Bacterial vaginosis is a definable clinical entity whose exact origin is unknown. A shift in normal vaginal flora from aerobic, predominantly but not exclusively lactobacilli, to a predominantly anaerobic flora characterizes the condition. More than one half of all women with bacterial vaginosis have no symptoms. The condition is not entirely benign. The potentially pathogenic bacteria present in the vagina in large numbers place these women at risk for postoperative morbidity and adverse obstetric outcome. Sexual transmission has not been proved, but therapeutic cures sometimes require that patient and partner be treated simultaneously. Recommended therapy is with metronidazole or clindamycin and must be given for 7 days for maximal effectiveness. Recurrence of disease can be a problem.
PIP: Bacterial vaginosis, the most common infectious cause of vaginitis, is characterized by a shift in normal vaginal flora from predominantly aerobic to mainly anaerobic flora. Incidence rates in various studies have ranged from 1-0-45%. Unclear are both the pathophysiology of the observed reduction in lactobacilli and whether bacterial vaginosis is sexually transmitted. Evidence for sexual transmission is provided by a significantly greater incidence of bacterial vaginosis in women with more than 5 sexual partners compared to those in a lifelong monogamous relationship, while bacterial detection in virgins and the failure to demonstrate benefits of partner treatment argue against sexual transmission. Use of an IUD does appear to be a risk factor. The only symptom consistently reported by women with bacterial vaginosis is a malodorous vaginal discharge; however, over half of women with this condition are asymptomatic. The standard criterion for diagnosis includes the presence of 3 of the following signs: the clue cell, homogeneous discharge that adheres to but is easily wiped off the vaginal wall, an elevated vaginal pH, and the potassium hydroxide test for volatile amines. Of concern is the potential for serious sequelae. The abnormal bacterial flora associated with vaginosis significantly impede the white blood cell response to infection. Gynecologic-obstetric sequelae include pelvic inflammatory disease, endometritis, postoperative vaginal cuff infections, preterm labor, premature rupture of membranes, and chorioamnionitis. Metronidazole and clindamycin are the most effective treatment agents. Given the long-term risks associated with bacterial vaginosis, a full course of antibiotics should be considered in both obstetric patients with this condition and women undergoing outpatient ambulatory invasive surgical procedures.