a desert in NW India and S Pakistan. About 77,000 sq. mi. (200,000 sq. km). Also called Great Indian Desert.
HIV tests are used to detect the presence of the human immunodeficiency virus (HIV), the virus that causes acquired immunodeficiency syndrome (AIDS), in serum, saliva, or urine. Such tests may detect antibodies, antigens, or RNA.
In the early stages of HIV infection, the virus itself is difficult to detect. Rather than looking for the virus, HIV testing usually involves looking at the body's reaction to the presence of the virus. The measure of the amount of virus in an individual's blood stream is called the viral load. Antibodies are produced by the body in reaction to the presence of a virus. An HIV antibody test measures the presence of antibodies in response to the presence of HIV. The most common HIV antibody tests are ELISA (EIA) and Western Blot.