Fourth generation human immunodeficiency virus (HIV) screening assays with an improved sensitivity for p24 antigen close the second diagnostic window in primary HIV infection

Frequency, Causes, and New Challenges of Indeterminate Results in Western Blot Confirmatory Testing for Antibodies to Human Immunodeficiency Virus

“…The former include third-generation ELISAs that utilize the antigen sandwich design for improved sensitivity, while the latter term refers to immunochromatographic tests or other simple antibody tests requiring less than 30 min of assay time. Since the viral capsid (core) p24 protein can be detected earlier than anti-HIV antibodies (93), attempts had also been made to develop a new generation of ELISA capable of simultaneously detecting the p24 antigen and anti-HIV antibodies (34,52,76,101,103). Significant reductions of the window period were achieved, which is ideal for blood screening and surveillance (102), but users were also advised to be mindful of possible limitations when utilizing such a combination assay (52,81,83).…”

Epidemiology of Human Immunodeficiency Virus in Prospective Blood Donors and Testing Algorithm Assessment with Real-Time PCR for Optimal Blood Safety Practice

“…On the other hand, if it were negative, it confirmed negative results. At the NBTS, HIV Ag-Ab detection was tested for all specimens using commercially available Genscreen Monolisa™ HIV Ag-Ab ULTRA ELISA kits manufactured by BIORAD (3,bd Raymond Poincare, 92430 Marnes-la-CoquetteFrance), according to the manufacturer's instructions [35][36][37]. …”

Detection of an Acute HIV-1 Infection Case in the Last Day of Diagnostic Window through a Combination of Two Fourth-Generation Screening Assays on a Brazilian Public Healthy Institution: We Close the Window

“…The third generation assays, which detect both IgM and IgG, have led to a further improvement in sensitivity and specificity. The fourth generation assays (HIV AgAb EIA) use combined, simultaneous detection of anti-HIV IgG and HIV core protein [7,8]. The advantage of combining antibody and antigen detection in a single immunoassay format is a reduction in the duration of negative tests during sero-conversion.…”

“…An HIV infection can potentially be detected with 4th generation HIV assays within the first 2weeks after exposure [10,13,14]. However, in addition to the first diagnostic window, a so-called second diagnostic window has been reported; this second diagnostic window may occur when 4 th generation HIV assays are used.…”