Tracking influenza outbreaks quickly and cheaply could get a whole lot easier thanks to a number of experimental devices that can accurately detect viral strains in an hour or so. Using microfluidic techniques, these ‘flu chips’ could lead to better disease surveillance and treatment
“We want to see better tests in the outpatient setting so physicians can get the best information available,” says CDC epidemiologist Dan Jernigan. “Within the last year we a have seen a number of these tests being developed.”
In March, Catherine Klapperich and her colleagues at Boston University described a miniaturized device embedded with tiny tubes that could extract flu RNA from a sample and amplify it using reverse-transcriptase polymerase chain reactions (RT-PCR) with 96% sensitivity. To her knowledge, no other assay previously used one chip for both tasks using a cohort of human samples.
In another first, Anubhav Tripathi and his colleagues at Brown University in Providence, Rhode Island, have developed a technique that relies on a DNA probe that binds and amplifies target viral RNA without relying on RT-PCR — a system the authors call a ‘Simple Method for Amplifying RNA Targets,’ or SMART. Reporting today in the Journal of Molecular Diagnostics, the researchers found that the SMART assay accurately detected flu in the lab, with studies involving clinical specimens underway to confirm the results. “They have done that through creative engineering of the primer and probes, and reengineering the assay development from the beginning,” says Klapperich, who was not involved in the Brown University study.
Importantly, unlike most laboratory-based assays currently approved for influenza testing by the US Centers for Disease Control and Prevention (CDC), these new point-of-care devices can be run under field conditions, thereby reducing the time from isolate sampling to diagnosis that can delay the pace of pandemic monitoring.
Beyond influenza, many groups are working on similar point-of-care diagnostics for a slew of other infectious diseases, too. Click below for a video about a new rapid and affordable way to detect HIV and syphilis in a developing world setting (as reported last year in Nature Medicine).
Image courtesy of anyaivanova via Shutterstock