Color-Coded HIV Test Detects Infection Quickly and Cheaply

Researchers have developed a new test for HIV - the virus that causes AIDS - that is reported to be ten times more sensitive and much less expensive than existing methods.  The new test could significantly improve diagnosis and treatment in the developing world.

The new HIV blood test uses microscopic gold flecks, or nanoparticles, to detect the presence of an HIV marker - a viral protein called p-24 - in the patient's blood serum, according to Molly Stevens, a professor of biomedical materials at Imperial College, London.

“And the way it does that is by making some gold nanoparticles aggregate together in a clump, and that will look blue to the eye, whereas if the disease-related protein isn’t there, then those nanoparticles will stay very separate, which will look red to the eye," said Stevens.

Stevens says the nanoparticle test is more sensitive than conventional HIV blood testing. So far, she says, researchers have successfully used the color test on both HIV-positive and uninfected individuals.

“And, in fact, also [with] patients with HIV who had a very tiny viral load that wasn’t able to be detected with conventional techniques.  So, we were actually able to detect virus in those patients that would have rendered a negative signal," she said.

Stevens says the goal now is to make the prototype HIV test more portable and user-friendly, so it can be delivered and administered anywhere. She says it would be especially useful in poorer regions of the world where medical resources are scarce, infection rates are high, and the need for simple, fast HIV screening is great.

Rapid HIV detection is critical to halting the spread of the life-threatening virus and allowing HIV-positive individuals to begin antiretroviral drug therapy as soon as possible.

An article on the development of a highly sensitive low-cost HIV test is published in the journal Nature Nanotechnology.