A group of norovirus experts within NoroNet has proposed a phylogeny based classification of noroviruses for both ORF1 and VP1 (ORF2) genotypes and a standardized strain nomenclature (Archives of Virology, in press).
ORF1 and VP1 typing
As recombination is common in noroviruses, and the recombination hotspot is the ORF1/ORF2 (VP1) overlap region, typing norovirus sequences on either side of this overlap is useful for identification. The consensus nomenclature proposed in NoroNet has been made available in the norovirus typing tool.
The strain name should be written as follows:
GI, norovirus GII, etc.
host/ Hu, Bo, Po etc. see below
country code (ISO)/ FR, DE, US, JP, etc.
year of sampling/
genogroup and genotype/ GII.P4_GII.4, or if only the ORF2 sequence
(ORF1 and VP1) is known: GII.4
name city , if necessary followed by a serial number
For example: norovirus GII/Hu/FR/2004/GII.Pg_GII.1/Paris23, norovirus GII/Hu/GB/2010/GII.P4_GII.4_NewOrleans2009/London48, or if only the capsid sequence is known: norovirus GII/Hu/FR/2004/GII.12/Paris25.
List of host name abbreviations