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.
Different types of antibody tests may be used for HIV screening: 1  All HIV tests used in the U.S. detect HIV-1, and some tests have been developed that can also detect HIV-2. 2  Combination tests have been developed that detect HIV antibody and the HIV antigen called the p24 antigen. Verify a positive with a second HIV antibody test that differentiates between HIV-1 and HIV-2. 2  If results between the first and second test do not agree, then the next test to perform is a HIV-1 RNA test (nucleic acid amplification test, NAAT).