WP 131 Trichomonas Vaginalis Nucleic Acid Clearance Following Treatment of HIV Negative Women

Tuesday, June 10, 2014
International Ballroom
Norine Schmidt, MPH1, Stephanie N. Taylor, MD2, Camille Fournet, RN1, Alys Adamski, MPH1, Arielle Colon, BS1, Norah Friar, BA1, Judy Burnett, BS3, David Martin, MD3 and Patricia Kissinger, PhD1, 1Department of Epidemiology, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, 2Section of Infectious Diseases, Louisiana State University Health Sciences Center, New Orleans, LA, 3Department of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA

Background:  Rescreening women for Trichomonas vaginalis (TV) infections is important as repeat infections are common, ranging from 5%-31%. Nucleic acid amplification testing (NAAT) too soon after treatment may result in false positives as a result of detection of remnant TV nucleic acids. The goal of this study was to determine the rate of false positive NAAT results at weeks 1-4 post treatment completion using culture as the gold standard.

Methods:  Women attending an STI clinic in New Orleans who were InPouch culture positive and treated with metronidazole (MTZ) were included.  Participants were scheduled for 4 weeks of follow up visits starting one week post-treatment completion; they provided self-obtained vaginal swabs (SOVS) and information regarding sexual exposure.  SOVS were tested using InPouch culture and Gen-Probe Aptima TV (GPATV) assay which targets ribosomal RNA.  Women who were culture positive at follow-up were considered re-infected/treatment failure and were not followed further. Incentives were $20 at baseline and $50 at each follow up visit.

Results:  To date, 39 women were InPouch+ at baseline and were followed.  Of these, 3 (7.7%) were InPouch TV+ at follow-up (1 at 1 week and 2 at 2 weeks) and reported no sexual exposure. Thus, these women were considered likely treatment failures and were no longer followed. Of the remaining cases, 5/29 (17.2%) were GPATV+ at 1 week, and 1/34 (2.9%) was GPATV+ at 2 weeks. All of these women (n=6) were simultaneously InPouch TV-, reported no vaginal sexual exposure, and were InPouch TV-/GPATV- at subsequent visits. No woman was GPATV+ at 3 or 4 weeks. 

Conclusions:  These data suggest that TV ribosomal RNA has been cleared from the vagina by 3 weeks post completion of successful MTZ treatment and that the GPATV assay can be relied on as a test-of-cure at this point and beyond.