Figure 1. Phylogenetic tree of noroviruses based on the 330-bp region (for GI) and 344-bp region (for GII) of the capsid N terminus/shell gene. Fourteen novel sequences were included, designated according to isolate code, place, and year (e.g., DR001-Madag04); 25 sequences of reference norovirus strains (6) were included, designated according to genogroup-genotype, place, country, and year (e.g.,GII-2/Melksham-GRB1994). Comparative strains are GI-1/NV-USA1968 (Norwalk, M87661), GI-2/SOV-GBR1993 (Southampton, L07418), GI-3/DSV-USA1993 (Desert Shield, U04469), GI-4/Chiba-JPN2000 (AB042808), GI-5/Musgrov-GBR1989 (Musgrove, AJ277614), GI-6/Hesse-DEU1998 (AF093797), GI-7/Wnchest-GBR1994 (Winchester, AJ277609), GI-8/Boxer-USA2001 (AF538679), GII-1/Hawai-USA1971 (U07611), GII-2/Melksham-GBR1994 (X81879), GII-3/Toronto-CAN1993 (U02030), GII-4/Bristol-GBR1993 (X76716), GII-5/Hillingd-GBR1990 (Hillingdon, AJ277607), GII-6/Seacrof-GBR1990 (Seacroft, AJ277620), GII-7/Leeds-GBR1990 (AJ277608), GII-8/Amstdam-NLD1990 (Amsterdam, AF195848), GII-9/VABeach-USA1997 (AY038599), GII-10/Erfurt-DEU2000 (AF427118), GII-11/SW918-JPN1997 (AB074893), GII-12/Wortley-GBR1990 (AJ277618), GII-13/Faytvil-USA1998 (Fayetteville, AY113106), GII-14/M7-USA1999 (AY130761), GII-15/J23-USA1999 (AY130762), GII-16/Tiffin-USA1999 (AY502010), and GII-17/CSE1-USA2002 (AY502009). Bootstrap values based on 1,000 generated trees are displayed at the nodes. The scale bar represents nucleotide substitutions per site.