Background:
Background: Trichomoniasis in women can manifest as asymptomatic carriage or abnormal vaginal discharge and bleeding due to cervicitis. Trichomonas vaginalis is transmitted by sexual intercourse, and is associated with the presence of other sexually transmitted diseases, adverse reproductive outcomes, and HIV infection. This is the first report of T. vaginalis prevalence from a nationally representative sample of women in the U.S.

Objective:
Objectives: To describe the prevalence of and factors associated with trichomoniasis using data from the National Health and Nutrition Examination Survey (NHANES) 2001-2002.

Method:
Methods: Women aged 14-49 years provided self-collected vaginal swabs. The vaginal fluids extracted from these swabs were used to evaluate for T. vaginalis using polymerase chain reaction (PCR).

Result:
Results: Overall, 1999 (84%) of 2383 participating women provided swabs that were evaluated by PCR. The overall prevalence of T. vaginalis was 3.1% (95% CI=1.9-4.9); for non-Hispanic whites 1.2% (95% CI=0.4-3.5), for Mexican Americans 1.5% (95% CI=0.7-3.4), for non-Hispanic blacks 13.5% (95% CI=9.9-18.5). Factors significantly associated with presence of T. vaginalis included first sex between ages 9 and 15 years, annual family income less than $20,000, education, and number of sex partners.

Conclusion:
Conclusions: T. vaginalis has an estimated prevalence of 3.1 % among a nationally-representative sample of U.S. women. A large racial disparity exists; the prevalence of T. vaginalis among non-Hispanic Black women was 11 times higher than in non-Hispanic white and Mexican-American women. Further research is needed to better understand the reasons for the racial/ethnic differences and to assist in reducing the overall burden of disease.

Implications:
Implications for Program, Policy, and Research: Routine screening in certain settings may be appropriate to decrease rates of disease and adverse reproductive health outcomes.