Rational Inquiry -Volume 6 Number 4
The Odd Claim of the HIV Dissenters: HIV does not Cause AIDS
A critical evaluation of their arguments
By Barbara B. Hemmingsen
Twenty years ago, a new human disease-AIDS-showed up in the United States, Europe and Africa; within a few years a virus was implicated. But not all scientists have accepted the evidence which has been obtained so far, the most prominent being Peter Duesberg, Professor of Molecular Biology at U.C. Berkeley and an expert on retroviruses, the "family" to which HIV belongs. Because of his past high standing in the scientific community-he is a member of the National Academy of Science-his opposing ideas stimulated additional studies. Abundant evidence now shows HIV is the cause of AIDS (Blattner et al., 1988). Yet, in 1998, Duesberg published a lengthy paper reiterating and expanding on his original idea that AIDS has other causes, and adding-he claims-some new evidence in support of his contention (Duesberg and Rasnick, 1998). What is it about his hypothesis that is so compelling that Duesberg and his supporters continue to advance them? What is the evidence that they are right and the majority of experts wrong.
Duesberg published several articles in the 1980s in which he claimed that HIV as the cause of AIDS does not fulfill Kochís postulates. These postulates are the logical steps to prove that a specific pathogen, in this case HIV, is the cause of particular disease, AIDS. The bacteriologist Robert Koch in 1876 was the first to apply them to prove that the bacterium Bacillus anthracis causes anthrax. The postulates are: (1) the same pathogen must be present in every clinical case of the disease under investigation, (2) the pathogen must be isolated and grown away from the infected host, (3) the cultured pathogen must cause the same disease when injected into a healthy, susceptible host, and (4) the same pathogen must be reisolated from the experimentally infected host. Koch and his successors successfully applied these postulates to diseases caused by bacteria and fungi, microorganisms that can usually be easily cultured away from their host. Koch modified his postulates as more was learned about pathogenic bacteria. For example, people infected with Salmonella typhi, the bacterial cause of typhoid fever, sometimes have no symptoms; hence, postulate 1 must be modified. Also, if a suitable susceptible animal host cannot be found for a human pathogen, then postulates 3 and 4 can not be satisfied as experimentation on humans is unethical.
The discovery of viral diseases also required modifications to Kochís Postulates (Evans, 1976). Viruses are not cells, rather they are genetic material (either RNA or DNA) surrounded by protein coats in their extracellular state. The genetic material, on entry into a suitable host cell, is sufficient to induce viral replication. Such replication can have deleterious effects on the host cells which cause symptoms in the host. Some viruses are able to integrate their genetic material into that of their hosts, the "latent state". Viruses must be cultivated together with their host cells; thus, postulate 2 must be modified.
Starting in 1981, the Centers for Disease Control began reporting, in its newsletter Morbidity and Mortality Weekly, cases of Pneumocystis pneumonia and cytomegolovirus infections in otherwise healthy adult males. These diseases were previously found only in severely immunocompromised humans. Eventually this profound immunosuppression (as evidenced by an accompanying constellation of diseases) was named Acquired Immunodeficiency Syndrome (AIDS) because there was no obvious reason for the patientsí profound immunosuppression. Some suggested causes were illicit drug (cocaine, heroin, amphetamines) or stimulant (amyl nitrite) use, but a microbial cause was at the top of the list and efforts were immediately made to culture microbes from persons with AIDS.
These efforts quickly established that neither fungi nor bacteria were likely pathogens. The French virologist Luc Montagnier and his collaborators succeeded in 1983 in culturing a retrovirus from the blood of AIDS victims and not from immunologically healthy people free of the diseases that define AIDS (Barre-Sinoussi et al., 1983; Gallo et al., 1984). This satisfied Kochís Postulates 1 and 2. Once the virus was available in quantity, it could be compared to other related and better known retroviruses that infect animals. It was also discovered that the virus-since named Human Immunodeficiency Virus, or HIV-preferentially infected white blood cells present in the blood, semen and vaginal fluids. This discovery explained why the delicate virus was spread from human to human via sexual intercourse or by exposure to blood (hemophiliacs, blood transfusion recipients, and injecting drug users). Soon after its discovery, a test was devised to detect antibodies against HIV in blood and blood products, and this method of transmission was denied the virus. Safe sex practices and needle exchanges have also interrupted the spread of HIV, although the conscientious use of the safe sex methods and the sharing of needles in injection galleries remain problems (Des Jarlais and Friedman, 1994).
Despite these successes, the third and fourth postulates could not be satisfied in the 1980s because no experimental animal proved susceptible to infection by HIV except the chimpanzee, a lab animal in such short supply that statistically valid numbers could not be used. Thus, the door was opened for the AIDS dissenters, scientists who interpreted the available evidence in the 1980s to mean that HIV was a harmless passenger virus which just happened to be present in AIDS patients. They claimed that AIDS is a disease of such lifestyle choices as drug and alcohol abuse and of promiscuous sex, especially homosexual sex. However, in the 1990s, the third and fourth postulates were satisfied as the result of a tragic laboratory accident in which 3 lab workers were exposed to concentrated, cloned, pure HIV. None had risk factors for AIDS, yet all 3 developed one or more of the AIDS-defining diseases or severe immunodepression (NIAID fact sheet, 2000). HIV was isolated from all 3 patients and shown, by molecular techniques, to be identical to the original virus. Although Duesberg no longer mentions Kochís Postulates in his writings, he has not allowed their completion to change his mind about the causes of AIDS.
One of Duesbergís recent publications (Duesberg and Rasnick, 1998) asks 12 questions which are really statements of his belief that HIV does not cause AIDS. He then attempts to support each of his beliefs. I will focus on just a few of the questions and show that each has been answered, and that the published data, which Duesberg does not cite, clearly support the hypothesis that HIV causes AIDS.
Duesberg and Rasnick (1998) ask: "Why would antibodies against HIV (a positive HIV test) which are so effective that leading AIDS researchers cannot detect HIV in most AIDS patients (Gallo, 1991; Weiss, 1991; Cohen, 1993) not protect against AIDS?" First, I will consider their statement that HIV canít be detected in most AIDS patients. The three citations in this sentence are to letters or a news report, none of which deal with the detection of HIV in AIDS patients. Research papers published in this same period (Hammer et al., 1993; Jackson et al., 1990) and subsequently (Mellors et al., 1997) report the consistent isolation of HIV from blood, semen and vaginal secretions of patients with AIDS. Why didnít Duesberg and Rasnick cite these publications? Second, I will consider the statement that antibodies against HIV in the blood should protect against AIDS. Duesberg and Rasnick apparently donít know that HIV as well as some other viruses are able to hide within human cells thereby escaping the circulating antibodies against them; these viruses persist and may reemerge and cause disease. The most familiar examples are varicella zoster (chickenpox) that reemerges to cause shingles, and herpes simplex that reemerges to cause cold sores. HIV is also able to hide in the cells of the human immune system, well protected from the circulating antibody.
Duesberg and Rasnick (1998) also ask: "Why have doctors and nurses never caught AIDS from over 800,000 American and European AIDS cases, particularly in the absence of a HIV vaccine?" What comes to mind is that very few doctors and nurses expose their skin or mucus membranes to the semen or vaginal fluids of patients with AIDS. However, health care workers do accidently stick themselves with patient blood. Through 1999, 56 documented cases of such HIV infection are known to the CDC; 25 of these have developed AIDS in the absence of other risk factors (NIAID fact sheet, 2000). Why do Duesberg and Rasnick ignore these cases?
Another question posed by Duesberg and Resnick (1998) is: "Why are 9 out of 10 AIDS patients males?" They point out, rightly, that viruses are gender-blind whereas lifestyle choices may be gender specific. However, they donít acknowledge that a gay man is believed to be the individual who brought the virus to America. From homosexuals, HIV spread to injection drug users, most of whom are male. Because HIV is spread from human to human by unprotected sex or by exchange of blood, it is not surprising that early in the epidemic most AIDS cases (92%) showed up in males. However, more women are now infected with HIV and are developing AIDS. In 1993-1995, about 18% of the 257,262 American AIDS cases reported to the CDC were women; this percentage was 23% for the 1996-2000 period (MMWR, 2001). The populations in Asia and Africa that exchange HIV via heterosexual sex have approximately equal numbers of men and women infected with HIV (UNAIDS, 2000; NIAID fact sheet, 2000). Why do Duesberg and Rasnick ignore these numbers? They are freely available from the Centers for Disease Control.
Although not part of their 12 questions, Duesberg and Resnick support their idea that recreational drugs cause AIDS by stating that "1% of AIDS patients are babies who shared drugs with their mothers before birth." Without doubt, one of the risk factors for being born with an HIV infection is a drug injecting mother who is HIV positive . But letís look at twins born to such mothers; both fetuses share the same drugs and approximately the same uterine environment. I can refer to 4 such cases described between 1984 and 1993 (Vilmer et al., 1984; Menz-Bautista et al., 1986; Young et al., 1990; Barlow and Mok, 1993). Three of the mothers admitted drug use, the fourth was married to a drug user. All of the mothers were positive for HIV antibody, HIV genetic material, or had AIDS. All four gave birth to a fraternal healthy twin (no sign of HIV or AIDS after 10 months to 6 years) and to a sick twin with evidence of HIV and the development of AIDS or AIDS Related Complex in 3 cases. Did Duesberg choose to ignore this evidence that it is the presence of HIV in the body that leads to AIDS, not the presence of recreational drugs?
It is evident from these examples that the HIV dissenters and deniers, led by their "scientific" guru Duesberg, are ignoring sound scientific evidence and methodology to arrive at their claims. Duesberg believes that HIV is a harmless passenger virus that just happens to be present in persons with AIDS. To arrive at this claim he uses information published in the scientific literature very selectively, ignoring all data and arguments that refute his views, and picking only material which he can interpret to support his ideas. He leans heavily on material from newspapers and popular magazines. When one of his points is challenged by indisputable facts, he simple drops it and goes on to another. This distinctive pattern we know so well from another case of bogus or irrational thinking: the creationistsí argument against evolution. It is troublesome that it is advanced by a member of the National Academy of Sciences.
Alcabes, P. et al. (1993). Incubation period of the human immunodeficiency virus. Epidemiol. Rev. 15: 303-318.
Barlow, K.M. and J.Y.Q. Mok (1993) Dizygotic twins descordant for HIV and hepatitis C virus. Arch. Diseases Childhood 68: 507.
Barre-Sinoussi, F. et al. (1983) Isolation of a T-lymphotrophic retrovirus from a patient at risk for acquired immune deficiency syndrome (AIDS). Science 220: 868-871.
Blattner, W. et al. (1988) HIV causes AIDS. Science 241:515-517.
Cohen, J. (1993) HHS: Gallo guilty of misconduct. Science 259: 168-170.
Des Jarlais, D.C. and S.R. Friedman (1994) AIDS and the use of injected drugs. Scientific Am. Feb. Issue, pp. 82-88.
Duesberg, P. and D. Rasnick (1998) The AIDS dilemma: drug diseases blamed on a passenger virus. Genetica 104: 85-132.
Evans, A.S. (1976) Yale J. Biol. Med. 49: 179-195.
Gallo, R.C. et al. (1984) Frequent detection and isolation of cytopathic retrovirus (HLV-111) from patients with AIDS and at risk for AIDS. Science 224: 500-503.
Gallo, R.C. (1991) . . .and his response. Nature (London) 351: 358.
Hammer, S. et al. (1993) Use of virologic assays for detection of human immunodeficiency virus in clinical trials: Recommendations of the AIDS clinical trials group virology committee. J. Clin. Microbiol. 31: 2557-2564.
Jackson, J.B. et al. (1990) Human immunodeficiency virus type I detected in all seropositive symptomatic and asymptomatic individuals. J. Clin. Microbiol. 28: 16-19.(This paper is a source of citations to the early literature on the detection of HIV from seropositive patients; some of these early isolation attempts failed because the methods were not sensitive enough.)
Mellors, J.W. et al. (1997) Plasma viral loads and CD4+ lymphocytes as prognostic markers of HIV-1 infection. Ann. of Internal Med. 126: 946-954.
Menz-Bautista, R. et al. (1986) Monozygotic twins discordant for the acquired immunodeficiency syndrome. AJDC 140: 678-679
Mortality and Morbidity Weekly Report(2001) vol. 50, no 21. is devoted to AIDS. (Available on the CDC web site www.CDC.gov).
NIAID fact sheet (2000) The evidence that HIV causes AIDS.(Available from www.niaid.nih.gov/factsheets/evidhiv.htm.)
UNAIDS (2000) Joint United Nations Programme on HIV/AIDS. (Available from www.unaids.org.)
Young, K.K.Y. et al. (1990) Discordant human immunodeficiency virus infection in dizygotic twins detected by polymerase chain reaction. Pediatric. Infect. Disease J. 9: 454-456.
Vilmer, E. et al. (1984) Possible transmission of a human lymphotropic retrovirus (LAV) from mother to infant with AIDS. Lancet, No. 8396, vol. II: 229-230.
Weiss, R. (1991) Provenance of HIV strains. Nature (London) 349: 374.
The author is a Professor of Biology at SDSU and the Secretary of SDARI.