Ck squares at the end of the branches represent the nef sequences sampled from Cameroon in this study, while red squares represent intragene recombinant fragments in our samples. Abbreviations HIV: Human Immunodeficiency Virus; CRF: Circulating recombinant form; URF: Unique recombinant form; RNA: Ribonucleic acid; PCR: Polymerase Chain Reaction. Competing interests The authors declare that they ha