Emergence in Taiwan of novel norovirus GII.4 variants causing acute gastroenteritis and intestinal haemorrhage in children.
Norovirus is the leading cause of viral gastroenteritis globally. Norovirus genotype GII.4 is responsible for the majority of outbreaks, but new variants are continuously emerging. The objective of the study was to delineate the clinical manifestations and complications associated with these new norovirus GII.4 variants in children. We investigated norovirus infections from the community outbreak in October 2011-September 2012 and an earlier outbreak in 2006-2007, in northern Taiwan. Norovirus genotypes and their variants were validated using molecular methods. A norovirus outbreak started in mid-2011 and continued through 2012 in northern Taiwan. Hospitalized children infected by norovirus in 2012 showed a significantly higher incidence of intestinal haemorrhage, as indicated by grossly bloody faeces (P=0.012) and occult blood in faeces (P < 0.001), and also presented with more high fever >39 °C (P < 0.001), fever >38.5 °C (P < 0.001) and fever of any temperature >38 °C (P < 0.001), compared with children hospitalized in 2006-2007. Analysis of 20 near-full-length genome sequences indicated an emergence of GII.4 2012 variants in 2011-2012. Circulating noroviruses can be divided into two clusters: GII.4 2012a, which is identical to the newly reported strain GII.4 Sydney 2012, and GII.4 2012b, which is close to GII.4 2006b, the earlier predominant strain. The emerging new variants of norovirus GII.4 caused a distinct clinical syndrome of acute gastroenteritis with severe fever and a high rate of intestinal haemorrhage in children. The genetic diversity associated with changing clinical manifestations poses major obstacles to norovirus control.
Division of Pediatric Gastroenterology, Chang Gung Children's Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan, ROC.
Shih-Yen
SY
Chen
Institute for Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, PR China.
Ye
Y
Feng
Division of Pediatric Gastroenterology, Chang Gung Children's Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan, ROC.
Hsun-Chin
HC
Chao
Division of Pediatric Gastroenterology, Chang Gung Children's Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan, ROC.
Ming-Wei
MW
Lai
Division of Pediatric Gastroenterology, Chang Gung Children's Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan, ROC.
Wen-Ling
WL
Huang
Department of Computer Science and Information Engineering, Chang Gung University College of Engineering, Taoyuan, Taiwan, ROC.
Chun-Yuan
CY
Lin
Graduate Institute of Clinical Medical Sciences, Chang Gung University College of Medicine, Taoyuan, Taiwan, ROC.
Chi-Neu
CN
Tsai
Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan, ROC.
Chyi-Liang
CL
Chen
Division of Pediatric Infectious Diseases, Chang Gung Children's Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan, ROC.|Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan, ROC.
Cheng-Hsun
CH
Chiu
D017250:Caliciviridae Infections / Q000453:epidemiology / Q000821:virology*; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D021821:Communicable Diseases, Emerging / Q000453:epidemiology / Q000821:virology*; D003625:Data Collection; D004196:Disease Outbreaks; D005243:Feces / Q000737:chemistry / Q000821:virology; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology / Q000821:virology*; D006471:Gastrointestinal Hemorrhage / Q000453:epidemiology / Q000821:virology*; D016679:Genome, Viral; D005838:Genotype; D060005:Genotyping Techniques; D006801:Humans; D007223:Infant; D008297:Male; D025202:Molecular Diagnostic Techniques; D008969:Molecular Sequence Data; D029322:Norovirus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D009780:Occult Blood; D010802:Phylogeny; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013624:Taiwan / Q000453:epidemiology