THE EMERGENCE OF NEISSERIA-GONORRHOEAE WITH DECREASED SUSCEPTIBILITY TO CIPROFLOXACIN IN CLEVELAND, OHIO - EPIDEMIOLOGY AND RISK-FACTORS

Background: Until 1992, almost all strains of Neisseria gonorrhoeae th at had been tested in the United States were susceptible to fluoroquin olones, including ciprofloxacin. However, among men with urethral gono coccal infections who attended one sexually transmitted disease clinic in Cleveland, Ohio, the prevalence of gonococci with decreased suscep tibility to ciprofloxacin increased from 2% in 1991 to 16% in 1994. Ob jective: To describe the emergence of and risk factors for gonococcal urethritis caused by gonococci with decreased susceptibility to ciprof loxacin. Resistance to ciprofloxacin was considered to be decreased if the mean inhibitory concentration was at least 0.12 mu g/mL and was l ess than or equal to 0.25 mu g/mL; this definition did not equate with the definition of clinical resistance. Design: Case-control study. Se tting: An urban sexually transmitted disease clinic. Participants: 51 case-patients and 106 controls. Measurements: Pulsed-field gel electro phoresis was used to identify individual genotypes of ciprofloxacin-re sistant and ciprofloxacin-susceptible isolates. Results: 55 of the 746 isolates of N. gonorrhoeae that were tested (7.4%) had decreased susc eptibility to ciprofloxacin, and the prevalence of N. gonorrhoeae with decreased susceptibility significantly increased during the study per iod. Case-patients were significantly less likely to have gram-negativ e diplococci seen on microscopic examination of urethral discharge (P less than or equal to 0.01) and were less likely to be treated for gon ococcal urethritis than were controls (P less than or equal to 0.001). Molecular typing suggested the spread of a single genotype of N. gono rrhoeae. Conclusions: Strains of gonococci with decreased susceptibili ty to ciprofloxacin appear to have become endemic in Cleveland, Ohio. The clinical significance of these isolates is not clear, but the pote ntial for the emergence of clinically important resistance may preclud e the use of fluoroquinolones as an alternative treatment for uncompli cated gonorrhea.