C-228. Evaluation of the OSOM® Trichomonas Rapid Test vs. Wet Prep Exam for Diagnosis of T. vaginalis Vaginitis in a Regional Clinical Microbiology Laboratory

L. Campbell1, S. Elsayed2, T. Lloyd1, D. L. Church1,2;
1Calgary Lab. Services (CLS), Calgary, AB, CANADA, 2Univ. of Calgary, Calgary, AB, CANADA.

Objective: To perform a clinical and economic evaluation of the OSOM® Trichomonas Rapid test [BioPacifica (Genzyme Diagnostics), Edmonton, Alta.] (RT) vs. microscopic examination of wet preparations (WP) for routine detection of T. vaginalis vaginitis. Study Setting: Calgary Laboratory Services (CLS) provides clinical microbiology services to ambulatory and hospitalized patients in the Calgary Health Region (CHR) via a centralized regional laboratory. CLS Microbiology prepares 150-180 WP slides on vaginal smears for microscopic exam each day. This method may not detect T. vaginalis vaginitis due to a loss of viable trophozoites with delayed sample transport. Methods: During the study period (11/05/2006 to 11/12/2006), vaginal swabs were tested for the presence of T. vaginalis using both WP and the RT assay. Resources utilized to perform each test method were documented and a cost comparison of using WP vs. RT was done. Results: A total of 1,009 vaginal samples were tested from ambulatory women with symptoms of vaginitis. The mean age of the enrolled women was 31.7 ± SD 11 yrs. All of the vaginal swabs were received and tested within the 36 h transportation limit required by the RT EIA assay. A total of 18 (2%) vaginal samples were positive by both methods. The RT did not detect one positive sample. Overall, the RT had excellent performance compared to WP with as sensitivity of 94.7%, specificity of 100%, and a positive and negative predictive value of 100% and 99.9% respectively. Although the material costs for performing the RT assay were higher, 0.2 FTE would be saved due to the improved diagnostic efficiency of batch EIA testing. Conclusions: Implementation of the OSOM® Trichomonas Rapid Test would improve the diagnostic efficiency of vaginitis testing in our laboratory setting.