User:Randroide/Atelier AIDS 2

Koch's postulates
According to denialists, HIV has failed to satisfy the Koch's postulates postulates. Peter Duesberg, among others, have claimed that Koch's first postulate is not adequately fulfilled because there are individual cases of AIDS in which HIV cannot be isolated. The Perth Group, led by Eleni Papadopulos-Eleopulos, has claimed that scientists have failed to satisfy the second postulate; they claim that a precondition of isolation is purification of the virus and that current isolates of HIV are not "pure".

Mainstream scientists argue that HIV does, in fact, fulfill Koch's postulates completely. In cases such as those cited by Duesberg, where HIV cannot be isolated, PCR shows that the virus is present. In any case, Koch's postulates have never been universally applicable. Even in Koch's time, it was recognized that some infectious agents were clearly responsible for disease in spite of the fact that they did not fulfill all of the postulates; Koch himself disregarded three postulates for cholera and typhoid fever. Currently, a number of infectious agents are accepted as the cause of disease despite not fulfilling all of Koch's postulates.

Pattern of spread
Denialists note that in North America and Western Europe, AIDS is non-randomly distributed, affecting certain groups of people more than others, and moreover it is fragmented into distinct sub-epidemics with different distributions of AIDS-defining diseases. According to dissidents, AIDS in Africa looks completely different from the corresponding syndrome in North America and Western Europe; one example that has been cited is that in Africa AIDS affects roughly equal numbers of men and women, while in North America and Western Europe it affects more men than women.

The consensus view is that regional variability in the pattern and spread of HIV/AIDS results from differences in the time of introduction of the virus, the social fabric of a given community, its culture, its sexual networks, the mobility of its people and the reaction of the government in mounting an AIDS control program. Regional variation in infection rates and infected populations is not unique to HIV/AIDS; for example, the epidemiology of hepatitis B is very different in the U.S. as compared to Asia. Transmission via bodily fluids has been well-demonstrated and is typical of an infectious disease: HIV behaves exactly like many other viruses in terms of its transmission through blood, sexual fluids,   and breast milk, suggesting that HIV does in fact spread like an infectious disease.

HIV harm questioned
In addition to the claims regarding the variations in AIDS definition between North America, Western Europe, and Africa, another fact cited as supporting the hypothesis that HIV is harmless is that a small number of HIV-positive people remain relatively healthy 15 or 20 years after testing positive for HIV. Conversely, some HIV-seronegative people develop what would have been considered AIDS-defining diseases had they tested positive.

According to the mainstream perspective, the long period of HIV infection preceding AIDS manifestations is to be expected; HIV can take years to cause the immunosuppression necessary to permit opportunistic disease to occur. Extensive studies conducted before treatment was available found the mean duration between HIV infection and the development of AIDS to be eight to ten years. By this measurement, Hepatitis C would also be a "harmless" virus, as its latent stage may run longer than 20 years. There are many other well-known infectious diseases that develop slowly with a long latency period between infection and disease, such as Creutzfeldt-Jakob Disease, syphilis, and leprosy; AIDS is hardly unique in this respect.

AIDS definition
Of substantial concern to AIDS denialists is the use of HIV antibody or viral testing as part of the definition of AIDS. Some of the approximately 30 AIDS-defining diseases, including Kaposi's Sarcoma (KS) and Pneumocystis jiroveci pneumonia (PCP, formerly Pneumocystis carinii), are considered diagnostic of AIDS only when serologic evidence of HIV is present. In the absence of such evidence, these diseases are thought to be related to other immune problems, and are not diagnostic of AIDS. In other words, according to denialists, the definition of AIDS is an example of circular logic: because a diagnosis of AIDS requires the presence of HIV antibodies, there can be no AIDS without HIV.

Two major systems of AIDS diagnosis used today are the World Health Organization system, for use in resource-limited settings (see WHO Disease Staging System for HIV Infection and Disease), and the CDC system used in the USA (see CDC Classification System for HIV Infection). European countries and Canada use a variation of the CDC definition that excludes CD4 counts. Supporters of these definitions point out that AIDS-defining diseases such as KS and PCP (and also very low CD4 counts) are exceedingly rare in people who are HIV-negative, and that it is standard practice in medicine to include a microbial test in disease diagnosis.

HIV test accuracy
Denialists claim that the process of testing individuals for the presence of HIV is flawed. They assert there is a high probability of encountering a false positive, which would falsely identify someone as HIV-positive due to cross-reactivity

A detailed criticism of the Western blot test and the "gold standard" of HIV isolation was published by Eleni Papadopulos-Eleopulos et al. in Bio/technology in 1993: Is a Western Blot Proof of HIV Infection? Their arguments rest on non-specificity of antibodies and lack of standardisation and reproducibility of HIV tests. In their conclusion, the authors state, "It is axiomatic that the use of antibody tests must be verified against a gold standard. The presently available data fail to provide such a gold standard for the HIV antibody tests. The inescapable conclusion from the above discussion is that the use of HIV antibody tests as predictive, diagnostic and epidemiological tools for HIV infection needs to be carefully reappraised."

In response, virologists contend that the accuracy of serologic testing has been verified by isolation and culture of HIV and by detection of HIV RNA by PCR, which are widely accepted "gold standards" in microbiology. The consensus view of the scientific community is that current methods of HIV antibody testing are remarkably accurate. The false-positive rate among the American public ranges from 0.0006 to 0.0007 percent. The false-negative rate for HIV antibody testing ranges from 0.001% to 0.3%, depending on the risk factors of the tested population.

Critics assert that many AIDS denialists' claims of inaccuracy result from an incorrect or outdated understanding of how HIV antibody testing is performed and interpreted. In the USA, the standard HIV diagnostic procedure combines two methods of detecting HIV antibodies: ELISA and Western blot.

AIDS treatment toxicity
Denialists claim the antiretroviral treatments prescribed to AIDS patients often cause the very symptoms they are supposed to delay. To support this claim, they cite two studies from the late 1980s whose authors said they found it difficult to distinguish adverse events possibly associated with administration of Retrovir (AZT) from underlying signs of HIV disease or intercurrent illnesses.

Mainstream scientists and doctors argue that dissidents are ignoring or unjustifiably dismissing abundant evidence demonstrating the effectiveness of modern antiretroviral medication. Harmful side effects do occur, and in some cases these can be severe or even deadly. However, multiple studies — conducted in Africa as well as Western countries — have found that, overall, anti-retroviral drug treatment is associated with a greatly decreased incidence of opportunistic infections and increased survival among HIV-positive people.