The variable sensitivity of HIV Ag/Ab combination assays in the detection of p24Ag according to genotype could compromise the diagnosis of early HIV infection.

Background: In France, HIV infection diagnosis was modified by a decree, published in 2010, that requires the use of HIV Ag/Ab assays able to detect at least 2 IU/ml of p24Ag. This measure raises the concern of the capacity of these assays to equally detect all HIV variants.

Objectives: To assess the performance of HIV Ag/Ab assays for the detection of p24Ag from diverse HIV isolates.

Reduction of the risk of transfusion-transmitted human immunodeficiency virus (HIV) infection by using an HIV antigen/antibody combination assay in blood donation screening in Cameroon.

Background: Improving blood safety without introducing nucleic acid testing in blood screening may be possible using antigen/antibody (Ag/Ab) combination assays, especially in resource-poor countries.

Study Design And Methods: To evaluate the potential reduction of human immunodeficiency virus (HIV)-transmitted infection using such an assay, a study was carried out aimed to compare the routine strategy for blood screening (S1), combining a rapid test (Determine HIV-1/-2, Inverness) and an enzyme immunoassay (human HIV-1/-2, Human Diagnostic) with an HIV Ag/Ab assay (S2, Genscreen ULTRA HIV Ag-Ab, Bio-Rad) in 2000 blood donations tested in Cameroon. Western blot and HIV RNA polymerase chain reaction were used to confirm the infection in reactive donors, and genotype was determined in HIV RNA-positive samples.