[The definition and epidemiology of bacterial vaginosis].

Bacterial vaginosis is a condition with a flora change in the vaginal where a lactobacilli-dominated flora is exchanged with an abundant complex flora dominated by strict and facultative anaerobic bacteria. The condition seldom occurs in prepubertal girls and post-menopausal women, suggesting an hormonal component in its etiology. Recurrent episodes of bacterial vaginosis are frequent. Three out of four criteria should be fulfilled for establishing the diagnosis of bacterial vaginosis, i.e., an increased (often homogeneous) vaginal discharge, a positive amine test, the presence of a great number of clue cells, a vaginal pH > or = 4.5. There are no hard data supporting that bacterial vaginosis is a sexually transmitted disease. Cytological changes (CIN I, II, III) have been found more often in women with bacterial vaginosis than in those without this condition. It has been proposed that nitrosamines from the abundant vaginal bacterial flora may be oncogenic, a correlation which, however, needs to be proved. The reservoir for one or more of the bacterial vaginosis-associated organism, e.g., some Bacteroides and Mobiluncus spp., Gardnerella vaginalis and Mycoplasma hominis, is probably the distal intestinal tract and the mouth. Sparse or even a moderate number of clue cells are present in many women who do not have bacterial vaginosis. A vaginal pH of 4.7 seems to be a better cut-off level than 4.5. There is a statistical correlation between bacterial vaginosis and obstetrical complications.