Description
The immunodeficiency viruses types 1 and 2 are characterised by significant genetic variability. They are genetically related to simian immunodeficiency viruses, and it is likely that HIV emerged following cross-species transmission of SIV. HIV-1 can be divided into various groups and subtypes, with recombination between viral strains common. Identification of HIV-1 subtypes has helped follow the movement of HIV-1 strains around the world. Different subtypes may affect some of the diagnostic and monitoring tests used for patient management; whether they may affect responses to relatedness between HIV strains in epidemiologically linked individuals.
