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Breakthrough Science: New HIV Test Can Tell Difference Between HIV-1 and HIV-2

What a long way we’ve come since the early days of the HIV test.


Back then, if your community was lucky enough to have a convenient place to get tested for free, they took your blood and then you held your breath -- for about two weeks, in fact, as you waited for the results.

But now, not only do we have a rapid antibody test from an oral swab, but today the U.S. Food and Drug Administration approved the Bio-Rad BioPlex 2200. It’s as sophisticated as it sounds.

The test can tell the difference between HIV-1, the most common type of HIV, and HIV-2. While HIV-2 is most common in West Africa, it has been seen in the United States. The viruses have similarities but are treated differently.

“Today’s approval provides healthcare professionals another option for the diagnosis of HIV infections,” Dr. Karen Midthun, director of the FDA’s Center for Biologics Evaluation and Research, said in a news release. “The ability to diagnose HIV infection early and differentiate between types of infection is important in the care of individuals as both diseases exhibit the same symptoms but progress at different rates.”

The BioRad test can detect HIV even when only antigens are present. Antigens present even before antibodies, so this means the virus can be detected quickly after infection.

“Early treatment has a lot of benefits, including less damage to the immune system, a longer life, and less ability to spread the virus. So it’s always important to get tested as soon as possible (after known exposure),” Dr. Amesh Adalja, a spokesman for the Infectious Diseases Society of America, told HIV Equal.

This test is among other “Fourth Generation” tests, which Adalja said really need to be the standard these days. After all, the International AIDS Symposium that just wrapped up in Vancouver, Canada was all about stressing the benefits of early detection and treatment.

“We’re seeing people move toward fourth generation, but it really should be the standard of care,” Adalja said. “It can take a while for these things to penetrate fully, but as they prove their worth more people will want to use them, and insurance companies will prefer them.”

The test even can detect the virus in organ donors so long as the blood specimen is collected while the heart is still beating.

The approval of the Bio-Rad test brings the number of HIV tests approved in the U.S. to nine.

Adalja noted that people presenting with acute infection – a flu-like illness that many people infected with HIV recognize as a red flag, particularly after an unsafe sexual experience – actually should be tested with a PCR test.

PCR tests actually can detect HIV’s genetic material, even before antigens present. As shown in the case of the Mississippi Baby, when HIV is caught at the time of acute infection it can quickly be harnessed and brought back under control. Unfortunately, once the antiretroviral medications stop, the virus rebounds. Earlier this week news broke of a teenager who has remained in HIV remission for 12 years without medication, but Adalja said the idea of curing HIV by early detection still isn’t known to be possible.