Researchers are currently focusing their efforts on new ways to fight the Zika virus, from developing technology to detect Zika outbreaks before they occur, to findings means to blocking viral transmission. However, how do we identify those who have already been infected so that they are aware of their status? One of the major issues with the Zika virus is that 80% of individuals who are infected are asymptomatic, and so they unintentionally spread the virus. With this in mind, rapid and cheap diagnostic tools are needed, to inform both patients and practitioners.
To that end, scientists from Florida Atlantic University (FAU) have developed an accurate, rapid, and inexpensive Zika virus diagnostics tool that is as small as a tablet and can detect infection outside of a laboratory.
Current Zika diagnostics tools detect the virus through tests that identify viral antibodies in the bloodstream. Unfortunately, these tests do not always differentiate between Zika antibodies and antibodies of other flaviviruses, such as Dengue, and Chikungunya. According to Waseem Asghar, PhD, lead investigator, assistant professor at the FAU College of Engineering and Computer Science and Charles E. Schmidt College of Science, “Because flavivirus antibodies cross-react with one another current tests cannot distinguish between them.”
To accurately detect Zika, a polymerase chain reaction (PCR) test is needed, which can cost around $20,000 (or more), and requires trained and skillful lab technicians to execute the procedures. It can also take hours to get results back from a PCR test.
Dr. Asghar said in an interview with Contagion®, “It requires trained personnel and high-tech lab to perform the PCR assay which is not suitable for … settings such as airports, community health centers etc. Furthermore, PCR assay takes several hours to test a sample. The device that we are developing can overcome many of these challenges as it will be low-cost [$2], automated (does not require trained personnel) and rapid (test results within 15 minutes)."
The new tool that Dr. Asghar and his team developed can differentiate between Zika, Dengue, and Chikungunya infections. The test requires only a saliva sample, which makes it convenient to use in remote locations that would not normally have access to expensive lab equipment and skilled technicians, such as airports or community health centers.
“The working principle of [the] device is that Zika viruses are first captured and isolated from a few drops of saliva/serum samples using magnetic beads functionalized with specific Anti-Zika Envelop antibodies. The isolated viruses are lysed using detergent, quickly. The virus lysis will change the conductivity of the solution which can be measured rapidly using impedance sensing. All the processing steps are done on a microfluidic device automatically. [The] device is made of plastic and paper, so its low-cost. It will take 15 minutes to do Zika testing using this platform and device,” Dr. Asghar told Contagion®.
This new Zika diagnostics tool draws on technology that the researchers previously developed for HIV detection. The HIV tool uses paper and plastic materials, a “cassette-sized container” that holds up to 12 samples, and a “receptacle about the size of a tablet.”
According to the researchers, this tool is not only cheap, but it can be easily developed, used, and disposed of. According to the University’s press release, the researchers developed this new tool to “reduce the impact of the outbreak until a vaccine is identified.” The team received a seed grant from the FAU Institute for Sensing and Embedded Network Systems Engineering, which “significantly contributed to the development of [the] current device prototype,” according to Dr. Asghar. In addition, the research team recently received a 1-year grant of $199,280 from the Florida Department of Health to commercialize the device.
Looking towards future application of the technology, Dr. Asghar told Contagion®, “The detection platform can be adapted to other pathogens and viruses such as influenza, chikungunya, Dengue, [hepatitis] B and C viruses.”
With new findings suggesting that Zika virus causes a host of complications constantly coming to light, it is important now, more than ever, to be able to detect Zika virus infection rapidly, so as to take necessary precautions.
Dr. Asghar developed this diagnostics tool in collaboration with Massimo Caputi, PhD, co-principal investigator and associate professor of biomedical science at Charles E. Schmidt College of Medicine, and Mariano Gacria-Blanco, MD, PhD, professor and chair of biochemistry and molecular biology at the University of Texas Medical Branch at Galveston.
