Summary by Tim Horn Edited by Martin Markowitz, md,

the first question to ask in attempting to understand the patho-genesis of hiv infection is not how the virus causes disease, but why. “In its natural host, ” Dr. Daniel Douek stated, “hiv does not cause disease. siv in old-world monkeys and chimpanzees in Africa does not cause dis-ease. These animals have very high viral loads, but none of them progress to aids. So why does the same virus, when you put it into humans, cause disease at all? No other infection in humans, whether it’s acute or chronic, causes such a profound and inevitable depletion of cd4+ cells.” To answer this question, scientists have attempted to shed light on how hiv infection causes cd4+ cell depletion in humans. It is universally accepted that hiv typically, but not always, runs a predictable course in the human body. During acute hiv infection, there’s a very high viral load. Around the time of seroconversion, the viral load usually de-creases and ushers in the chronic phase of infection, which lasts ap-proximately ten years until the onset of aids. As for the cd4+ cell count