OBJECTIVE: To define an entity of abnormal vaginal flora: aerobic vaginitis.
DESIGN: Observational study.
SETTING: University Hospital Gasthuisberg, Leuven, Belgium.
SAMPLE: 631 women attending for routine prenatal care or attending vaginitis 
clinic.
METHODS: Samples were taken for fresh wet mount microscopy of vaginal fluid, 
vaginal cultures and measurement of lactate, succinate and cytokine levels in 
vaginal fluid. Smears deficient in lactobacilli and positive for clue cells were 
considered to indicate a diagnosis of bacterial vaginosis. Aerobic vaginitis was 
diagnosed if smears were deficient in lactobacilli, positive for cocci or coarse 
bacilli, positive for parabasal epithelial cells, and/or positive for vaginal 
leucocytes (plus their granular aspect).
RESULTS: Genital complaints include red inflammation, yellow discharge, vaginal 
dyspareunia. Group B streptococci, escherichia coli, staphylococcus aureus and 
trichomonas vaginalis are frequently cultured. Vaginal lactate concentration is 
severely depressed in women with aerobic vaginitis, as in bacterial vaginosis, 
but vaginal succinate is not produced. Also in contrast to bacterial vaginosis, 
aerobic vaginitis produces a host immune response that leads to high production 
of interleukin-6, interleukin-1-beta and leukaemia inhibitory factor in the 
vaginal fluid.
CONCLUSION: Aerobic vaginitis is associated with aerobic micro-organisms, mainly 
group B streptococci and E. coli. Its characteristics are different from those 
of bacterial vaginosis and elicit an important host response. The most severe 
form of aerobic vaginitis equals desquamative inflammatory vaginitis. In theory, 
aerobic vaginitis may be a better candidate than bacterial vaginosis as the 
cause of pregnancy complications, such as ascending chorioamnionitis, preterm 
rupture of the membranes and preterm delivery.