Inference of the evolutionary history of human infections with simian foamy virus (SFV). a. Circular maximum clade credibility (CMCC) tree of 173 SFV polymerase (pol) sequences generated by Bayesian analysis using the programs BEAST  and FigTree (http://tree.bio.ed.ac.uk/software/figtree/) and a relaxed molecular clock. Trees were midpoint rooted. Final alignment length was 391-bp. Similar trees were inferred by maximum likelihood and neighbor-joining methods (data not shown). Inferred histories of the new human SFVs from DRC are shown with arrows. Major clades without human sequences from DRC are collapsed. b. Subtree of CMCC tree showing detailed phylogenetic relationships of human infections in the Cercopithecus and Chlorocebus clade. Dots and triangles indicate SFV sequences from nonhuman primates (NHPs) from Cameroon and Gabon, respectively. New SFV sequences from NHPs in DRC are in italics. SFV sequences identified in humans are in bold and country of origin is abbreviated (CAM, Cameroon; Gab, Gabon, DRC, Democratic Republic of Congo). Code for NHP species is first letter of genus followed by first two letters of species with animal name or code in parentheses, except for Ptt (Pan troglodytes troglodytes). c. Subtree of CMCC tree showing detailed phylogenetic relationships of human infection in the Colobus clade. New SFV sequence from C. angolensis from DRC is in italics. Dots indicate new SFV sequences from NHPs from Cameroon. SFV sequences identified in humans from DRC are in boxes. Code for NHP species is first letter of genus followed by first two letters of species with animal name or code in parentheses. Bootstrap support for NJ and ML analyses and posterior probabilities are given at selected nodes in that order. Reference sequences were obtained from GenBank.