O1.3 - Increasing rates of non-albicans Candida species and fluconazole resistant Candida albicans in women with recurrent vulvovaginal candidiasis in a UK region
Azoles have been the mainstay of recurrent vulvovaginal candidiasis (RVVC) for years with initially no evidence of increasing prevalence of non-albicans Candida or azole resistant Candida albicans in our UK region. We noticed a recent anecdotal increase of these cases so we formally assessed their prevalence from vaginal samples in women with RVVC over the past 3-years.
Methods:
Retrospective data search of vaginal samples submitted to microbiology for yeast isolation between April 2018 and March 2021. Samples with clinical details of RVVC had full species identification by MALDI-TOF MS analysis and antifungal susceptibility performed using disc diffusion and microbroth dilution assay for MIC. Duplicate samples from the same patient within 12 months were excluded. Any differences in prevalence between the years were determined using Chi-squared with Yates correction.
Results:
Candida cultures were performed on 4597(18%) women with RVVC with 1828(39.8%) growing yeasts. Between 2018/2019 and 2020/21 there was a drop in the number, and proportion positive, of RVVC samples, probably due to the COVID-19 pandemic. Despite this drop, the prevalence of samples with non-albicans Candida and with fluconazole susceptible dose-dependent (SDD) and resistant (R) yeast isolates increased during the 3 years. C. krusei was also identified for the first time in 2020/21. Most resistant cases were in C. albicans and the majority were tested in Primary Care. The majority of fluconazole resistant isolates were either SSD or R to itraconazole (77% and 23% respectively) and intermediate or resistant to voriconazole (36.4% and 60% respectively), highlighting the difficulty in managing these cases.
Conclusion:
There was a significant increase in the prevalence of non-albicans Candida and fluconazole resistant C. albicans in RVVC cultures over these 3-years. Successful treatment of such cases can be very challenging.
Most of the resistant cases were in C. albicans and the majority were tested in Primary Care. The reasons for this remain unclear but it may be related to reduced access to health care and self-treatment during the pandemic, and/or a policy change which encouraged empirical treatment of candidiasis symptoms in Primary Care with yeast cultures/speciation/antifungal susceptibilities reserved for those with multiple episodes suggestive of RVVC.
