Clinical Significance

Acquired Immunodeficiency Syndrome (AIDS) can be caused by two etiologic agents which are designated as Human Immunodeficiency Virus Type 1 and Human Immunodeficiency Virus Type 2. In North America, infection with HIV-2 is rare. Published serological data reveal that AIDS patients and individuals infected by HIV-1 produce antibodies against HIV-1 proteins. The presence of antibodies to HIV-1 is indicative of previous exposure to HIV-1 but is not necessarily a diagnosis of AIDS. Samples which are repeatedly reactive for HIV-1 antibodies should be tested using additional and more specific tests. The lifetime risk of an asymptomatic person confirmed as having antibodies to HIV-1 developing AIDS or and AIDS related condition is not known. A diagnosis of AIDS can be made only if an individual meets the case definition of AIDS established by the Center for Disease Control. Further, HIV-1 has been isolated from asymptomatic, seronegative individuals presumably before seroconversion following exposure. Absence of antibody to HIV-1 CANNOT be taken as absolute proof that an individual is free of HIV-1 or incapable of transmitting the virus. In neonates, presence of antibodies to HIV-1 is indicative of exposure to HIV-1, but not necessarily of HIV-1 infection, due to acquisition of maternal antibodies which persist for up to six months.