The deaths of many thousands in the developing world should weigh heavily on their souls. Driven by delusions, misguided ideology and in some cases profit, their scientifically unfounded claims have provided an excuse for governments to deny life-saving medications to millions in need. But the real effect of AIDS deniers - those who insist HIV does not exist or that it is a harmless virus - risks being measured in the countless deaths of men, women and children.
Justice John Sulan in the Supreme Court of South Australia last week threw out an appeal lodged by a man convicted of infecting one woman with HIV and exposing two others to the virus. The man claimed, backed by two commentators, that HIV does not exist and that if it does, it cannot be transmitted via heterosexual sex.
The South Australian case made headlines around the world - a horrifying example of two self-styled experts seeking to overturn decades of established HIV science, this time in defence of a man who knowingly put the lives of three women at risk.
On January 31 last year, Andre Chad Parenzee was convicted of three counts of endangering life. He had unprotected sex with three women at a time when he knew he had HIV, despite the fact he had been warned there was a risk he could transmit the virus. He appealed his conviction, relying on one ground: a miscarriage of justice.
His appeal read, in part: "There is no proof that HIV, if it exists, is sexually transmitted. There is no scientific evidence that AIDS is caused by a unique infectious agent."
Flying in the face of more than 25 years of respected scientific and medical research and practice, Parenzee and the "experts" from The Perth Group sought to argue that the existence of HIV, and therefore AIDS, was in doubt.
The prosecution's case drew on the expertise of some of the world's leading HIV specialists. They included the co-discoverer of HIV, Robert Gallo, the director of the Institute of Human Virology at the University of Maryland school of medicine, and David Cooper, the director of the Australian National Centre in HIV Epidemiology and Clinical Research. A former Australian of the Year and immunologist, Sir Gustav Nossal, the emeritus professor Peter McDonald from Flinders University and Dominic Dwyer, a medical virologist at Westmead Hospital, also gave evidence.
Since Gallo and Luc Montagnier discovered HIV in 1983-84, the epidemic has grown into an international health emergency. Economies have been ruined, national security threatened and millions of orphans have been destined to a life of poverty and sickness.
Thirty million have died from the disease and 40 million are infected with HIV around the world. In Australia, where the disease cut a deadly swathe through the gay community, HIV has killed 7000 and infected 24,000. There are now 17,000 people living with the virus.
In light of these irrefutable facts, many legal and scientific experts could not believe the case made it to court. "It was like fighting the Flat Earth Society all over again," says the director of public prosecutions in South Australia, Stephen Pallaras, QC.
"I was extremely disappointed that we even had to argue this case … this was an argument that was always doomed to fail, it was never supported by science."
Asked how best to counter those who seek to bring such matters to court, Pallaras says, grimly: "By beating them every time they stick their head up."
Mark Wainberg, a professor in molecular biology and virology, the director of the McGill AIDS Centre in Montreal and the co-chairman of the 16th International AIDS Conference, says the tactics of the AIDS deniers make his "blood run cold".
Wainberg points to the policies of the South African President, Thabo Mbeki, who since 2000 has regularly denied HIV is the cause of AIDS and prevented life-saving medications reaching the millions who need them.
"Without question, he is personally responsible for the deaths and illness of many thousands of his countrymen and women," Wainberg says from his Montreal office.
Craig McClure, the executive director of the International AIDS Society, is equally scathing of the effect AIDS deniers have had on attempts to rein in HIV. Between 2 million and 4 million people may have died "as a result of that delay in [the distribution of treatments] in South Africa alone", he says. Fuelling Mbeki's views on HIV are Australia's AIDS deniers, Valendar Turner and Eleni Papadopulos-Eleopulos - known as The Perth Group - the two key witnesses in Parenzee's defence. Describing the Parenzee case as a landmark, Wainberg and McClure say it will serve as a precedent around the world as AIDS deniers build their case on the internet, in publishing and, now, in court.
Beyond denialist theories, which require a suspension of disbelief at the best of times, there is the link between some AIDS denialist groups and the lucrative alternative medicine industry.
As late as last June, the South African Health Minister, Manto Tshabalala-Msimang, was urging people with HIV to reject their proven, life-saving anti-retroviral treatment in favour of a potion containing beetroot, lemon juice, olive oil and garlic. There are many other equally ineffective yet tasty concoctions doing the rounds of this troubled country.
About 5.5 million people, including 240,000 children under 15, are living with HIV, UNAIDS says; the increasing death toll has driven life expectancy to below 50 in some provinces in South Africa. Those are figures that the multimillionaire German businessman Matthias Rath found difficult to ignore. His crusade to promote "micronutrient-based AIDS remedies" puts him at the front of a long line of entrepreneurs looking for a quick buck from a human tragedy wrought on a large scale.
In the US, the doctor of one high-profile HIV-positive AIDS denialist, Christine Maggiore, is fighting accusations of medical neglect after her three-year-old daughter died from AIDS in September 2005.
Maggiore, who denies that HIV is a lethal virus, refused to take medication that would have prevented her child from developing HIV. She uses the internet and Mothering Magazine to proselytise against the use of anti-retrovirals by HIV-positive women.
And it is not just the South African Government that has allowed itself to indulge in unproven theories on HIV. The Gambian President, Yahya Jammeh, announced in February that he had found a cure for AIDS and began treating HIV-positive patients with a herbal preparation in the presidential palace.
Dwyer has seen the damage such debates can have. He says as the Parenzee case played out, patients came to him confused. "They were asking me, 'Are the doctors wrong, am I doing the right thing by taking these drugs?"'
Dwyer says the deniers did not offer any scientific evidence to back up their claims. "If you let that debate go on and you prevent people from being treated or diagnosed, then it is just downright dangerous."
Cooper does not believe this should end with the judgement, and has called on Papadopulos-Eleopulos's and Turner's employers and the professional associations to which they belong to consider whether they are fit to retain their positions.
Turner works at the West Australian Health Department and Papadopulos-Eleopulos at the Royal Perth Hospital as a biophysicist. Neither is in contact with patients or HIV medicine.
And the Australasian College of Emergency Medicine, of which Turner is a member, told the Herald it could not act until a complaint had been received.
Judge Sulan was scathing of the evidence presented by Papadopulos-Eleopulos and Turner. He rejected the premise that HIV had not been isolated as a virus, finding there was "no longer any genuine scientific dispute about that proposition".
"I reject the evidence of Ms Papadopulos-Eleopulos and Dr Turner. I conclude … that they are not qualified to give expert opinions. No jury would be left in any doubt that HIV is the cause of AIDS or that it is sexually transmissible."
The AIDS deniers - who did not return the Herald's calls - have lost this round, and science, for the moment, prevails.