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Molecular Virology and Epidemiology

The identification of HIV led to intense activity in the field of molecular virology that continues to the present time. Three structural and six regulatory genes, which together encode at least 15 viral proteins, were identified and their relationship to the complex mechanisms of HIV replication soon unfolded.[7] These findings were crucial to an understanding of the replication cycle of HIV and its relationship to the pathogenic mechanisms of HIV disease. In addition, they provided an avenue to identify important targets for the development of effective antiretroviral drugs.

The study of the molecular virology of HIV also opened the door to the study of the molecular epidemiology of HIV.[19] The science of molecular epidemiology was essential in defining the evolving heterogeneity of HIV throughout the world, including the presence of circulating recombinant forms of the virus[20] and the origin of HIV in the human species. With regard to the latter, the zoonotic nature of HIV was established by the close phylogenetic relationship between HIV-2, first identified in West African individuals in 1986 (ref. 21), and the simian immunodeficiency virus in sooty mangabeys. In 1999, it was shown that HIV-1 had probably originated from the Pan troglodytes troglodytes species of chimpanzees, in which the virus coevolved over centuries.[22] Because chimpanzees are killed for food in parts of sub-Saharan Africa, the species jump probably occurred by accident.