Low-Cost Technology Diagnoses Influenza Early

A novel technology is showing promise as the basis for a much-needed home test to diagnose influenza quickly, before the window for taking antiviral drugs closes.

A fast, inexpensive diagnostic test, similar to the quick throat swabs for Streptococcus pneumoniae tests, is especially important for influenza, which causes widespread illness and an average of 36,000 deaths annually in the USA alone.

A scientist at the Georgia State University (Atlanta, GA, USA) and a colleague at the University of Cincinnati (OH, USA) launched a search for a fundamental approach for diagnosing influenza and other viral disease because of drawbacks with existing tests. Those tests can produce results in about 15 minutes. However, they are expensive and sometimes give false negative results when the patient is infected with the influenza virus.

The influenza viruses have two major antigens, hemagglutinin and neuraminidase, which determine the specific strain of the virus. Changes in hemagglutinin and/or new combinations of hemagglutinin and neuraminidase signal the emergence of a new strain of virus. The novel technology uses various forms of carbohydrates that can capture the hemagglutinin and neuraminidase, and via a color change or other signal, indicate both infection and the specific type or strain of influenza virus. Information on the strain would be important, enabling doctors to pick the most effective antiviral drug. The innovative approach has other potential advantages, including quicker results, lower cost, and greater reliability.

Influenza binds to N-acetyl neuraminic acid or sialic acid present on the surface of cells. The investigators are developing robust synthetic analogs of sialic acids that can be used as capture and reporter molecules in point of care diagnostics. The synthesis, stability and the ability of these molecules to capture influenza virus at room temperature without the addition of inhibitors was the crux of the technology. The approach so far is living up to expectations, with laboratory experiments verifying that it can detect influenza viruses. The team of Suri Iyer, PhD, and Allison Weiss, PhD, plan to move ahead in the autumn with tests on samples taken from human volunteers. The study was presented at the 246th National Meeting & Exposition of the American Chemical Society held September 8-12, 2013 in Indianapolis (IN, USA).

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Georgia State University
University of Cincinnati