Trichomonas Vaginalis: The STD You Haven't Heard Of

Though trichomoniasis is the most common sexually transmitted disease (STD) of all, many people haven't ever heard of it. Caused by Trichomonas vaginalis, a microscopic parasite, it can cause no symptoms at all, or it can present with symptoms such as vaginal discharge, vaginal itching, and redness.

One new study funded in part by Johns Hopkins University looked at who's most likely to get Trichomoniasis. The research showed that the infection is extremely common in older women. For the study, more than 7,500 women between 18 and 89 were tested for Trichomonas vaginalis in what is thought to be the biggest STD analysis to date in the U.S. Researchers found that women 50 and over had the highest infection rate (13 percent) while women in their 40s had an 11 percent infection rate.

"We were trying to determine the prevalence of Trichomoniasis both in women who are symptomatic and asymptomatic," explained co-study author Christine C. Ginocchio, Ph.D., M.T. (ASCP), chief of the division of infectious disease diagnostics in the Department of Pathology and Laboratory Medicine for North-Shore-LIJ Health System Laboratories in Lake Success, New York. "Though people tend to not think of women in their 40s and 50s as having STDs, we found this not to be true."

And, she added, "There are a lot of women walking around with Trichomonas vaginalis who probably have no idea that they have it." Yet despite the fact that the incidence of Trichomoniasis is higher than the incidence of gonorrhea and chlamydia combined, women aren't routinely screened for it. When women are screened for STDs, a test for Trichomoniasis should be included, Ginocchio says. And, she added, their partners also should be screened since if they have Trichomonas vaginalis infection and are not treated, they will just pass it back and forth with their partner.

Once diagnosed, trichomoniasis responds quickly to treatment, says Jill Rabin, MD, professor of obstetrics and gynecology at Hofstra North Shore-LIJ School of Medicine.

"Antibiotics will be prescribed," Rabin says. "It's treated with a vaginal gel or cream, or oral antibiotic, and once treatment starts, it takes about one week to clear up."  

But if it's not treated, trichomoniasis can cause a myriad of health problems such as an inflammation of the vagina, and it can cause premature labor in a pregnant woman.

Trichomoniasis does not affect a woman's ability to get pregnant, Rabin says.

To prevent Trichomonas vaginalis you should:

● Limit your number of sexual partners.

● Make sure you use barrier protection unless you are in a long term relationship and are mutully monogamous.

● Use a condom to prevent transmission and pregnancy.


"Sexually Transmitted Parasite Trichomonas Vaginalis Twice as Prevalent in Women Over 40, Study Finds." 12 July 2011. Science Daily.