History of HIV/AIDS
HIV is considered a new virus as
no records of it exist in history or in dead bodies. Our best
understanding of the origin of HIV is that it started in central Africa
and started spreading, slowly at first, around 1930. The closest known
virus to HIV is called SIVcpz and it is found in a certain species of
chimpanzees in central Africa. This virus, SIVcpz, entered the human body
by accident: these chimpanzees are hunted in a very bloody way and eaten
raw or sometimes their blood is drunk by people. SIVcpz does not cause
disease in humans, but it mutates (changes its structure) very rapidly.
Unfortunately, it mutated to HIV in some human. This human then spread it
to his/her sexual partners and they passed it on further. For many years
HIV was limited to a small region of Africa, however, with the explosion
in tourism, air travel, mobility of people, and many other factors that
became common in the 1960s, the virus spread rapidly all over the world.
Today, it is one of the worst nightmares for public health. As of May 2001
it has killed over 22 million people worldwide, 34 million are living with
the infection and will die of it, and the dead have left behind 14 million
HIV+ is a term used to denote any person who is
infected by HIV. Similarly, sometimes the term HIV- is used to denote any
person who is NOT infected by HIV.
Is HIV/AIDS hereditary?
NO. It is acquired through sex with an infected
person or if the blood of an infected person enters the body of another
person through cuts, punctures or by transfusion.
HIV stands for Human Immunodeficiency Virus. This virus
infects a number of different cells of the human immune system. The most
susceptible cell is a type of white blood cell called the CD4
T-lymphocyte, which plays a very important part in the functioning of the
immune system. HIV slowly and steadly destroys these immune cells until
the body is left defenseless against all and every disease. When the count
of CD4 cells goes below a certain number (200 cells per cubic millimeter
of blood), the person is said to have progressed to the AIDS stage, the
final stage before death.
Viruses are tiny single cell
organisms that can cause disease. Viruses are very picky and infect very
specific cells which we call host cells. Their life cycle consists of
entering a host cell, and replicating themselves using the machinery of
the host cell. The host cell is eventually destroyed and the new virus
cells are released by budding or at cell death when it bursts open.
different ways of
acquiring this infection
In infected people, the virus is present mainly
in the blood, and in the seminal fluids of man and vaginal secretions and
breast milk of women. To transmit it from one person to another requires
either the blood of an infected person enter into the body of another, or
through sex, or from mother to child. The highest risk from sex is from
anal sex, followed by vaginal sex, and a much smaller risk from oral sex.
Blood contact can be through transfusion of infected blood, reuse of
needles without sterilization for injections or tattoos, or by accidental
pricks by such needles if they are not properly disposed.
AIDS stands for Acquired Immunedeficiency
Syndrome. The word syndrome specifies that it is a condition or stage of
infection and not a specific disease. The word "acquired" specifies that
this syndrome is not genetic (hereditory) but acquired by an individual as
a consequence of infection with HIV. Once HIV enters the human body, it
slowly and steadly destroys the CD4 immune cells until the body is left
defenseless against all and every disease. When the count of CD4 cells
goes below a certain number (200 cells per cubic millimeter of blood), the
person is said to have progressed to the AIDS stage. It is the final stage
of HIV infection before death.
Cure for HIV/AIDS so
There are many reasons for this.
Among the most important are: (i) the host cell of HIV is a very important
regulator of the immune system, so we cannot afford to indiscriminately
destroy it; we have to design drugs that only destroy the infected cells.
(ii) once HIV infects a host cell, it prevents the cell from displaying
markers indicating that it is infected, thus making it hard for the immune
system to tell whether a cell is infected or not. (iii) the virus can stay
in a dormant state inside a cell for years. So even if a medicine can
destroy all the infected cells, the virus reappears at a later date after
the person has stopped taking the medicine. (iv) it mutates very rapidly,
and learns to evade the medicines.