Vaginitis: current microbiologic and clinical concepts.

Infectious vaginitis occurs when the normal vaginal flora is disrupted; it may arise when saprophytes overwhelm the host immune response, when pathogenic organisms are introduced into the vagina or when changes in substrate allow an imbalance of microorganisms to develop. Examples of these types of vaginitis include the presence of chronic fungal infection in women with an inadequate cellular immune response to the yeast, the introduction of trichomonads into vaginal epithelium that has a sufficient supply of glycogen, and the alteration in bacterial flora, normally dominated by Lactobacillus spp., and its metabolites that is characteristic of "nonspecific vaginitis". The authors review microbiologic and clinical aspects of the fungal, protozoal and bacterial infections, including the interactions of bacteria thought to produce nonspecific vaginitis, that are now recognized as causing vaginitis. Other causes of vaginitis are also discussed.