Genomic diversity and transmission patterns of Yersinia pestis in Inner Mongolia Autonomous Region, China

According to WHO, plague, caused by Yersinia pestis, has resurged since 2000. Inner Mongolia, harboring a quarter of China’s plague foci, has accounted for 80% of national plague cases in the past five years. Despite its pivotal role in Chinese plague epidemiology, the genetic diversity and transmission dynamics of Y. pestis in this region remain under-investigated. Our analysis of 585 Y. pestis strains from Inner Mongolia (1948–2021) revealed three primary lineages, with 2.MED3 being predominant. We further delineated seven sub-phylogroups in 2.MED3, with 2.MED3.1.2 and 2.MED3.1.4 showing recent dominance. These two subgroups reveal dual transmission patterns: localized short-distance spread and long-distance dispersals over 300 km. Xilingol League is highlighted as a key source and reservoir for Y. pestis, predominantly spreading from central-eastern to southwestern Inner Mongolia, including occasional reverse transmissions. These findings enhance understanding of Y. pestis diversity and transmission in Inner Mongolia, aiding in enhanced surveillance and control measures. Analysis of the genomes and spatiotemporal distribution of Yersinia pestis in Inner Mongolia, China, reveals its genetic diversity and dual transmission patterns, including localized short-distance spread and long-distance dispersals.