Age, race, socioeconomic factors increase risk of T. vaginalis.(News)

JACKSONVILLE, FLA. -- First sex between ages 9 years and 15 years, lower socioeconomic status, and lower education levels are significantly associated with presence of Trichomonas vaginalis, according to the first report of T. vaginalis from a nationally representative sample of women in the United States.

A large racial disparity is another feature of T. vaginalis. Prevalence rates are 11 times greater among non-Hispanic blacks, compared with non-Hispanic white and Mexican American women.

"Routine screening in certain settings may be appropriate to decrease rates of disease and adverse reproductive health outcomes," Dr. Emilia Koumans said at a conference on STD prevention sponsored by the Centers for Disease Control and Prevention.

Using 2001-2002 data from the National Health and Nutrition Examination Survey (NHANES), Dr. Koumans, lead author Dr. Madeline Y. Sutton, and their associates assessed 1,999 self-collected vaginal swabs for presence of T. vaginalis. Study participants were 14-49 years old. Mexican Americans and adolescents were oversampled in the NHANES data to better represent the general population, said Dr. Koumans, a medical officer in the division of STD prevention at the CDC.

An estimated 3.1% overall prevalence of T. vaginalis was determined using polymerase chain reaction testing. Non-Hispanic black participants had a prevalence of 13.5%, compared with 1.5% for Mexican Americans and 1.2% for non-Hispanic whites.

T. vaginalis is a very common sexually transmitted disease, Dr. Koumans said, with an estimated 170 million new cases per year worldwide. "From my understanding of the literature, the predominant mode of T. vaginalis [transmission] is through sex," she ...