Chuck Bednar for redOrbit.com – Your Universe Online
Engineers at Columbia University have developed a new smartphone accessory capable of testing for HIV and syphilis in a finger prick blood sample in just 15 minutes, according to new research published Wednesday in the journal Science Translational Medicine.
According to the developers of the device, it provides a low-cost alternative to lab-based blood tests, performing an enzyme-linked immunosorbent assay (ELISA) without requiring any stored energy. Instead, the unit draws all of its power from the smartphone to which it is connected.
The accessory simultaneously detects three infectious disease markers using a blood sample from a finger pick. Specifically, it performs a triplexed immunoassay not available in a single test at this time (HIV antibody, treponemal-specific antibody for syphilis, and non-treponemal antibody for active syphilis infection) and takes just 15 minutes to deliver its results.
Samuel K. Sia, an associate professor of biomedical engineering at Columbia Engineering, and his colleagues recently sent their device to health care workers in Rwanda. They used it to test the whole blood samples of 96 patients enrolled in voluntary counseling and testing centers or in clinics designed to prevent mother-to-child transmission of such diseases.
“Our work shows that a full laboratory-quality immunoassay can be run on a smartphone accessory,” Sia explained. “Coupling microfluidics with recent advances in consumer electronics can make certain lab-based diagnostics accessible to almost any population with access to smartphones. This kind of capability can transform how health care services are delivered around the world.”
The professor and his colleagues set out to build upon previous work in developing smaller diagnostic hardware that can quickly diagnose HIV, syphilis, and other sexually transmitted diseases at the point-of-care. He explained that early diagnosis in and treatment of pregnant mothers “greatly reduce adverse consequences to both mothers and their babies.”
A breakthrough for STD detection
The new device (or dongle) was designed to be small and light enough to fit into one hand, and can conduct assays on disposable plastic cassettes with pre-loaded reagents where disease-specific zones provide a read-out similar to an ELISA array. Sia estimated that the device would have a manufacturing cost of $34, while ELISA equipment typically costs over $18,000.
The device features two innovations designed to limit power consumption so that it can be used in regions with limited access to electricity. They used a “one-push vacuum” that is mechanically activated by the user in place of the power-consuming electrical pump, and using the audio jack for power and data transmission eliminated the need for a battery.
During the Rwanda-based field test, health care workers were given 30 minutes of training on how to use the device, which the developers said included a user-friendly interface to guide them step-by-step through each test using pictorial directions. Of the patients using the device, 97 percent said that they would recommend it due to its simplicity, fast turn-around time, and ability to test for multiple diseases.
“Our dongle presents new capabilities for a broad range of users, from health care providers to consumers,” said Sia. “By increasing detection of syphilis infections, we might be able to reduce deaths by 10-fold. And for large-scale screening where the dongle’s high sensitivity with few false negatives is critical, we might be able to scale up HIV testing at the community level with immediate antiretroviral therapy that could nearly stop HIV transmissions and approach elimination of this devastating disease.”
“We are really excited about the next steps in bringing this product to the market in developing countries, and we are equally excited about exploring how this technology can benefit patients and consumers back home,” he added.
—–
Follow redOrbit on Twitter, Facebook, Instagram and Pinterest.
Comments