Vaginal colonization of Escherichia coli and its relation to contraceptive methods.

The prevalence rate of vaginal colonization with E. coli was studied prospectively among 495 healthy premenopausal women, and factors associated with vaginal carriage of E. coli were examined. Vaginal colonization with E. coli was found in 12% of women, and was significantly correlated with phase of the menstrual cycle (p less than 0.05), prior use of antibiotics (p less than 0.05), current genital complaints (p less than 0.05), history of previous urinary tract infection (p less than 0.001), and use of diaphragm or cervical cap for contraception (p less than 0.005). The high prevalence rate among diaphragm or cervical cap users remained significant when other confounding factors were kept constant (p less than 0.05). This observation may explain the association of diaphragm use and urinary tract infection demonstrated in previous epidemiologic studies and confirmed in the present study (p less than 0.05).