Panel A: Phylogenetic analysis of 164 partial pol sequences from Cameroon. A neighbor-joining analysis of partial pol sequences (protease and the amino terminus of RT) using the Kimura 2-parameter method of distance calculation was performed with representative strains of varying subtypes and CRF (identified by name). The scale bar indicates genetic distance of 1%. Nodes with significant bootstrap support (>70%) and containing Cameroon sequences are indicated with color. Panel B: Relative proportions of different subtypes or CRF. RF = recombinant form.