To avoid positive results attributable to residual DNA, the Centers for Disease Control and Prevention recommends avoiding repeat testing with nucleic-acid based tests within 3 weeks after treatment of chlamydial (Chlamydia trachomatis [CT]) or gonococcal (Neisseria gonorrhoeae [GC]) infection. We retrospectively analyzed the duration of detectable DNA from a longitudinal cohort of adolescent women after diagnosis and treatment of infection with CT, GC, or Trichomonas vaginalis (TV).
Vaginal swabs were obtained weekly from young women for up to 12 weeks (observation period) after treatment of CT, GC and TV infections. Swabs were tested using a commercially available first generation nucleic acid amplification test (NAAT) for CT and GC, and a laboratory developed NAAT for TV. Kaplan-Meier statistics were used to estimate median time to the first negative DNA-based polymerase chain reaction (PCR) result.
Observation periods were available for analysis for 195, 82 and 102 treatments for CT, GC, and TV infection, respectively. Median time to a first negative PCR result for CT, GC, and TV was 9 (range 0–84), 6 (0–76), and 7 (0–84) days, and by day 21, 89%, 95%, and 85% were negative, respectively.
Data from this retrospective analysis indicate that greater than 85% of these young women did not have detectable CT, GC, or TV DNA by day 21 post-treatment. This data may be useful to clinicians for patient management and post-treatment testing purposes.
This study examined the length of time required to obtain a negative amplified DNA result after appropriate treatment of Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis.
From the *Indiana University School of Medicine, Indianapolis, IN; and †University of Alabama Birmingham School of Medicine, Birmingham, AL.
Acknowledgments: A special thanks to the study participants and Young Women’s project team. This study was supported by a grant from the National Institute of Allergy and Infectious Diseases (U19A143924).
The authors declare no conflicts of interest.
This study was presented in part at the 2008 National STD Prevention Conference, Chicago, IL; March, 2008.
Correspondence: James A. Williams, BS, Indiana University School of Medicine, 635 Barnhill Drive, Room MS224, Indianapolis, IN 46202. E-mail: firstname.lastname@example.org.
Received for publication October 4, 2013, and accepted December 30, 2013.