From the Guidelines
Trichomonas is a common sexually transmitted infection caused by the parasite Trichomonas vaginalis, primarily affecting the vagina in women and the urethra in men, and is usually treated with oral metronidazole, as recommended by the CDC in 2002 1. The infection can cause symptoms such as vaginal discharge with an unpleasant odor, genital itching, painful urination, and discomfort during sex, but about 70% of infected people do not show symptoms.
- The standard treatment is a single 2-gram dose of metronidazole (Flagyl) or tinidazole (Tindamax) taken by mouth, or alternatively, 500 mg of metronidazole twice daily for 7 days, with cure rates of approximately 90-95% 1.
- Both sexual partners should be treated simultaneously to prevent reinfection, and sexual activity should be avoided until both partners complete treatment and symptoms resolve.
- Trichomonas is diagnosed through laboratory tests of vaginal or urethral samples, with culture being the most sensitive commercially available method of diagnosis, although microscopy of vaginal secretions can also be used, but has a sensitivity of only about 60-70% 1. The parasite survives by attaching to mucous membranes and feeding on bacteria and cells in the genital tract.
- Without treatment, the infection can persist for months or years, increasing the risk of HIV transmission and, in pregnant women, causing complications like premature birth and low birth weight, as noted in the 1998 guidelines for treatment of sexually transmitted diseases 1. Treatment of patients and sex partners results in relief of symptoms, microbiologic cure, and reduction of transmission, as stated in the 2002 CDC guidelines 1.
From the FDA Drug Label
Trichomonas vaginalis
Trichomonas vaginalis infection is a venereal disease.
Metronidazole possesses direct trichomonacidal activity against T. vaginalis.
Tinidazole is indicated for the treatment of trichomoniasis caused by Trichomonas vaginalis.
Trichomonas (Trichomonas vaginalis) is a venereal disease caused by the organism Trichomonas vaginalis. It is a sexually transmitted disease that can infect both females and males. Metronidazole and tinidazole are two antibiotics that have been shown to be effective against T. vaginalis, with direct trichomonacidal activity against the organism 2, 3, 2.
From the Research
Definition and Prevalence of Trichomonas vaginalis
- Trichomonas vaginalis is a sexually transmitted parasite that causes the most common nonviral sexually transmitted infection worldwide 4, 5, 6.
- It is estimated to affect 3.7 million women and men in the United States, with health disparities prominent in its epidemiology, particularly among African Americans 4.
- The infection is associated with various adverse outcomes, including increased risk of human immunodeficiency virus (HIV) acquisition, cervical cancer, preterm birth, and other pregnancy complications 4, 6, 7.
Diagnosis and Treatment of Trichomonas vaginalis
- Diagnosis of Trichomonas vaginalis can be performed using various methods, including point-of-care assays and nucleic acid amplification tests, which can be conducted on genital specimens such as urine 4.
- The recommended treatment for Trichomonas vaginalis is metronidazole or tinidazole, with a single oral dose of metronidazole being the preferred treatment in men 4, 8.
- However, metronidazole resistance has been reported, and alternative treatments such as intravaginal metronidazole/miconazole and other 5-nitroimidazole drugs are being explored 8, 5, 7.
Clinical Significance and Screening
- Trichomonas vaginalis infection is a significant public health concern, particularly among women of reproductive age, and is associated with various reproductive sequelae and HIV acquisition risk 4, 5, 6.
- Screening for Trichomonas vaginalis is recommended for all women with vaginal discharge, and for asymptomatic women who are at high risk of infection, such as those with HIV infection 4, 6.