Clackamas County AIDS Relief Effort

AIDS History

AIDS origination controversy

UNAIDS Background Brief: HIV, AIDS and the reappearance of an old myth
March 2000
http://www.unaids.org/special/index.html

The human immunodeficiency virus (HIV) has been decisively established as the cause of AIDS. Notwithstanding the evidence, a small but vocal group has continued to question the link between HIV and AIDS. Periodically, this results in media attention and generates some renewed public interest in their views. Most recently, there has been controversy in the South African and international media over the South African government's announcement that it would convene an international panel to
reexamine the scientific evidence surrounding AIDS, including evidence regarding the cause and diagnosis of the disease. The debate has also recently resurfaced in other countries.

HISTORY OF THE CONTROVERSY

The argument that HIV does not cause AIDS first attracted broad public attention in an article, published in Cancer Research in 1987, written by Professor Peter Duesberg of the University of California in Berkeley. Duesberg's contentions were rejected by
the scientific community, but attracted attention in the
mainstream press and found resonance with specific groups outside the scientific community. For example, his attacks on the 'AIDS
establishment', whom he accused of perpetuating the myth of AIDS for their own ends, were appealing to a public who already had a
growing sense of disenchantment with the medical community more
broadly. Similarly, his attribution of AIDS to specific lifestyle
choices found favor with parts of society, especially those critical of the gay movement.

At the time that the controversy started, there were still some questions unanswered on the precise mechanisms of HIV disease.
Ten years later there is a more complete understanding of how HIV causes AIDS.

MYTHS AND CONSPIRACY THEORIES SURROUNDING DISEASE

There are many reasons why people may subscribe to myths or conspiracy theories about disease. AIDS, in particular, is a disease that lends itself to the perpetuation of myths and to different forms of denial. For example, myths that deny the existence of AIDS can respond to people's emotional needs or to a
desire to reassure themselves that they can avoid changing their behaviour. HIV is transmitted through behaviours that are
essentially private.

Visible symptoms of the disease only appear after many years, making it easier for people not to accept that HIV will eventually cause AIDS. Therefore, the idea of reexamining the evidence regarding the causes of AIDS may provide hope that if a
cause other than HIV is identified, a cure might more readily be found.

KEY MYTHS AND FACTS RELATING TO HIV AS THE CAUSE OF AIDS

MYTH ONE: HIV DOES NOT CAUSE AIDS. AIDS IS JUST A NEW NAME FOR
OLD DISEASES

AIDS stands for acquired immune deficiency syndrome.

Human Immunodeficiency Virus (HIV) infects cells of the immune system, mainly CD4 cells and macrophages, key elements of the cellular immune system, destroying or impairing their function in
the process. Progressive HIV infection results in the progressive depletion of the immune system, leading to immune deficiency. The
immune system is said to be deficient when it can no longer play its role. The cellular immune system is important to fight off
infections, and to keep cancers from developing. People with cellular immune deficiency are much more vulnerable to infections
such as Pneumocystis carinii pneumonia, toxoplasmosis, systemic and oesophageal candidiasis, generalized herpes zoster, cryptococcal meningitis, and to cancers such as Kaposi's sarcoma.
These diseases are very rare amongst people without immune
deficiency. Some of these diseases, namely those that are strongly associated with severe immunodeficiency, are called 'opportunistic' diseases, because they use the opportunity of a
weakened immune system to develop.

Immune deficiency can also be present as a consequence of rare inherited diseases, and be acquired through cancer chemotherapy or immunosuppressive therapy in transplant recipients. However, HIV infection is the most common cause of acquired immune deficiency. The symptom complex associated with acquired
deficiency of the cellular immune system was called 'AIDS' when people realized they were looking at an epidemic of acquired
immunodeficiency for which an explanation was lacking. It was soon apparent that the syndrome was frequent in groups with certain behavioural characteristics, such as homosexuals or
injecting drug users or certain geographical groups. The missing link that explained why some people in these groups developed
AIDS, and others with the same behavioral or ethnic backgrounds did not, was found in 1985, when HIV was discovered. In cohort
studies of such groups, presence of HIV infection predicted overwhelmingly who would develop AIDS.

HIV infection typically follows the following course: a) primary acute infection with a characteristic clinical picture; b)
prolonged period without obvious, visible symptoms - although laboratory studies can demonstrate continuous disease progression
and c) a severe immunodeficiency resulting in the development of
secondary opportunistic infections and tumors that, in turn,represent the major causes of death in AIDS patients. The spectrum of opportunistic infections may differ in different
geographical locations, depending on the prevalence of certain pathogens (parasites, fungi, bacteria and viruses) to which
immunocompromised individuals may be exposed.

The evidence that HIV causes AIDS is overwhelming. Numerous
laboratory, clinical research and epidemiological studies have shown, for example, that:

There is significant correlation between the level of viral production and viral load and disease prognosis. The onset of AIDS is greatly delayed in individuals who have low levels of
viral replication, while patients with high amounts of the virus in the blood and lymph nodes have a much worse prognosis.

When HIV infection is treated successfully with highly active antiretroviral therapy, the immune systems recovers partly and the disease manifestations of HIV infection often disappear, even if the patient had already progressed to AIDS. What symptoms remain is a function of the extent to which the immune system was
irreversibly damaged prior to the institution of therapy. The clinical response to therapy can be monitored and predicted by measurement of the amount of HIV in blood and lymph nodes.

The main risk factors for HIV transmission (unprotected
heterosexual or homosexual intercourse; blood transfusions; and needle-sharing during injection-drug use) are not new, but never
resulted in a massive increase of morbidity and mortality prior to the appearance of HIV.

AIDS and HIV infection are invariably linked in time, place and population groups.

Additional evidence that HIV causes AIDS comes from unfortunate accidental infections such as the one in which three laboratory
workers who had no other risk factors developed AIDS after
accidental exposure to a pure, molecularly cloned strain of HIV. In all three cases, HIV was isolated from the infected individual, sequenced and shown to be the infecting strain of the
virus.

MYTH TWO: AIDS CAN OCCUR WITHOUT HIV

The existence of immunodeficiency was documented long before the
onset of the AIDS epidemic but was extremely rare in the absence of cancer chemotherapy. These immunodeficiencies have a very
specific pathogenesis and clinical manifestations. Some very rare types of immunodeficiency occasionally present with the clinical
symptoms of AIDS. However, surveys conducted in many countries have shown the number of these cases to be insignificant compared
to the numbers cases of HIV-induced immune deficiency.

MYTH THREE: SEROPOSITIVITY TO HIV CAN BE WIDESPREAD WITHOUT AIDS

Speculation that HIV does not cause AIDS has in part been fuelled by arguments that point to the existence of groups of individuals
who have been HIV-positive for many years without progressing to AIDS.

The course of HIV infection and the development of AIDS vary significantly between different individuals indicating the presence of multiple factors which may influence the outcome of
infection. In the most reliable cohort studies conducted on individuals in different regions of the world amongst those who
do not receive antiretroviral therapy AIDS symptoms develop on average approximately 8 to 10 years after initial HIV infection. About 5-10% of HIV-positive individuals develop AIDS symptoms very rapidly during the first years of infection and about the
same proportion may be infected with HIV for 15 or more years without progressing to AIDS. It follows that the overwhelming
majority of people with HIV infection will develop AIDS unless treated with antiretroviral therapy in a timely manner.

MYTH FOUR: THE VALIDITY OF AIDS EPIDEMIOLOGICAL RESEARCH IS QUESTIONABLE BECAUSE HIV TESTING IS UNRELIABLE

Testing for the presence of infections often uses the detection of antibodies, that the human body produces in response to the presence of a pathogen These antibodies are specific to a given pathogen similar to a security lock and its key. Diagnosis of
infection using antibody testing is one of the best established concepts in medicine. Examples include the diagnosis of viral
hepatitis, rubella, and many other infectious diseases. Antibody testing for these diseases has never been questioned. HIV antibody tests exceed the performance of most other infectious
disease tests in both sensitivity and specificity. Recent HIV antibody tests have sensitivity and specificity in excess of 98%
and are therefore extremely reliable.

Developments in testing methodology also enabled detection of viral genetic material, antigens and the virus in body fluids and
cells. While not widely used for routine testing due to high cost and requirements in laboratory equipment, these tests have confirmed the validity of the antibody tests.

Due to under-diagnosis, under-reporting, and reporting delays, surveillance based on cases with clinical manifestations of the
acquired immune deficiency syndrome is unreliable in most
countries - especially those with weak health care systems. Thus, epidemiological data on the spread of HIV are most commonly based on the measurement of HIV levels in various populations. Such
studies use the antibody tests described above and are performed according to internationally accepted procedures, including
measures to ensure quality control.

Over the past decade many countries have built up surveillance systems that include well selected populations such as women
attending ante-natal care which allow for extrapolation to larger populations in the countries. More recently, population based studies in a series of countries have proven the reliability of
such systems. WHO and UNAIDS assist countries in their efforts to compile reliable estimates on prevalence and trends of HIV. Estimates resulting from these efforts are based on the best
available data in all countries. Studies that are based on small or questionable samples are excluded.