Diagnostic test for HIV in window period is?

ANSWER: (C) P 24 antigenREF: Harrisons Internal Medicine 17,h edition Chapter 182. Human Immunodeficiency Virus Disease: AIDS and Related DisordersIn June 1996, blood banks in the United States added the p 24 antigen capture assay to the screening process to help identify the rare infected individuals who were donating blood in the time (up to 3 months) between infection and the development of antibodies. In 2002 the ability to detect early infection with HIV wTas further enhanced by the licensure of nucleic acid testing (NAT) as a routine part of blood donor screening. These refinements decreased the interval between infection and detection (window period) from 22 days for antibody testing to 16 days with p 24 antigen testing and subsequently to 12 days with nucleic acid testing.Also know:The standard blood screening test for HIV infection is the ELISACommercial EIA kit that contains antigens from both HIV-1 and HIV-2 and thus are able to detect eitherThe fourth generation EIA tests combine detection of antibodies to HrV with detection of the p 24 antigen of HIVThe most commonly used confirmatory test is the Western blotWhile the Western blot is an excellent confirmatory test for HIV infection in patients with a positive or indeterminate EIA, it is a poor screening test.Separate western blot are done for HIV 1 and HIV 2In addition, the tests detecting levels of HIV RNA can be used to determine prognosis and to assess the response to ARV therapies.