Advances in the understanding of bacterial vaginosis

Bacterial vaginosis is a disease that results from massive overgrowth of vaginal bacterial flora. The exact etiology is unknown. The major components of the normal bacterial flora, peroxide-producing lactobacilli, are replaced by non-peroxide-producing lactobacilli, allowing overgrowth of anaerobic and gram-negative aerobic flora. Anaerobic bacteria produce enzymes, aminopeptidases, that degrade protein and decarboxylases that convert amino acids and other compounds to amines. Those amines contribute to the signs and symptoms associated with the syndrome, raising the vaginal pH and producing a discharge odor. The excessive amounts of bacteria characteristic of the syndrome attach to epithelial cell surfaces, resulting in "clue" cells. Nearly half the patients report no noticeable symptoms, but many develop a characteristic copious, malodorous discharge within six months if untreated. Serious infectious sequelae are associated with bacterial vaginosis, including salpingitis, abscesses, endometritis and pelvic inflammatory disease. There is also a danger to pregnant women because of premature rupture of the membranes and premature labor. Clindamycin and metronidazole are considered effective therapy for the disease. Treatment of sexual partners remains controversial since sexual transmission has not been proven unequivocally.