Maximum likelihood phylogenetic analysis of HAV genotype IA sequences (VP1/2A region). Phylogenetic tree of 129 genotype IA Tunisian HAV sequences from six Tunisian towns (78 new sequences from the present study and 51 reference sequences from GenBank). Branch lenghts were estimated with the best fitting nucleotide substitution model (HKY + G) according to a hierarchical likelihood ratio test , the scale bar at the bottom indicates 0.02 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%). The 78 sequences from the present study are highlighted in red, the 51 reference sequences in blue. Sequence names of new and reference sequences include town and year of sample collection (see the “Sequence datasets” section in Methods).