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Trichomonas Vulvovaginitis

Written by Ada’s Medical Knowledge Team

Updated on

What is trichomoniasis?

Trichomoniasis is a sexually transmitted infection (STI) caused by a parasite called Trichomonas vaginalis. The infection most commonly affects women aged 40-49[1], although it can affect anyone sexually active, and men can also be infected but may not show any symptoms.[1]

Infection with Trichomonas vaginalis can lead to inflammation of genital organs such as:[2]

  • Urethritis: Inflammation of the urethra (the tube that allows urine to pass out of the body)
  • Cystitis: Inflammation of the bladder
  • Vaginitis (women): inflammation of the vagina
  • Epididymitis (men): inflammation of the epididymis, the coiled tube behind each testicle where sperm mature
  • Prostatitis (men): inflammation of the prostate gland

Common symptoms can include an unusual discharge from the penis or vagina, itching of the genitals, burning sensation when urinating and pain during sexual intercourse.[3] Effective treatment is with antibiotics.

Risk Factors for Trichomoniasis

Trichomoniasis can be acquired from unprotected sexual intercourse.[1] However, the parasite is not thought to be passed on through oral or anal sex.[3] Risk factors can include:[3]

  • Having sex without using a condom
  • Multiple sexual partners
  • History of sexually transmitted infections (STIs)
  • Sharing of adult toys that have not been cleaned

Trichomoniasis Symptoms

Symptoms of Trichomoniasis vary depending on who is affected. In women, symptoms can include:[2][3]

  • abnormal vaginal discharge; this can be very little to copious amounts, frothy, yellow-green in color and have a fishy smell.
  • itching, soreness and swelling around the vagina
  • pain or discomfort when urinating: also known as dysuria
  • pain when having sex: also known as dyspareunia

Men generally do not show any symptoms. However, if a genital organ becomes inflamed, they may experience:[1][2][3]

  • thin white discharge from the penis
  • pain or discomfort when urinating
  • soreness, redness and swelling around the penis

It's also important to remember that although men may not show any symptoms, they can still infect their partner.[3]

Diagnosis

Trichomoniasis infection is suspected in men and women who show clinical signs and symptoms of genital organ inflammation caused by a Trichomonas parasite. A doctor may suspect an infection and may take a patient history along with a physical examination.[4]

After this, laboratory investigations can be carried out, and a doctor or nurse may take a swab sample from the penis or vagina. The swab samples are analyzed, and tests include:[2][4]

  • Microscopy: examining the sample using a microscope to detect the Trichomonas parasite quickly.
  • Culture: the sample is sent to the laboratory and cultured for several days to identify the presence of the parasite.

From the swab samples collected, a nucleic acid amplification test (NAAT) may also be used to diagnose Trichomoniasis and is regarded as gold standard testing. This technique makes the organism easier to detect and is also available as a self-test kit.

In men, a urine sample can also be used to detect Trichomoniasis.[4] The urine can be sent for culture, making a diagnosis more likely. If Trichomoniasis is suspected, antibiotic treatment may be started before receiving your test results to ensure prompt treatment and prevent spreading to others.[4]

Trichomoniasis Treatment

Trichomoniasis treatment involves medication with antibiotics. The Center for Disease Control and Prevention (CDC) currently recommends using Metronidazole to treat Trichomoniasis. The CDC suggests:[5]

  • Metronidazole 500 mg 2 times per day for 7 days for women
  • Metronidazole 2 g orally in a single dose for men

Treatment of sex partners is also vital to cure a Trichomoniasis infection. Metronidazole may have side effects, including a metallic taste in the mouth, and if taken with alcohol, it can cause nausea and flushing of the skin.[2]

An alternative medication regimen can be Tinidazole 2 g orally in a single dose.[5] Tinidazole can be more effective and have fewer side effects; however, it can be usually expensive.[5]

There are some basic measures which you can do to prevent trichomoniasis; these are:[2][6]

  • Regular and correct use of condoms
  • Avoiding unsafe sex practices such as frequently changing partners or having sex with a partner who has multiple partners
  • Avoid sharing adult toys.

Trichomoniasis FAQs

Q: What is Trichomoniasis? A: Trichomoniasis is a sexually transmitted infection caused by a parasite called Trichomonas vaginalis. It’s a common STI and can be acquired due to unprotected sex with infected individuals.

Q: Is Trichomonisasis curable? Yes, Trichomoniasis can be cured with antibiotics that a doctor prescribes. Metronidazole is the medication that is currently prescribed and is also safe to use in pregnancy.

Q: How long can trichomoniasis be dormant in a woman? There's no dormancy period for a Trichomoniasis infection, which means if you are infected, you have acquired Trichomoniasis.

Q: How long does it take for trichomoniasis to show up? You can experience symptoms 5-28 days after infection; sometimes, these can develop much later or may not show at all.

Q: How to test for trichomoniasis? Trichomoniasis tests include collecting a swab sample from the vagina or penis and can undergo analysis by using a microscope or evaluating through a culture of the parasite. Nucleic acid amplification tests (NAATs) are the gold standard of testing and are available as home-test kits.

Q: Can a woman get Trichomoniasis on her own? No, Trichomoniasis infection is passed only through unprotected sexual intercourse.


  1. Schumann JA, Plasner S. Trichomoniasis. [Updated 2021 Dec 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK534826/

  2. Merck Manuals [MSD Manuals]. Trichomoniasis. [2020]. Available from: https://www.msdmanuals.com/professional/infectious-diseases/sexually-transmitted-infections-stis/trichomoniasis

  3. National Health Service [NHS]. Trichomoniasis, Overview. [November 2021]. Available from: https://www.nhs.uk/conditions/trichomoniasis/

  4. National Health Service [NHS]. Trichomoniasis, Diagnosis. [November 2021]. Available from: https://www.nhs.uk/conditions/trichomoniasis/diagnosis/

  5. Center for Disease Control and Prevention [CDC]. Sexually Transmitted Infections Treatment Guidelines, 2021, Trichomoniasis. [July 2021]. Available from: https://www.cdc.gov/std/treatment-guidelines/trichomoniasis.htm

  6. National Health Service [NHS]. Trichomoniasis, Prevention. [November 2021]. Available from: https://www.nhs.uk/conditions/trichomoniasis/prevention/

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