A smartphone dongle for diagnosis of infectious diseases at the point of care

Abstract

This work demonstrates that a full laboratory-quality immunoassay can be run on a smartphone accessory. This low-cost dongle replicates all mechanical, optical, and electronic functions of a laboratory-based enzyme-linked immunosorbent assay (ELISA) without requiring any stored energy; all necessary power is drawn from a smartphone. Rwandan health care workers used the dongle to test whole blood obtained via fingerprick from 96 patients enrolling into care at prevention of mother-to-child transmission clinics or voluntary counseling and testing centers. The dongle performed a triplexed immunoassay not currently available in a single test format: HIV antibody, treponemal-specific antibody for syphilis, and nontreponemal antibody for active syphilis infection. 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.

Application of nanodiagnostics in point-of-care tests for infectious diseases

“…[19][20][21][22] Among these applications, nanodiagnostics have drawn more and more attention for the infectious diseases because of their unique characteristics in early detection, high sensitivity, and the potential for POCT. 15 Toward this direction, lots of novel and efficient nanodiagnostics for infectious diseases have been developed. Most importantly, these nanotechnology-based systems have potential to develop the POCT platforms with portable, robust, and affordable properties to detect infectious diseases in the developing countries.…”

Cellphone-based diagnostic devices

“…Cellphones especially outweigh over others in terms of their convenience in myriad situations in mundane life. It is no wonder that researchers have pursued their use as compelling measurement devices for examination, data collection, and transmission in and from remote and resource-limited settings [24][25][26][27]. When it comes to health care exploration, cellphones may bridge existing gaps between patients and timely, affordable healthcare, especially in more remote regions.…”

“…Note, the LOD of this system has been established as 1000 copies mL −1 . In other research, Laksanasopin et al created a low power consumption smartphone attachment capable of triplexed ELISA assays specific to HIV and syphilis [25,105]. Further, cellphone-based optical devices have also been used for early diagnosis of human eye cataracts [106] without expensive equipment or highly trained medical staff.…”

Using electronic readers to monitor progress toward elimination of mother‐to‐child transmission of HIV and syphilis: An opinion piece

“…e l s e v i e r . c o m / l o c a t e / i j g o been developed [8], with the potential to transform the diagnostic landscape and provide simple, fast, low-cost, high quality tests using smartphone technology. Provisional results from a small field trial carried out in Rwanda are promising, but larger studies are needed [8].…”