New procedure Can Detect HIV Days Earlier Than Current US Tests

BY DMITRY RASHNITSOV

A new HIV test created by Abbott Pharmaceuticals is claiming to speed up the process by which people will get their results.

Currently, most people who get tested for HIV will give a swab of their mouth or a few drops of blood from a prick in their finger. The test takes about 20 minutes to complete and if it comes back with a positive result, the person is then asked to take a confirmatory test which can take up to two weeks to complete. The confirmatory test takes a full blood sample.

The new Abbott’s ARCHITECT HIV Ag/Ab Combo assay is the first test approved in the United States that can simultaneously detect both HIV antigen and antibodies, in the confirmatory test process. Studies have demonstrated that Abbott’s new test may detect HIV days earlier than antibody-only tests.

“Since individuals are most infectious to others shortly after infection, detecting HIV earlier is critical and life saving,” said Peter Leone, M.D., medical director, North Carolina HIV/STD Prevention and Control Branch, University of North Carolina, Chapel Hill. “A significant percentage of new HIV infections are transmitted by someone with an undetected acute infection, so identifying more people earlier offers a significant opportunity for counseling, which can reduce high-risk behaviors and also initiate antiretroviral treatment for early-stage infection, if appropriate.”

Studies conducted by the Centers for Disease Control and Prevention (CDC) show that current antibody-only tests miss up to 10 percent of HIV infections in some high- risk populations because they do not detect antigens. However, Abbott’s new assay detects the HIV p24 antigen, or the direct presence of HIV, allowing for diagnosis of early infections days before antibodies emerge.

“Abbott has long been a pioneer in HIV testing — from the world’s first test to detect HIV antibodies in 1985 — to second and third generation immunoassay and molecular tests – and now the development of the country’s first antigen and antibody combination test,” said Brian Blaser, senior vice president, Diagnostics, Abbott.  ”Abbott is committed to fighting HIV and to bringing novel tests to physicians in order to help patients get the care they need as soon as possible.”

The new test, from Abbott, still doesn’t work immediately after infection. But it cuts the crucial window period between infection and detection by “at least a week, and it could be as much as 20 days,” Abbott Senior Director, Gerald Schochetman, said.

The weeks soon after a person contracts HIV are the acute phase of HIV infection. This is when the virus replicates wildly, before the immune system kicks in to slow it down. A person is highly infectious during this time — but may still test negative for HIV on tests that look only for anti-HIV antibodies.

“The most sensitive third-generation antibody tests will pick up about 42% of acute-phase infections, whereas the new combination assay picks up about 90% of those in the acute phase,” Schochetman says. “It is a substantial increase over current tests.”

Abbott’s new test already is approved in Europe. The U.K. and France use the test as their primary HIV screening test.

The CDC estimates that there are 56,000 new cases of HIV in the United States annually, and that every nine and a half minutes, someone in the country is infected with HIV. UNAIDS estimates that 2.7 million people throughout the world are newly infected with HIV each year.