University of Florida researchers, with funding from the state of Florida, have developed a rapid, cost-effective point-of-care test for the Zika virus that can be used in the field.
Z. Hugh Fan, Ph.D., a professor and George N. Sandor Faculty Fellow at the Herbert Wertheim College of Engineering’s department of mechanical and aerospace engineering, and John Lednicky, Ph.D., a research professor at the College of Public Health and Health Professions’ department of environmental and global health, led a team that developed a miniaturized device for analysis of the virus in blood, saliva, and urine specimens. Using the device, they demonstrated the reproducible detection of Zika virus.
The team has published the results of their current research in the journal Angewandte Chemie International Edition, and UF has filed for a patent on the technology.
“Zika virus caused a widespread epidemic of disease in the Americas in 2016, and cases continue to occur because the virus has now become established in the Western Hemisphere. Simple to use, quick-working, and cost-effective devices that can be used to help diagnose Zika infections are sorely needed,” Lednicky said. “In particular, many methods are beyond the reach of physicians and laboratories in resource-strapped countries, and when available, the results of the confirmatory tests often take weeks to reach the medical caregivers.”
Because fever due to Zika virus is not specific, (countless viruses induce fever) and an infection by the virus can be misdiagnosed, it is important to have a point-of-care testing platform to accurately and quickly identify Zika virus infection for patient management and clinical diagnostics. In addition, because Zika virus generally causes mild or no symptoms, affected patients in an outbreak area may not seek medical care. The virus can then be transmitted through other non-vector-borne transmissions, including sexual activities and blood transfusion. A point-of-care testing platform could be useful for screening asymptomatic patients to prevent possible Zika virus transmission, as well as for safeguarding the blood supply at blood-donation sites.
Current Zika tests require special equipment, and results can take up to three weeks to be reported to the attending physician.
“Our invention is designed as a point-of-care device that can be performed at the physician’s office, and the test results are available within an hour,” Lednicky said. “Apart from being cheap and easy to use, the device does not require expensive instruments to perform, and the results are easy to interpret and thus do not require extensive training.”
The new UF device features innovative ball-based valves that enable the storage and sequential delivery of reagents, a mixing unit where the reaction (virus lysis) takes place, and a paper-based detection unit that allows for detection of the results by the naked eye or with the use of a cellphone camera.
“We use an isothermal nucleic acid amplification method rather than (the) often-used polymerase chain reactions (PCR) so that thermal management is simpler,” Fan said.
The paper unit is placed in a commercially available coffee mug that provides a constant temperature for the development of the resulting color.
The next step for Fan and Lednicky will be to do a large-sample validation test using their device.
Generally, symptoms of Zika disease are mild, including fever, rash, conjunctivitis, muscle and joint pain, malaise, and headache, which usually last for two to seven days. The World Health Organization (WHO) reports that the majority (about 80 percent) of people infected with Zika virus do not develop any symptoms. However, in October 2015, Brazil reported an association between Zika virus infection and microcephaly and other congenital anomalies in fetuses and newborns. Infection with the virus was also found to sometimes lead to Guillain-Barré syndrome, a condition in which the immune system attacks parts of the peripheral nervous system. To date, a total of 86 countries and territories have reported evidence of mosquito-transmitted Zika virus infection.