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Overview

What Is Trichomoniasis?

Trichomoniasis is a curable sexually transmitted infection caused by the parasite Trichomonas vaginalis. It can affect people of any sex and is usually spread through sexual contact. Many people have no noticeable symptoms, so they may not know they have the infection. Understanding what is trichomoniasis can help people seek testing and treatment when needed.

Symptoms

Trichomoniasis Symptoms

  • Women may have itching or irritation around the vagina or vulva.
  • Men may have itching or irritation inside the penis.
  • Burning with urination can occur in women or men.
  • Genital redness or soreness may occur in women or men.
  • Women may have unusual vaginal discharge that can be thin, thick, or have an unusual odor.
  • Men may have discharge from the penis.
  • Women or men may have discomfort during sex.

How It Spreads

How Trichomoniasis Spreads

Trichomoniasis usually spreads through penis-to-vagina or vagina-to-vagina sexual contact involving an infected partner. Transmission can occur when the infected person has no symptoms and does not know they have the parasite. The infection is not caused by poor hygiene.

  • A person can become reinfected if a current sex partner has not been treated.
  • An untreated partner may pass the infection back after one person completes treatment.
  • Having trichomoniasis does not prove when the infection was acquired or identify a particular partner with certainty.
  • Symptoms may be absent or appear later, so the timing of symptoms cannot reliably show when exposure occurred.

Common question

Partner exposure

A person generally does not develop trichomoniasis without exposure to the parasite, most often through sexual contact. This does not justify blame: symptoms may appear long after exposure, and either partner may have had no symptoms.

Risk Factors

Trichomoniasis Risk Factors

  • Having a new sex partner may increase the chance of exposure.
  • Having multiple sex partners may increase the chance of exposure.
  • Inconsistent condom or barrier use may increase the chance of transmission.
  • A previous sexually transmitted infection is associated with a greater chance of acquiring another infection.
  • Having a sex partner with trichomoniasis increases the chance of infection.
  • Recent exposure that was not tested or treated can allow infection to continue or recur.

Some factors, such as barrier use, testing, and completing treatment, can be changed to reduce risk. A person cannot reliably control or infer a partner’s infection status from appearance or symptoms, because trichomoniasis may cause no symptoms. These risk factors are medical considerations, not judgments about anyone’s behavior.

Complications

Trichomoniasis Complications

When untreated, trichomoniasis can cause ongoing genital inflammation and may contribute to pregnancy-related problems. It is also associated with an increased susceptibility to acquiring or transmitting HIV. Trichomoniasis does not transform into HIV, and there is no fixed timeline for it to do so.

  • Reinfection can occur when a partner is not treated or when treatment is not completed.
  • During pregnancy, infection may be associated with complications that require discussion with an obstetric or sexual-health clinician.
  • Trichomoniasis may increase the risk of acquiring HIV when a person is exposed to HIV.
  • Trichomoniasis may increase the risk of transmitting HIV to a sex partner in someone who has HIV.

When extra care is needed

Pregnancy and HIV considerations

Tell a clinician promptly about possible exposure during pregnancy, known HIV infection, or symptoms that continue after treatment. Timely evaluation can guide safe treatment, partner care, and testing for other sexually transmitted infections without assuming that a severe complication will occur.

Diagnosis

How Trichomoniasis Is Diagnosed

A clinician may ask about symptoms and sexual exposure and examine the affected area when appropriate. Depending on the patient and symptoms, the clinician may collect a vaginal, cervical, urethral, or urine sample. Because symptoms can overlap with other conditions, a trichomoniasis test is needed to confirm the infection.

  • Rapid antigen tests may detect proteins from Trichomonas vaginalis in a collected sample.
  • Molecular tests can detect the parasite’s genetic material and may be used on genital or urine samples.
  • Microscopic examination can look for the parasite in a sample, although detection may depend on the sample and timing.
  • Culture can be used in some settings when a laboratory method is available and clinically appropriate.

Treatment & Management

Trichomoniasis Treatment

Trichomoniasis treatment commonly uses an oral nitroimidazole medicine such as metronidazole or tinidazole. The clinician chooses the exact drug and regimen based on factors such as pregnancy status, allergies, medication interactions, and whether infection has recurred. Metronidazole for trichomoniasis should be taken only as prescribed.

  • Take the full prescription even if symptoms improve before the medication is finished.
  • Avoid sex until treatment and partner treatment are complete as advised by the clinician.
  • Ensure current sex partners receive evaluation or treatment to reduce the chance of reinfection.
  • Return for care if symptoms persist or recur after treatment.

Medication safety

Use treatment exactly as prescribed

Do not self-treat with leftover antibiotics or share trichomoniasis medication with someone else. Ask a clinician or pharmacist about alcohol, drug interactions, pregnancy, breastfeeding, and possible side effects before or during treatment.

Prevention

Preventing Trichomoniasis

  • Use condoms or other barriers consistently and correctly during sex.
  • Limit sexual exposure to partners who have not been evaluated or treated when infection is suspected.
  • Get tested when symptoms, a partner’s diagnosis, pregnancy, or sexual history indicates testing may be appropriate.
  • Complete the prescribed treatment and follow the clinician’s instructions before resuming sex.
  • Make sure current sex partners are evaluated and treated when recommended.

Routine screening recommendations depend on symptoms, pregnancy, sexual history, local guidance, and a clinician’s assessment. There is no single screening schedule that applies to everyone. Prevention steps reduce risk but cannot guarantee that infection will not occur.

Outlook and Prognosis

Outlook for Trichomoniasis

Trichomoniasis is usually curable with appropriate prescription treatment, and symptoms often improve afterward. Without treatment, the infection can persist, and symptoms may recur if a partner remains untreated or if another condition is present. Follow-up is important when symptoms do not improve as expected.

When Should You See a Doctor

When Should You See a Doctor?

  • Seek care for unusual genital discharge.
  • Seek care for genital itching or soreness.
  • Seek care for burning with urination.
  • Seek care for pain or discomfort during sex.
  • Arrange testing after learning that a recent sex partner has trichomoniasis.
  • Contact a clinician promptly during pregnancy after possible exposure.
  • Return for evaluation if symptoms continue after treatment.

Prompt sexual-health evaluation can provide confidential testing, treatment, partner guidance, and testing for other sexually transmitted infections. Because trichomoniasis may cause no symptoms or resemble other infections, do not rely on symptoms alone to decide whether testing is needed.