Detection of Trichomonas vaginalis, Gardnerella vaginalis, and Candida Species in Affirm VPIII, Papanicolaou Smear Test and Gram Stain

Background: Infectious vaginitis is caused primarily by three different groups of microbial pathogens (Trichomonas vaginalis, Candida spp., and Gardnerella vaginalis). The objective of this study was to compare the Affirm VPIII assay using a DNA hybridization technique with the Papanicolaou (Pap) smear test and the Gram stain in the detection and identification of these three organisms. Methods: A total of 300 vaginal samples were collected from women that were either symptomatic for vaginitis or asymptomatic women that were being seen for routine obstetric or gynecological care. The presence of T. vaginalis, Candida spp., and G. vaginalis was evaluated by using the Affirm VIII assay (Becton Dickinson, USA), Pap smear test, and Gram stain method, respectively. Results: With the Affirm VPIII assay, 1 (0.3%) patient tested positive for T. vaginalis, 99 (33.0%) patients were positive for G vaginalis, and 18 (6.0%) were positive for Candida spp. The detection rates of Trichomonas infection, bacterial vaginosis and candidiasis by the Pap smear test and Gram stain method were 0.7% versus 0%, 16.3% versus 35.7%, and 1.7% versus 9.7%, respectively. The differences between the detection rates of the above three organisms between the Pap smear test and the Gram stain method were statistically significant (P<0.05). Conclusion: The Affirm VPIII assay was more sensitive than the Pap smear test and more specific than the Gram stain method for the detection and identification of these three organisms. In addition, the results of the Affirm VPIII assay are quick to obtain and are simple and easy to interpret. (Korean J Clin Microbiol 2012;15:104-109)