title: Human Immunodeficiency Virus Diagnostic Testing: 30 Years of Evolution.
abstract: A concern during the early AIDS epidemic was the lack of a test to identify individuals who carried the virus. The first HIV antibody test, developed in 1985, was designed to screen blood products, not to diagnose AIDS. The first-generation assays detected IgG antibody and became positive 6 to 12 weeks postinfection. False-positive results occurred; thus, a two-test algorithm was developed using a Western blot or immunofluorescence test as a confirmatory procedure. The second-generation HIV test added recombinant antigens, and the third-generation HIV tests included IgM detection, reducing the test-negative window to approximately 3 weeks postinfection. Fourth- and fifth-generation HIV assays added p24 antigen detection to the screening assay, reducing the test-negative window to 11 to 14 days. A new algorithm addressed the fourth-generation assay's ability to detect both antibody and antigen and yet not differentiate between them. The fifth-generation HIV assay provides separate antigen and antibody results and will require yet another algorithm. HIV infection may now be detected approximately 2 weeks postexposure, with a reduced number of false-positive results.
authors.affiliation: Summa Health, Department of Pathology and Laboratory Medicine, Akron, Ohio, USA, and Northeast Ohio Medical University, Rootstown, Ohio, USA alexandt@summahealth.org.
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Alexander
mesh_terms: D003955:Diagnostic Tests, Routine / Q000379:methods* / Q000639:trends; D006678:HIV / Q000276:immunology / Q000302:isolation & purification; D015658:HIV Infections / Q000175:diagnosis*; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000639:trends