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Suspected ceftriaxone-resistant pharyngeal gonorrhoea — DFSRH MCQ

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HardSTI ManagementSuspected ceftriaxone-resistant pharyngeal gonorrhoeaDFSRH

A 34-year-old man attends a specialist sexual health service after condomless oral sex in Thailand. Pharyngeal nucleic acid amplification testing and culture confirm Neisseria gonorrhoeae; urethral and rectal tests are negative. He receives directly observed ceftriaxone 1 g intramuscularly and reports no sexual contact thereafter. Eight days after treatment, a pharyngeal test-of-cure culture again yields N. gonorrhoeae. The local laboratory reports a ceftriaxone minimum inhibitory concentration of 0.25 mg/L. He remains asymptomatic, and the original isolate is no longer available. Which is the most appropriate immediate management plan?

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Correct answer: E — Report probable ceftriaxone treatment failure to UKHSA, immediately refer the isolate for national confirmation, and obtain specialist advice on susceptibility-directed retreatment

Explanation lettering: D = shown as B · E = shown as C · C = shown as D · B = shown as E

This is probable ceftriaxone treatment failure rather than reinfection or residual nucleic acid: viable gonococci have been cultured more than 72 hours after directly observed recommended treatment, and further sexual exposure is denied. The pharyngeal site and acquisition in the Asia-Pacific region further increase concern for resistant infection. A local ceftriaxone MIC above 0.125 mg/L constitutes suspected resistance, but confirmation by the UKHSA national reference laboratory is required before the case is classified as confirmed resistance. UKHSA should therefore be notified immediately, the post-treatment isolate referred without delay, and retreatment determined with specialist microbiological advice using susceptibility results. Alternative options are limited and pharyngeal efficacy is an important discriminator. A is inappropriate because simply repeating ceftriaxone delays the required resistance investigation. C is premature: gentamicin plus azithromycin is an option only when susceptibility, particularly to azithromycin, supports it; pharyngeal failure rates are also higher. D is likewise premature. Ertapenem has been used for extensively drug-resistant infections, but the reported three-day regimen was pragmatic and not supported by clinical-trial evidence. E confuses culture positivity with an early positive NAAT: persistent nucleic acid can cause a culture-negative, NAAT-positive result, whereas this patient has viable organisms on culture and requires immediate escalation.

Reference: Managing incidents of ceftriaxone-resistant Neisseria gonorrhoeae in England (21 November 2022) — https://www.gov.uk/government/publications/ceftriaxone-resistant-neisseria-gonorrhoeae-incident-management/managing-incidents-of-ceftriaxone-resistant-neisseria-gonorrhoeae-in-england Managing incidents of ceftriaxone-resistant Neisseria gonorrhoeae in England (21 November 2022) — https://www.gov.uk/government/publications/ceftriaxone-resistant-neisseria-gonorrhoeae-incident-management/managing-incidents-of-ceftriaxone-resistant-neisseria-gonorrhoeae-in-england GRASP report: data to September 2025 (18 December 2025) — https://www.gov.uk/government/publications/gonococcal-resistance-to-antimicrobials-surveillance-programme-grasp-report/grasp-report-data-to-september-2025