QUEBEC CITY – When screening women for gonorrhea and chlamydia, screen them for Trichomonas vaginalis, too.
If left untreated, T. vaginalis (TV) can increase a woman’s risk for acquiring HIV from a sexual partner, or transmitting HIV to a sexual partner, according to the Centers for Disease Control and Prevention.
To determine the rates of coinfection for TV in women who are being screened for other STDs, Christine C. Ginocchio, Ph.D., of North Shore–Long Island Jewish Health System Laboratories in Lake Success, N.Y., and her colleagues collected samples from 7,593 women aged 18-89 years who were undergoing routine screening for chlamydia and gonorrhea. In all, 7,590 results were obtained from 30 labs in 21 states.
Overall, the prevalence of TV was 8.7%, compared with 6.7% for chlamydia and 1.7% for gonorrhea. TV was the most common of the three infections among women aged 30-39 years (8%), 40-49 years (11%), and 50 years and older (13%). The median age of the women who were positive for TV was slightly older (26 years), compared with that of the women who were positive for chlamydia and gonorrhea (22 years), according to the findings presented at a congress of the International Society for Sexually Transmitted Diseases Research.
The prevalence of TV (8.5%) fell between that of chlamydia (14%) and gonorrhea (3.3%) in women aged 18-19 years, and was 8.3% in women aged 20- 29 years, compared with 8% for chlamydia and 2% for gonorrhea.
The prevalence of TV as a coinfection with chlamydia and/or gonorrhea was relatively low across all age groups, but it occurred most often in younger women. TV and chlamydia coinfection occurred in approximately 2% of women aged 18-19 years. Other TV coinfections occurred in 1% or fewer of any age group.
When data were broken down by race, the prevalence of all three infections was greatest among black women. TV was the most prevalent (20%), compared with chlamydia (12%) and gonorrhea (4%) in these women. The prevalence of TV in other races was 11% in American Indians/Alaskan Natives, 7% in Native Hawaiians/Pacific Islanders, 6% in whites, 5% in Hispanics, 4% in Asians, and 7% in other or unknown races.
The women were seen in a range of settings including family practices, emergency departments, hospital inpatient settings, STD clinics, and jails. Prevalence data based on collection site showed that the prevalence of TV was highest in jail settings (22%) and emergency departments (17%). TV was the most common infection in all but family practice and internal medicine settings, where the prevalence was approximately 6%, compared with 7% for gonorrhea and 2% for chlamydia.
The findings support data from previous studies and indicate that the prevalence of TV varies widely based on the population being studied. The findings also support data from previous studies of racial disparity in TV.
However, "the high TV prevalence in all age groups suggests that all women being screened for chlamydia and gonorrhea should also be screened for TV," Dr. Ginocchio said.
Dr. Ginocchio said that she had no financial conflicts to disclose.