ML phylogenetic tree of HIV-1 subtype B <i>pol</i> (∼1000 pb) sequences circulating in Panama (<i>n</i> = 761) and other Central American countries (<i>n</i> = 694).

<p>The branches are colored according to the geographic origin of each sequence, as indicated at the legend (top left). Red shaded boxes highlight the position of the twelve Panamanian HIV-1 subtype B clades (B_PA-I to B_PA-XII). Gray shaded box highlights the position of the major Central American clade (B_CAM). The <i>a</i>LRT support values for each clade are indicated at bottom. The tree was rooted using HIV-1 subtype D reference sequences. The branch lengths are drawn to scale with the bar at the bottom indicating nucleotide substitutions per site.