Human Immunodeficiency Virus 1/O/2 (HIV-1/O/2) Antigen/Antibody (Fourth Generation) With Cascade Reflex to Supplementary Testing*

CDC-recommended algorithm for laboratory diagnosis of HIV infection, including acute and primary infection.

Reactive (repeatedly) specimens must be investigated by additional supplemental tests. A negative test for an individual does not preclude exposure to or infection with HIV-1 and/or HIV-2. Negative results can occur if the quantity of the marker present in the sample is too low for detection by the assay or if the marker is not present during the stage of disease in which a sample is collected.

Association of Public Health Laboratories. Suggested Reporting Language for the HIV Laboratory Diagnostic Testing Algorithm. APHL 2019. APHL Web site. https://www.aphl.org/aboutAPHL/publications/Documents/ID-2019Jan-HIV-Lab-Test-Suggested-Reporting-Language.pdf. Accessed November 2019.

Centers for Disease Control and Prevention. Laboratory testing for the diagnosis of HIV infection : updated recommendations. CDC Stacks Web site. https://stacks.cdc.gov/view/cdc/23447. Accessed November 2019.

Clinical and Laboratory Standards Institute. Criteria for Laboratory Testing and Diagnosis of the Human Immunodeficiency Virus Infection, Approved Guideline. M53-A. Wayne, Pa: CLSI; 2011.