(Acquired Immuno-Deficiency Syndrome) is a progressive and fatal
condition caused by a breakdown of the body's immune system by a
virus called HIV (Human Immuno-deficiency Virus). This condition
leaves the subject vulnerable to a host of life-threatening opportunistic
infections, neurological disorders, unusual malignancies, and a
group of other manifestations and complications. It is probable
that a person once infected will be infected for life. Strictly
speaking, the term AIDS refers only to the late stages of the disease.
This disease is referred to as a modern pandemic affecting people
all over the world. Since reported first in 1981, AIDS has become
a major worldwide concern.
all live in an environment packed with microbes that are often harmful
to health such as parasites, virus, bacteria, etc. All these are
potentially capable of harming human body. But what shields the
body from their bombardments is the immune system. The immune system
in particular consists of certain categories of white cells in the
blood, the lymphocytes, that endlessly patrol the body from their
base, and the lymphoid organs.
As an organism invades the body, the T4 lymphocytes flash a signal
to the T-lymphocytes and B-lymphocytes to counter the invasion.
The T-lymphocytes directly attack the invader whereas the B-lymphocytes
take help of antibodies that bind to the organism and destroy it.
When these cells function normally, they help the body fight infections
and diseases caused by viruses and bacteria. When the body is infected
with HIV, the basic T4-lymphocytes, the command center of the immune
system, get affected, thereby paralysing the body's defenses. AIDS
begins when an individual is infected with HIV, continues with a
phase in which a person has no signs or symptoms of the disease,
and progresses to signs and symptoms that show a persons immune
system is no longer working properly. Therefore, AIDS is the advanced
stage of HIV infection.. At this stage of the disease, many people
develop opportunistic infections (OI) such as Pneumocystis carinii
pneumonia, certain cancers such as Kaposi's sarcoma or develop other
manifestations such as neurological involvement, weight loss syndrome
etc. For people with AIDS, these OIs are often severe and sometimes
fatal because the immune system is so damaged by HIV that the body
can no longer fight off the bacteria, viruses, and other microbes
that cause the OIs.