Articles & Experts

The Importance of Testing for Trichomonas

Wednesday, May 18, 2022

by Sekisui Diagnostics

Estimated global incidence of Trichomonas vaginalis compared to three other curable STIs (Chlamydia trachomatis, Neisseria gonorrhoeae, and syphilis) according to WHO

Trichomoniasis is a common, curable, non-viral sexually transmitted infection caused by a motile protozoan parasite called Trichomonas vaginalis. Trichomonas (sometimes referred to as “Trich”) infects the vagina and sometimes urethra and is transmitted during unprotected sex. It is roughly as big as a white blood cell, and it is thought to be responsible for approximately 15-20% of symptomatic vaginitis infections.

Both men and women can get a Trichomonas infection, but it is more commonly detected in women.

Formerly considered a nuisance infection, trichomoniasis is now recognized as a cause of serious health problems. Nevertheless, it continues to be highly underdiagnosed and undertreated.

The World Health Organization estimates an incidence of 276 million new cases of T vaginalis each year and a prevalence of 187 million infected individuals between the age of 15 and 49 years old. In the United States, the Centers for Disease Control and Prevention estimates that there were more than two million trichomoniasis infections in 2018. The incidence of trichomoniasis in Europe is similar to that in the United States. In Africa, the prevalence of trichomoniasis may be much higher. The prevalence of vaginal T vaginalis infection was estimated to be 11-25% among African study populations.



Only about 30% develop any symptoms of trichomoniasis. When symptoms do occur, they range from mild irritation to severe inflammation. Some people with symptoms get them within 5 to 28 days after being infected. Others do not develop symptoms until much later, and those symptoms can come and

  1. It is important to note that people without symptoms can still pass the infection on to others. Trichomonas symptoms in women can be differentiated from other common forms of vaginitis.

Men with trichomoniasis may notice:

  • Itching or irritation inside the penis
  • Burning after urination or ejaculation
  • Discharge from the penis



Trichomoniasis can be treated with medication but left untreated it can last for months or even years and lead to serious complications. For example, trichomoniasis can cause genital inflammation, which makes it easier to get infected with HIV or to pass the HIV virus on to a sex partner. Pregnant women with trichomoniasis are more likely to have their babies too early (preterm delivery). Also, babies born to infected mothers are more likely to have a low birth weight (less than 5.5 pounds).

A woman with untreated trichomoniasis has a greater chance of having an infected uterus and Fallopian tubes. This infection, called pelvic inflammatory disease, can cause belly pain, fever, and perhaps the inability to have children (infertility), a pregnancy outside the uterus (ectopic pregnancy), and chronic pelvic pain.


Treatment and Prevention

Since it is a STI, the best way to prevent Trichomonas is to have protected sex. Re-infections with Trichomoniasis are also possible. The best way to avoid re-infections is for the patient to avoid having sex for seven days after treatment has been administered. Trichomoniasis is typically treated with the following antibiotics: Tinidazole 500mg x 4 tablets as a single dose or Metronidazole twice a day for 5-7 days.

NAATs [nucleic amplification assay tests], with reported sensitivities of 83%–90%. Suitable for Laboratory and Point-of-Care (POC) setting:

  • Offers 95% agreement with culture and wet mount combined
  • A test-and-treat approach in one visit
  • Detects the antigen; does not require live organism
  • Yields results in 10 minutes or less
  • Offers objective, easy-to-read two-color results
  • Is the only CLIA-waived rapid test for the detection of trichomoniasis

Advantages of a Test and Treat Approach

  • Prevent spread – Quick diagnosis allows the clinician to provide appropriate and immediate treatment to prevent further spread of Trichomoniasis
  • Patient compliance – Ensures the patient starts medication immediately
  • Prevent inappropriate treatment – Accurate diagnosis results in avoidance of syndromic management