What you should know about trichomoniasis

What you should know about trichomoniasis

Trichomoniasis is an infection which is transmitted sexually. It can be passed on by others by vaginal, oral , or anal sex.

Trichomonas vaginalis is a parasite that causes trichomoniasis, or trich, which is highly curable if a person seeks care. According to the Centers for Disease Control and Prevention ( CDC), however, only about 30 percent of people with trich experience symptoms.

Trich can lead to complications, without treatment. This can affect a child, and the risk of contracting and transmitting HIV also tends to increase.

Trichomoniasis is one of America’s most common sexually transmitted infections ( STIs), where the CDC reports it affects nearly 3.7 million people. It is the most prevalent curable STI.

Causes and spread

A man urinating
A person with trichomoniasis may experience discomfort when urinating.

T. Vaginalis, the trich-causing parasite, can pass from one person to another during sex. It can be transmitted by a person during oral , anal, or vaginal sex or by genital contact.

Trich in females most often affects the lower genital tract. In males, this affects the urethra, the tube that passes through urine.

Other parts of the body, such as the anus, hands, or mouth, usually can not get infected.

The following people have a higher chance of getting trich:

  • females
  • people with more than one sexual partner
  • those with a history of trich or other STIs
  • people who have unprotected sex

As a person’s number of sexual partners develops, so does their risk of getting trich.


Symptoms may occur 5 to 28 days after exposure, or they can or may not appear later.

They can affect both males and females differently when symptoms are present.

Minor signs include discomfort but someone with a more serious case may have discharge inflammation.

Possible symptoms in females include:

  • frothy, foul-smelling vaginal discharge, which may be clear, white, gray, yellow, or green
  • vaginal discharge with blood
  • genital irritation
  • discomfort during sex or when urinating
  • swelling in the groin
  • frequent urination
  • in rare cases, lower abdominal pain

Symptoms in males may include:

  • discharge from the urethra or penis
  • itching in the penis
  • burning sensations after ejaculating or urinating
  • frequent need to urinate
  • pain when urinating


Trichomoniasis can lead to several complications, including those below.

Problems during pregnancy

Experts have linked trichomoniasis with complications during pregnancy, including:

  • preterm birth
  • early rupture of the membrane
  • low birth weight in newborns
  • infertility

Sometimes a woman can pass the infection on to the newborn during childbirth, but this is uncommon.

During pregnancy, taking metronidazole treatment is safe.

Other problems

Trich could increase the risk of infections in the reproductive tract.

At least one study suggests that trich and human papillomavirus (HPV), the virus that causes cervical cancer, may also be related. However, more research is needed to make the association clearer.

HIV risk

A trich infection can increase the risk of getting HIV and other STIs, especially in females.

Scientists believe that this increased risk could be due to:

  • inflammation
  • a reduced immune response
  • changes in the balance of vaginal flora, in females

These factors may lower a person’s natural protection from the virus.

Tests and diagnosis

To diagnose a trichomoniasis infection, a doctor will:

  • carry out a pelvic exam
  • take a sample of vaginal or penile discharge for examination under a microscope
  • take a vaginal swab for a culture test in a laboratory

The results of a lab test will come back in about a week.

Preparing for the appointment

Women will aim at arranging the appointment for a time when it is unlikely they will be menstruating.

They should stop using deodorant on the vulva before appointment, because this hides the odor and can cause irritation. The doctor can also advise them to avoid vaginal intercourse or to insert any products, including tampons, in the vagina 24–48 hours in advance

A test on Pap (smear) does not scan for trich. If a person has a clear Pap check, trich or another STI can still be present.

As trich increases the risk of transmitting HIV, HIV-patients should also have a trich test at least once a year.

If the result is positive

If the test results are positive, a health care provider will recommend medication and decide what to do next.

The person will need to:

  • inform all of their sex partners, as they will also need a test
  • take the whole dose or course of treatment to stop the infection from coming back
  • avoid sexual contact until the treatment is complete
  • seek further advice if symptoms remain a few days after finishing a course of antibiotics

The doctor can suggest checking for other STIs, as well.


In males and females Trich is easy to treat, including during pregnancy.

Treatment usually involves a single dose of the antibiotic being taken by mouth. A doctor may also prescribe topical application of a vaginal suppository or a cream.

Parasite-killing antibiotic medications include metronidazole (Flagyl) and tinidazole (Tindamax).

People should not consume alcohol while taking metronidazole, as an adverse reaction may occur which may lead to abdominal cramps, nausea , headaches and flushing.

If after taking the treatment symptoms continue, a person should go back to see their doctor again.

Breastfeeding after treatment

People should not be taking tinidazole while they breastfeed.

Metronidazole is safe to use but a doctor can recommend that you wait 12–24 hours before breastfeeding after taking it.


Both sexual partners may also seek medication to avoid infection or reinfection.

Ways to avoid an infection or reinfection risk include:

  • limiting the number of sexual partners
  • avoiding sex for 7–10 days after treatment for trich
  • not using a douche, as this can affect the healthy bacteria in the vagina
  • limiting or avoiding the use of recreational drugs and alcohol, as these increase the risk of unsafe sex
  • using a condom for protection during sex

To some extent, a condom may prevent transmission, but it is not completely reliable because the parasite may pass from person to person on areas of the body that it does not cover.

Anyone with symptoms or who thinks they’ve been exposed to trich should talk to a doctor.


Trichomoniasis is an infection which is transmitted by sex. It easily spreads and can lead to complications but there is effective treatment.

Treatment can prevent complications, and prevent the spread of trich to another person.