C-157. Diagnosis of C. trachomatis, N. gonorrhoeae and T. vaginalis Infections using Urine and Various Swab-types for Self-Collected Vaginal Samples

M. A. Chernesky, D. Jang, E. Portillo, M. Smieja, Y. Feng;
St. Joseph's Hlth. Care, Hamilton, ON, CANADA.

Background: Women may be infected with C. trachomatis [CT], N. gonorrhoeae [GC] or T. vaginalis [TV] without symptoms. Screening, with non-invasive samples are required to identify and treat lower tract infections to prevent upper genital tract complications. First void urine [FVU], (first 20 ml) may be difficult to collect accurately. Our studies examined the ability of APTIMA assays [Gen-Probe Inc.] to detect CT and GC and transcription mediated amplification analyte specific reagents [ASR] to detect TV in self-collected vaginal swabs and FVU. We also determined ease of collection, sample preferences and compared different types of swabs and transport media. Methods: A total of 289 women self-collected an FVU and 3 vaginal swabs in a randomized fashion; an APTIMA swab [AS] into APTIMA buffer, a flocked swab [FS] into APTIMA buffer and the flocked swab of an ESwab kit [ES] into ESwab media [Copan Diagnostics Inc.]. The samples were tested within 48 hours for CT and GC in the APTIMA Combo 2 [AC2] assay and for TV ASR from Gen-Probe. A patient was considered positive for CT, GC, or TV if at least 2 of 4 samples were positive for a particular infection. Results: Infection prevalences were 12.8% [37/289] for CT, 3.1% [9/289] for GC, 2.4% [7/289] for CT and GC together and 13.5% [39/289] for TV. Percent sensitivities were as follows: for CT and GC, 100 by all 3 swabs and 97.2 by FVU; for TV 92.3 by AS or FS, 87.2 by ES and 86.8 by FVU. Percent specificities were as follows: for CT 98.8 by AS, 99.6 by FS and 100 by ES and FVU; for GC 100 by all samples; for TV 98.8 by AS, 99.2 by FS, 99.6 by ES and FVU. The majority of women reported that self-collecting swabs was very easy and was preferred over collecting urine. Conclusion: Women easily collected their own vaginal sample for the diagnosis of CT, GC and TV. Flocked swabs in APTIMA buffer and flocked ESwab media detected the same patients infected with CT and/or GC as the AC2 collection and transportation system. The ASR showed versatility by detecting most TV infections with AS or FS. Screening asymptomatic women with self-collected samples for CT, GC and TV appears to be a useful approach.