Vulvovaginal candidiasis and asymptomatic vaginal colonization in Portugal: Epidemiology, risk factors and antifungal pattern

Abstract

Vulvovaginal candidiasis (VVC) has been identified as a global issue of concern due to its clinical, social and economic implications. The emerging relevance of VVC makes it crucial to increase the knowledge on its epidemiological and etiological features in order to improve its prevention and treatment. Thus, this study aimed to reveal the incidence, microbiology, antifungal pattern and risk factors of VVC in Portugal. For that, high vaginal samples were collected from 470 symptomatic and asymptomatic participants; Candida spp. were identified with molecular techniques and their antifungal susceptibility was analysed with E-tests. The results revealed an incidence of VVC among women with vulvovaginitis of 74.4%. Furthermore, 63.7% of asymptomatic women were colonized with Candida spp. Importantly, women with history of recurrent vaginal infections, those who use over-the-counter antifungals, oral contraceptive pills and non-cotton underwear were found to be at significantly higher risk of developing VVC. Candida albicans was the most common species (59%), followed by Candida glabrata (27%), in a total of 8 distinct species, with similar distribution among colonized and infected participants. Of note, various isolates, especially of the most common species, showed low susceptibility towards fluconazole. In contrast, only few isolates showed low susceptibility towards caspofungin. Overall, this study suggests that the identification of species causing VVC and their antifungal susceptibility are urgently needed in clinical practice in order to improve the decision for the most adequate treatment. It also suggests that avoiding certain risk behaviours may prevent the development of VVC.

Vapor-Phase of Essential Oils as a Promising Solution to Prevent Candida Vaginal Biofilms Caused by Antifungal Resistant Strains

“…For this study, C. albicans ( n = 3), C. glabrata ( n = 8), C. krusei ( n = 1), and Candida guilliermondii ( n = 1) vaginal isolates belonging to a collection of yeasts created by the Candida Research Group of the Centre of Biological Engineering of University of Minho, in the scope of a large-scale recovery of vaginal specimens of Candida carried out in health centres and a university campus in the north of Portugal, were used [ 7 ]. The identity of all isolates was obtained by PCR-based sequencing using specific primers (ITS1 and ITS4) against the 5.8S subunit gene [ 7 , 27 ]. Minimum inhibitory concentration (MIC) for each species was determined by the Epsilometer-test (E-test) methodology and according to the guidelines provided by the manufacturer.…”

“…Minimum inhibitory concentration (MIC) for each species was determined by the Epsilometer-test (E-test) methodology and according to the guidelines provided by the manufacturer. Fernandes et al [ 7 ] also tested reference strains with MICs characterized by the CLSI19 microdilution method to ensure the reliability of the E-test results. In addition, a potential interpretation of MICs based on CLSI M60 was also performed [ 7 ].…”

“…Fernandes et al [ 7 ] also tested reference strains with MICs characterized by the CLSI19 microdilution method to ensure the reliability of the E-test results. In addition, a potential interpretation of MICs based on CLSI M60 was also performed [ 7 ]. All the isolates used are at least resistant to one of the antifungal agents (fluconazole, ketoconazole, or caspofungin) [ 28 , 29 ].…”

“…Table 1 presents the MIC of each antifungal and the features reported by women at the moment of vaginal sample collection, including symptoms of vaginal infection, previous vaginal infections, use of over-the-counter antifungals, and relevant health conditions. This study followed the Data Protection Legislation and was approved by the Portuguese Health Ethical Commissions (SECVS-UM 092/2017, CES-S Norte 49/218, CESHB 151/2018, CES-USLAM 23/2018, CESHSOG 5/2018) [ 7 ].…”

“…During episodes of VVC, the innate immune responses may differ, and this fact suggests that the host environment performs a key role in the host–pathogen interaction [ 3 ]. Candida organisms are capable of colonizing the vaginal environment asymptomatically; however, several factors may contribute to the development of infection, including pregnancy, immunosuppression (HIV/AIDS or diabetes mellitus), sexual activity, hormonal fluctuations, smoking, obesity, and the use of sodium glucose cotransporter 2 (SGLT2) inhibitors, broad spectrum antibiotics, or oral contraceptives [ 4 , 5 , 6 , 7 ]. Furthermore, the vaginal pathogenicity of Candida organisms is facilitated by several virulence factors including the biofilm formation on vaginal walls and intrauterine devices (IUDs) [ 8 ].…”