Comparison of a TaqMan-based real-time polymerase chain reaction with conventional tests for the detection of Trichomonas vaginalis
- 1Laboratory Reference and Research Branch, Division of Sexually Transmitted Diseases Prevention, NCHSTP, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
- 2Sexually Transmitted Infections Reference Centre, Institute for Communicable Diseases, National Health Laboratory Services, Johannesburg, South Africa
- Correspondence to: Dr A Pillay Centers for Disease Control and Prevention, Division of STD Prevention, Laboratory Reference and Research Branch, 1600 Clifton Road, MS-G39, Atlanta, GA 30333, USA;
- Accepted 20 October 2006
- Published Online First 7 November 2006
Objective: To compare a TaqMan-based real-time polymerase chain reaction (PCR) with conventional PCR, culture, and wet-mount microscopy for the diagnosis of trichomoniasis in women.
Methods: Vaginal swabs from 119 women were tested for Trichomonas vaginalis by wet mount and culture. Paired vaginal lavage and urine specimens were tested by conventional and real-time PCR.
Results: Using an expanded “gold standard”, defined as a positive culture result using vaginal swabs and/or a positive PCR test using TVK3/7 primers, the overall prevalence of T vaginalis in the study population was 65.5% (78/119). The detection rate of T vaginalis was 65.5% (78/119) and 36.9% (44/119) by conventional PCR using vaginal washings and urine specimens, respectively; 68.9% (82/119) by real-time PCR using vaginal washings and 61.3% (73/119) by real-time PCR using urine specimens. The sensitivities of conventional PCR using vaginal washings and urine and real-time PCR using vaginal washings and urine, compared with the gold standard were 100%, 56.4%, 100% and 76.7%, and the specificities of these tests were 100%, 97.6%, 82.9% and 97%, respectively.
Conclusions: The real-time PCR test proved to be significantly more sensitive than culture and wet-mount microscopy, although its specificity was slightly lower than these tests. In addition, it was more sensitive, rapid and less time consuming than conventional PCR for the detection of T vaginalis.
Published Online First 7 November 2006
AP was the principal investigator for the study and lead author for the paper; FR and GF performed wet-mount and culture testing; AP, YH and RCB designed the study.The authors would like to express their sincere thanks to Evan Secor, David Cox, Patricia Shewmaker, Paul Levett and Maria Tondella from the Centers for Disease Control, Atlanta; Jane Schwebke from the University of Alabama at Birmingham; and Tania Crucitti from the Institute of Tropical Medicine, Belgium for providing microbial isolates or DNA used in this study.
Competing interests: None declared.
The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the Centers for Disease Control and Prevention.