Monday, December 15, 2008

AIDS is caused by HIV

When in the late 1990s an intrahospital epidemic in Benghazi, Libya resulted in infection of about 400 children with AIDS, I thought that I'd wish to popularize what we know about this disease and to devote these texts to the Benghazi victims. Since I started this blog, I have written many times to defend the Bulgarian medics accused in spreading the virus (see my posts with label "HIV trial in Libya", the latest of them here), but never to educate. I even thought that I need not write educational texts about AIDS because there are already many of them written by other, more competent authors. Now, however, I am going to write at least one such post.
These days, Indian journalist Rupa Chinai wrote on the WIP site a series of three articles about the AIDS situation in India. Intelectual honesty requires that I link directly to my opponent's writings, but I am unwilling, because I find their contradiction to the best available AIDS knowledge too dangerous if used by somebody as medical advice. Rupa has talent and compassion and presents real problems, such as the massive supply of bogus AIDS diagnostic tests giving false results and the inability of Indian health care system to control (and even monitor) properly the spread and progression of AIDS. However, she is also highly critical to science (which she calls "Western" science) and particularly to current scientific consensus about AIDS and the so-called by her "AIDS lobby" - a loose association of researchers, pharmaceutical companies and Western government agencies as well as international ones such as UNAIDS. Taken together, these convictions lead her to AIDS (HIV) denialism. Actually Rupa claims only to be unbiased observer of the debate between mainstream scientists and "the dissidents" (as denialists prefer to call themselves), but her preferences to the latter seem clear to me; and even if she was truly standing in the middle, this would be enough to me to regard her as belonging to the other camp, exactly as I regard Sarah Palin's wish to teach both creationism and Darwinism as indicative of her being a creationist, though she doesn't insist Darwinism to be thrown away from school.
Thinking what arguments to put forward in favour of the HIV causation of AIDS, I first wanted to point out that anti-retroviral drugs significantly increase the life span of infected patients. However, after reading Rupa's third (last) article, I was happy that I hadn't talked about the drugs, because it featured a group of HIV positive women who had lost their husbands to AIDS but remained in a reasonably good condition for many years by adhering to a healthy lifestyle, adequate (to their opinion) nutrition and "traditional" medicine. While I am glad that these women do so well, I think that they would do even better (and longer) on anti-retroviral drugs, and hope that nobody follows their example. Contrary to what these women, their so-called doctors and Rupa think, it is easy for the "AIDS lobby" to explain their cases: the "bright" period between encountering HIV and developing an AIDS-defining illness varies much between individuals and is 10 years on average. For the women in the report, this period has been so far 12-14 years, which doesn't differ dramatically from 10 years. So they seem just to have longer than average "bright" periods. I bet that other HIV-infected Indians have followed the same strategy but have had shorter than average bright periods, as the elementary calculus of mean values requires. These people, similarly to many Africans, have paid with their lives for the decision to be natural, traditional and non-Western and now aren't around to tell Rupa their stories.
I also wanted to refer Rupa to the Layperson's Guide to the Scientific Literature, published by Prometheus in three parts (1, 2, 3). However, it would hardly be of any use to her in this particular case, because AIDS denialists (similarly to other knights of anti-science and pseudo-science) are characterized by persistent absence of any works published in the peer-reviewed scientific literature; instead, they talk directly to the science-doubting lay public. I am sure that members of the public regard the poor scientific record of "dissidents" as proving not their incompetence but suppression of these good guys by the conspiring big bad "AIDS lobby". Turning one's own incompetence and professional impotence into virtue - what a feat! Why don't these people make careers as PR experts?
So let me return back to basics in my search for arguments. 19th century German microbiologist Robert Koch established four postulates for proving causal relationship between a particular microbe and a disease. Namely, the microbe must (1) be found in all organisms suffering from the disease, (2) be isolated from a diseased organism and grown in a pure culture, (3) cause disease when introduced from this culture to a healthy organism (typically an experimental animal) and (4) be isolated from the inoculated, diseased new host.
In the early years of AIDS research, scientists had problems with the 3rd and 4th postulate because HIV is highly host-specific and common experimental animals are resistant to it. In the late 1980s, three lab workers were infected with a pure, defined HIV strain by accident. They became HIV+ and developed AIDS. As Jon Cohen writes in top scientific journal Science in 1994, this incident alone means fulfilling Koch's postulates for HIV causation of AIDS. However, as noted in the same article, it failed to convince HIV denialists. Is anybody surprised? And can we expect any anti-scientist to change his theories when confronted by contradicting empirical data? After all, if anti-science people would allow their opinions to be influenced by facts, they wouldn't be anti-science, they would be pro-science.
Also in the 1990s, Koch's postulates were also proven using as experimental animal the chimpanzee, which is the natural host of HIV-1 (see Tim Teeter's article HIV Causes AIDS: Proof Derived from Koch's Postulates). Another animal model are immunodeficient mice "humanized" by grafting human immune cells. These mice are susceptible to HIV infection and special measures are needed to prevent them from dying within 1.5 months (Watanabe et al., 2007).
In his post Age of Unreason Prometheus wrote, "Much of “alternative” medicine encourages people to abandon scientific principles that have brought us in the West to a level of health and longevity that are unrivalled in human history. If we want to see what happens (when science is abandoned), we only have to look to those parts of the world where – for economic or philosophical reasons – scientific medicine is unavailable." Like Prometheus (and unlike Rupa), I think that "Western" science cannot be blamed for the poor life quality and short life span of people who are either prevented from accessing its fruits or, alas, reject them by deliberate choice.


programmer craig said...

Maya, thanks for posting this. I didn't even know there was such a thing as HIV "denialists". I found that wiki link very interesting... especially because so many of them seem to have at least some credentials. I wonder how often this goes on in other less "visible" areas of scientific research?

Maya M said...

Thank you! You are right, unfortunately. Every time when science touches a subject of human emotions, it becomes impossible to convince all people (or even all experts) in the theories best explaining known facts. Examples are the thoroughly discredited but still popular theory that vaccines cause autism (covered in some of my posts) and the idea that patients with cancer shouldn't have chemotherapy.