Infection dynamics and molecular mechanisms of prevalence of new variant and emerging Rotaviruses prevailing in Asia

为阐明主要传播于亚洲国家的轮状病毒新变异和新类型的遗传特征，进行了全基因组序列分析和系统发育分析。在中国和孟加拉国，主要基因型分别为G1P[8]/G3P[8]和G2P[4]，其中检测到含有动物轮状病毒基因片段的重组病毒。在中国、孟加拉国和缅甸检测到带有P[8]-VP4基因型新变体的轮状病毒，主要与全球新兴的G9型相关。对来自亚洲和其他地区的各种新出现的轮状病毒株（基因型G1P[6]、G2P[6]、G3P[2]、G3P[6]、G3P[9]、G4P[10]、G6P[9]、G8P[1]、G9P[19]）进行全基因组分析，结果表明，这些毒株可分为：1)人轮状病毒不同基因群之间的重组毒株，2)人与动物轮状病毒之间的重组毒株，3)直接传播给人的动物轮状病毒。这些发现表明，重组和种间传播可能是导致人类轮状病毒新变异和新类型的主要机制。

To elucidate genetic characteristics of new variants and emerging types of rotavirus that spread to mainly in Asian countries, whole genomic sequence analysis and phylogenetic analysis were conducted. In China and Bangladesh, the predominant genotypes were G1P[8]/G3P[8], G2P[4], respectively, among which reassortant viruses containing gene segments derived from animal rotavirus were detected. Rotaviruses with P[8]b, a new variant of P[8]-VP4 genotype, were detected in China, Bangladesh, and Myanmar, and mostly associated with globally emerging type G9. Whole genomic analysis of various rotaviruses strains with emerging genotypes from Asia and other regions (genotypes G1P[6], G2P[6], G3P[2]、G3P[6], G3P[9], G4P[10], G6P[9], G8P[1], G9P[19]) revealed that these strains could be classified into 1)reassortant between different human rotavirus genogroups, 2)reassortant between human and animal rotaviruses, and 3) animal rotaviruses that directly transmitted to humans. These findings indicated that reassortment and interspecies transmission may be the main causing mechanisms of new variants and emergingtypes of human rotaviruses.