Objectives:Since 2014,non-GII.4 norovirus genotypes have increasingly challenged the predominance of GII.4,particularly in Asia.This study analyzed the epidemiological and genetic characteristics of norovirus outbreak...Objectives:Since 2014,non-GII.4 norovirus genotypes have increasingly challenged the predominance of GII.4,particularly in Asia.This study analyzed the epidemiological and genetic characteristics of norovirus outbreaks from January 2017 to June 2024 in a district of Beijing,China.Methods:We tested 2,016 stool samples collected from 309 acute gastroenteritis outbreaks for norovirus using real-time RT-PCR.Partial polymerase and capsid sequences of norovirus-positive samples were amplified and sequenced for phylogenetic analysis.Additionally,we performed genome amplification and sequence analysis on seven GII.7[P7]strains.Results:Between January 2017 and June 2024,150 norovirus outbreaks were reported,with GII norovirus causing 83.3%of these outbreaks.We identified 16 distinct genotypes.Among the 102 GII genotype outbreaks,non-GII.4 norovirus outbreaks(81.4%)significantly outnumbered GII.4 norovirus outbreaks(18.6%).The three most prevalent genotypes during the study period were GII.2[P16](46.1%,47/102),GII.3[P12](14.7%,15/102),and GII.4 Sydney[P16](12.7%,13/102).GII.2[P16]predominated in 2017,2018,and 2020,while GII.3[P12]was the dominant genotype in 2022.Multiple genotypes emerged in 2023.In the first half of 2024,GII.4 Sydney[P16]became predominant(36.9%),while a novel GII.7[P7]variant emerged,accounting for 26.3%of outbreaks.All seven GII.7[P7]genome sequences formed an independent branch in both VP1 and polymerase regions.Conclusions:Our findings demonstrate that non-GII.4 noroviruses play an increasingly important role in outbreaks in Beijing.Continuous surveillance is needed to better understand and control norovirus outbreaks in future epidemic seasons.展开更多
基金Supported by High-level Public Health Technology Talent Construction Project:Discipline Backbone-01-026.
文摘Objectives:Since 2014,non-GII.4 norovirus genotypes have increasingly challenged the predominance of GII.4,particularly in Asia.This study analyzed the epidemiological and genetic characteristics of norovirus outbreaks from January 2017 to June 2024 in a district of Beijing,China.Methods:We tested 2,016 stool samples collected from 309 acute gastroenteritis outbreaks for norovirus using real-time RT-PCR.Partial polymerase and capsid sequences of norovirus-positive samples were amplified and sequenced for phylogenetic analysis.Additionally,we performed genome amplification and sequence analysis on seven GII.7[P7]strains.Results:Between January 2017 and June 2024,150 norovirus outbreaks were reported,with GII norovirus causing 83.3%of these outbreaks.We identified 16 distinct genotypes.Among the 102 GII genotype outbreaks,non-GII.4 norovirus outbreaks(81.4%)significantly outnumbered GII.4 norovirus outbreaks(18.6%).The three most prevalent genotypes during the study period were GII.2[P16](46.1%,47/102),GII.3[P12](14.7%,15/102),and GII.4 Sydney[P16](12.7%,13/102).GII.2[P16]predominated in 2017,2018,and 2020,while GII.3[P12]was the dominant genotype in 2022.Multiple genotypes emerged in 2023.In the first half of 2024,GII.4 Sydney[P16]became predominant(36.9%),while a novel GII.7[P7]variant emerged,accounting for 26.3%of outbreaks.All seven GII.7[P7]genome sequences formed an independent branch in both VP1 and polymerase regions.Conclusions:Our findings demonstrate that non-GII.4 noroviruses play an increasingly important role in outbreaks in Beijing.Continuous surveillance is needed to better understand and control norovirus outbreaks in future epidemic seasons.
