SIDA is an acronym used in several countries for acquired immunodeficiency syndrome (AIDS), a disease of the human immune system caused by the human immunodeficiency virus (HIV).

HIV is the cause of AIDS

"AIDS is caused by infection with a virus called human immunodeficiency virus (HIV)."1

This is the standard explanation of what causes AIDS. But what evidence do scientists have to support the fact that HIV causes AIDS? And why do some websites say that the world has got it terribly wrong – that HIV does not cause AIDS at all?

As an independent AIDS organization founded in 1986, AVERT has taken a keen interest in the ongoing debate about what causes AIDS. As well as investigating the consensus position, we have followed and carefully considered the arguments of the dissident minority who claim that HIV is harmless or even that it might not exist. This topic is vitally relevant to how our organization works to prevent people developing AIDS and to help those who are suffering.

It is AVERT's considered opinion that the evidence that HIV causes AIDS is abundant and conclusive. This page outlines some of that evidence, while also mentioning how some dissidents have interpreted things differently. In particular, we'll look for proofs of the following:

AIDS is a new epidemic disease
AIDS does not occur without HIV
HIV infection is the only factor that predicts who will develop AIDS
Surveillance statistics support the HIV theory
Modern antiretroviral treatment is highly beneficial.