HIV AND AIDS

The myths, the virus and the burden of proof

By Kevin Hopkins and Kim Wyness

De Rebus Nov. '00

"Is it possible for one so burdened, to discharge the onus of proving that HIV does in fact cause AIDS?"

Until President Thabo Mbeki gave attention to reports that drug treatments were ineffective in forestalling the progress of HIV, we had never heard that there was any doubt that HIV causes AIDS. Now, after various conferences and talk-shows, a legal question still resonates unresolved and possibly waiting to erupt: "Is it possible for one so burdened, to discharge the onus of proving that HIV does in fact cause AIDS?'

The obvious question: So what if HIV does not cause AIDS?

There are infinite reasons why this question could be important or significant, depending on who you are. But, despite our identity as individuals, the answer is relevant to us collectively as the public. The somewhat ironically labelled 'dissident' group of scientists claims that there is no true scientific way of establishing that HIV is the cause of AIDS. If the dissidents are correct, then billions of rands of public money are being misspent and hundreds of thousands of people have put their lives in the hands of medical establishment that has erroneously based its research and treatment on a premise founded on an unsubstantiated assumption. But if the dissidents are wrong, and the more conventional 'popular' theory that HIV does cause AIDS is correct, then the efforts of the dissidents to subvert the accepted approaches to treatment are dangerous and place the public at risk.

The general acceptance of the popular theory - that HIV causes AIDS - has extremely far-reaching effects. The theory's deep roots have penetrated the fertile soil of the commercial terrain; there is no better example of this than in the insurance industry. Insurers are, understandably, reluctant to accept HIV-related risk. Attempts to exclude HIV-infected insured persons also exclude AIDS sufferers, usually on the assumption that AIDS is caused by HIV. The dissident theory, which disputes this, then by obvious implication becomes significant. The true sugnificance, however, has as yet not fully materialised.

It's a question of proof

The dissident theory has created ripples in the previously calm pond of popular thought that there is an accepted causal nexus linking the two conditions. The dissident view claims that the popular theory of HIV causing AIDS, although accepted cannot be proved scientifically. This raises some extremely important questions on the legal issues of evidence governing the proof of facts. In light of this new dissident theory, a relevant question is whether the courts are entitled to take judicial notice of the popular theory, or whether the popular theory - and that which it represents - is so notorious that it is entitled to be removed from the evidence.

Is there any good reason to unsettle the general rule that 'he who avers must prove'? Proof is important because if insurer cannot prove that HIV causes AIDS then the very basis of many repudiations and exclusions is without legal justification. When ever we speak of proof, we cannot escape issues of onus and who carries the burden of proof. This involves a substantive inquiry into exactly what has to be proved by whom.

Limiting the liability, Exclusion clauses and Exclusionary causes

A contract of insurance must, by definition, clearly identify the risk against which the insured is covered; for example, the risk of illness, death or even the cost of medical treatment. To illustrate the point, consider the risk of falling ill and suppose that the insured does indeed so ail. It is trite that the onus will rest on the insured to prove that the risk insured against has materialised, a doctor's report may suffice for this purpose. In Eagle Star Insurance Co Ltd v Willey 1956 (1) SA 330 (A) Centlivres CI held that the insured must bring his claim 'within the four corners of the promise made to him'. He promise - in this case the promise to indemnify - may be limited by a clause excluding a certain defined risk. The purpose of these 'exclusionary clauses' is to restrict the insurer's liability. But these restrictions do affect the onus of proof; if the risk is limited in the contract, then it is the insured who bears the onus of proving on a balance of probabilities that his claims falls within the limited description, But Reinecke and Van Der Merwe, in their work General Principles of Insurance (Durban: Butterworths 1989) at para 189 contend, we submit correctly, that this does not mean that the insured must prove that the event on which his claim is based was not excepted from the risk. The onus of proving that it was so excepted rests on the insurer.

The point is well illustrated in Aegis Insurance Co Ltd v Consani NO 1996 (4) SA 1 (A) where the policy obliged the insurer to pay the deceased estate the amount of R1 million should the death result from, inter alia, an accident or by violent means. The policy went on to provide that the liability of the insurer was excluded in the case of suicide. The court confirmed the general rule that the burden of proving that a loss fell within the excepted peril always fell upon the insurer. In practice this meant that the insured's deceased estate bore the onus of proving that the insured was dead and that his death was accidental - no more. There was a separate onus on the insurer to prove that the cause of death ought to exclude its liability, in this case because it was caused by suicide. (The issues in this case complicated matters because in order for the respondent to show that the death was accidental, he would have to disprove suicide since that was clearly what the evidence suggested. There was ultimately no need for the applicant to address the onus that it had to prove suicide because the initial onus on the respondent to prove that the cause of death fell within the four corners of the policy had not itself been discharged.)

HIV, AIDS and the burden Of proof

Exclusion from liability in the case of HIV and related risk is done contractually. Where perils related to HIV have been accepted it will usually be the insurer who will bear onus of proving that the illness, or death as it may be, is HIV-related. Practitioners should be cautioned against simply accepting the applicability of the general rule to every case because the issue of 'onus' may have been agreed to by the parties contractually in the policy wording. This type of evidence must be established by an expert witness. Expert opinion is, in general, required to explain the workings and reliability of technical matters, The cause of illness or death by HIV, or indeed the existence thereof is, we submit, a matter to be determined by an expert, In order to justify the exclusion of liability, the insurer will have to lead expert evidence which will, on a balance of probabilities, have to satisfy the court that the illness or death does in fact follow as a consequence of HIV. If the insurer's expert witness can do this, then the insurer will have justified his prima facie case for exclusion.

But, can the insurer repudiate liability on the HIV exception if the claim is based on the insured being diagnosed with AIDS? Surely, the pure legal answer to this question will depend on whether the risk of AIDS has also been excluded from the policy. If the policy wording does not specifically exclude AIDS, but only HIV-related risks, then the insurer must, in order to escape liability, be able to prove that AIDS is a consequence of HIV or, stated differently, that HIV causes AIDS. The dissident argue that this is an impossible onus to discharge. If they are correct then their 'deconstruction' of the 'HIV causes AIDS' hypothesis could have major implications for the insurance industry where this consequence is either presumed or else imported into the assessment of risk.

How uncertain must the cause be not to justify as exclusion of liability?

The dissident view challenges the premise that HIV cause AIDS. The effect of this challenge means that courts must, in our view, be satisfied that the insurer has, on a preponderance of probabilities, convinced it that HIV causes AIDS. The test whether something has been proven on a 'preponderance of probabilities' involves a comparative analysis between two separate hypotheses so that the court can, on the evidence available, prefer the one above the other. The onus will not be satisfied if the party who has the duty to prove cannot persuade the court that his version is more probable than the other. In the scenario that we have structured, the insurer would have to place evidence before the court carrying a reasonable degree of probability, so that in the words of Lord Denning, a court may say that 'we think it more possible than notŠ.' (Millar v Minister of Pensions [947] 2AB ER 372 - 374) Hoffman and Zeffert confirm in their authoritative work The South African Law of Evidence 4th ed (Durban: Butterworths 1948) at 526 that this formulation has been adopted by our courts.

In this case the rest of the sentence would read to the effect that it should be established as being more probable that AIDS is caused by HIV than it is not. This statement is significant because the dissidents claim that the popular theory is fundamentally flawed to the extent that it offers no proof that HIV is the cause of AIDS, let alone proof to suggest that AIDS is more than likely caused by HIV. Whether or not the dissidents can put forward a better theory as to what causes AIDS is, seemingly, irrelevant. As Hoffman and Zeffert (above) correctly point out at 526-527, even if the party who bears the onus is able to produce some evidence in his favour and the other party none at all, the court may feel that the evidence produced is insufficiently probable to prove the point. That raises the obvious question of what exactly the dissidents allege it is that renders the popular theory fatal.

Questioning the HIV equals AIDS hypothesis - the dissident view

The dissidents argue that it is impossible to prove that HIV causes AIDS because it has in fact never been proved that a human immunodeficiency virus exists at all. This is because HIV has been classified as a retrovirus, and the only scientifically acceptable method of isolating and identifying retroviruses has never been successfully used in the study of HIV.

This method apparently involves culturing cells, isolating suspected retroviral particles and then studying these isolated particles by using electron micrographs (which are in essence photographs of the virus through an electron microscope). This is done to ensure that they do indeed possess the requisite characteristics of a retrovirus. In the initial study in which HIV was identified, the electron micrograph that was used was actually of an unpurified cell culture and not of isolated retroviral particles. Scientists appear to agree that it is impossible to identify retroviruses in a cell culture - they must, it would seem, first be isolated.

Subsequent studies in which electron micrographs were taken of isolated retroviral particles, identified as HIV, serve only to cast doubt over the accuracy of HIV's classification as a retrovirus, according to the dissidents. This is because the observed particles do not fit the description of retroviruses, which are apparently spherical in nature, have diameters of 100-120nm and are covered in 'knobs' (which are essential for locking onto the cell membrane of the host cell). The particles identified as HIV were not spherical in nature, they were considerably larger (approximately 120-240nm in diameter) and smooth. There are also other significant differences. It is characteristic for retroviruses to leave the host cell intact after replication, but the HI virus actually destroyed the host cell.

Of particular significance to the lawyer and his quest for proof, is the dissident's claim that, without scientifically isolating and identifying HIV as a retrovirus, it is impossible to identify an HIV-specific antibody - the basis of HIV testing. Antibodies are produced by the body's immune system in response to infectious agents (antigens), and HIV testing involved testing for the presence of HIV-specific antibodies (antibodies that are produced only when HIV is present) in the blood. If these antibodies are present, then it is accepted that the individual has been exposed to HIV and is therefore infected.

However, the dissidents question the origin of HIV-specific antibodies. Scientists involved in the initial isolation and identification of HIV used what they called an 'HIV-specific antibody' to prove the existence of the HIV. They said that, because these antibodies reacted when exposed to certain particles, the particles must be HIV. But scientists agree that the only way to prove that an antibody is specific to one antigen is first to isolate the antigen and then identify the only antibodies that are present when that antigen is present. It is, however, apparently impossible to prepare specific antibodies before the antigen to which they specific has been isolated. How then, ask the dissidents, could it be possible to have identified an HIV-specific antibody without first establishing that the antigen - in this case the retrovirus - exists? The point being made by the dissidents, it would appear, is that until, the nature of HIV is scientifically proved, it is impossible to say that it is the cause of AIDS. There are in fact other interesting and compelling reasons put forward by the dissidents to suggest that the cause of AIDS may, in itself, not even be a virus at all. For example, it is well known that viruses cannot survive outside of a host cell for more than a few hours, yet haemophiliacs have been known to contract AIDS from blood transfusions where the plasma is stored for months as a dry, flaky, yellowish powder in which a virus could apparently not survive. How would it have been possible for the haemophiliac to get AIDS from a virus if a virus cannot be so transferred?

These are some of the questions that remain unanswered, even after the various AIDS conferences and talk-shops. Until they are answered by science satisfactorily, the legal issue of whether a court ought to be entitled to assume that HIV causes AIDS is in doubt.

Conclusion

Despite this doubt, insurers can still avoid liability contractually - even if the cause of AIDS is uncertain - but they may have to revise their policy wording. If not and if Reinecke and Van der Merwe's approach is followed by the courts (in the case of the excepted risk in the policy is HIV-related and if the claim is incidental to the consequences of AIDS), then the onus of proving that HIV causes AIDS will fall on the shoulders of the insurer. This is an impossible onus to discharge according to the dissidents. If the insurer fails, as intimated, then it must be held liable to indemnify.

Kevin Hopkins Ba LLB (Rhodes) is a lecturer in law at the University of the Witwatersrand and Kim Wyness Mtech (Chiropratic (TWR) is a chiropractor in Johannesburg. De Rebus is the magazine of the Law Society of South Africa.