Characterization of a new simian T-lymphotropic virus type 1 (STLV-1) in a wild living chimpanzee (Pan troglodytes verus) from Ivory Coast: evidence of a new STLV-1 group

A new strain of simian T-lymphotropic virus type 1 in blood samples from a chimpanzee that lived in the tropical rainforest of Ivory Coast is described. The sequence obtained from the long terminal repeat region of the genome is significantly divergent from all known human and nonhuman primate T-lymphotropic virus type 1 strains (96.3 % homology to the closest related strains from Central African subtype B) and clusters with none of the established clades. The tax sequences reveal two sequence differences that seem to be unique as they are not found in any of the HTLV-1 or STLV-1 tax sequences from the public databases. 255 SIMIAN T-LYMPHOTROPIC VIRUS TYPE 1 (STLV-1) and humanT-lymphotropic virus type 1 (HTLV-1) are closely related. STLVs have been found in numerous nonhuman primate species.1–5 STLV-1 and HTLV-1 nucleotide sequence homolo-gies range from 85 to 98%. However, some of the most closely related STLV-1 and HTLV-1 strains are less divergent than are HTLV-1 subtypes compared with each other.5 These observa-tions suggest multiple interspecies transmissions, both amon