Diagnosis and clinical manifestations of bacterial vaginosis

Among 640 randomly selected women who were attending a sexually transmitted disease clinic and did not have trichomoniasis, 33% had bacterial vaginosis as defined by a composite of four clinical criteria: (1) Vaginal discharge was homogeneous; (2) vaginal discharge had a pH greater than or equal to 4.7; (3) vaginal discharge had an amine-like odor when mixed with 10% potassium hydroxide; (4) vaginal discharge contained clue cells representing greater than or equal to 20% of vaginal epithelial cells. Previously published Gram stain criteria for bacterial vaginosis correlated better than results of semiquantitative cultures for Gardnerella vaginalis with presence or absence of clue cells and with composite clinical criteria. Of 293 women with bacterial vaginosis by Gram stain criteria, 65% had symptoms of increased vaginal discharge and/or vaginal malodor, while 74% had signs of characteristic homogeneous vaginal discharge or amine-like odor. Elevated vaginal pH was the least specific and amine-like odor the least sensitive sign of bacterial vaginosis. Gram stain criteria for bacterial vaginosis were not associated with the concentrations of endocervical or vaginal inflammatory cells but were significantly associated with a clinical diagnosis of pelvic inflammatory disease. After adjusting for coinfection, sexual behavior, and other variables, bacterial vaginosis remained associated with adnexal tenderness (odds ratio = 9.2, p = 0.04). Bacterial vaginosis, previously implicated as a risk factor for obstetric infections, may be a risk factor for pelvic inflammatory disease.