Diagnosis of Bacterial Vaginosis: Amsel’s Criteria vs Nugent’s scoring

Abstract

Bacterial Vaginosis (BV) is the most common cause of vaginitis. If untreated, it is associated with serious complications. BV is a poly-microbial, synergistic infection, involving over-growth of multiple bacterial pathogens. Vaginal flora becomes altered leading to increased pH due to decrease in lactobacilli (which produce H2O2).Although Nugent's criterion is considered as the gold standard in diagnosis of BV, routinely a combination of various methods is used for the diagnosis of bacterial vaginosis(BV). In the present study we compared Amsel's composite clinical criteria with Nugent's method for the diagnosis of BV. The study was undertaken from February - November, 2015 at a Tertiary Care Hospital in Hyderabad. The study consisted of women with complaints of vaginal discharge. BV was diagnosed based on Amsel's criteria and Nugent's scoring. For each case, the following were interpreted: pH, Whiff test (a test in which vaginal secretions are mixed with 10% KOH resulting in a fishy odor typical of bacterial vaginosis)and the presence of the clue cells on vaginal wet smear. Gram staining was performed for Nugent's method. The present study included 362 cases of abnormal vaginal discharge. Prevalence of BV was 48%. Age group 24-29 years was most affected. Amsel's criteria detected 170/362 whereas Nugent score identified 173/362 subjects as having bacterial vaginosis. In comparison with Nugent's criteria the sensitivity, specificity, positive predictive value and negative predictive value of Amsel's criteria were 78.72%, 92.35%, 75.51% and 93.54%. The prevalence rate of BV in present study high. With limited resources in developing countries like ours, there is a great need for inexpensive diagnostic methods for bacterial vaginosis. Amsel's criteria is as good as Nugent's scoring in diagnosis of BVand it is simple, easy, cost effective, fast and reliable, and can be done in OPD which can be used for precise and fast treatment. Keywords Bacterial vaginosis, Amsel's criteria, Nugents scoring, Clue cells, Whiff test, Vaginal Discharge