Figure 2. Phylogenetic relationships among human and pig strains of Hepatitis E virus (HEV), based on a 242-bp sequence of ORF1 (nucleotides 125-366). Rooted tree (A) and unrooted tree (B). In the rooted tree, all the Dutch swine sequences are depicted with the foreign isolates that cluster with those sequences, as well as prototype isolates from different clusters. The distances can be estimated by using the scale, and the numbers are confidentiality rates. In the unrooted tree, eight Dutch swine sequences selected on the basis of diversity are depicted with isolates from different geographic origins. The numbers correspond with distances. NLSw15, 20, 22, 28, 36, 50, 68, 76, 82, 85, 91, 99, 105, and 122: 14 Dutch pig HEV. US1, US2 and USswine: United States human and pig HEV strains, respectively (19). Greece 1 and Greece 2: Greek human HEV strains (13). Arg1 and Arg 2: Argentinian human isolates (20). VH1 and VH2: Spanish human isolates; and E11: Spanish slaughterhouse sewage isolate (21). Burma1: Burmese human isolate (22). Italy1: human isolate (13). Barcelona: sewage isolate (23). Pakistan: human isolate (24). China1: human isolate (25). India1: human isolate (GenBank acc. no. X99441). NZ1: New Zealand human isolate (GenBank acc. no AF215661). Nepal: human isolate (26). Egypt: human isolate (22). Morocco: human isolate (7). NewChina (T1):GenBank acc. No AJ272108).