Maximum likelihood phylogenetic analysis of HAV sequences (VP1/2A region). Phylogenetic tree of 81 HAV sequences from Sousse, Mahdia, Monastir, Tunis and Kairouan and 27 reference sequences (genotype I, II, III and V) downloaded from GenBank. The 81 sequences from Tunisia are highlighted in red; their name includes, after a progressive number (1 to 81) followed by “Tu”, a capital letter indicating the town from which the sample was collected (A: Sfax; B: Sousse; C: Mahdia; D: Monastir; E: Tunis; F: Kairouan) and, at the end of the name, the sampling year (e.g. _09 stands for 2009, _10 stands for 2010, and so on). See Methods for further details. The 27 reference sequences are reported by their Accession number followed by the genotype they belong to. Branch lenghts were estimated with the best fitting nucleotide substitution model (TrN + I + G) according to a hierarchical likelihood ratio test , the scale bar at the bottom indicates 0.04 nucleotide substitutions per site. One *along a branch represents significant statistical support for the clade subtending that branch (p < 0.001 in the zero-branch-lenght test and bootstrap support >75%).