New developments in the etiology and pathogenesis of bacterial vaginosis.

Bacterial vaginosis is unlike the "classic" sexually transmitted diseases. Unlike cervical infection with Chlamydia or salpingitis caused by N. gonorrhoeae, no single etiologic agent has been identified, and the organisms which are associated with infection have all been found as members of endogenous vaginal flora, with the possible exception of Mobiluncus species. If, as we suspect, BV is due to interactions among various organisms found in the vagina during vaginal health, we must determine what changes in the microbial or chemical ecology determine the development of BV. If, for instance, BV is simply due to an inversion in the concentrations of various organisms such that the anaerobes which are usually present in low numbers become predominant and the lactobacilli which usually predominate become few in number, we must determine which causes what. That is, does some organism or environmental change allow the anaerobes to overgrow and thereby inhibit the lactobacilli, or does some change inhibit the lactobacilli, thereby, allowing the other flora to overgrow? Answers to questions such as these await further research.