Trichomoniasis: The Most Common STI Most People Have Never Heard Of
✍️ Written by: HOP Medical Centre Health Content Team
📅 Published: September 2026 | 🔄 Last Reviewed: September 2026
Trichomoniasis symptoms rarely come up in everyday conversation about STDs, which is strange given the numbers involved. The World Health Organization estimates approximately 156 million new cases of Trichomonas vaginalis infection occurred globally among people aged 15-49 in a single recent year (https://www.who.int/news-room/fact-sheets/detail/trichomoniasis), making it the most common curable STI worldwide, ahead of chlamydia and gonorrhoea combined.
At HOP Medical Centre, trichomoniasis gets far less attention in patient conversations than its actual prevalence would suggest. This guide covers why that gap exists, what trichomoniasis symptoms actually look like, and why so many cases go undiagnosed.
Why Trichomoniasis Symptoms Go Unnoticed So Often
Trichomoniasis is caused by a parasite, not a bacterium or virus, which sets it apart from most other common STDs. Between 50% and 85% of cases are estimated to be asymptomatic, meaning the large majority of people carrying the infection never notice anything at all.
When trichomoniasis symptoms do appear, they differ noticeably between men and women. Women tend to have more noticeable symptoms, including a frothy, often foul-smelling discharge, genital irritation, and discomfort during urination or sex. Men rarely show symptoms at all, and when they do, symptoms are typically mild: some discharge, mild irritation, or burning after ejaculation.
Trichomoniasis Symptoms by Sex
| In Women | In Men |
|---|---|
| Frothy, yellow-green, foul-smelling discharge | Often no symptoms at all |
| Genital irritation, itching, or soreness | Mild discharge from the penis, when present |
| Pain or discomfort during sex or urination | Burning after ejaculation or urination |
This asymmetry is a major reason men are often diagnosed only after a female partner tests positive first, through contact tracing rather than their own symptoms prompting a test.
Why Trichomoniasis Matters Beyond the Immediate Symptoms
Left untreated, trichomoniasis can persist for months or years without resolving on its own, and the infection remains transmissible the entire time. Research also links trichomoniasis to a 1.5 times increased risk of HIV acquisition, alongside associations with pregnancy complications and increased vulnerability to other reproductive health issues.
- You notice unusual discharge, odour, or genital irritation
- A partner has been diagnosed with trichomoniasis
- You’re being screened for other STDs and want fuller coverage
- You’ve had a new sexual partner and haven’t tested recently
- You’re pregnant, given the associated pregnancy-related risks
How Trichomoniasis Is Diagnosed and Treated
Diagnosis typically involves examining a vaginal or urethral swab sample, sometimes under a microscope or through more sensitive lab-based testing methods. Unlike some STDs where testing depends heavily on symptom timing, trichomoniasis testing works reasonably well regardless of whether symptoms are present.
Treatment is straightforward: a course of antibiotics, typically metronidazole or tinidazole, effectively clears the infection in most cases. Both partners need treatment simultaneously to avoid reinfecting each other, and current clinical guidance favours a multi-day antibiotic course over older single-dose approaches for better outcomes.
Trichomoniasis Testing at HOP Medical Centre
Trichomoniasis screening is included in HOP Medical Centre’s Package E, alongside Chlamydia, Gonorrhoea, Mycoplasma Genitalium, Mycoplasma Hominis, and Ureaplasma testing, using a urine or vaginal swab sample. Full package details and current pricing are available at (https://hop.sg/stdscreening/).
Frequently Asked Questions About Trichomoniasis
1. Why haven’t I heard of trichomoniasis before, if it’s this common?
It receives far less public attention than chlamydia, gonorrhoea, or HIV, despite higher global case numbers, partly because most cases cause no symptoms and go undiagnosed.
2. Can trichomoniasis go away on its own?
No. Without treatment, it can persist for months or years and remains transmissible throughout that time.
3. Why do women get symptoms more often than men?
The reasons aren’t fully understood, but it’s a consistent pattern across research. Men are frequently diagnosed only after a partner tests positive first.
4. Is trichomoniasis dangerous?
It’s treatable and curable, but untreated infection is linked to increased HIV acquisition risk and pregnancy-related complications.
5. How is trichomoniasis treated?
With a course of antibiotics, typically metronidazole or tinidazole. Both partners need treatment together to prevent reinfection.
More Questions About Trichomoniasis Testing
6. Does a standard STD panel automatically include trichomoniasis?
Not always. At HOP Medical Centre, it’s included in Package E specifically, alongside several other infections.
7. Can trichomoniasis be tested for without symptoms?
Yes. Testing works effectively regardless of whether symptoms are present, unlike some infections that depend heavily on symptom timing.
8. Is trichomoniasis linked to other STDs?
It’s associated with increased risk of acquiring HIV, and its presence often prompts broader STD screening given overlapping risk factors.
9. Can trichomoniasis come back after treatment?
Reinfection is possible if a partner isn’t treated simultaneously. Completing the full antibiotic course as prescribed reduces this risk.
Trichomoniasis symptoms staying under the radar, despite the infection’s global prevalence, is exactly why routine screening matters more than symptom-watching. HOP Medical Centre’s Orchard and Tampines clinics include trichomoniasis testing in Package E.