The Science of HIV - Introduction

We have come a long way in our understanding of a complex collection of life-threatening diseases collectively known as Acquired Immune Deficiency Syndrome (AIDS), since 1981, when the first AIDS cases affecting homosexual men in San Francisco and New York were reported. Initially, there was considerable uncertainty as to what might be the cause of AIDS and many theories involving infectious agents and even factors related to lifestyle (e.g. recreational drug use or multiple sexual partners) were proposed. This statement, the opening sentence in an article published in the journal Science in May 20, 1983, by the group headed by Luc Montagnier, then in Paris, heralded a new era in the fight against AIDS:

"A retrovirus […] has been isolated from a Caucasian patient with signs and symptoms that often precede the acquired immune deficiency syndrome (AIDS)."

In another study published almost exactly a year later in the same journal, the American Robert Gallo and his co-workers isolated another retrovirus from blood samples of many AIDS patients and suggested that this virus may be the primary cause of AIDS. Later, it was confirmed that these two separately isolated viruses were the same, and the ‘AIDS’ virus was renamed Human Immunodeficiency Virus (HIV). By identifying the infectious agent that caused AIDS, it became possible to initiate the next stage in the fight against it, the search for a cure (or at least turning this otherwise fatal disease into a manageable chronic condition). It was simply a case of knowing who the enemy was in order to devise the best strategy to combat it.

The medical term for the worldwide spread of an infectious disease like AIDS is 'pandemic'. In 2003, estimates for the total global number of people living with HIV range between 36 and 45 million, of which around 5 million are new infections. In the UK, there are around 50,000 HIV-infected people.

In this article, we will try to answer the following questions based on our current knowledge of HIV:
What is HIV?
What does HIV do?
Why is it so hard to find a cure for HIV AIDS?
What are the origins of HIV?