Antecedent antimicrobial use increases the risk of uncomplicated cystitis in young women

Clin Infect Dis. 1997 Jul;25(1):63-8. doi: 10.1086/514502.


To examine whether antecedent antimicrobial use influenced subsequent relative risk of urinary tract infection (UTI) in premenopausal women, data were analyzed from two cohorts of women observed prospectively for 6 months to determine risk factors for UTI. Using a Cox proportional hazards model to adjust for covariates, we found that 326 women in a University cohort and 425 women in a health-maintenance organization cohort were at increased risks for UTI (2.57 [95% confidence interval (CI), 1.24-5.32] and 5.83 [95% CI, 3.17-10.70], respectively) if antimicrobials had been taken during the previous 15-28 days but not during the previous 3, 7, or 14 days. The increased risks were noted both for women whose antimicrobial use was for treatment of a previous UTI and for women who received antimicrobials for other illnesses. These results suggest that recent antimicrobial use increases a woman's risk of UTI, perhaps by altering the indigenous urogenital flora and predisposing to vaginal colonization with uropathogens.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Anti-Infective Agents / adverse effects*
  • Cohort Studies
  • Cystitis / epidemiology*
  • Cystitis / etiology
  • Female
  • Follow-Up Studies
  • Humans
  • Longitudinal Studies
  • Prospective Studies
  • Recurrence
  • Risk Factors


  • Anti-Infective Agents