Abstract

Foremost amongst human pathogens, the human immunodeficiency virus (HIV) exhibits a great genetic variability. The resultant fluidity of HIV enzymatic proteins allows them to remain functional whilst simultaneously evading immune surrveillance and antiretroviral therapy. This very variability, however, has been turned to powerful advantage in the study of the movement and evolution of HIV strains within and between human populations. Molecular analyses that estimate the relatedness between viral isolates, conducted in tandem with epidemiological studies, provide a new clarity of insight into the modes and routes of HIV transmission and epidemic spread. In this paper the principles underlying the molecular study of HIV and the achievements of this new field of epidemiology in southern and eastern Asia are reviewed.