Researchers at Columbia University say they've developed an inexpensive smartphone add-on device that can detect and diagnose HIV and syphilis.
In a pilot study in Africa, the $34 device that plugs into the headphone jack of a smartphone was almost as effective as much more expensive blood-testing diagnostic equipment in identifying antibodies signaling the presence of HIV and syphilis, the researchers say.
Existing diagnostic equipment can cost as much as $18,000, they note.
The trial in Rwanda included 96 patients including women who were at risk of passing sexually transmitted diseases to their unborn children.
In the pilot study, the device, which uses a finger-prick blood test, performed all of the optical, mechanical and electronic operations of a lab-based blood test in 15 minutes, powered completely by the smartphone.
In the Africa testing by Rwanda healthcare workers to see how often the device accurately identified the target antibodies, it scored a sensitivity of 92 to 100 percent, the researchers say.
Samuel Sia, a professor of bioengineering, led the Columbia development team.
"Our work shows that a full laboratory-quality immunoassay can be run on a smartphone accessory," he says.
Such devices can make some kinds of normally lab-based diagnostics available in any region where the population has access to smartphone, he says.
"This kind of capability can transform how health care services are delivered around the world," he suggests.
The Columbia device was developed to be small and light enough to be held in one hand and perform diagnostics using disposable plastic cassettes with pre-loaded reagents with disease-specific zones yielding an objective readout.
In the field test, the Rwanda healthcare workers were able to use the devices after just 30 minutes of training, following an included user-friendly interface leading them through each test with step-by-step pictorial directions, and built-in timers to alert them to each of the subsequent steps.
The Columbia device is also capable of recording test results for later review.
The device "presents new capabilities for a broad range of users, from health care providers to consumers," Sia says. "By increasing detection of syphilis infections, we might be able to reduce deaths by 10-fold."
Researchers described the Columbia effort, funded by a grant from the Gates Foundation and other funders, in the journal Science Translational Medicine.
A larger-scale clinical trial is planned with the goal of securing approval by the World Health Organization for use of the device in developing countries, the researchers say.
