Trichomoniasis is a common sexually transmitted infection (STI) caused by a microscopic parasite. Many individuals may not realize they have it, making understanding its nature important for sexual health and preventing transmission.
Understanding Trichomoniasis
Trichomoniasis, often referred to as “trich,” is caused by a single-celled protozoan parasite called Trichomonas vaginalis. This parasite typically resides in the lower genital tract, specifically the vulva, vagina, cervix, or urethra in women, and inside the penis (urethra) in men. Transmission primarily occurs through sexual contact, including vaginal-penile intercourse, or from vagina-to-vagina contact. While less common, it can also spread through genital touching.
In the United States, trichomoniasis is considered the most common nonviral sexually transmitted infection, with an estimated 2.6 million people affected. Globally, it is estimated that 160 million cases of infection are acquired annually. Despite its prevalence, only about 30% of infected individuals develop noticeable symptoms.
Recognizing the Signs
Itching is a common symptom associated with trichomoniasis, affecting the genital area in both women and men. For women, this can manifest as itching, soreness, or redness around the vaginal opening and within the vagina. Men may experience irritation or itching inside the penis. The severity of these symptoms can range from mild irritation to more significant inflammation.
Beyond itching, women might notice unusual vaginal discharge, which can be thin or foamy, and vary in color from white, yellow, to greenish, often accompanied by a foul or “fishy” odor. Other signs can include discomfort or pain during urination and during sexual intercourse. Some women may also experience spotting or light bleeding.
For men, additional symptoms may include a discharge from the penis, burning sensations after urination or ejaculation, and a frequent urge to urinate. When symptoms do appear, they typically emerge within 5 to 28 days after exposure, though for some, it might take much longer. The absence of symptoms means that infected individuals can unknowingly transmit the parasite to sexual partners.
Diagnosis and Treatment
Diagnosing trichomoniasis involves a healthcare professional performing an examination and conducting laboratory tests. A physical exam may reveal signs of inflammation or unusual discharge. To confirm the infection, a sample of vaginal fluid, urethral discharge, or urine is collected and examined. Microscopy, where the sample is viewed under a microscope to identify the parasite, is a common method. More sensitive diagnostic methods include Nucleic Acid Amplification Tests (NAATs), which detect the parasite’s genetic material and are considered highly accurate.
If trichomoniasis is confirmed, treatment typically involves prescription oral antibiotics. Metronidazole and tinidazole are the medications commonly prescribed to eliminate the parasite. These antibiotics can be given as a single large dose or a course taken over several days.
It is important for all sexual partners to receive treatment concurrently to prevent reinfection and further spread of the parasite. Individuals undergoing treatment are advised to avoid sexual activity for about one week after completing medication to allow for full recovery and to ensure the infection has cleared. Follow-up testing may be recommended for women, usually three weeks to three months after treatment, to confirm the infection is gone.