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    Abstract:
    In this report, we present new data on the diversity and geographical distribution of genetic variants in Crimean-Congo hemorrhagic fever virus (CCHFV) in Russia. Partial S, M, and L segment sequences of the CCHFV genome were obtained from 500 serum samples from CCHF patients and 103 pools of ticks collected in the south of the European region of Russia in 2007–2017. The investigated viral strains belonged to the lineages Europe 1 (596 samples), Africa 3 (1 sample) and a new genetic lineage, Europe 3 (6 samples). The Russian CCHFV strains of the Europe 1 lineage formed four subgroups (Va-Vd) correlated with the geographical site of virus isolation. Segment reassortment events between strains of different subgroups within lineage Europe 1 were revealed. The complete S, M and L genome segments of 18 CCHFV strains belonging to different subgroups of the Europe 1 lineage and the complete S segments of 3 strains of the Europe 3 lineage and 1 strain of the Africa 3 lineage were sequenced. The analysis of the geographical distribution of CCHFV genetic variants in southern Russia revealed local viral populations with partially overlapping boundaries.
    Keywords:
    Lineage (genetic)
    Reassortment
    Molecular Epidemiology
    In this work, nineteen influenza A/H3N2 viruses isolated in Mexico between 2003 and 2012 were studied. Our findings show that different human A/H3N2 viral lineages co-circulate within a same season and can also persist locally in between different influenza seasons, increasing the chance for genetic reassortment events. A novel minor cluster was also identified, named here as Korea, that circulated worldwide during 2003. Frequently, phylogenetic characterization did not correlate with the determined antigenic identity, supporting the need for the use of molecular evolutionary tools additionally to antigenic data for the surveillance and characterization of viral diversity during each flu season. This work represents the first long-term molecular epidemiology study of influenza A/H3N2 viruses in Mexico based on the complete genomic sequences and contributes to the monitoring of evolutionary trends of A/H3N2 influenza viruses within North and Central America.
    Reassortment
    Molecular Epidemiology
    Viral phylodynamics