AIDS

Acquired Immune Deficiency Syndrome (AIDS) is an infectious disease which
causes degeneration of the body's immune system. It is caused by the Human
Immunodeficiency Virus (HIV), a virus transmitted through bodily fluids such
as blood and semen. The most common ways to contract HIV include unprotected
sexual activity and the use of unsterilized needles by users of intravenous
recreational drugs. Blood transfusions of contaminated blood as well as
blood products to treat hemophilia have also been major routes of infection.

Not everyone who is infected with the HIV virus is considered to have AIDS.
The AIDS diagnosis is usually made when a certain level of damage has been
done to the immune system and is defined by the occurrence of opportunistic
infections. Opportunistic infections are caused by agents usually unable to
induce diseases in healthy humans. Up until that point, the person is
considered simply HIV-positive. The immune damage can be quantified by the
decrease of the helper T cell count, the HIV target cells in the blood. If
the person's T-cell count has fallen below 200, an antiretroviral treatment
is indicated.

History of the AIDS problem

HIV is closely related to viruses causing AIDS-like diseases in many
primates, and it is generally believed to have been transferred from animals
to humans at some time during the early twentieth century, though some
evidence suggests it may have been transferred earlier in several isolated
cases. The exact animal source, time, and location of the transfer (or
indeed, how many transfers there were) is not known. A virus virtually
identical to human HIV (known as Simian Immunodeficiency Virus, or SIV) has
been found in chimpanzees, but it is not certain that the transfer was from
chimps to humans or whether both chimps and humans were infected from a
third source.

Scientific studies have suggested the virus spread initially in West Africa,
but it is possible that there were several separate "initial sources",
including somewhere in South America. The earliest sample known to contain
HIV was taken in 1959 in what is now the Democratic Republic of the Congo.
Other early samples include one from an American male who died in 1969, and
a Norwegian sailor in 1976.

A misconception holds that the virus was introduced to North America by one
person, Patient Zero (q.v.).

Effects of AIDS

HIV causes disease by infecting the CD4+ T cells. These are a subset of
leukocytes (white blood cells) that normally coordinate the immune response
to infection. By using CD4+ T cells to replicate itself, HIV spreads
throughout the body and at the same time depletes the very cells that the
body needs to fight the virus. Once a HIV+ individual's CD4+ T cell count
has decreased to a certain threshold, they are prone to a range of diseases
that the body can normally control. These opportunistic infections are
usually the cause of death.

AIDS Prevention

HIV infection is entirely preventable by following simple, basic
precautions. The only known cause of transmission is the exchange of bodily fluids.

   * Use a condom during all sexual activity. Anal sex is a particularly
     high-risk behavior. A few people have been infected with HIV from
     giving oral sex to an infected partner, but it is considered very low
     risk. If you want to be absolutely certain you're safe, use a condom
     (or dental dam for cunnilingus) even during oral sex.
   * Do not share needles. If you use drugs intravenously, such as heroin,
     do not share your needle with someone else, and do not use a needle
     that has been used by others. In many places you can find a local
     needle exchange program where you can trade a used needle for a clean
     one, without any legal hassles.
   * Medical workers who follow universal precautions or body substance
     isolation can prevent the spread of HIV from patients to workers, and
     from patient to patient. The risk of being infected with HIV from a
     single needlestick is less than 1 in 200. Post-exposure prophylaxis
     with anti-HIV drugs can further reduce that small risk.

AIDS Treatment

There is still no known cure for AIDS according to allopaths, and many
people still die every year, particularly in Third World countries where
treatments are either not available or prohibitively expensive. Current and
experimental treatments for AIDS are covered in the HIV section. Work on a
vaccine continues, but progress has been slow.

AIDS denialism

Some people and organizations (particularly in Africa) refuse to believe in
AIDS, claiming that it is a Western plot to weaken the developing world.
This is often called AIDS denialism. This denial of the nature of the AIDS
problem has itself compounded the AIDS crisis, by preventing discussion and
adoption of preventive measures. This view was until recently prominent
within the African National Congress government of South Africa. The ANC has
recently shown signs of rejecting AIDS denialism.

Alternative Theory

A few scientists continue to question the connection between HIV and AIDS,
or even the very existence of HIV. See Duesberg hypothesis.

Kary Mullis, nobel prize laureate and inventor of the polymerase chain
reaction (an important biotechnical process), and who has been described as
possessing "creative nonconformity that verges on the lunatic" claims that
HIV does not cause AIDS.

There are multiple groups, i.e. the "Scientific Group for Reappraising the
HIV-AIDS hypothesis", which includes hundreds of "AIDS dissidents". They
report that they are usually denied access to AIDS conferences. The opinions
of these scientists range from doubts of the existence of retroviruses or
HIV to testing methods to epidemiological conclusions, doubts of the
existence of an independent "AIDS" disease" and critique of conventional
HIV-AIDS researchers' methods.

Current Status

As of the year 2002 AIDS is a global pandemic, and it shows no signs of
slowing down. It is estimated that over 40 million people worldwide are
HIV-positive and about 13 million have already died from AIDS-related
disease, mainly tuberculosis. If such trends continue it is likely that the
global death toll for AIDS will be comparable to other plagues such as the
Black Death and the Spanish Flu.

In Western countries, the infection rate of HIV has slowed somewhat, due to
education of safe sex practices. In some populations, however, such as young
urban gay men, infection rates show signs of rising again. In Britain the
number of people diagnosed with HIV increased 26% from 2000 to 2001. This is
of major concern to public health workers. AIDS continues to be a problem
with illegal sex workers and injection drug users. The death rate has also
fallen considerably, as combinations of AIDS treatment drugs (often called
"cocktails") have proven to be an effective (if expensive) means of
suppressing HIV.

However in Third World countries (especially Sub-Saharan Africa), poor
economic conditions (leading to the use of dirty needles in healthcare
clinics) and lack of sex education means continued high infection rates.
Some countries in Africa now have around 25% of the working adult population
who are HIV-positive, the highest being Botswana with 35.8% (1999 estimate -
source World Press Review). As these people begin to develop full-blown
AIDS, they will be unable to work, and require significant medical care.
This is likely to cause a collapse of societies and governments in the
region, further increasing the suffering and hardship faced. Many
governments in the region continued to deny that there was a problem for
years, and are only now starting to work towards solutions. Lack of adequate
health-care, ignorance towards the disease and its causes, as well as the
money to educate and treat are the main reasons that most AIDS deaths occur
in Third World countries. Social movements in countries like South Africa,
as well as international development agencies such as Oxfam, have insisted
that developing countries should be permitted to manufacture cheap copies of
patented AIDS medicines, a move generally resisted by the pharmaceutical
companies.

Immunity

In 1983, FIV (Feline Immunodeficiency Virus) was discovered by Neils
Pederson, doing research on a cat that seemed to be showing AIDS-like
symptoms. A close relative of AIDS, it led to an immediate scare that it
could spread to a number of wild cat species which are already endangered.
Tests for the disease began on various african wild cat species. To the
surprise of most involved, the disease was turning up everywhere. The
infected wild cat species simply were not showing symptoms like the
housecats were. This led to a high level of curiousity as to how the wild
species were managing to be infected without this happening.

The initial theories - that the disease was remaining inactive in their
systems, that the disease was only present in small amounts, or that the
disease wasn't killing the cells that it infected - were all proven wrong.
It turned out that the virus was present in huge quantities, and was killing
many T-cells. Infected cats from species that didn't show symptoms, however,
were simply replacing them as quickly as they were destroyed. It appeared
that the wild cat species that were studied had a genetic adaptation to the
disease. Housecats, which had not contracted the disease until recently, had
no such immunity.

Research has since progressed to primates, and has found a widely varying
level of immunity to symptoms from SIV between chimpanzees from different
regions of Africa. This has profound implications for research on HIV, not
only in ensuring equal natural resistance to the disease amongst laboratory
animals, but in the future effects of the disease on humans. In some parts
of Africa, HIV infects more than one in every four people. Thus, the disease
is a major factor in natural selection for these people. It seems likely
that, given enough time, humans may develop a similar immunity.

How to - Physics - History - Companies - Internet - Video Games - List of Phobias - September 11, 2001
Radio - Timelines - Chemistry - Genealogy - Family - Film - SARS - Cancer - Medicine - DVD - Calendar
Countries - Disease - Health Science - Dentistry - Economics - AIDS - Law - Autism - Statistics - Bible
Recipes - Architecture - Computers - History of the Internet - Personal computer - Apple Macintosh
War - Presidents of the United States - United States Constitution - Universe - Philosophy - Animals
Biology - United States Constitution - Marketing Topics - Sports - Television - History of Computing

Debt Help - Free Credit Report - Mortgages - Loans - Cheap Flights