Bacterial vaginosis can be diagnosed using the following Amsel criteria. The presence of three of the following four criteria provides sufficient evidence for a clinical diagnosis of BV.
Gold standard for diagnosis of BV is vaginal Gram stain to assist in the diagnosis of BV (Nugent or Speigel criteria). A normal Gram stain would show lactobacillus (long Gam-positive rods) only or lactobacillus with gardnerella. When a more mixed flora is present and lactobacillus is absent or present in low numbers, the smear would be interpreted as consistent with BV.
Cultures are not recommended.DNA probe--Affirm™ V.P. III, can detect high levels of G. vaginalis.
Other diagnostic modalities include PIP activity and sialidase tests (BVBlue). These tests detect abnormal pH, high levels of trimethylamine or high levels of proline aminopeptidase.