Pattern of Candida species isolated from patients with diabetes mellitus and vulvovaginal candidiasis and their response to single dose oral fluconazole therapy.

OBJECTIVE: Patients with diabetes mellitus are at increased risk of vulvovaginal candidiasis (VVC). Besides Candida albicans, they often have infection due to non-C. albicans Candida species such as C. glabrata. Oral single dose fluconazole (150 mg) is commonly used to treat VVC in non-diabetic individuals with response rate varying from 70 to 90%. However, there is paucity of related information in diabetic women with VVC. Present study has been conducted to systematically assess the effect of fluconazole therapy among diabetic patients with clinically symptomatic VVC.
METHODS: Study subjects included 85 consecutive patients with diabetes mellitus (type 2=70 and type 1=15) and 62 non-diabetic women who had clinical signs and symptoms of VVC and in whom evidence of candidiasis was documented by presence of yeast on direct microscopy followed by culture. Single dose fluconazole (150 mg) was given orally to all the subjects in a supervised manner. Subjects were reassessed on 14th day after fluconazole therapy and a repeat high vaginal swab was taken for direct microscopy and fungal culture. Total glycosylated haemoglobin (HbA1) was measured to assess glycaemic control.
RESULTS: There were no significant differences in the frequency of pruritus (55.9 vs. 56.7%), vaginal discharge (63.8 vs. 69.0%), dyspareunia (25.0 vs. 20.0%), and percentage yeast positivity (67.5 vs. 54.7%) between diabetic and control groups before the start of fluconazole therapy. Following fluconazole therapy, vaginal discharge on examination and yeast positivity on direct microscopy continued to remain positive in higher percentage of subjects in the diabetic group as compared to non-diabetic subjects (52.5 vs. 36.4%; P =0.22 and 50.7 and 29.0%, respectively, P =0.07, respectively). Overall 67.1% of patients with diabetes and 47.3% of controls continued to show persistence of Candida growth on high vaginal swab culture following fluconazole treatment (P=0.042). Candida glabtara was the most common species isolated in patients with diabetes mellitus and its frequency was significantly higher in them when compared to control group (54.1 vs. 22.6%, P<0.001). C. albicans was the most common species isolated in controls. Species-specific response to fluconazole showed that 81.3% of patients in the diabetic group and 78.6% of the non-diabetic controls continued to show fungal growth when C. glabrata was the organism grown (P=0.99). However, in case of C. albicans, 45.4% of the patients in the diabetic group and only 21.5% of the controls had persistent Candida growth following fluconazole therapy (P=0.22).
CONCLUSION: Overall only one third of patients with diabetes mellitus and VVC respond to single dose 150 mg of fluconozole therapy. Limited response in the clinical symptoms and culture negativity following single dose fluconazole therapy in diabetic subjects with VVC is explained by the high prevalence of C. glabrata in them. The present study involved only 85 patients and majority of them had type-2 diabetes mellitus. There is need to perform similar study in large number of diabetics subjects including patients with type-1 diabetes mellitus and assess various alternative treatment protocol which are also effective in C. glabrata infection.