Evaluation of the BD MAX™ Vaginal Panel for the detection of vaginal infections in a sexual health service in the UK

Abstract

The aim of this study is to compare the performance of the BD MAX™ Vaginal Panel (Becton, Dickinson and company, Franklin Lakes, NJ, USA) in the diagnosis of bacterial vaginosis (BV), candidiasis and trichomoniasis with current standard tests in a UK specialist sexual health service. Women with abnormal vaginal discharge attending the service who had not used douches or vaginal treatment in the preceding 48 hours had two vulvovaginal swabs taken: one for Chlamydia and gonorrhoea nucleic acid amplification test (NAAT) and one for testing on the BD MAX™ Vaginal Panel on the BD MAX System. Speculum examination was then performed and vaginal swabs taken for vaginal pH, and microscopy of vaginal secretions: Gram stain for Candida and BV using the Hay–Ison score and wet-mount for clue cells and Trichomonas vaginalis (TV). Forty-six (23.6%) women were negative for all three infections on the Vaginal Panel. Ninety-three were positive for BV (47.7%), 70 (35.9%) for Candida and 9 (4.6%) had TV detected. Thirty-six women tested positive for both BV and Candida on the BD MAX™. The investigational test sensitivity for all Candida species was 86.4% with a specificity of 86.0% and for BV the sensitivity was 94.4% with a specificity of 79%. The sensitivity for BV was good but specificity is lower than previously described and may reflect the high rates of sexually transmitted infections in this population which potentially altered the vaginal microbiome. The lower specificity and sensitivity for Candida is not unexpected as a high proportion of women are colonised with Candida, and in all cases other pathogens were found to account for their symptoms. NAATs do not provide the immediate results available from in-clinic microscopy but were easy to perform and process and offer benefits over the traditional “high vaginal swab” performed in primary care and other settings where immediate microscopy is unavailable.