Comparison of clinical and gram stain diagnosis methods of Bacterial Vaginosis among pregnant women in Ethiopia

Background: Bacterial Vaginosis (BV) is characterized by an increased thin homogenous white vaginal discharge accompanied by fishy odour and increased vaginal pH. It is associated with different gynecologic and poor obstetric outcome. Bacterial vaginosis can be easily diagnosed by combination of two Amsel's criteria. Objective: The aim of this study was to evaluate the accuracy of Amsel's criteria individually or in combination of two for the clinical diagnosis of bacterial vaginosis among pregnant women in Ethiopia. Material and Methods: In this cross sectional study 252 pregnant women were screened for bacterial vaginosis. Vaginal swabs were collected for pH determination, saline wet mount microscopic examination to detect clue cells, KOH preparation for whiff test and Gram-stain evaluation of vaginal flora for diagnosis of bacterial vaginosis by Nugent scoring system. Accuracy of clinical diagnosis using individual and two of Amsel's criteria was evaluated. Results: The prevalence of BV was 18.3% by Amsel's two of three criteria and 19.4% Gram by Nugent's methods. Comparing with Nugent scoring methods, the clinical diagnosis by Amsel's criteria had sensitivity of 85.7%, specificity of 98%. The most sensitive and specific individual Amsel's criterion was clue cells. Amsel's criteria with the lowest sensitivity and specificity were whiff test and vaginal pH respectively. Combination of clue cells with vaginal pH test were the highest in sensitive while whiff test with clue cells were the highest in specificity than the other combined two Amsel's criteria. Conclusion: Amsel's criteria diagnosis of bacterial vaginosis can be simplified by using a combination of the two criteria, vaginal pH and clue cells, in settings where time or Gram staining is not available.