What causes Trichomoniasis and How is a Trichomoniasis infection treated?

Syphilis, gonorrhea, herpes, papillomavirus, chlamydia, you’d think that would be enough bacteria and viruses to worry about, especially at a moment when you’re preoccupied with something more pressing.

But there’s more. The cause of trichomoniasis is neither a bacterium nor a virus. It’s the cause of a microscopic parasite, a protozoan called Trichomonis vaginalis that (despite its name) infects both men and women.

Men usually have no symptoms, although they can sometimes have urethritis, an inflammation of the urethra that causes pain inside the penis or slight burning after urination or ejaculation. Women are more frequently symptomatic, and typically have a frothy and malodorous yellow-green discharge and discomfort during intercourse and urination. The genital area can also be irritated or itchy.

The infection is easily treated with a regimen of metronidazole, the only medication available in the United States for the treatment of trichomoniasis. Cure rates are very high, 90 to 95 percent, and treating sexual partners probably increases the cure rate even further. This means treating asymptomatic men, who can still transmit the infection if they are not treated. The disease can also be transmitted by vulvar contact between women, so female sexual contacts of infected women must also be tested and treated.

The infection can be diagnosed in women by pelvic examination, small red sores on the vaginal wall or cervix are usually apparent. Tests can also be done on a sample of vaginal fluid or urine. It is harder to detect the parasite in men.

The usual admonitions apply: abstain, use condoms, limit the number of sex partners, limit sexual contact to one uninfected partner. If you have symptoms, get treatment and counsel from a health care professional, and don’t have sex again until you’re better.