Phylogenetic analysis of 16 pol sequences from FSWs from different cities of Argentina. A neighbor-joining phylogenetic tree analysis was performed with the Kimura two-parameter method of distance estimation using reference sequences. The genetic distance corresponding to the lengths of the branches is shown by the bottom line. Studied samples are in bold. Underlined samples are inter-subtype recombinants. Sample 01AR4008a and 01AR4008b belong to the same patient.