Demographic and behavioural factors associated with antimicrobial susceptibility to azithromycin and ceftriaxone in Neisseria gonorrhoeae.

Antimicrobial resistance of Neisseria gonorrhoeae (NG) is of global public health concern. The aim of this study was to explore demographic and behavioural factors associated with antimicrobial susceptibility of NG to ceftriaxone and azithromycin. Gonococcal isolates (n = 391) from clients attending the Auckland Sexual Health Service, New Zealand, from July 2014 - June 2015 (n = 206), and July 2017 - June 2018 (n = 185), were tested for susceptibility to ceftriaxone and azithromycin. Laboratory data were linked with behavioural and demographic data. Geometric mean azithromycin MICs increased across the two time periods (0.239 mg/L in 2014/15 to 0.347 mg/L in 2017/18, p < 0.001), and ceftriaxone MICs decreased (0.007 mg/L in 2014/15 to 0.005 mg/L in 2017/18, p < 0.001). Demographic and behavioural factors were not associated with differences in ceftriaxone MICs; however azithromycin MICs were higher in men who have sex with men (0.356 mg/L) compared with the heterosexual study population (0.192 mg/L, p < 0.001) and were lower in Pacific peoples (0.201 mg/L, p < 0.001) and Maori (0.244 mg/L, p = 0.05) compared with those of European ethnicity (0.321 mg/L). Our findings show that azithromycin MICs increased in our region between 2014 and 2018; associations were seen with sexual orientation and ethnicity.

Keeping track of antimicrobial resistance for Neisseria gonorrhoeae in Auckland, New Zealand: past, present and future considerations.

AIMS: Neisseria gonorrhoeae (NG) has developed resistance to a wide range of antimicrobials. Population level data is essential to determine empiric treatment regimes. We sought to identify antimicrobial resistance patterns for NG in the Auckland region from 2008-2016, and review the utility of current methods of antimicrobial resistance testing. METHODS: Antimicrobial susceptibilities and demographic data from NG isolates derived from patients attending the Auckland Regional Sexual Health Service and Auckland City Hospital were analysed to determine resistance rates and trends over time. Antimicrobial susceptibility testing was performed by agar dilution using Clinical and Laboratory Standards Institute (CLSI) interpretation criteria. RESULTS: Results for 2,302 isolates from 1,941 patients were analysed. While ciprofloxacin resistance increased between 2008 and 2011, resistance rates for all antibiotics declined from 2013-2016. In 2016, 22% (53) of isolates were resistant to ciprofloxacin, 7% (17) to penicillin, 31% (76) to tetracycline and 0.8% (2) exhibited decreased susceptibility to ceftriaxone. CONCLUSION: Ceftriaxone is still suitable as a component of gonorrhoea treatment in our region but resistance to other agents prohibits their use for empiric treatment regimens. Current methods of detecting antimicrobial resistance for NG needed to be updated so that they are fit for purpose.

Antimicrobial susceptibility among Neisseria gonorrhoeae in New Zealand in 2002.

AIM: To estimate the prevalence of antimicrobial resistance among Neisseria gonorrhoeae, and to determine whether the increase in ciprofloxacin resistance observed in Auckland in 2001 had occurred in other parts of the country. METHODS: The antimicrobial susceptibility of N. gonorrhoeae (isolated in New Zealand over a 4-month period between April and August 2002) was tested at either LabPlus, Auckland District Health Board, or at ESR, using the same agar dilution method. RESULTS: The prevalence of resistance to the antimicrobials tested was: ceftriaxone, 0%; ciprofloxacin, 6.8%; penicillin, 9.0%; spectinomycin, 0%; and tetracycline, 27.8%. There were few statistically significant geographical differences in resistance within New Zealand. Gonococcal infections acquired in Asia were more likely to be ciprofloxacin and penicillin resistant than infections acquired in New Zealand. CONCLUSIONS: Ciprofloxacin resistance among N. gonorrhoeae in New Zealand has reached a level where this antibiotic is no longer the most appropriate first-line treatment. In fact, ceftriaxone should now be considered the most reliable option for the treatment and control of gonorrhoea in New Zealand, particularly in the Northland/Auckland region.