What is AIDS?
AIDS stands for acquired immune deficiency syndrome.
AIDS is the result of damage to the immune system. A damaged immune system is unable to protect the body against certain specific ‘opportunistic’ infections and tumours.
These infections and tumours are called opportunistic because they are caused by organisms normally controlled by the immune system, but that ‘take the opportunity’ to cause disease when the immune system has been damaged.
The timing and types of clinical problems affecting persons with AID can vary widely and this is why it is termed a syndrome. AIDS is a collection of different signs and symptoms that are all part of the same underlying medical condition, human immunodeficiency virus infection.
Infection with HIV is the necessary precondition for the development of AIDS; a fact widely acknowledged throughout the scientific community.
It is possible for someone’s immune system to be compromised through mechanisms other than HIV infection, leading to some of the same infections that are seen in AIDS. A number of rare congenital immunodeficiencies, certain blood diseases, chemotherapy, the drugs given after organ transplantation, and idiopathic CD4 lymphocytopenia can all cause immune suppression.
Although it is clear that HIV has a central role in the development of AIDS, questions remain concerning some of the specific mechanisms by which HIV damages the immune system. This system is complex and can be affected in many ways by a retrovirus such as HIV. The role that other co-factors play in the development of immune damage is under investigation.
There are a minority who deny that HIV causes AIDS. Claims have been made that AIDS is the result of an immoderate lifestyle; that an artificial link was created in the interests of profit by scientists and pharmaceutical companies; or that AIDS and/or the drugs developed to treat HIV are part of a racially motivated conspiracy. While no back-up for these theories has been found, the arguments are used to bring welcome notoriety to some or as a justification for others in a position of power to withhold funding of treatment. Absence of treatment has led to increased transmission and unnecessary morbidity and mortality.
There are three established criteria used to prove a link between a pathogenic (capable of causing disease) agent and a disease. There must be an epidemiological association. That is, the suspected cause must be strongly associated with the disease. Numerous studies, done over time and around the world, demonstrate that people with AIDS have antibodies to HIV. Modern culture techniques and tests such as the polymerase chain reaction (PCR) can identify the presence of HIV in patients with AIDS.
Secondly, there must be the ability to propagate the pathogen outside the host. This has been done with animal models.
The third tenet, that transfer of a pathogen from one person to someone previously uninfected can produce disease, has been made obvious in many ways including accidental occupational exposures resulting in AIDS or a diagnosis of AIDS in infants born to HIV-infected mothers. The notion that HIV does not cause AIDS bears discussion only because it is still being used by some to justify the denial of treatment and care to others.