Phylogenetic tree of region E of the norovirus capsid.

<p>This figure is generated by using the neighbor-joining algorithm with BioNumerics software (version 5.1; Applied Maths Sint-Martens-Latem, Belgium).</p

The type of settings of outbreaks caused by GII.4 variants and non-GII.4 variants.

<p>The type of settings of outbreaks caused by GII.4 variants and non-GII.4 variants.</p

Norovirus GII.4 variants in outbreaks during July 2000 to June 2008.

<p>Norovirus GII.4 variants in outbreaks during July 2000 to June 2008.</p

Norovirus GII reference genotypes used in this study.

<p>*Zheng et al. Virology, 2006.</p>†<p>Personal communication from the Food-borne Viruses in Europe (FBVE) and Centers for Disease Control and Prevention (CDC) in US Network.</p