METHODS: IMD cases and MenY strains from January 1, 2015 to August 11, 2023 were analyzed for clonal analysis and prediction of susceptibility to MenB vaccines. MenY strains of ST-23 CC from Quebec were analyzed with global MenY strains by core-genomic multi-locus sequence typing (cg-MLST).
RESULTS: Since 2015 the serogroup distribution of IMD in Quebec has shifted from predominantly MenB to mainly MenY, with most (80.9 %) of the latter belonging to ST-23 CC. The median age of MenY cases due to ST-23 CC were statistically younger than MenY cases due to non-ST-23 CC. MenY of ST-23 CC showed genetic diversity and the major genetic cluster were similar to the Swedish Y1 strain. The increase in invasive MenY disease in Quebec was due to a sub-clade of Lineage 23.1 which caused an elevated proportion of severe disease in young adults.
CONCLUSIONS: The increase in invasive MenY disease in Quebec, Canada was driven by the expansion of a sub-clade of Lineage 23.1 in young adults. Currently available quadrivalent A,C,W,Y-conjugate meningococcal vaccines were predicted to provide protection against these strains.
方法:对2015年1月1日至2023年8月11日的IMD病例和MenY菌株进行克隆分析和对MenB疫苗的敏感性预测。通过核心基因组多位点序列分型(cg-MLST),用全球MenY菌株分析了魁北克ST-23CC的MenY菌株。
结果:自2015年以来,魁北克IMD的血清群分布已从主要的MenB转变为主要的MenY,后者的大多数(80.9%)属于ST-23CC。由于ST-23CC引起的MenY病例的中位年龄在统计学上比由于非ST-23CC引起的MenY病例年轻。ST-23CC的MenY显示出遗传多样性,主要遗传簇与瑞典Y1菌株相似。魁北克侵袭性MenY疾病的增加是由于谱系23.1的亚进化枝导致年轻人中严重疾病的比例升高。
结论:魁北克侵袭性MenY病的增加,加拿大是由于在年轻人中扩展了Lineage23.1的分支。目前可用的四价A,C,W,预测Y-缀合脑膜炎球菌疫苗提供针对这些菌株的保护。