The combination HIV-1/HIV-2 includes detection of subtypes of HIV-1 not included in HIV-1, EIA alone. HIV-2 is closely related to HIV-1 regarding nucleic acid sequence and clinical disease. HIV-2 is endemic to West Africa with nearly all cases in the United States identified in citizens or travelers from West Africa. Rarely, HIV-1 Western blot indeterminate results may be due to HIV-2 infection in a patient who has been exposed to HIV-2. The Western blot is useful to confirm repeatedly reactive EIA results.
The etiological agent of acquired immunodeficiency syndrome (AIDS) has been recognized as a retrovirus, human immunodeficiency virus (HIV-1). The virus is believed to be transmitted by sexual contact, blood transfusion, feto-maternal transmission, breast feeding and intravenous drug abuse. The presence of circulating antibodies to the virus indicates prior exposure of the individual to viral antigen(s). The presence of antibody to HIV is not in itself diagnostic of AIDS. Likewise, a non-reactive test result does not exclude the possibility of exposure to or infection with HIV. Specimens that screen positive and are repeatedly reactive are confirmed by Western Blot.
If HIV-1/HIV-2 EIA Antibody screen is reactive, then HIV-1 Antibody Western Blot will be performed.
