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A Blood Test for HIV

The next critical advance after the identification of HIV was the development of a sensitive and specific test for antibodies to HIV that could be used for diagnosing individuals (with confirmation by immunoblot analysis) and for large-scale screening.[23] This fundamental scientific advance had immediate and profound implications for public health. With an ELISA to detect antibodies to HIV, the blood supplies in the United States and other developed countries were screened for HIV and rendered extremely safe by 1985 (ref. 24), thereby preventing millions of potential transfusion-related infections. HIV antibody tests have subsequently been used in numerous epidemiological and natural history studies to clarify the global scope and evolution of the epidemic.[25] Only with the availability of this simple screening was the real and potential scope of the AIDS pandemic fully appreciated.

Before the ELISA for HIV, clinicians were generally seeing individuals who were in the late stages of disease and had a life expectancy measured in months.[26] The availability of the blood test allowed investigators to readily identify asymptomatic individuals infected with HIV, to describe more accurately the true clinical course of HIV disease, and to follow the natural history of the disease prospectively in individuals for whom a time of seroconversion could be determined.