摘要：Noroviruses are a leading cause of outbreaks ofgastroenteritis. This study examined the incidenceand molecular characteristics of norovirus outbreaksin healthcare and non-healthcare settingsin Victoria, Australia, over 2 years (2014–2015).Norovirus was detected in 65.7% and 60.4% ofgastroenteritis outbreaks investigated for the years2014 and 2015 respectively. There was a significantdecline in the number of norovirus outbreaks in theperiod 2014 to 2015 although in both years norovirusoutbreaks peaked in the latter part of the year.Norovirus Open Reading Frame (ORF) 2 (capsid)genotypes identified included GI.2, GI.3, GI.4,GI.5, GI.6, GI.9, GII.2, GII.3, GII.4, GII.6, GII.7,GII.8, GII.13 and GII.17. GII.4 was the most commongenotype detected. In addition, the followingORF 1/ORF 2 recombinant forms were confirmed:GII.P4_NewOrleans_2009/GII.4_Sydney_2012,GII.P12/GII.3, GII.Pb (GII.21)/GII.3, GII.Pe/GII.2and GII.Pe/GII.4_Sydney_2012. A significantdecline was noted in the chief norovirus strainGII.Pe/GII.4_Sydney_2012 between 2014 and2015 but there was a re-emergence of a GII.P4_NewOrleans _2009 norovirus strain. Outbreaksinvolving the GII.P17/GII.17 genotype were alsodetected for the first time in Victoria. GI genotypescirculating in Victoria for the 2 years 2014 and2015 underwent a dramatic change between the2 years of the survey. Many genotypes could occurin both healthcare and non-healthcare settingsalthough GI.3, GII.6, and GII.4 were significantlymore common in healthcare settings. The studyemphasises the complex way in which noroviruscirculates throughout the community.
