Vaginal candidal infection: clinical features of diagnostics methods

Abstract

Goal. To study clinical features of the vaginal candidal infection and carry out a comparative analysis of the microscopy, cultural and real-time PCR methods for identifying Candida fungi. Materials and methods. The study involved 107 female subjects: Group 1: 56 women with Candida fungi found in their vaginal secrets by laboratory tests; Group 2: 51 women with absent clinical and laboratory signs of the urogenital infection. The laboratory test methods were as follows: microscopy, cultural and biomolecular (real-time PCR (RT PCR) - Florocenosis-Candida). Key findings. Pathologic vaginal secretion (76.8%) and hyperemia of vaginal and vulvar mucous tunic (41.1%) belong to the key clinical manifestations of the vaginal candidal infection. Caseous vaginal discharge was revealed in 33.9% of patients from Group 1, homogenous creamy discharge - in 42.9%, and homogenous mucous non-transparent vaginal discharge - in 23.2% of patients from Group 1. The patients had the following etiologic agents: C. albicans (94.6%), C. glabrata, (3.6%) and C. krusei (1.8%). Candida spp. identification results using the cultural and microscopy methods coincided in 78.6% of all cases, RT PCR and microscopy - in 66.1%, and RT PCR and cultural methods - in 87.5% of all cases. There were no reliable differences in the quantitative results for Candida fungi by the cultural and RT PCR methods: below 102 CFU/mL and below 102 GE/mL - 12.2 and 8.9%, respectively, 103-104 CFU/mL and 103-104 GE/mL - 44.9% and 33.9%, over 104 CFU/mL and over 104 GE/mL - 42.9 and 57.2%, respectively(p > 0.05). Conclusion. Candidal colonization of the vaginal mucous tunic was accompanied by specific clinical manifestations of urogenital candidosis in 76.8% of all cases; C. albicans was revealed in most of the subjects (94.6%). The real-time PCR method used for Candida spp. identification and quantitative determination demonstrated higher sensitivity and specificity vs. microscopy as well as sensitivity and specificity being comparable to the cultural diagnostics method.