title: Molecular and epidemiological features of GIIb norovirus outbreaks in Victoria, Australia, 2002-2005.
abstract: The epidemiology of GIIb norovirus outbreaks and the characteristics of GIIb open reading frame (ORF) 2 recombinant forms are poorly understood and this study examined these questions using norovirus-associated gastroenteritis outbreaks in Victoria, Australia, during 2002-2005. Twenty-one GIIb outbreaks were detected and were the second most common ORF 1 norovirus outbreak genotype (5%) after GII.4 (90%). Both GIIb and GII.4 outbreaks peaked in warmer months of the year but their periodicity was different. ORF 2 sequencing analysis was carried out in the two regions previously designated C and D. RT-PCR region D primers were less sensitive than region C primers. No evidence of recombination between regions C and D was found. ORF 2 genotypes for the 21 GIIb outbreaks were: GII.1 (10 outbreaks), GII.3 (10 outbreaks) and, apparently for the first time, GII.13 (1 outbreak). GIIb outbreaks could occur in a broad range of settings and there was no correlation between ORF 2 genotype and setting except that all 5 outbreaks involving mainly young children were associated with GIIb/GII.3.
authors.affiliation: Victorian Infectious Diseases Reference Laboratory, North Melbourne, Victoria, Australia.
authors.forename: L D
authors.initials: LD
authors.lastname: Bruggink
authors.forename: J A
authors.initials: JA
authors.lastname: Marshall
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000821:virology*; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D005838:Genotype; D006801:Humans; D007223:Infant; D008875:Middle Aged; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D029322:Norovirus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D010802:Phylogeny; D012621:Seasons; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014739:Victoria / Q000453:epidemiology; D014764:Viral Proteins / Q000235:genetics
chemical_list: D014764:Viral Proteins