Emergence of complex and diverse CRF02-AG/CRF06-cpx recombinant HIV type 1 strains in Niger, West Africa.

On the basis of partial env and gag subtyping, we documented that the majority of HIV-1 strains circulating in Niger were CRF02-AG (54.3%) or CRF06-cpx (18.1%) and that 9% of the samples were possible recombinants between CRF02 and CRF06. To determine in more detail the precise structure of these viruses we sequenced the full-length genomes for three such strains (97NE-003, 00NE-036, and 00NE-095). From the bootscan and phylogenetic tree analysis it is evident that the new viruses are the result of recombination events between CRF02-AG and CRF06-cpx strains. Importantly, each virus had a different complex recombinant structure with multiple breakpoints, leading to viruses with complex mosaic patterns.