What are the results of a high vaginal swab for vulvovaginal candidiasis?

From the Guidelines

Vulvovaginal candidiasis diagnosis is typically confirmed by a high vaginal swab, which is used to collect a specimen for fungal culture and microscopy, although culture has remained the gold standard for diagnosis of vaginal fungal infections 1.

Key Findings

• The results of a high vaginal swab for vulvovaginal candidiasis can be confirmed by microscopy, however, this method has poor sensitivity 1.
• Yeast cultures can lead to a delay in diagnosis and treatment, taking a minimum of 48–72 hours 1.
• Molecular testing, such as polymerase chain reaction (PCR), has been found to have high clinical accuracy for diagnosing vulvovaginal candidiasis, with sensitivity and specificity of 90.9% and 94.1%, respectively 1.

Treatment

• If the results confirm vulvovaginal candidiasis, treatment with an antifungal agent such as fluconazole (150mg single dose) or clotrimazole (100mg vaginal tablet for 7 nights) is indicated 1.
• Topical applications of clotrimazole (1% cream) or miconazole (2% cream) for 7-14 days are also effective treatments for vulvovaginal candidiasis 1. Some of the key points to consider when interpreting the results of a high vaginal swab for vulvovaginal candidiasis include:
• The sensitivity and specificity of the diagnostic method used, with molecular testing having higher sensitivity and specificity than microscopy 1.
• The species of Candida present, as some species such as C. glabrata may have lower sensitivity with PCR testing 1.
• The clinical presentation of the patient, with symptoms consistent with vulvovaginal candidiasis increasing the likelihood of a positive diagnosis 1.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Results of High Vaginal Swab for Vulvovaginal Candidiasis

The results of a high vaginal swab for vulvovaginal candidiasis can vary depending on the study and the methods used. Here are some key findings:

• In a study published in 2010 2, high vaginal swabs were collected from 250 females, and Candida species were isolated in 100 (40%) of cases.
• The most common species isolated were C. albicans (30%), C. tropicalis (21%), C. parapsilosis (10%), C. parakrusi (8%), C. glabrata (8%), and C. krusei (3%) 2.
• Another study published in 2011 3 found that yeasts were detected in 60 of 122 (49.2%) patients with acute VVC cases, 110 of 249 (44.2%) with RVVC cases, and in 35 of 103 (34%) healthy controls.
• The study also found that the use of chromID Candida agar (CAN2) was a rapid and reliable medium for immediate identification of C. albicans and for detecting polyfungal populations in vaginal specimens 3.
• A study published in 2020 4 noted that Candida albicans is the most prevalent pathogenic yeast-related to vulvovaginal candidosis (VVC), but did not provide specific results for high vaginal swabs.

Species Identification and Antifungal Susceptibility

The identification of Candida species and their antifungal susceptibility is crucial for effective treatment. Here are some key findings:

• A study published in 2010 2 found that Clotrimazole was effective against 68 (70%) of Candida species, while Fluconazole was effective against 29 (36.2%) and Nystatin was effective against 51 (63.5%).
• Another study published in 2022 5 suggested that clotrimazole, miconazole, terconazole, and intravaginal boric acid are recommended for recurrent vulvovaginitis caused by both Candida albicans and non-albicans species.
• The study also noted that identification of species will influence treatment decisions, and treatment may be modified based on prior response to a specific agent, especially in non-albicans species 5.