Have you read the book Inventing the AIDS Virus by Peter Duesberg? Do you know of any new studies that actually prove HIV has anything to do with AIDS? As I understand it, there were never any original studies.

J.D.

I must confess, I have not read this book. However, I have talked to many people who have read it and with others who claim that HIV does not cause AIDS. Most of this controversy dates back to the beginning of the HIV epidemic, when it was difficult to find the virus, and we diagnosed AIDS not by blood tests for the virus but by measuring the body's own disease-fighting antibodies.

Today, I and virtually all experts in the field are 100 percent positive that HIV causes AIDS. Here is just some of the evidence:

• We now can quite easily find HIV in a patient's blood, using a test that measures the "viral load." Most people who test positive for HIV develop AIDS. Very few cases of diseases similar to AIDS occur in patients who test negative for HIV.
  
• HIV-infected people whose illness progresses rapidly to AIDS have high levels of HIV in the blood. HIV-infected people whose illness does not progress rapidly to AIDS have very low or undetectable blood levels of HIV.
  

• Treatment with drugs that attack HIV reduces the amount of HIV in the blood. When treatment lowers HIV levels, the immune system improves. Patients who receive anti-HIV treatment do not progress to AIDS as quickly as people who do not receive treatment.
  
• The death rate from AIDS has declined in the last few years, as treatments have been directed against HIV.
  
• If you give chimpanzees HIV or the very similar virus called SIV (simian immunodeficiency virus), they develop AIDS. If you prevent SIV infection in chimpanzees, they do not get AIDS.
  

Duesberg and others claim that AIDS is due to behaviors such as gay sex and drug abuse. But what about the huge numbers of people with AIDS -- the majority of AIDS patients worldwide, in fact -- who have never abused drugs or practiced gay sex? Countless patients have developed AIDS through a single act of heterosexual intercourse, or through a single blood transfusion or by receiving blood products for hemophilia (in the days before blood was routinely screened).

And what about babies who got HIV from their mothers? I consider the following example to be pretty strong evidence that HIV causes AIDS: A mother tests positive for HIV, though she has no symptoms. Her baby is born totally normal and tests positive for HIV. Five years later, the child dies of AIDS.

I am afraid that people like Duesberg may have had good intentions in the beginning, but now they may be scrambling to defend their position -- either to save their reputations, or to continue making money on books.Duesberg and others claim that AIDS is due to behaviors such as gay sex and drug abuse. But what about the huge numbers of people with AIDS -- the majority of AIDS patients worldwide, in fact -- who have never abused drugs or practiced gay sex? Countless patients have developed AIDS through a single act of heterosexual intercourse, or through a single blood transfusion or by receiving blood products for hemophilia (in the days before blood was routinely screened).

And what about babies who got HIV from their mothers? I consider the following example to be pretty strong evidence that HIV causes AIDS: A mother tests positive for HIV, though she has no symptoms. Her baby is born totally normal and tests positive for HIV. Five years later, the child dies of AIDS.

I am afraid that people like Duesberg may have had good intentions in the beginning, but now they may be scrambling to defend their position -- either to save their reputations, or to continue making money on books.