Genetic characterization of norovirus GII.4 2006b variants from Jeju island, South Korea.

Ninety-seven fecal specimens collected from children with acute gastroenteritis between 2007 and 2008 that were found to be negative for group A rotavirus in prescreening by ELISA with VP6-specific antibody were re-screened for viruses by reverse transcription (RT)-PCR. Forty (41.2%) samples were found to be positive for virus by RT-PCR; of these, norovirus (32.5%, n = 13) and rotavirus (32.5%, n = 13) were the most common, followed by astrovirus (5.0%, n = 2) and enterovirus (2.5%, n = 1). Co-infection was found in 11 (27.5%) samples. Phylogenetic analyses of the ORF2 nucleotide sequences of 21 norovirus strains showed that 19 (90.5%) belonged to the genogroup GII genotype 4 and two (9.5%) belonged to genogroup GI genotype 4. The GII.4 strains demonstrated high sequence homology and were closely related to new 2006b variants observed in Europe, China, Hong Kong, and Japan in 2006. This study provides new information concerning the recent global epidemic of 2006b strains.