Though ELISA tests (enzyme-linked immunosorbent assays) are the gold standard for diagnosing a whole slew of infectious diseases, the technology has remained stuck within hospital labs. What if you could carry an ELISA machine with you in your pocket? Imagine field testing for diseases, halting their spread and initiating therapy at an early stage for those infected. Researchers at Columbia University have actually developed such a device that works in conjunction with a smartphone to provide results within minutes.
The device uses the smartphone as the power source and performs a triplexed immunoassay for HIV antibody, treponemal-specific antibody for syphilis, and non-treponemal antibody for active syphilis infection. Such a combination immunoassay has not been previously available in a unified test.
It has already been trialed in field tests in Rwanda on 96 people enrolled in disease transmission prevention programs and volunteers in counseling and testing centers. The device will cost roughly $34 to manufacture, orders of magnitude cheaper than conventional ELISA machines while providing similar accuracy of results.
From the study in Science Translational Medicine:
In a blinded experiment, health care workers obtained diagnostic results in 15 min from our triplex test that rivaled the gold standard of laboratory-based HIV ELISA and rapid plasma reagin (a screening test for syphilis), with sensitivity of 92 to 100% and specificity of 79 to 100%, consistent with needs of current clinical algorithms. Patient preference for the dongle was 97% compared to laboratory-based tests, with most pointing to the convenience of obtaining quick results with a single fingerprick. This work suggests that coupling microfluidics with recent advances in consumer electronics can make certain laboratory-based diagnostics accessible to almost any population with access to smartphones.
Study in Science Translational Medicine: A smartphone dongle for diagnosis of infectious diseases at the point of care…