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Trichomoniasis is a sexually transmitted infection caused by the parasite Trichomonas vaginalis.
Trichomonas vaginitis; STD - trichomonas vaginitis; STI - trichomonas vaginitis; Sexually transmitted infection - trichomonas vaginitis
Trichomoniasis is found worldwide. In the United States, the highest number of cases are seen in women between age 16 and 35. Trichomonas vaginalis is spread through sexual contact with an infected partner. This include penis-to-vagina intercourse or vulva-to-vulva contact. The parasite cannot survive in the mouth or rectum.
The disease can affect both men and women, but the symptoms differ between the two groups. The infection usually does not cause symptoms in men and goes away on its own in a few weeks.
- Discomfort with intercourse
- Itching of the inner thighs
- Vaginal discharge (thin, greenish-yellow, frothy or foamy)
- Vaginal itching
- Vulvar itching or swelling of the labia
- Vaginal odor (foul or strong smell)
- Burning after urination or ejaculation
- Itching of urethra
- Slight discharge from urethra
Exams and Tests
In women, a pelvic examination shows red blotches on the vaginal wall or cervix. A wet prep (microscopic examination of discharge) may show signs of inflammation or infection-causing organisms in vaginal fluids. A pap smear may also diagnose the condition.
The disease can be hard to diagnose in men. Men are treated if the infection is diagnosed in any of their sexual partners. Men may also be treated if they have ongoing symptoms of urethral burning or itching despite treatment for gonorrhea and chlamydia.
The antibiotic metronidazole is commonly used to cure the infection. A newer drug, called Tinidazole may be used.
You should not drink alcohol while taking the medicine and for 48 hours afterwards. Doing so can cause severe nausea, abdominal pain, and vomiting.
Avoid sexual intercourse until treatment has been completed. Sexual partners should be treated at the same time, even if they have no symptoms. If you have been diagnosed with a sexually transmitted infection, you should be screened for other ones.
With proper treatment, the outcome is likely to be excellent.
Long-term infection may cause changes in the tissue on the cervix. These changes may be seen on a routine Pap smear. In such cases, treatment should be started and the Pap smear repeated 3 to 6 months later.
Treatment of trichomoniasis helps prevents the spread of the disease to sexual partners. Trichomoniasis is common among persons with HIV.
This condition in pregnant women has been linked to premature birth. More research is needed.
When to Contact a Medical Professional
Call for an appointment with your health care provider if any unusual vaginal discharge or irritation is noted.
Also call for an appointment if you suspect that you have been exposed to the disease.
A monogamous sexual relationship with a known healthy partner can help reduce the risk of sexually transmitted infections, including trichomoniasis.
Other than total abstinence, condoms remain the best and most reliable protection against sexually transmitted infections. Condoms must be used consistently and correctly to be effective.
Schwebke JR. Trichomonas vaginalis. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 281.
Telford SR III, Krause PJ. Babesiosis and other protozoan diseases. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 361.
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.