Point-of-care (POC) diagnosis of bacterial vaginosis (BV) using VGTest™ ion mobility spectrometry (IMS) in a routine ambulatory care gynecology clinic

A new CE-marked portable desktop ion mobility spectrometer (VGTest) was used for detection of malodorous biogenic amines indicative of bacterial vaginosis (BV). This study aimed to assess the performance of this testing method for the first time in a routine ambulatory care clinic and to determine the relative levels of biogenic amines in vaginal fluid of BV. Vaginal and cervical swabs (n = 57) were surveyed for infections. Cases of BV (n = 18) confirmed positive according to "Amsel" criteria and normal controls (n = 39) showing no infection under clinical examination and testing negative in wet mount microscopy were included in the IMS analysis. The trimethylamine (TMA) content in vaginal fluid of the BV-positive cases, AUC(TMA)/AUC(Total) [mean 0.215 (range 0.15-0.35)] was significantly higher than normal controls [mean 0.06 (range 0.048-0.07)] p < 0.0001. The putrescine (1,4-diaminobutane, PUT) and cadaverine (1,5-diaminopentane, CAD) of BV-positive cases were above controls at borderline significance. The AUC(TMA)/AUC(Total) ratios correlated neither with AUC(PUT)/AUC(Total) nor AUC(CAD)/AUC(Total) among BV-positive patients. In contrast, among normal controls all the biogenic amines were at a low level and the linear regression analysis revealed striking positive correlations of AUC(TMA)/AUC(Total) with AUC(PUT)/AUC(Total) (p < 0.05) and AUC(CAD)/AUC(Total) (p < 0.001). The test shows 83 % sensitivity and 92 % specificity at a cut-off of AUC(TMA)/AUC(Total) = 0.112 and AUC of receiver operator characteristic = 0.915 (0.81-0.97, 95 % CI). VGTest-IMS is accurate and feasible for point-of-care testing of BV in the ambulatory care setting. Further evaluations are in progress to assess the utility of VGTest-IMS for differential diagnosis of candidosis, non-BV infection and common inflammatory conditions.