Comparison of latex agglutination, wet preparation, and culture for the detection of Trichomonas vaginalis

OBJECTIVES: To compare the performance of three diagnostic methods for Trichomonas vaginalis infection-latex agglutination, saline wet mount, and culture. METHODS: Vaginal swabs from 3807 women attending antenatal clinics were tested for the presence of T vaginalis by latex agglutination. All positives and the following two negatives were tested by wet preparation and culture. RESULTS: The prevalence of infection by latex agglutination was 5.4%. Using an expanded gold standard based on the wet mount and culture results, the sensitivity of the latex agglutination test was 98.8% (95% CI 95.9 to 99.9) and specificity was 92.1 (89.2 to 94.5). The kappa index for test agreement was 0.93 for latex and culture and 0.88 for latex and wet preparation. CONCLUSION: The latex agglutination test is a highly sensitive test for detecting T vaginalis infection. It is a simple rapid test and has the potential for use in screening and diagnostic settings.