Diagnosis of Bacterial Vaginosis (BV) Using Nugent Criteria and a New Point-of-Care Chromogenic BV Blue Test for Detecting Elevated Vaginal Fluid Sialidase Enzyme

Abstract

Bacterial vaginosis (BV) is a condition that predisposes women to increased susceptibility to sexually transmitted diseases, including human immunodeficiency virus (HIV) infections and obstetric complications. The etiology of BV is diverse and the diagnostic methods currently adopted include Amsel criteria, and Nugent score (improved Gram stain) that requires microscopy and expert interpretation. We evaluated vaginal swabs from 56 premenopausal women with clinical signs suggestive of BV, using the Nugent criteria and a new BV Blue test for the detection of elevated vaginal fluid sialidase enzyme. For the Nugent criteria, slides were Gram stained and a score of 0-10 was assigned, considering the relative proportions of large Gram positive rods (lactobacilli), small Gram-negative or Gram variable rods and curved Gram-variable rods. The BVBlue test detected the presence of elevated vaginal sialidase enzyme in samples from 49(87.5%)women, compared with Nugent score of 7-10 interpreted as BV occurrence in 36 (64.2%) subjects. The BVBlue test is yet to be introduced in Nigeria as a routine screening BV test, and it is simple, rapid, and objective for the diagnosis of BV. It has the potential to facilitate prompt diagnosis and appropriate treatment of BV in the absence of microscopy.

Keywords: Bacterial Vaginosis, Sialidase, Nugent Score

Journal of Medical Laboratory Sciences Vol. 14 (1) 2005: pp. 37-42