Trichomoniasis

What Is Trichomoniasis?

Trichomoniasis (or "trich") is a common sexually transmitted infection caused by a tiny parasite called Trichomonas vaginalis. Despite the fancy name, it's one of the most treatable STIs around — a single antibiotic tablet usually clears it completely.

It's more common than many people realise. Globally, it's one of the most prevalent non-viral STIs. In Ireland, it's regularly diagnosed at sexual health clinics, though it's somewhat underreported because many people — particularly men — have no symptoms and never get tested.

Trich is not caused by bacteria or a virus — it's a protozoan parasite that lives in the urogenital tract. This means it needs specific antiparasitic treatment, but it responds very well to the right medication.

How Do You Get It?

Trichomoniasis spreads through sexual contact involving the genitals. It primarily affects the vagina, vulva, cervix, urethra, and bladder.

• Vaginal sex (the most common route of transmission)
• Genital-to-genital contact without penetration
• Sharing sex toys that haven't been cleaned or covered with a condom

Trich is less commonly transmitted through anal or oral sex. It does not spread through kissing, hugging, toilet seats, or shared towels — the parasite needs a warm, moist genital environment to survive and can't live outside the body for long.

You can have trichomoniasis without knowing it and pass it on to a partner. This is why testing is important even when you feel fine.

Symptoms

Here's the tricky part: up to 70% of people with trichomoniasis have no symptoms. When symptoms do appear, they usually show up within 5–28 days of infection.

Symptoms in women and people with vaginas:

• Unusual vaginal discharge — often frothy, greenish-yellow, and with a strong fishy or unpleasant odour
• Vaginal itching, burning, or soreness
• Redness and swelling of the vulva
• Pain or discomfort during sex
• Pain or burning when urinating
• Lower abdominal discomfort (less common)

Symptoms in men and people with penises:

• Often no symptoms at all — men are frequently asymptomatic
• Discharge from the penis (thin, whitish)
• Burning or discomfort during urination or after ejaculation
• Mild irritation inside the penis

Even without symptoms, trich can still cause irritation or inflammation, and untreated infection has been linked to increased risk of acquiring or passing on HIV. It's also associated with preterm birth and low birth weight during pregnancy — another reason testing during pregnancy is worthwhile.

Testing & Diagnosis

Testing for trichomoniasis is straightforward:

• For women/people with vaginas: a swab from the vagina — either taken by a clinician or a self-taken swab in some clinics
• For men/people with penises: a urine sample or, less commonly, a urethral swab

Trich is often picked up during a routine STI screen. It's not always included in standard panels, so if you want to make sure you're tested for it, mention it specifically when you're at the clinic.

In Ireland, you can get tested at:

• Your GP — can arrange swabs and refer you if needed
• HSE Sexual Health Clinics — free and confidential, nationwide
• Brook Ireland — free testing for under-25s in Dublin
• GUIDE Clinic, St. James's Hospital, Dublin
• Dean Clinic, Cork
• Private sexual health clinics — rapid results, nationwide

Results are typically back within a few days. If you've had a new partner recently or have symptoms like unusual discharge or irritation, book a test.

Treatment

Trichomoniasis is treated with antibiotics — specifically antiparasitic antibiotics called nitroimidazoles. In Ireland, the most commonly prescribed is:

• Metronidazole — usually a single 2g oral dose, or a 5–7 day course of lower doses (400mg twice daily). Both are highly effective.
• Tinidazole — an alternative single-dose option, sometimes used if metronidazole doesn't work.

Important points about treatment:

• Avoid alcohol for 24 hours after metronidazole (48 hours after tinidazole) — it causes a very unpleasant reaction
• Don't have sex (including oral sex) until you and your partner(s) have both finished treatment and are symptom-free
• Both partners must be treated at the same time, otherwise you'll just keep reinfecting each other
• You can be reinfected after treatment — there's no lasting immunity

A follow-up test is sometimes recommended 3 months after treatment to confirm clearance, especially if symptoms return or reinfection is possible.

Why It Matters (Even Without Symptoms)

Trich might not make you feel terribly unwell, but untreated infection has real health implications:

• Ongoing inflammation of the genital tract
• Increased susceptibility to other STIs, including HIV
• During pregnancy: linked to premature labour and low birth weight
• Passing it on to partners who may develop more significant symptoms

The simplest thing you can do is get tested regularly and get treated promptly if you test positive. It's a minor inconvenience compared to the alternative.

Partner Notification

If you test positive for trichomoniasis, all recent sexual partners (typically within the last 4 weeks, or your most recent partner if longer) should be told so they can get tested and treated too.

Your clinic can help you with this. You can notify partners yourself, or use a confidential partner notification service where the clinic contacts them without revealing your identity. Either way, getting partners treated is essential — without it, you're likely to keep reinfecting each other.

Prevention

• Use condoms consistently for vaginal sex — condoms significantly reduce the risk of trich transmission
• Use dental dams for oral-vaginal contact
• Clean sex toys between partners, or use a fresh condom on them each time
• Get tested regularly — particularly if you have new or multiple partners
• Ensure partners are tested and treated before resuming sex after a positive result

There's no vaccine for trichomoniasis, but consistent condom use substantially lowers your risk. Regular testing catches it early and keeps transmission down.

Support & Resources

• HSE Sexual Health: sexualwellbeing.ie — clinic finder and STI information
• Brook Ireland: brook.ie — free sexual health services for under-25s in Dublin
• GUIDE Clinic: St. James's Hospital Dublin — specialist GUM clinic
• Dean Clinic, Cork: Sexual health services in the South
• Your GP: Can test, diagnose, and prescribe treatment. All consultations are confidential.