- What is Trichomoniasis?
- Who Is Most At Risk For Getting Infected With Trichomoniasis?
- How Is Trichomonas Infection Diagnosed?
- How Is Trichomoniasis Treated?
- What If I Get Trichomoniasis While Pregnant?
- How Can I Prevent Vaginitis?
- Trichomoniasis, caused by a parasite known as Trichomonas vaginalis, is the most prevalent nonviral sexually transmitted infection in the United States.
- It accounts for 10%–25% of all vaginal infections.
- About 3.7 million men and women are diagnosed with trichomoniasis annually in the US, and 174 million cases worldwide.
- Most people (70%–85%) infected with vaginalis have minimal to no symptoms.
- vaginalis infection increases your risk of getting human immunodeficiency virus (HIV) two to threefold.
- Up to 53% of women with HIV infection are infected with vaginalis.
- The diagnosis of trichomoniasis requires laboratory testing. According to the CDC, all women with vaginal discharge should be tested for trichomoniasis.
What is Trichomoniasis?
Trichomoniasis is the most prevalent nonviral sexually transmitted infection in the United States. It accounts for 10%–25% of all vaginal infections.
The Centers for Disease Control and Prevention (CDC) estimates that in the US, 3.7 million men and women are diagnosed with trichomonas annually. Worldwide,174 million cases are diagnosed annually.
The microbe that causes trichomoniasis infection is the protozoa, Trichomonas vaginalis (T. vaginalis).
Most people (70%–85%) infected with T. vaginalis have minimal to no symptoms. Also, untreated infections might last for months to years.
Since T. vaginalis spreads readily between sexual partners, the best way to prevent trichomoniasis is through consistently and correctly using condoms during vaginal intercourse.
Who Is Most At Risk For Getting Infected With Trichomoniasis?
Researchers have found a higher prevalence of trichomoniasis in:
- Women age 40 years and older (11%)
- STI clinic patients (26% of symptomatic women and 6.5% of asymptomatic men)
- Incarcerated women (9%–32%) and men (2%–9%)
- Lower education level
- Women who douche regularly
- People with a greater number of lifetime sexual partners
T. vaginalis infection increases your risk of getting human immunodeficiency virus (HIV) two to threefold. And up to 53% of women with HIV infection are infected with T. vaginalis.
T. vaginalis infection is associated with an increased risk for pelvic inflammatory disease (PID). Therefore, doctors recommend routine T. vaginalis screening of asymptomatic women with HIV infection.
Interest in T. vaginalis has increased recently due to studies showing complications from the infection. It is well known that trichomoniasis is a common cause of vaginal itching, odor, and discharge in women. Men commonly experience urethritis.
T. vaginalis infection increases your transmission risk for both HIV and pelvic inflammatory disease (PID). Consistent use of condoms helps to decrease your risk of acquiring T. vaginalis.
Newer data link trichomoniasis to:
- Premature rupture of membranes
- Preterm delivery
- Low birth weight
- Neonatal death
- HIV transmission
- Pelvic inflammatory disease
- Chronic prostatitis
- Increased risk for cervical dysplasia and neoplasia
- Male infertility
How Is Trichomoniasis Infection Diagnosed?
The most common symptoms in women are:
- Frothy white, gray, yellow, or green vaginal discharge with an unpleasant odor
- Vaginal spotting or bleeding
- Burning or itching
- Redness, swelling
- Frequent urge to urinate
- Pain with urination and/or sexual intercourse
The most common symptoms in men are:
- Urethral discharge
- Burning with urination or ejaculation
- Frequent urge to urinate
The diagnosis of trichomoniasis requires laboratory testing. According to the CDC, all women with vaginal discharge should be tested for trichomoniasis.
The most common symptoms of T. vaginalis in women are frothy, white, gray, yellow, or green discharge with an unpleasant odor.
Because T. vaginalis infection is strongly associated with the presence of other sexually transmitted infections (STIs), you should also be tested for gonorrhea, chlamydia, syphilis, HIV infection, hepatitis B, and hepatitis C.
In multiple studies, most women with T. vaginalis infections also had bacterial vaginosis.
Several tests can diagnose trichomoniasis, including:
- examination of samples of vaginal fluid, urethral discharge, or urine under a microscope (wet mount)
- cell cultures
- antigen tests (if the Trichomonas parasite is present, antibodies bind to it, and the test undergoes a color change)
- tests that look for Trichomonas DNA
The CDC now recommends that vaginal secretions be checked using molecular (antigen and DNA) diagnostic tests. The sensitivity is better, and you get results in less than an hour.
If you are diagnosed with T. vaginalis, you should also be tested for gonorrhea, chlamydia, syphilis, HIV infection, hepatitis B, and hepatitis C.
How Is Trichomoniasis Treated?
Doctors can cure trichomoniasis with antibiotics. Your physician may recommend metronidazole (Flagyl) or tinidazole (Tindamax).
You must avoid alcohol for the first 24 hours after taking metronidazole or 72 hours after taking tinidazole. It can cause severe nausea and vomiting.
Once treated, there is a 17% reinfection rate within three months, so ensure you get retested for T. vaginalis three months following treatment. Data are insufficient to support retesting men.
All of your sex partners must receive treatment to prevent becoming reinfected. Abstain from intercourse until all parties have been treated and symptoms resolved.
What If I Get Trichomoniasis While Pregnant?
The treatment of trichomoniasis during pregnancy has been controversial due to questions about the safety of metronidazole in pregnancy.
More recent studies show that T. vaginalis can cause the following complications during pregnancy:
- Premature labor and delivery
- Low birth weight
- Transmission to the baby during delivery (rare)
The American College of OBGYN reports that it is safe to take metronidazole after the first trimester of pregnancy.
Metronidazole (Flagyl) is safe after the first trimester of pregnancy. Tinidazole (Tindamax) is a newer medication with fewer published studies, making metronidazole the drug of choice for treating trichomoniasis in pregnancy.
How Can I Prevent Vaginitis?
There are things you can do to help lower your chances of getting vaginitis:
- Maintain good personal hygiene
- Avoid wearing tight jeans or spandex
- Don’t douche or use vaginal sprays or perfumed soaps
- Practice safe sex
- Get screened for sexually transmitted infections
- Have regular gynecologic exams to maintain vaginal health.
Most infected people (70%–85%) with trichomoniasis show minimal to no symptoms, and untreated infections can last for months to years.
Luckily, trichomoniasis is curable with antibiotics like metronidazole (Flagyl) or tinidazole (Tindamax). However, alcohol must be avoided after taking these medications to prevent nausea and vomiting.
If your doctor has diagnosed you with trichomoniasis, get tested for other sexually transmitted infections. Also, perform a T. vaginalis retest three months after your treatment is complete.
Copyright: myObMD, Inc | Author: Lisa Shephard, MD | Editor: Jennifer Abayowa and Dayna Smith, MD | Reviewed September 20, 2023.
- Meites e, Gaydos CA, Hobbs C, Kissinger P, Nyirjesy P. A Review of Evidence-Based Care of Symptomatic Trichomoniasis and Asymptomatic Trichomonas vaginalis Infections. Clinical Infectious Diseases. 2015; 61(S8) S837–S848, https://doi.org/10.1093/cid/civ738.
- Sutton M, Sternberg M, Koumans EH, McQuillan G, Berman S. The Prevalence of Trichomonas vaginalis Infection among Reproductive-Age Women in the United States, 2001–2004 Clinical Infectious Diseases. 2007; 45,(10): 1319–1326 https://doi.org/10.1086/522532.
- Vaginitis in the Nonpregnant Patients, ACOG Practice Bulletin Number 215, January, 2020.