Neisseria Gonorrhoeae in Newcastle upon Tyne 1995-1997: Increase in Ciprofloxacin Resistance

Abstract

Fluoroquinolones and third generation cephalosporins are the most effective antimicrobial agents for the treatment of gonorrhoea. However, clinically significant resistance to fluoroquinolones in Neisseria gonorrhoeae has been reported worldwide including Britain. The aim of this analysis was to study the factors relating to ciprofloxacin resistance and treatment failure. A total of 201 patients attending the Newcastle Genitourinary Medicine (GUM) clinic from 1995-1997 who were diagnosed with culture positive gonorrhoea was analysed. Treatment failure rates for ciprofloxacin were determined and the minimum inhibitory concentration (MIC) was measured for all cases of treatment failure. The case notes of all patients who had strains with MICs of ciprofloxacin in the resistant range (<0.05 μg/ml) were reviewed to determine the clinical outcome. The ciprofloxacin resistance with treatment failure was seen in 5% (8/160). All the 8 cases of treatment failure were heterosexual and had isolates resistant to penicillin and 4 cases (50%) were also resistant to tetracycline. All were sensitive to spectinomycin and ceftriaxone. Most of the cases probably acquired their infection from the Far East. As ciprofloxacin resistance seems to be associated with overseas exposure, changes in the standard treatment of gonorrhoea are not justified but consideration should be given to appropriate alternatives when the infection may have arisen from where such resistant strains are endemic. Monitoring fluoroquinolone resistance is now essential for ensuring adequate treatment of infections with resistant strains and for maximizing the time of usage of fluoroquinolones to treat gonorrhoea.