Diagnostic Value of DNA Hybridization Test for Gardnerella vaginalis, Candida spp., and Trichomonas vaginalis in Women with Vaginal Discharge

Abstract

Objective: The aim of this study was to determine the efficiency of DNA hybridization in women with vaginal discharge evaluated by conventional laboratory methods including wet mount, whiff test, and Gram stain used in combination for the diagnosis of Gardnerella vaginalis, Candida spp., and Trichomonas vaginalis vaginitis. Material and Methods: A prospective study involving 63 women reporting with abnormal vaginal discharge from January to July 2007 in our hospital was performed. The vaginal smears were evaluated by whiff test, wet mount, Gram stain and DNA hybridization test and the results were recorded. Results: Thirty nine (61.9%) women were negative for all the three infections by conventional laboratory methods whereas 50 (79.4%) were negative by DNA hybridization test. G. vaginalis was identified as the causative organism in 11 (17.5%) patients by conventional laboratory methods and in 5 (7.9%) patients by DNA hybridization test. Nine patients (14.3%) were diagnosed with Candidiasis by conventional laboratory methods compared to 6 (9.5%) patients by DNA hybridization test. Conventional laboratory methods detected combined Gardnerella and Candida infections in 2 (3.2%) patients, whereas 1 (1.6%) patient was positive for both infections by DNA hybridization test. Two (3.2%) patients were identified with T vaginalis by conventional laboratory methods and 1 (1.6%) by DNA hybridization test who incidently was also positive for G. vaginalis and Candida. Conclusion: There is not superiority of the DNA hybridization test over conventional laboratory methods in the diagnosis of vaginitis in our study. We suggest that conventional laboratory tests as used in our settings is useful in diagnosing vaginitis when used in conjunction with consistent clinical signs, instead of using an expensive alternative method, DNA hybridization test.