Introduction

"AIDS is caused by infection with a virus called human immunodeficiency virus (HIV). This virus is passed from one person to another through blood-to-blood and sexual contact."¹

That's the standard explanation of what causes AIDS. But what evidence do scientists have to support this theory? And why do some websites say that the world has got it terribly wrong – that HIV does not cause AIDS at all?

As an independent AIDS organisation founded in 1986, AVERT has taken a keen interest in the ongoing debate about what causes the disease. As well as investigating the consensus position, we have followed and carefully considered the arguments of the dissident minority who claim that HIV is harmless or even that it might not exist. This topic is vitally relevant to how our organisation works to prevent people developing AIDS and to help those suffering from the disease.

It is AVERT's considered opinion that the evidence that HIV causes AIDS is abundant and conclusive. This page outlines some of that evidence, while also mentioning how some dissidents have interpreted things differently. In particular, we'll look for proofs of the following:

• AIDS is a new epidemic disease
• AIDS does not occur without HIV
• HIV infection is the only factor that predicts who will develop AIDS
• National statistics support the HIV theory
• Modern antiretroviral treatment is highly beneficial.

Who doubts that HIV causes AIDS?

By far the most significant scientist to question the HIV/AIDS theory is Professor Peter Duesberg, a virologist at the University of California at Berkeley, who first wrote about this topic in 1987. Throughout the 1990s and into the new millennium, as HIV/AIDS researchers announced many new discoveries and amassed huge volumes of data, Dr Duesberg remained unconvinced. He admits that HIV exists, but he maintains that it is harmless, and that AIDS is caused by non-contagious factors including drug abuse, malnutrition, and even the very drugs used to combat HIV.²

Other dissidents (often called "denialists" by their opponents) include the Perth Group of medical scientists from Australia. The Perth Group (led by Dr Eleni Papadopulos) claims that nobody has conclusively proven the existence of HIV, so any proof that HIV causes AIDS has no foundation.³

Dissident arguments have received attention from the popular media, as well as from scientific journals. And with the rise of the Internet, alternative views have found a much wider audience, so that scarcely anyone interested in AIDS can have failed to hear of them.

Some of their followers are intrigued by conspiracy theories involving sinister drug companies or government persecution of minority groups. But alternative explanations can also appeal to those diagnosed with HIV or AIDS, who read that their condition might not be fatal, that they shouldn't take toxic drugs, and that unprotected sex poses no risks. Even a few AIDS service organisations have adopted non-HIV viewpoints.⁴

However, the proportion of scientists who doubt that HIV causes AIDS is tiny, and shows no sign of increasing. Interest in dissident views appears to have dwindled after the excitement surrounding Thabo Mbeki's AIDS panel and the Durban Declaration in 2000. It seems likely that new and better evidence, including the obvious benefits of modern drug treatments, has caused many former-dissidents to change their minds.

What is AIDS?

Confusingly, there are many definitions of AIDS. Before we can begin to look for a cause, we must first work out exactly what type of illness we are talking about.

In early 1981, doctors in New York and California began to report some bizarre new disease outbreaks. In both places, previously healthy young men were showing up with rare illnesses including Kaposi's sarcoma and PCP, which until then had been virtually unheard of among such people. Within months, dozens of similar cases had been reported in 23 American states and in the UK, representing the start of a massive and unprecedented epidemic.⁵

Doctors soon discovered a distinctive feature of these cases. More than anything else, the men were lacking a specific type of white blood cell, which is essential to a healthy immune system. Normally, people have between 600 and 1,500 "CD4+ cells" (also called T helper cells) in each cubic millimetre of their blood. But the men with the strange new disease typically had very much lower levels. This immune deficiency explained why they were so vulnerable to disease.

The cases were clearly related in time and by population group (initially gay men and injecting drug users). No cause of immune deficiency could be found, but it was clearly not inherited. Scientists therefore grouped together all of these strange new cases under the heading "Acquired Immune Deficiency Syndrome" – or AIDS for short.

In 1982, no-one claimed to know what caused AIDS, so the first definition was based on the diagnosis of one of 13 rare diseases known to be linked to immune deficiency (including Kaposi's sarcoma and PCP) "occurring in a person with no known cause for diminished resistance to that disease".⁶ Over the years, the US definition has been refined as hundreds of thousands of similar cases have been documented, sometimes involving other diseases, but always associated with the same distinctive immune deficiency.⁷ Other definitions have also been developed to suit different situations elsewhere in the world.⁸

The latest US AIDS definition was created in 1993. Under this definition, someone has AIDS if they have one of 26 specific diseases (28 in children) but no known cause of immune deficiency other than HIV (with some diseases, a positive HIV test is required); or if they have a CD4+ cell count below 200 cells per cubic millimetre of blood, or less than 14% of all lymphocytes, plus a positive HIV test.⁹

Europe and Canada have similar AIDS definitions to the US, but do not include low CD4+ cell counts.

The main purpose of all AIDS definitions is to enable surveillance, so that authorities can gauge the extent of the problem and respond accordingly.

Problems with the definition?

The US AIDS definition usually requires a positive HIV test. This means that any connection between HIV and AIDS is artificially strengthened because HIV-free AIDS cases are discounted. In other words, the definition already assumes that HIV causes AIDS, so it can't be used to prove that theory. However, it is possible to redefine AIDS without reference to HIV or even to any other diseases.

The immune deficiency definition of AIDS requires a CD4+ cell count consistently below 200 cells per cubic millimetre of blood, which cannot be explained by any factor other than HIV (such as cancer, malnutrition, radiation or chemotherapy). No HIV test is required.

It turns out that the vast majority of people who have been diagnosed with AIDS in the USA or in Europe fit these criteria. They form a population that barely existed before 1980, but which now numbers hundreds of thousands. People with such severe immune deficiency are at very high risk of developing serious illnesses like PCP and usually die quickly (unless they take antiretroviral drugs). We can use this simple, unambiguous definition to test the association between HIV and AIDS.^{10, 11}

How can we prove that HIV causes AIDS?

Koch's Postulates

In the nineteenth century, the German scientist Robert Koch developed a set of four "postulates" to guide people trying to prove that a germ causes a disease. Scientists agree that if HIV satisfies all of these conditions with regard to AIDS then it must be the cause of AIDS:¹²

Koch 1: The germ must be found in every person with the disease
Koch 2: The germ must be isolated from someone who has the disease and grown in pure culture
Koch 3: The germ must cause the disease when introduced into a healthy person
Koch 4: The germ must be re-isolated from the infected person

Other evidence

Even Koch recognized that in some cases not all of his conditions could be met, so other evidence should also be considered. This is particularly true when the germ is a virus rather than a bacterium.¹³ Modern scientists are willing to consider a wide range of evidence. In particular, we can ask five key questions:

• Do surveillance statistics show a relationship between HIV and AIDS?
• How well does HIV infection predict illness and death?
• Do drugs designed to combat HIV benefit people with AIDS?
• Are there any credible causes besides HIV?
• What can we learn from Africa?

We'll address these questions after looking at Koch's Postulates.

Koch 1: The germ must be found in every person with the disease

The US Centers for Disease Control and Prevention (CDC) defines a condition called idiopathic CD4+ T-lymphocytopenia, or ICL for short. Someone is diagnosed with ICL if they have a CD4+ cell count below 300 cells per cubic millimeter, or 20% of all T lymphocytes, on at least two occasions, but have no detectable HIV infection, nor any other known cause of immune deficiency (such as cancer therapy). As many dissidents have pointed out, this is essentially a definition of HIV-free AIDS. So just how common is this condition?

In 1993, a CDC task force published the results of an exhaustive survey of ICL in the USA. They had reviewed 230,179 AIDS-like cases reported since 1983 and identified 47 patients with ICL (plus 127 uncertain cases). All of the other people with AIDS who had received an HIV test produced a positive result. What's more, the team closely investigated the ICL cases and discovered that they didn't fit the usual AIDS profile. There were 29 male and 18 female patients, and 39 of them were white (4 others were of Asian descent). In 29 cases, the researchers couldn't fit the people into conventional risk groups for AIDS (homosexual men, haemophiliacs, injecting drug users, and the sexual partners of such groups). Whatever these 47 cases represent, they don't seem to be typical of the massive epidemic that we're interested in.¹⁴

The findings of the ICL survey are backed up by large-scale monitoring studies, including the Multicenter AIDS Cohort Study (MACS). During the MACS, scientists monitored the health of 2,713 gay and bisexual men who tested negative for HIV antibodies. Over several years, only one of these men had persistently low CD4+ cell counts, and he was undergoing cancer therapy designed to weaken his immune system. Similar results have been found among blood donors, recipients of blood and blood products, injecting drug users and other groups.¹⁵

As Dr Duesberg has pointed out, quite a lot of people (mostly in the early 1980s) have been diagnosed with AIDS in the USA despite never taking an HIV test, and nobody knows whether these people were HIV-positive or not. However, based on the much larger sample of people who have been tested, Koch's first postulate has certainly been satisfied. The only way by which dissidents have been able to come up with significant numbers of HIV-free "AIDS" cases is by using much looser definitions of AIDS. Such definitions include many people with milder immune deficiency, which is generally not fatal.^{16, 17}

What about false positive test results?

Diagnosis of infection using antibody testing is one of the best-established concepts in medicine. The World Health Organisation and the US National Institutes of Health agree that modern HIV tests are extremely reliable, and are even more accurate than most other infectious disease tests.^{18, 19}

Nevertheless, some dissidents have tried to dismiss the association between AIDS and HIV by claiming that many of those who test positive are not really infected with HIV. In particular, Christine Johnson has listed dozens of conditions reported to have produced false positive reactions on at least one occasion (under particular circumstances, using particular test kits).²⁰

It is true that no test is perfect. However, what the dissidents usually don't mention is how rare the reports of false positive results have been, especially in recent years. Nor do they mention that every person who uses a test kit is trained to spot the telltale signs of a suspicious result, and to keep testing by various methods until no doubt remains. The conditions that cause false positive results are not only very uncommon, but are also typically short-lived, whereas HIV infection does not go away.^{21, 22}

The dissident theory cannot satisfactorily explain why scientists have been able to use various techniques to detect the virus itself in virtually everyone with AIDS, as well as in most people with positive antibody test results, as explained in the next section. These methods (including DNA PCR, RNA PCR and viral culture) are not affected by any of the factors said to produce false positive results in antibody testing. Nor can the alternative theory fully explain why the association between AIDS and antibody test results is so exceptionally strong: virtually everyone with AIDS tests positive, while more than 99% of the US public tests negative.

Koch 2: The germ must be isolated from someone who has the disease and grown in pure culture

Koch required that the germ be isolated from all other material that could possibly cause disease, so that his third and fourth postulates could be properly tested.

In May 1983, Luc Montagnier and his colleagues in France reported the isolation of a virus they named LAV, which infected and killed CD4+ cells. A year later, the American Robert Gallo announced he had isolated a virus called HTLV-III and found a way to grow it in culture. It was later discovered that the two viruses were genetically indistinguishable, and they were renamed HIV.²³

Researchers have been able to isolate and culture HIV from most AIDS patients whom they have examined (as well as from many other people with HIV antibodies).²⁴ They have isolated the virus from blood cells (called PBMC), blood plasma, lymph nodes, semen, vaginal fluids, amniotic fluids, bone marrow, brain, cerebrospinal fluid, intestines, breast milk, saliva, urine and tears, and cultured it in various cell types.²⁵ Images taken using electron microscopy and other techniques have shown virus-like particles that have the size, shape, structure, density, proteins and behaviour expected of retroviruses.^{26, 27}

Techniques developed in the mid-1990s have made it much easier to extract and sequence the complete genetic material (genome) of an isolated virus.^{28, 29} The Los Alamos database now contains hundreds of full-length HIV genomes from around the world, each containing the same nine genes.³⁰ Based on genetic similarities and differences, these sequences have been used to define family trees of HIV types, groups and subtypes as well as hybrids called recombinant forms.³¹

Whole or partial HIV genomes have been detected in numerous AIDS patients, using a technique called PCR (the same technology is used to find DNA evidence with which to convict murderers or to settle paternity suits, as well as to detect the germs that cause hepatitis, tuberculosis and other diseases). Almost everyone who tests positive for HIV genetic material also tests positive for HIV antibodies, and vice versa, while those who test negative for one thing also lack the other.³² People who have been exposed to the same source of infection contain genetically very similar HIV strains – similar enough for court convictions.³³

Scientists have used a standard technique of genetic science called molecular cloning to obtain highly purified HIV. Genetic material extracted using PCR or other techniques has been introduced into bacteria or other cells (usually using phages or plasmids), which then produce many exact copies (clones) of the viral genes. If cloned viral genomes are inserted (transfected) into human cells then they produce a new generation of infectious HIV particles, which are free from contamination.³⁴

What about the Perth Group?

A small band of Australian scientists claims HIV has never been properly isolated. The Perth Group has set a challenge offering a cash reward to anyone who achieves HIV isolation according to a special set of rules, and they insist that no other method is valid.³⁵

The Group has never said that HIV does not exist. Instead, because they've not yet awarded the prize, they say that HIV has never been conclusively proven to exist. They don't trust any HIV tests, because they have not been verified using their "gold standard" of isolated virus. The Group uses the isolation argument to dismiss just about every type of evidence that HIV causes AIDS.³⁶

Almost all virologists believe that the Perth Group's conditions are unnecessary. They say nobody has ever used such rules to isolate any type of virus, and that other techniques are much more effective. According to the Perth Group's rules, nobody has isolated or proven the existence of the viruses said to cause small pox, influenza, measles, mumps and yellow fever.

Some experts say the Group's rules are deliberately unreasonable, and the small print ensures that the prize will never be awarded, even though all of the main requirements have already been met.^{37, 38} Dr Duesberg is among those who have tried in vain to claim the reward by insisting that HIV definitely exists and has been isolated using the most rigorous methods available.³⁹ Still, no experimenter has been quite fastidious enough to satisfy the Perth Group.^{40, 41}

Koch 3 and 4: The germ must cause the disease when introduced into a healthy person, and the germ must be re-isolated from the infected person

The third and fourth postulates are much harder to prove. It's considered unethical to deliberately infect someone with pure HIV, so such an experiment has never taken place. However, there is no reason why the transmission has to be deliberate.

There have been three reports of lab workers developing immune deficiency after accidentally exposing themselves to purified, cloned HIV. As mentioned above, such cloned virus is free of all contamination from the original source. None of these people fitted conventional risk groups for the disease. In each case, HIV was isolated from the individual and, by genetic sequencing, was found to be the strain to which they'd been exposed. One of these workers developed PCP and had a CD4+ cell count below 50 cells before starting antiretroviral treatment.⁴²

Still, three examples don't make a totally conclusive proof, so it's worth looking for more evidence.

One line of argument can be based on animal experiments.⁴³ In some studies, chimpanzees deliberately infected with HIV-1 have gone on to develop AIDS-like conditions (though this appears to be rare),⁴⁴ while HIV-2 has had the same effect on baboons.⁴⁵ Macaque monkeys have developed AIDS after being infected with a hybrid virus called SHIV, which contains genes taken from HIV.⁴⁶ And in mice engineered to have a human immune system, HIV produces the same patterns of disease as in humans.⁴⁷

If we're prepared to bend the rules a bit further, we can look at people who've been infected with non-purified HIV. Such cases at least suggest that AIDS is infectious, though they don't rule out the possibility that more than one germ is involved.

Scientists have documented numerous cases of people developing AIDS after becoming infected with HIV as a result of blood transfusions, drug use, mother-to-child transmission, occupational exposure and sexual transmission. In such cases, they have recorded the development of HIV antibodies (seroconversion) using a series of blood tests, before progression to AIDS. Seroconversion is often accompanied by a mild flu-like illness or swollen glands.⁴⁸

Until the mid-1990s, nobody claimed that HIV had fulfilled Koch's last two postulates. Even today, the proof is not quite perfect. But many scientists believe the evidence is now strong enough to put the case beyond reasonable doubt.⁴⁹

Surveillance statistics

Most countries with high rates of HIV have conducted regular national HIV surveillance studies since the early 1990s. AIDS case reporting began much earlier, in the early 1980s. All of the data are available to the public online.

AIDS case statistics are generally expected to underestimate the scale of AIDS epidemics, especially in African countries, because many cases go unreported. However, it is reasonable to assume that trends in the number of reports should roughly correspond to trends in the overall epidemic.

Of all countries, Thailand has one of the best records of HIV surveillance, with around 70 sites included each year since 1990. Thailand also has relatively good infrastructure for the reporting of AIDS cases. On the right is a graph showing trends in Thai statistics between 1984 and 2000 (later reports are omitted because they may be affected by reporting delays).⁵⁰

The graph shows that during the 1990s there was a dramatic increase in AIDS case reports. This increase came after a sharp rise in HIV prevalence, with a time lag of a few years (nearly 200,000 HIV tests conducted between 1985 and 1987 produced fewer than 100 positive results).⁵¹ Such a time lag is exactly what the HIV theory predicts, because most people are expected to live with HIV for some time before developing AIDS.

Thailand is not unique. Exactly the same pattern can be seen in statistics worldwide, from Albania (where HIV and AIDS are both very rare) to Zimbabwe (where AIDS case reports soared during 1987-95, following the trend in HIV prevalence).^{52, 53}

This trend can also be seen within countries, since regions, cities or population groups with higher HIV prevalence report a higher rate of AIDS.⁵⁴

How well does HIV infection predict illness and death?

A mountain of evidence shows that much can be predicted from a positive test result. For example:

• At least half of people develop AIDS-defining conditions within 10 years of HIV infection, if they don't take antiretroviral drugs. Only a few do not develop AIDS within 20 years.⁵⁵

• HIV-positive Americans and Canadians are over 1,000 times more likely to develop AIDS-defining diseases (such as PCP and Kaposi's sarcoma) than those who test negative.^{56, 57}

• A study in Uganda found that HIV-positive people were 16 times more likely to die over five years than those who tested negative. For those aged 25-34 years old, HIV infection raised the death rate by a factor of 27.⁵⁸ Similar results have been found in Tanzania, Malawi, Rwanda and other parts of Africa.^{59, 60, 61, 62}

• A study of female sex workers in Thailand found the death rate to be over 50 times greater among those who tested positive. All of the positive women died of conditions associated with immune deficiency, compared with none of the negative women.⁶³

• During a 16-year study of homosexual and bisexual men in the US, 60% of HIV-positives died compared with 2.3% of HIV-negatives.⁶⁴

• In the UK between 1979 and 1992, death rates increased massively among HIV-positive haemophiliacs, but remained unchanged among the rest.⁶⁵ Similar research in the USA found that HIV-positive haemophiliacs were 11 times more likely to die over a ten-year period, compared with those who tested negative.⁶⁶

• In a European study of babies born to HIV-positive women, none of those who tested negative developed AIDS, compared to 30% of those who tested positive. By their first birthday, 17% of the HIV-positive babies had died.⁶⁷

Alternative theories cannot explain why HIV tests should be so effective at predicting illness and death in so many diverse groups of people from all parts of the world.

It is even possible to predict the likelihood that someone will soon develop AIDS by measuring the amount of HIV in their blood, which is known as "viral load". Such measurements can be made using PCR, branched-DNA signal-amplification (bDNA) or quantitative microculture techniques. For example, the table below shows just how useful bDNA forecasts can be:⁶⁸

Viral load (RNA copies per millilitre of blood plasma)	Proportion of patients developing AIDS within six years
less than 500	5.4%
501-3,000	16.6%
3,001-10,000	31.7%
10,001-30,000	55.2%
more than 30,000	80.0%

Dr Kary Mullis, who invented the PCR process, has questioned its ability to measure viral load. However, his arguments have been theoretical, and are not backed up by large-scale surveys, which have repeatedly shown a clear association between viral load and progression to AIDS (in all parts of the world).^{69, 70} Dr Mullis' objections do not apply to the unrelated bDNA and quantitative microculture techniques. Modern bDNA tests produce very similar viral load counts to modern PCR tests (though this was less true of some earlier models).⁷¹ As with antibody tests, there is no convincing alternative explanation for why viral load counts should be such useful indicators.

Effective drug treatments

The first drug licensed for fighting HIV was zidovudine, better known as AZT, which gained approval in 1987. Studies found that AZT reduced viral load in HIV-positive people, and improved the health of those with AIDS. However, the positive effects of AZT did not last very long, and a major investigation known as the Concorde Study found that people who started taking the drug shortly after HIV infection received little or no long-term benefit (though neither did they fare any worse).^{72, 73, 74}

Since the mid-1990s, other types of anti-HIV drugs have also been available, including protease inhibitors, which were designed specifically to target HIV proteins.⁷⁵ It has been found that when different drugs are taken together, they bring much longer-lasting benefits than AZT alone.

Large-scale, controlled studies have consistently shown that the right combination of drugs can dramatically reduce incidence of AIDS and death. One drug is better than none, and two is better than one, but a combination of three drugs (from two different classes) is much better still. Virologists explain that this is because HIV finds it a lot harder to evolve resistance to several drugs at the same time.^{76, 77, 78}

Recent studies in Africa suggest that treatment is as effective there as it is in Europe and America.⁷⁹

In most people, the drugs cause a sharp fall in viral load. However, some patients do not experience such an effect, and these people are far more likely to develop AIDS or to die. This fact in itself very strongly suggests that HIV causes AIDS.⁸⁰

The benefits of more effective drug treatments can be seen in national statistics from rich countries in which most people have had access to them. On the right is a graph of HIV diagnoses, AIDS diagnoses and AIDS deaths in the UK between 1990 and 2001. This graph shows that the numbers of AIDS diagnoses and deaths dropped significantly between the end of 1995 and the end of 1998. This trend followed the widespread introduction of combination therapy.⁸¹

Similar patterns can be seen in statistics from other European countries, Canada, Australia and the USA.⁸² However, it should be noted that US statistics were distorted during the period 1990-1996 because of a major expansion in the AIDS surveillance case definition in 1993. For the first time, people could be diagnosed with AIDS on the basis of a low CD4+ cell count. The majority of these people would have gone on to develop AIDS-defining diseases before death, so would have been included in the statistics anyway, but the change in definition meant they were diagnosed earlier.

The distortion caused by the change in definition was temporary, and cannot account for the major declines in AIDS diagnoses and deaths that occurred in the USA during the late 1990s. Nor can the declines be explained by trends in HIV incidence.^{83, 84, 85} Incidence of AIDS-defining infections like PCP rose during the early 1990s and then decreased significantly between 1995 and 1998.^{86, 87}

The ability of antiretroviral drugs to prevent mother-to-child HIV transmission has been demonstrated around the world.⁸⁸ Following the widespread introduction of these drugs during pregnancy, the number of reported AIDS cases among American children has fallen to around 100 per year, compared to nearly 1,000 per year in the early 1990s.⁸⁹

Drug abuse and other factors

Dissidents who claim that HIV does not cause AIDS have felt compelled to come up with alternative causes. These generally include recreational drugs (including heroin, cocaine, amphetamines and nitrite inhalants known as "poppers"), malnutrition, lack of clean drinking water, clotting factors used in blood transfusions, and anti-HIV drugs such as AZT. Some groups also suggest semen, "immune overload", antibiotics, benzene, stress, or lack of sleep.

In the early 1980s, when only a small number of AIDS cases had been reported, the medical establishment gave some of these possible causes very serious consideration. But such theories quickly lost favour as more cases emerged among men, women and children who did not fit the established risk groups, and it was established that affected people had been exposed to the bodily fluids of other affected people.⁹⁰

Today, most scientists believe that controlled studies of drug users, heterosexuals, homosexuals, haemophiliacs and twin babies have consistently shown that HIV is the only factor that predicts who will develop AIDS. Associations in time and place between trends in drug use or promiscuity and trends in AIDS diagnoses are considered much too weak to prove causation.^{91, 92}

Dr Duesberg has claimed that some HIV-negative drug users have developed AIDS-like immune abnormalities and diseases. But his definition of "AIDS-like" is very vague, and none of these cases would merit an AIDS diagnosis.^{93, 94, 95}

Antiretroviral drugs can have toxic side effects. However, there is no evidence that anti-HIV drugs cause the severe immune deficiency typical of AIDS, and there is abundant evidence that currently recommended courses of antiretroviral therapy can improve the length and quality of life of HIV-positive people.^{96, 97, 98, 99}

Certain AIDS-related diseases are more common among some population groups than among others. This is not surprising, and it does not mean that they cannot all have the same underlying cause.^{100, 101}

Severe malnutrition is a known cause of immune deficiency. That is why all definitions of AIDS specify that there must be no evidence of severe malnutrition. Poor nutrition is also thought to make people with HIV more vulnerable to illness, so improving diet is an essential component of programmes to help HIV-infected people around the world. Still, such actions are not by themselves sufficient, because thousands of Africans who are well fed and cared for continue to die from AIDS. As the next section explains, there is no evidence that deterioration in diet or living standards can explain AIDS in Africa, which appears to be a totally new disease.

AIDS in Africa

Some dissidents claim there is no great new AIDS epidemic in Africa, just the same old diseases caused by poverty, hunger and poor sanitation. They say that official statistics are misleading because AIDS in Africa may be diagnosed on the basis of various clinical symptoms without an HIV test if none is available.¹⁰² We'll challenge these claims using four lines of argument.

Firstly, medical records from a number of African countries show marked increases in a number of AIDS-related diseases during the late 1970s and early 1980s. These records suggest that AIDS was probably rare or non-existent before that time.¹⁰³

Secondly, as discussed above, numerous studies have found that people who test positive for HIV face a much higher risk of illness and death. Surveillance studies show that HIV prevalence rates have soared across sub-Saharan Africa since the early 1980s, and are now extremely high. It is therefore reasonable to estimate that millions are ill and dying.¹⁰⁴

Thirdly, since the early 1980s, African countries with high HIV prevalence have suffered increased burdens of disease and death, as measured by censuses and surveys. For example:

• Between the 1980s and mid 1990s, adult death rates rose significantly in countries where HIV had been widespread for many years (such as Uganda, Zambia and Zimbabwe), but not in countries where rates had been lower.^{105, 106}

• Increases in death and disease have disproportionately affected young and middle-aged adults, especially those living in urban areas. Relatively well-paid professionals including teachers and doctors have been among the worst hit. This pattern is not typical of diseases caused by malnutrition or dirty water, which generally target the poor and the elderly.^{107, 108, 109}

• In several countries, the number of orphans has risen so dramatically that communities can no longer cope, and child-headed households are now commonplace. Such changes indicate that sexually active adults are dying while children (and the elderly) are surviving. Household surveys have revealed a strong correlation between rates of orphanhood and adult HIV prevalence.^{110, 111, 112}

• Patterns of disease have changed. For example, rates of Kaposi's sarcoma have soared,¹¹³ and tuberculosis - which was once confined to the poor, the weak and the elderly - today kills numerous well-fed Africans in the prime of life.^{114, 115}

Not all of sub-Saharan Africa has been equally affected by the recent changes. For example, Southern Africa has suffered much more than Western Africa, even though the regions have experienced similarly high levels of extreme poverty, malaria, food shortages and conflict. The only factor associated with the changes is HIV prevalence.^{116, 117}

Fourthly, the number of reported AIDS cases has risen across sub-Saharan Africa. Most experts believe these statistics vastly underestimate the scale of the epidemics because the reporting systems are inadequate. This inadequacy is partly due to frequent misdiagnosis (compounded by AIDS-related stigma), but is mostly due to poor infrastructure and lack of access to healthcare. In addition, the quality of the reporting systems varies from one country to another. Nevertheless, it is possible to spot two clear patterns in the data.

The first obvious trend is that the number of reported AIDS cases increased everywhere during the 1980s. As in all other parts of the world, this increase followed a rise in HIV prevalence. The second trend concerns the number of AIDS cases reported per million of population. In general, the highest rates have been recorded by Southern African countries where HIV has been widespread for many years, while the lowest rates tend to come from Western African countries with historically much lower HIV prevalence. The lowest AIDS rate of all is reported by the island nation of Madagascar, where until recently HIV was extremely rare.¹¹⁸

The only major exception to the pattern in AIDS case rates is South Africa, which has reported relatively low figures. However, HIV prevalence did not reach very high levels in South Africa until the mid-1990s, several years later than in nearby countries such as Zambia and Zimbabwe. In addition, South Africa stopped reporting AIDS cases in 1996, before most other African countries, and before the rise in HIV had had a chance to take effect.¹¹⁹

Compelling evidence of the impact of AIDS in South Africa since that time comes from studies of death certificates. These show that the annual number of reported deaths (from all causes) rose by 57% between 1997 and 2002. Among those aged 25-49 years old, the increase was 116%.¹²⁰ Rates of death from AIDS-related conditions increased according to a distinctive age distribution, which peaked among the age groups 0-4 and 25-49 years. Other conditions showed no such pattern. The estimated number of AIDS deaths based on these data is similar to estimates based on HIV prevalence.¹²¹

What we don't know

There are still a few things we don't know about HIV and AIDS.

For example, we don't really know why both HIV and AIDS have become generally common in some African countries but not in Europe or the US – though we do have some theories. Contributing factors include the much higher prevalence of untreated sexually transmitted diseases in Africa (which greatly increase the chances of HIV transmission) and, quite possibly, differences between HIV subtypes. In addition, people who have poorer general health (including those who have malaria or tuberculosis) tend to have more HIV in their bodily fluids, which makes them more likely to transmit the virus.

Different patterns of sexual networking also have an effect. Viral loads are especially high during the first few weeks after infection, so the risk of transmission is then much higher. This means that people who have several concurrent sexual partners are able to spread the virus very efficiently before they test positive or fall ill.^{122, 123, 124, 125, 126}

Due to lack of access to HIV testing and treatment, as well as educational and cultural factors, the vast majority of Africans do not know their HIV status, and many people, especially women, find it very difficult to adopt strategies that would lower their risk of becoming infected or of infecting others.

The concentration of an infectious disease among particular groups is not unusual. Hepatitis B is transmitted via much the same routes as HIV, and in Western countries it has similar risk groups. Hepatitis C (which is primarily spread via blood) is largely confined to injecting drug users, and recent increases in syphilis (usually sexually transmitted) have been fuelled by outbreaks among men who have sex with men. Surveillance statistics from throughout the Western world show that AIDS is becoming increasingly common outside the traditional risk groups, following a similar trend in HIV cases. In 2003, around a third of new American AIDS diagnoses, and two-thirds of those among women, occurred among non-drug using heterosexuals.¹²⁷

Something else we don't fully understand is how HIV causes AIDS. Again, however, we do have some theories, which explain how the virus might be able to stop the immune system working properly in a number of ways, not just by directly killing cells.¹²⁸ Ignorance about precisely how something happens is not proof that it does not happen.

Conclusion

There is no single scientific paper that proves HIV causes AIDS. Instead there are tens of thousands of papers containing a wide range of evidence that, taken together, make the case overwhelming.

People should be encouraged to question scientific orthodoxy. However, the views of AIDS dissidents, which have been well known for many years and thoroughly debated in scientific journals, have failed to win support. The core arguments of the Perth Group (that HIV has not been isolated according to their own particular rules) and Dr Duesberg (that no one can explain precisely how HIV causes AIDS) do not invalidate the wide range of evidence outlined on this page. The HIV theory is compelling because it provides a simple, unique cause that consistently accounts for all of the observed phenomena.

As an independent AIDS organisation, AVERT is primarily interested in what works. Studies have repeatedly shown that antibody testing is a highly effective way of predicting risk for AIDS; that modern antiretroviral treatment brings dramatic benefits; and that people who avoid exposure to HIV do not get AIDS. We will therefore continue wholeheartedly to recommend these things.

Related sections

• HIV structure, subtypes and origins
• History of HIV and AIDS
• HIV and AIDS statistics
• AIDS in Africa

Last updated November 3, 2005