Christine Maggiore was a major figure in the HIV denial community – those who deny that the human immunodeficiency virus is the cause of acquired immunodeficiency syndrome (AIDS). Maggiore died at 52 at home on December 26th. At this time there is no official cause of death, but she was treated over the last six months for pneumonia, according to reports.

Maggiore founded Alive & Well, a group dedicated to the notion that HIV does not cause AIDS, in 1993 and since that time has been a fervent advocate of so-called HIV denial. In fact she argued that her own survival as an untreated person with HIV was evidence that HIV does not cause AIDS. It is now recognized, however, that some people have inherent resistance to HIV and researchers are learning more about the genetics of such resistance.

Maggiore’s dedication to HIV denial, however, still had tragic consequences. She decided to breast feed both her children, despite the fact that breast feeding increases the risk of contracting the virus. Her daughter, Eliza, died at the age of 3 apparently from pneumonia that was likely an opportunistic infection due to advanced AIDS. She never had her children tested or treated for HIV.  Her pediatrician, interestingly, was anti-vaccine crank Dr. Jay Gordon. He claims to support the conclusion that HIV causes AIDS, but his website used to contain some squirely comments on HIV that suggested he may have had some denialist sympathies.

Maggiore never acknowledged that her daughter’s death was due to HIV or AIDS. The HIV denial community rallied around her, claiming the death was due to an allergic reaction to amoxicillin. Denial is a powerful thing.

The autopsy report is unequivocal. There was strong evidence that Eliza had an advanced case of AIDS from HIV, including AIDS encephalitis (brain infection). Her cause of death was pneumocystis carinii pneumonia caused by AIDS – this is a common opportunistic infection in AIDS and extremely rare in an immunocompetent individual. The autopsy left no reasonable doubt that Eliza died from complications of AIDS.

But of course there is always room for unreasonable doubt.

The evidence that HIV causes AIDS is now overwhelming. There are always deeper complexities to such questions, but the basic fact the a viral infection causes the clinical syndrome of AIDS is well-established. Treatments aimed at HIV delay the onset of AIDS and have greatly extended the life expectancy of HIV positive patients.

And yet it is apparently a common human cognitive vulnerability that we find conspiracy theories compelling – some people much more than others. The notion that HIV is a big lie perpetrated by Big Pharma and a complicit medical establishment enthralls some. Once inside that world, then all of the complexities that normally attend any complex medical (or historical or scientific) phenomenon can be twisted and made to seem as if they cast doubt on well-established facts. All contradictory evidence can be dismissed as part of a conspiracy, or rationalized away (HIV deniers, for example, argued that pneumonia is common, so why blame Eliza’s case on HIV – ignoring the conclusive evidence from the autopsy). Confirmation bias sets in – and that turns suspicions into unshakable beliefs.

Denialism itself is a special form of pseudoscience.  Denialists are pseudoskeptics – they pretent to apply the principles of skepticism (doubt) but they are dedicated to a final conclusion, and so they twist the process to their desired outcome. For example, denialists wrongly apply criteria, they constantly move the goalpost, they cherry pick evidence as necessary. They behave like any other pseudoscientist, but with the goal of denying a scientific conclusion that is probably true rather than establishing one that is probably not true.

As always, there is a very human dimension to these issues and very personal tragedies. My sympathies are with Maggiore’s family at her untimely death around the holiday season.

But we also must remember that Christine Maggiore put herself at the center of a popular controversy. She put her own unscientific beliefs ahead of the scientific community, with tragic consequences. And in the end she turned her own life story into a cautionary tale about the dangers of pseudoscience.