Low rates of p24 antigen detection using a fourth-generation point of care HIV test

Over one-quarter of people living with HIV infection in the UK are unaware of their HIV infection.1 HIV point-of-care testing (POCT) can greatly improve the uptake and acceptability of HIV testing across hospital and community settings2 3 and, until now, has been carried out using a third-generation antibody assay. As such, cases of suspected PHI are referred for fourth-generation combination testing. Identification of PHI is important, as identification during this hyperinfectiousness period may reduce onward HIV transmission events,4–6 and early intervention with antiretroviral therapy may enhance the long-term clinical outcome.7–10 A significant advance in HIV POCT has been the development of the Determine HIV-1/2 Ag/Ab Combo assay (Inverness Medical, now renamed Alere). This is the first rapid fourth-generation assay for simultaneous detection of HIV p24 antigen and antibodies to HIV-1 and HIV-2. However, this assay has been introduced into routine care in …