Accuracy of clinical diagnosis of bacterial vaginosis by human immunodeficiency virus infection status

Objective: To assess the accuracy of clinical diagnosis of bacterial vaginosis (BV) by using Amsel criteria, overall and by human immunodeficiency virus (HIV) infection status. Methods: Women with HIV, or at risk for HIV, participated in the HIV Epidemiology Research Study, a prospective study conducted in 4 US sites. At enrollment and follow-up visits, scheduled at 6-month intervals for ≤5 years, participants received gynecologic examinations, had specimens collected, and underwent standardized interviews. We used McNemar test statistic to evaluate agreement between Amsel criteria and Nugent scoring. Using Nugent scoring as the reference standard, we calculated sensitivity and specificity for Amsel criteria and for 3 other classifications of clinical BV. Our results are based on data collected from 9140 study visits by 862 HIV-infected women and 421 HIV-uninfected women. Results: Amsel criteria and Nugent scoring did not agree in the classification of BV cases (P < 0.01). Amsel criteria had poor sensitivity (60%; 95% confidence interval, 58%-61%) and specificity (90%; 95% confidence interval, 89%-91%) with wide differences in test properties by study site. We found no differences in diagnosing BV by HIV infection status. Conclusions: The under- and overdiagnosing of BV clinically suggests that the accuracy of Amsel criteria for routine screening of asymptomatic women might be lower than previous estimates; that clinicians need more rigorous training to apply subjective Amsel criteria accurately; or that wide heterogeneity in cases might prevent agreement between clinical and laboratory diagnoses, with future research needed to better understand the criteria or morphotypes associated with specific adverse outcomes.