Introduction Since 2013 an ongoing international inter-laboratory quality control program (NGQCP) has analysed the capability of 16 national reference laboratories to diagnose and perform antimicrobial susceptibility testing (AST) for Neisseria gonorrhoeae in Latin America. The program is supported by PAHO/WHO for the GASP-RELAVRA network and coordinated by the Sexually Transmitted Disease Reference Laboratory (LC) - INEI from Argentina. Results of the 2016 fourth round of the NGQCP are presented.
Methods A panel with 5 isolates belong to Neisseriaceae family, is envoyed once by year. A questionnaire is attached to collect information from each codified laboratory (lab). The 2008 WHO panel and ATCC 49226 reference strains were distributed. NGQCP evaluate: presumptive and confirmatory identification and, AST by disk diffusion and Minimum inhibitory concentrations (MICs) determination by either agar dilution or Etest methods. MIC interpretations were based on the criteria of the Clinical Laboratory Standards Institute (CLSI).
Results Fifteen labs recovered isolates. Complete conventional presumptive and confirmatory identification was made by 73% and 87% of labs, respectively. Only 3 labs introduced a different confirmatory methodology. The 97.3% (72/74) of diagnostics were included in the category genus and species correct. Three (3/15) labs not realised β-lactamase detection. Disk diffusion assessment showed 31 minor, 2 major and 3 very major discrepancies. The overall agreement of MIC results (MICs±1 log2 dilutions) between 8 labs, including the LC, compared to the modal MICs was 90% (277/307). Percentage agreements by antibiotics was: penicillin 83% (49/59); tetracycline 89% (64/72); ciprofloxacin 93% (53/57); ceftriaxone 90% (53/59); cefixime 88% (7/8) and azithromycin 98% (51/52)
Conclusion NGQCP is an essential pillar for an effective surveillance program in order to ensure that their data are reliable. We expect more labs in the Region realise MIC determination by agar dilution methods and improve level of concordance for AST.