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Quick Update: Is this the End of Humanity? - Ceftriaxone and Azithromycin "Resistant" Neis

Leading photo:

UPDATE: they finally determined endpoint MICs

  • CRO = 0.5

  • AZT > 256

This is the real deal y'all.

  • Public Health England reported an imported case of N. gonorrhoeae infection with treatment failure (CRO only, followed by SPT)

  • Not treated with double regimen (CRO+AZT)

  • Genital infection was cured, but throat was persistently positive

  • Not a surprise since throat infections are harder to get rid of, and ALL reported cases of CRO failure so far have exclusively been pharyngeal infections

  • Caused by a bug with:

  • CRO MIC > 0.125

  • EUCAST breakpoint for R: >0.125

  • CLSI breakpoint for R: >0.25

  • AZT MIC > 0.5

  • EUCAST breakpoint for R: >0.5

  • CLSI epidemiological cutoff (ECV) for NWT: >=2

  • End point MICs were not reported, so we don't know if this bug would be considered R/NWT for both drugs when using CLSI breakpoints/ECVs

  • Currently treated with ETP IV: based on MIC 0.032, but no breakpoint exists

  • Is this terrifying? Yes, but there are things to consider

  • Hawaii Department of Public Health has reported isolates with CRO MICs 0.125 by agar dilution and AZT MIC > 256, yet these infections were successfully treated with double regimen

  • Hawaii paper did not specify whether these include pharyngeal infections, and if so, whether treatment was successful

  • Would this UK case have been successfully treated with the double regimen? We'll never know

  • UK uses EUCAST BPs, which are lower than CLSIs

  • Let's wait and see how this turns out.......

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