Drifting towards ceftriaxone treatment failure in gonorrhoea: risk factor analysis of data from the Gonococcal Resistance to Antimicrobials Surveillance Programme in England and Wales

Abstract

Objectives: Treatment of Neisseria gonorrhoeae is threatened by the emergence of antimicrobial resistance. We analysed data from the Gonococcal Resistance to Antimicrobials Surveillance Programme (GRASP) in England and Wales to identify groups most at risk of reduced susceptibility to the currently recommended first-line therapy, ceftriaxone.

Methods: Data from GRASP between 2007 and 2013 on ceftriaxone susceptibility and strain types were analysed. Risk factors associated with isolates exhibiting a ceftriaxone minimum inhibitory concentration (MIC) of ≥0.015 mg/L (CTR ≥0.015 mg/L) were identified using logistic regression.

Results: One third of isolates from men who have sex with men (MSM) (1279/4203) and 9.9% from heterosexuals (458/4626) exhibited CTR ≥0.015 mg/L. Between 2007 and 2013, the modal MIC for isolates remained at 0.004 mg/L for MSM but increased from 0.002 to 0.004 mg/L for heterosexuals. Among MSM, CTR ≥0.015 mg/L was associated with Asian ethnicity (crude OR: 1.42; 95% CI 1.07 to 1.88) and previous gonorrhoea (1.34; 1.16 to 1.54). Among heterosexuals, CTR ≥0.015 mg/L was associated with older age (35+ years: 4.31; 3.34 to 5.55), ≥6 sexual partners (1.58; 1.01 to 2.44) and sex abroad (2.23; 1.71 to 2.91). CTR ≥0.015 mg/L was less likely in isolates from heterosexuals of black Caribbean or African ethnicity (0.29; 0.20 to 0.41, 0.66; 0.43 to 0.99), with a concurrent chlamydial infection (0.25; 0.19 to 0.34) or women (0.57; 0.46 to 0.71). Over 600 isolates (CTR ≥0.015 mg/L) were typed; the majority were in Genogroup 1407, containing sequence type 1407.

Conclusions: The emergence and spread of gonorrhoea with reduced susceptibility to ceftriaxone seems a realistic prospect, most likely in those involved in 'rapid-transmission' or bridging sexual networks.

Keywords: ANTIBIOTIC RESISTANCE; EPIDEMIOLOGY (GENERAL); GENITOURINARY MEDICINE; NEISSERIA GONORRHOEA; PUBLIC HEALTH.