Acquired Immuno Deficiency Syndrome(AIDS)
The acquired Immuno-deficiency syndrome (AIDS) is fatal illness caused by a retrovirus called Human immuno-deficiency virus (HIV). The HI virus breaks down the body’s immune system, leaving the victim vulnerable to a host of life threatening opportunistic infections viz., neurological disorders or unusual malignancies. The term AIDS refers only to the last stage of the HIV infection. There are five groups of adults at risk for developing AIDS. They are
1. Homosexual or Bisexual males (60%)
2. Intravenous drug abusers (23%)
3. Recipients of blood and blood products (2%)
4. Heterosexual contacts (6%)
5. Haemophiliacs (1%)
The HIV is 10000th. of a millimetre in diameter. It is a protein capsule containing two short strands of genetic material (RNA) and enzymes. The virus replicates in actively dividing T4 lymphocytes and can remain in lymphoid cells. The virus has the unique ability to destroy human T4 helper cells or T -4 cells. (a type of human T - lymphocytes). There are two types of HIV. The most common virus HIV - 1 and a more recently discovered virus HIV -2. Once a person is infected, the virus remains in the body lifelong. The virus also infects other cells of immune system such as B-cells, macrophages, and nerve cells.
The incubation period of HI virus varies from few months to 6 years or more. When the virus reproduces, the infected T-helper cells are destroyed that leads to profound lymphopenia with a total lymphocyte count often below 500/mm3 of blood.
Human Immuno - deficiency virus is not transmitted by contamination that is insects or food or drinking water.
Human Immuno-deficiency virus is transmitted from person to person in the following ways.
i. Sexual transmission ii. Blood contact iii. Maternal - foetal transmission.
AIDS is the first and foremost sexually transmitted disease. Veginal, anal or oral sex can spread AIDS from person to person. Adolescent girls and women above 45 years of age are more prone to get HIV infection.
ii. Blood Contact:
AIDS is transmitted by transfusion of contaminated blood. Needle sharing by drug users is also another method of transmission.
iii. Mother to child transmission:
HIV may pass from an infected mother to her foetus through
placenta orto her infant during delivery or by breast feeding.
HIV or AIDS is not transmitted through following ways