive again within months, often due to untreated partners or new exposures 13.
• Guidelines: The CDC recommends retesting all women about three months after treatment, particularly in high-risk groups and during pregnancy 13.
• Challenges: Adherence to retesting guidelines is low, especially among Black women and those with limited healthcare access 13.

Special Scenarios

Pregnancy

• Risks: Trichomoniasis during pregnancy can increase the risk of preterm birth and low birth weight 4,12.
• Testing & Follow-Up: Pregnant women who test positive should be treated, and retesting is especially important due to high reinfection rates 12,13.

Impact on HIV

• HIV Shedding: Treating trichomoniasis reduces genital HIV viral load, which can lower the risk of HIV transmission 10.

When to Seek Further Care

• If symptoms persist after treatment
• If you or your partner have multiple sexual partners
• If you belong to a high-risk group or are pregnant
• If you have concerns about reinfection or partner notification

Conclusion

Trichomoniasis testing plays a pivotal role in sexual and reproductive health. Early and accurate diagnosis not only prevents individual complications but also curbs the spread of infection in the community. Here’s what you need to remember:

• Testing is vital for detection, especially because most cases are asymptomatic and complications can be severe 1,4,10,12.
• Multiple test options exist, varying in accuracy, speed, and accessibility—NAATs and rapid antigen tests are now preferred for their high sensitivity and ease of use 1,2,3,7,9,11.
• Positive results require treatment of both the patient and sexual partners, with strong emphasis on retesting to catch reinfection 10,12,13.
• Special attention should be given to high-risk groups and pregnant women, where testing and follow-up can prevent serious outcomes 1,12,13.
• Newer, user-friendly tests—including self-collected and point-of-care options—are making it easier to get tested and treated promptly 1,3,9.

By understanding the purpose, process, and implications of trichomoniasis testing, individuals and healthcare providers can work together to improve outcomes and reduce the burden of this common STI.