What is AIDS ?

Explanation

The word AIDS stands for Acquired Immuno Defecieny Syndrome.
This means deficiency of immune system, acquired during the lifetime of an individual indicating that it is not congenital disease. Syndrome means a group of symptoms. It was first reported in 1981 in the USA.
In the last twenty five years or so, it has spread all over the world killing more than 25 million persons.
It was first time reported in India in the year 1986, in Tamil-nadu.
It is caused by the Human Immuno Deficiency Virus (HIV), a member of a group of viruses called retrovirus.
They have an envelope enclosing RNA as a genetic material.
After the successful entry in the human body, the virus enters in the macrophage. And with help of reverse transcriptase enzyme DNA replication occurs. This phenomena is known as temenism. By this viral DNA, it produces new virus constantly.
Macrophage acts as a factory of HIV. At this time, HIV enters in the helper T-lymphocytes and by duplication it reproduces and progenies of virus come into existence.
Newly constructed virus, make the prey to T-cells by blood. So number of T-cells decreases.
Helper T-cells (WBCs-lymphocytes) become less in number. So, there is long, persistence of fever and weight loss occurs.
Due to deficient Immunity, various infections occur.