Fourth generation HIV test
HIV test
The rapid HIV diagnostic test, the Determine HIV 1/2 Ag/Ab Combo from Inverness Medical has now received CE marking and is available for use in a range of healthcare settings. By enabling simultaneous and separate detection of HIV p24 antigen and antibodies for HIV-1 and HIV-2 in human serum, plasma, or whole blood, the new test increases the ability to detect and diagnose primary HIV infection. The test can detect HIV infection 2-20 days earlier than HIV antibody tests only (with an average mean of 5 days). During HIV infection, p24 antigen is produced during the first few weeks and is detectable 7-9 days earlier than the appearance of HIV antibodies. As a result, the p24 antigen is an ideal marker in aiding early HIV diagnosis. Fourth-generation HIV-screening assays represent the latest advance in HIV serological tests by being able to detect HIV antibody and HIV-1 p24 antigen simultaneously; they were developed to detect acute, as well as latent infections, and be rapid and cost-effective. Most fourth-generation diagnostics are laboratory based tests (e.g. ELISAs) and are not appropriate for point-of-care application or for use in challenging environments, such as remote developing world settings. The new test gives clear visual results in 20 minutes, and so is suitable for direct use during a patient visit. The easy-to-use, robust format of the test means that no electricity, water or bulky lab equipment is required. The new test has an excellent sensitivity of 100% for patients at the chronic stage of infection and a specificity of 99.23% and 99.66% for HIV antibodies and HIV-1 p24 antigen respectively.
Alere international
