Phylogenetic tree displaying the genetic relationships between GIV NoVs. The tree includes a total of 102 sequences. Sequences from the present study are shown in bold (ID number, followed by the year of identification, and by the suffix “sw” for sewage samples and “cl” for clinical samples). To simplify the tree, a single sample (ID 1694) was used to represent 57 of our samples the sequences of which were found to be identical. The tree also includes all animal (GIV.2) and human (GIV.1) sequences available in GenBank for the genomic region under study. The animal prototypes reported in the phylogenetic tree are: EF450827 (lion/GGIV.2/Pistoia/06/ITA), JF781268 (CAT/giv.2/CU081E/USA/2010), and FJ875027 (dog/GIV.2/Bari/91/ITA). The human prototypes include AF414426 (Fort Lauderdale/560/1998/US), AF414427 (Saint Cloud/624/1998/US), and the strain JQ613567 recently completely sequenced (Lake Macquarie/NSW2680/2010/AU). We also included sequences identified by our group in the previous studies from sewage samples (FN663936, FN663935, FN663942, FN663932, FN663934, FN663930, FN663933, FN663929, FN663937, FN663943, and 980/2007/ITA), clinical samples (673/2006/cl and 675/2006/cl), and one mussel sample (I85089/2011)