PCR detection of Trichomonas vaginalis

Do you have yellowish-green, frothy, unpleasant-smelling discharge, genital itching or burning? The cause may be Trichomonas vaginalis, a tiny sexually transmitted parasite. PCR from urine or a swab reliably detects it in women and men, and the infection is easily treated.

Who is this test for

• women with increased, yellowish-green or frothy, unpleasant-smelling discharge;
• women with genital itching, redness and burning or pain during intercourse;
• men with burning when urinating or after ejaculation, or mild urethral discharge;
• people whose partner has been diagnosed with trichomoniasis;
• after unprotected intercourse or a change of partner;
• pregnant women with increased discharge, on a gynaecologist’s recommendation.

What the test reveals

PCR finds genetic traces of the parasite Trichomonas vaginalis in urine or a swab. Trichomoniasis is one of the most common sexually transmitted infections worldwide, and most infected people have no symptoms. Men are often carriers only and unknowingly transmit the infection.

Untreated infection in pregnancy is associated with premature birth and low birth weight, while inflamed mucosa facilitates transmission of other sexually transmitted infections, including HIV. Testing is therefore worthwhile even when symptoms are mild. Similar discharge may be caused by bacterial vaginosis and candida, so a doctor often checks several pathogens at once.

The test and preparation

Women provide a vaginal swab or first-catch urine; they can also collect a vaginal swab themselves at home using a self-sampling kit obtained from a branch and return the sample to the branch. Men provide first-catch urine or a genital swab.

For urine, the first urination in the morning is best, or after not urinating for at least two hours. Collect only the first stream, around 10 to 20 mL. Do not take the swab during menstruation; avoid vaginal creams, pessaries or douching for two to three days beforehand. If possible, provide the sample before treatment begins. Bring the urine sample as soon as possible, preferably within 2 hours.

Symptoms usually appear between five days and four weeks after infection. If you have no symptoms and are testing after a risky contact, wait at least two weeks.

What your results mean

• Positive: you have trichomoniasis. It is treated with tablets prescribed by a doctor, and partners must be treated at the same time. Avoid intercourse until treatment is complete and symptoms have gone.
• Negative: trichomonas was not found. If symptoms persist, bacterial vaginosis, candida or another inflammation may be the cause, so the doctor continues investigations.

A doctor interprets the result alongside examination and other findings. Reinfection is common, so women are advised to have a follow-up test around three months after treatment. PCR is not performed earlier than approximately two weeks after treatment because it may detect remnants of destroyed parasites.

How to arrange testing

The test is performed without a referral or appointment. A nurse takes the swab; urine samples or swabs collected at home can be submitted at any of our branches (listed on the Contactpage). Testing is also available anonymously, without disclosing personal details. Prices for all tests and panels are listed in the price list. Trichomonas, alongside chlamydia, gonorrhoea, mycoplasmas, ureaplasma and HPV, is included in the STD7 Extended Panel, and other options are described on the Sexually transmitted infection testingpage.

Frequently asked questions

How is trichomonas transmitted?

Almost always through sexual intercourse. Transmission through towels, toilet seats or swimming pools is very unlikely.

Can men have trichomonas?

Yes. In men, infection usually causes no symptoms or only mild ones, so it is often discovered only when their partner is diagnosed. Men are most often tested using first-catch urine.

Is trichomoniasis dangerous?

Not with treatment, which is simple. Untreated infection may persist for months and increases the risk of premature birth in pregnant women.

Should a partner without symptoms be treated?

Yes. The partner is treated at the same time, even without symptoms, because otherwise the infection returns.