SEATTLE – Both a high rate of trichomoniasis among sexually active teenage and adult women who seek self-testing and the elevated rate of adverse reproductive health outcomes in infected women raise the question of whether trichomoniasis should be a reportable infection in the United States, Charlotte A. Gaydos said.
Some 10% of the more than 1,500 women who were recruited through the Internet and offered free self-testing, and who then submitted vaginal samples, were positive for this sexually transmitted infection (STI) in an observational study reported at the annual meeting of the Society for Adolescent Health and Medicine. Rates were highest among those aged 25-29 years and among blacks.
These findings, coupled with the adverse health effects of trichomoniasis, may have implications for tracking the infection in the population, according to lead investigator Charlotte A. Gaydos, Dr.P.H., a professor in the division of infectious diseases at Johns Hopkins University in Baltimore.
Trichomoniasis is currently not reportable to the Centers for Disease Control and Prevention, she noted. But study estimates from the CDC suggest that there are 7-8 million new cases every year in the United States.
Infected men and – in particular – women have elevated rates of adverse reproductive health outcomes, including pelvic inflammatory disease, low infant birth weight, and premature delivery. Furthermore, this STI has been increasingly implicated as a risk factor for HIV transmission, she said.
"My question to the proponents of adolescent health and health for women in general is, should we start to do surveillance for Trichomonas [vaginalis] in the United States, so that we can have good data?" Dr. Gaydos asked. "I think more studies are needed."
Additionally, "should we make this a reportable infection in the future?" she inquired, given the many negative outcomes associated with trichomoniasis and the fact that it can be asymptomatic.
The investigators studied women who were recruited through IWantTheKit.org, an educational Internet program on STIs that offers free self-testing to sexually active individuals aged 14 years or older in Denver, Philadelphia, Alaska, Maryland, West Virginia, selected counties in Illinois, and Washington, D.C.
"We know that submission of self-collected samples at home can remove some barriers for adolescents and other women in testing for sexually transmitted diseases," Dr. Gaydos commented. "We have shown in the past that an Internet-recruited population can do this for Chlamydia and gonorrhea."
Starting in mid-2006, the program added testing for trichomoniasis to its existing testing for Chlamydia and gonorrhea. Women ordered the kit online and sent self-collected vaginal samples by U.S. mail to the testing lab. They also completed questionnaires on demographics and risk factors.
The lab tested for trichomoniasis using a nucleic acid amplification test, which has a sensitivity of about 90%, compared with roughly 50% for wet prep and 70% for culture, according to Dr. Gaydos.
The women were instructed to call for their test results in 1-2 weeks, and – should they forget to call – to indicate their preferred method of notification (e-mail, cell phone, letter, or text message).
A total of 1,525 women requested and returned self-collected vaginal swab kits in 2006-2010.
Overall, 10% of women tested positive for trichomoniasis, Dr. Gaydos reported. In addition, 10% tested positive for Chlamydia, 1% tested positive for gonorrhea, and 18% tested positive for at least one of the three infections studied.
By age, the rate of trichomoniasis ranged from 8.3% among those aged 20-24 years to 11.5% among 25- to 29-year-olds. And by race, it ranged from 0% among Asian women to 13.2% among black women.
In a multivariate analysis, women were more likely to have trichomoniasis if they were black compared with white, Asian, or other race/ethnicity (odds ratio, 2.69); did not have health insurance (OR, 1.57); did not have a bachelor’s degree (OR, 5.53); had 2-15, or 16 or more partners in the past year vs. none or a single partner (OR, 1.60 and 3.51); were bisexual (OR, 2.00); did not always use a condom (3.04); or had a partner who had an STI (OR, 1.71).
Age, having had trichomoniasis previously, and having had any STI in the past were not independent risk factors for trichomoniasis, according to Dr. Gaydos.
Participants reported hearing about the program in a variety of ways. "About 30% say that they found it surfing the Internet, and about 28% say they heard about it on the radio, which is how we advertise the presence of the kit in our local areas most of the time," Dr. Gaydos said. Additionally, small proportions reported learning about the program from friends, fliers, and partners.