14-02-2013, 11:23 AM
Diagnosis of HIV by Elisa
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HIV (Human Immunodeficiency Virus)
It is a virus that attacks the human immune system. Someone infected with the virus can live with HIV or be HIV positive for many years without becoming ill or showing symptoms. During this time however, HIV remains in the body damaging the immune system and the person remains infectious; able to spread the virus to others.
aids
Over time, HIV can damage the immune system to such a degree that infections may begin to occur as a result of a weakened immune system. Eventually, one may acquire various illnesses due to the damage done by the virus. When this happens this is called aids or acquired immune deficiency syndrome. That is, a collection of illnesses.
History of AIDS
In June 1981, scientists in the United States reported the first clinical evidence of a disease that would become known as Acquired Immune Deficiency Syndrome or AIDS. Twenty-seven years later, the AIDS epidemic has spread to every corner of the world. Over 22 million people have lost their lives to the disease and over 39 million people are today living with HIV.
What is the difference between HIV and AIDS?
In simple terms - you can't 'catch' AIDS. You can, however, catch HIV. Being infected with HIV does not mean that one has AIDS, but if left undiagnosed and/or untreated, HIV infection damages the immune system and can progress to AIDS. The immune system's function is to fight off infections and other diseases. If your immune system is damaged or not working well, you are at risk of life-threatening infections and cancers. HIV attacks and destroys the disease fighting cells of the immune system. The body is left with a weakened defence against disease.
ELISA method
In an ELISA test, a person's serum is diluted 400-fold and applied to a plate to which HIV antigens have been attached. If antibodies to HIV are present in the serum, they may bind to these HIV antigens. The plate is then washed to remove all other components of the serum. A specially prepared "secondary antibody" an antibody that binds to human antibodies is then applied to the plate, followed by another wash. This secondary antibody is chemically linked in advance to an enzyme.