4:00 Dose of EIDology: Remembering the Emergence of HIV

The deadliest emerging disease of all time came about in my lifetime.  I have a vivid memory of being in grade school and working on a science fair project about "germs", and my mother told me I should include a disease called "AIDS", because it was going to become very important.  I wrote it on the posterboard, and when asked "what I meant by AIDS", I sternly replied that "it was very important".  Clearly I had no idea what it was or why it was important, but it certainly became so.  That incident happened in 1985, only a year and a half after the causative agent, human immunodeficiency virus, was first isolated, and a year before Ronald Reagan publicly acknowledged the disease after 20,000 American had already died.  It was the same year that Rock Hudson died of it, and Ryan White was banned from attending public school.  Tens of thousands were already infected in the US by then, and many had died.  

The Loss of Queen's Freddie Mercury was a Sobering Reality

The numbers on HIV and AIDS are to this day astounding.  It is estimated that up to 40 million people have died of it since the outbreak began.  An estimated 1 in 20 American adults are HIV positive or in some stage of progression to clinical AIDS [note: HIV is an infectious virus, and AIDS is the disease it causes.  One can be -and often is- HIV infected ("HIV+") prior to developing the disease AIDS].

AIDS has a fascinating history, but biologically speaking where did it come from?  Some things that are clear is that is has entered into the human population more than once, and that it has been around far longer than we have recognized.  The biological ancestor of HIV is simian immunodeficiency virus (SIV), which causes a disease similar to AIDS in other primates.  Humans were infected with SIV almost certainly through hunting/bushmeat slaughter, and then began transmitting it amongst themselves.  As SIV adapted to humans, it became what we now called HIV.  The two major strains of HIV came from two separate introductions and adaptations of SIV.  HIV-1 came from an SIV strain found in chimpanzees, and HIV-2 came from a strain of SIV found in white-collared monkeys.  Rumors abound about where HIV and AIDS came from, many of them vitriolic in nature.  The truth is far less sinister.  The wrong hunters encountered the wrong primates, and the rest, as they say, is history.