New Vaginal Pathogens Panel starts Feb. 17

PCR-based test detects DNA of bacteria and yeast

Salem Health Laboratories is pleased to announce a new test for the qualitative detection of bacteria and yeast associated with bacterial vaginosis/vaginitis (BV), vulvovaginal candidiasis (VVC) and trichomonal vaginitis (TV).

Vaginal Pathogens Panel (LAB7147 – Xpert Xpress MVP) uses PCR-based technology to detect DNA of bacteria and yeast associated with BV, VVC and TV and can aid in the diagnosis of BV, VVC and TV. It replaces the current DNA probe test, Vaginitis/Vaginosis by DNA Hybridization (LAB70640 – BD Affirm), starting Monday, Feb. 17.

Specimen collection

• Swabs can be collected by the health care provider or by patient self-collect.
• The Multiplex Vaginal Panel will require a different sample collection kit from the current Vaginitis/Vaginosis assay. The new assay is compatible only with vaginal specimens collected with the Xpert Swab Specimen Collection kit (Catalog Number: SWAB/G-50-US).
• For transport, use the Xpert Swab Transport Reagent tube included in the Xpert Swab Collection kit.
• See attached collection instructions for:
  • Clinician collection
  • Patient collection

Collection changes

The Vaginal Pathogens Panel will use a different collection device compared to the BD Affirm assay. See photo examples below of the new collection device and the old collection device:

• New Vaginal Pathogens Panel collection device

• Old BD Affirm collection device. This collection device will no longer be in use as the BD Affirm assay will no longer be offered after the switch over to the Vaginal Pathogens Panel.

Specimen acceptability requirements and appropriate transport

·         Sample Type: Vaginal swab collected using the Xpert Swab Specimen Collection kit

·         Volume: Single swab in Xpert Swab Transport Reagent tube

·         Transport container: Xpert Swab Transport Reagent tube

·         Transport: Room temperature or refrigerated 2–28 C

·         Sample stability: 42 days

·         Storage: Room temperature or refrigerated 2–28 C

Specimen retention

·         7 days

How to order

·         Test name: Vaginal Pathogens Panel

·         Test code: LAB7147

·         CPT code: 81515

·         Synonyms: MVP, Vaginosis, Vaginitis, Trichomonas, Trichomonas vaginalis

Specimen rejection criteria

·         Unlabeled specimens.

·         Sources other than vaginal (all other sources will be rejected).

·         Use of other swabs other than the one in the kit is not acceptable.

·         Transport swabs only in the Xpert Swab Transport Reagent tube (included with collection kit). Do not transport swabs in saline or any other preservative.

Test location and turnaround time (TAT)

Test locations: Salem Health Laboratories (molecular department)

Days performed: Daily

TAT: 75 minutes

Test methodology

Real-time Polymerase Chain Reaction (PCR). Qualitative results only.

·         Bacterial Vaginosis: Detected or Not Detected

·         Candida spp: Detected or Not Detected

·         Candida glabrata/krusei: Detected or Not Detected

·         Trichomonas vaginalis: Detected or Not Detected

Reference range

·         Bacterial Vaginosis: Not Detected

·         Candida: Not Detected

·         Candida glabrata/krusei: Not Detected

·         Trichomonas vaginalis: Not Detected

Result interpretation

One major difference between the Vaginal Pathogens Panel and the (LAB7147 – Xpert Xpress MVP) and the Vaginitis/Vaginosis by DNA Hybridization (LAB70640 – BD Affirm) is the detection targets used to determine if a sample is positive for bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC).

First, the Gardnerella vaginalis target, which was used to determine if a sample was positive for bacterial vaginosis. The equivalent to this target is the Bacterial Vaginosis target, which uses an algorithm to determine if a sample is positive for bacterial vaginosis. Rather than relying on a single bacterial target, the algorithm used in the Vaginal Pathogens Panel looks for several bacterial targets consistent with a diagnosis of bacterial vaginosis.

The second change in detection targets is the Candida target. On the BD Affirm test, there was a single Candida target. On the new Vaginal Pathogens Panel, there will be two Candida targets — the Candida spp target and the Candida glabrata/krusei target. The Candida spp target and the Candida glabrata/krusei target will detect several Candida species that are associated with VVC (Candida albicans, C. tropicalis, C. parapsilosis, C. dubliensis, C. glabrata, C. krusei). Note that the test does not differentiate between the various Candida species. 

Sensitivity and specificity

The Vaginal Pathogens Panel has an advantage over the BD Affirm in the detection of bacterial vaginosis (BV), vulvovaginal candidiasis (VVC) and trichomonal vaginitis (TV). The Vaginal Pathogens Panel uses PCR-based technology compared to the DNA-probe technology of the BD Affirm.

In a study published in the Journal of Clinical Microbiology, PCR-based methods detected BV with a sensitivity of 96.9% and specificity of 92.6%. The BD Affirm detected BV with a sensitivity of 90.1% and 67.6% specificity. For VVC, the same study found that PCR-based methods had a 97.7% sensitivity and 93.2% specificity, and the BD Affirm had a 58.1% sensitivity and 100% specificity. For TV, the study found that PCR-based methods had a sensitivity of 98.1% versus 46.3% for the BD Affirm.

Testing questions?

Call Salem Health Laboratories:

o    Salem Health Laboratory – Building A: 503-814-3130

o    Salem Health Laboratory – Dallas: 503-623-7303

o    Salem Health Laboratory – State Street: 503-814-1662

o    Client services: 503-814-5227