Trichomoniasis, or “trich,” is a common sexually transmitted infection (STI).

In the US, trichomoniasis is one of the most common non-viral STIs. It can cause a genital or urinary infection.

Trichomoniasis is often asymptomatic. The CDC reports that only 30% of people who have contracted trich develop any symptoms at all.

When symptoms do occur, they often begin 5 to 28 days after exposure. For some people, it can take much longer.

The most common symptoms include:

Trich is caused by a parasite called Trichomonas vaginalis. It travels from person to person through genital contact during sex or from shared sex toys.

It isn’t transmitted through contact such as hugging, kissing, sharing dishes, or sitting on a toilet seat. In addition, it can’t be spread through sexual contact that doesn’t involve the genitals or shared sex toys.

Studies show rates of infection are higher in people who have vaginas. You may be more likely to contract trichomoniasis if you:

  • have a history of other STIs
  • have sex without a condom or other barrier method
  • use intravenous drugs

Trichomoniasis cannot be diagnosed through symptom observation alone. Remember, when symptoms do occur, they’re often similar to those of other STIs.

It’s important to get tested. A healthcare professional will perform a physical exam and take samples of vaginal fluid, urethral discharge, or urine to examine under a microscope or test for the organism’s genetic material.

In some cases, at-home testing for trichomoniasis may be an option. This usually involves collecting a genital swab or urine sample at home and mailing it off to a lab for testing.

Trichomoniasis can be cured with antibiotics, such as:

  • metronidazole (Flagyl)
  • secnidazole (Solosec)
  • tinidazole (Tindamax)

Some clinicians recommend avoiding alcohol while taking this class of medications; however, data is inconclusive.

Make sure your sexual partners are tested and take the medication, too. Not having any symptoms doesn’t mean they haven’t acquired it. Avoid sexual contact for a week after you and all partners have been treated.

Trichomoniasis causes genital inflammation that can make it easier to contract other STIs, including HIV.

Some infections commonly occur alongside trichomoniasis, including gonorrhea, chlamydia, and bacterial vaginosis. If left untreated, these co-occurring infections can result in pelvic inflammatory disease (PID).

Undiagnosed or untreated PID can cause:

  • chronic abdominal or pelvic pain
  • ectopic pregnancy
  • infertility

Trich can cause unique complications during pregnancy, including preterm delivery, low birth weight, and transmission during childbirth.

If you’re pregnant and suspect that you’ve contracted trich or another STI, consult a healthcare professional as soon as possible. Prompt diagnosis and treatment can prevent complications for you and your pregnancy.

Without treatment, trich can be ongoing. With treatment, it’s usually cured within a week. If your symptoms last longer than a week, talk with a healthcare professional about getting retested and retreated.

You can contract trich again if a partner wasn’t treated or if a new partner has contracted it. You can reduce your risk by making sure all partners get tested and treated. It’s also important to clean all sex toys.

Your healthcare professional may recommend getting a follow-up test around three months after you complete treatment for vaginal trichomoniasis. During this period, the re-acquisition rate can be as high as 17%.

Due to a lack of data supporting rescreening for urethral trichomoniasis, retesting usually isn’t recommended for people who have penises.

Q:

My partner has an STI, but I don’t have any symptoms. Why would I need to get tested or take the same medication?

Anonymous patient

A:

Oftentimes, people who have acquired STIs like chlamydia, gonorrhea, and trich don’t have any symptoms. It’s not uncommon for people to find out that they have it only after they’ve been tested.

When a sexual partner is diagnosed with an STI, the CDC recommends that all partners be treated while waiting for test results on themselves. This lowers the chance of complications.

It’s easier for conditions that start in the vagina to move up into the uterus, fallopian tubes, and abdominal cavity. This causes the serious condition PID.

For people with penises, delaying diagnosis and treatment carries the risk of developing more difficult-to-treat conditions and unknowingly passing them on to other people.

The best way to prevent complications of STIs is to check for and treat them before they become more serious.

Judith Marcin, MDAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

Trichomoniasis can affect people of any anatomy. It’s usually asymptomatic, so the only way to know whether you’ve contracted the infection is to get tested. It can be cured with antibiotics.

However, repeat infection is possible. Condoms and other barrier methods can reduce your risk of contracting trichomoniasis and other STIs.