CRF22_01A1 is involved in the emergence of new HIV-1 recombinants in Cameroon.

Cameroon is a West African country where high genetic diversity of HIV-1 has been reported. The predominant CRF02_AG is involved in the emergence of more complex intersubtype recombinants. In this study, we sequenced the full-length genome of a novel unique recombinant form (URF) of HIV-1, 02CAMLT04 isolated in blood donors in urban Cameroon. Phylogenetic tree and bootscan analysis showed that 02CAMLT04 was complex and appeared to be a secondary recombinant derived from CRF02_AG and CRF22_01A1. The genomic composition of 02CAMLT04 strain showed that it is composed of three segments; twenty four percent of the genome is classified as CRF02_AG, spanning most of the envelope gene. The remaining seventy six percent of the genome is classified as CRF22_01A1. In addition, the sequence analysis of 13 full-length sequences from HIV-1 positive specimens received from Cameroon between 2002 and 2010 indicated that five specimens are pure CRF22_01A1 viruses, and six others have homology with CRF22_01A1 sequences in either gag, pol or env region where as 6% of strains contain portions of CRF22_01A1. Further study demonstrated that CRF22_01A1 is a primary prevalence strain co-circulating in Cameroon and is involved in complex intersubtype recombination events with subtypes (D or F), subsubtypes (A1 or F2) and CRFs (CRF01_AE or CRF02_AG). Our studies show that novel recombinants between CRF22_01A1 and other clades and recombinant forms may be emerging in Cameroon that could contribute to the future global diversity of HIV-1 in this region and world wide.