Detecting the flu virus in one minute

22 November 2019

A team of researchers from the Physics Department at Oxford University and their collaborators have developed a new method that allows extremely rapid detection of pathogenic viruses – in as little as one minute – which is significantly faster than existing diagnostic tests.

Infectious diseases caused by viruses represent a huge global public health concern, causing many thousands of deaths annually. Notable viruses that cause human disease include HIV, influenza, Ebola, hepatitis C, dengue, Zika, measles and rabies. Influenza alone results in the deaths of up to 650,000 people every year during annual epidemics, with higher death rates recorded during more severe pandemics such as the 1918 Spanish flu which killed more than 50 million people worldwide. In spite of the high mortality rates associated with these viruses, we do not currently have a fully effective toolkit of diagnostic assays to detect and identify these dangerous pathogens.

Reduced treatment costs; reduced morbidity

Early detection of viruses helps provide targeted therapy, reduces treatment costs and morbidity, and leads to more efficient disease management and control. Traditional diagnostic approaches for virus detection are often hampered by long waiting times or limited sensitivity and specificity.

The new method invented by the Oxford team uses positively charged molecules, like calcium ions, to bind short DNA strands to intact virus particles. When these DNA strands are labelled by bright fluorescent dyes, they result in a facile and rapid labelling of the exterior of the virus particle. Fluorescently-labelled viruses are easily observable by light microscopy, allowing their properties to be characterised in terms of aggregation, morphology and particle size.

Simple, rapid and cost-effective

Using influenza as a model virus, the Oxford team have shown that clinical isolates of virus particles can be labelled and detected in as little as one minute, substantially faster than existing diagnostic tests. The method is general and can be extended to the detection of a wide variety of other pathogenic viruses.

The new method has several advantages over existing virus detection techniques. It provides a simple and rapid method for counting whole virus particles, which is particularly important in the production of viral vaccines. The Oxford team has also shown that viruses can be detected directly in complex biological samples without the need for purification or amplification of the viruses; such a detection is simple and cost-effective, and does not require expensive reagents.

Current work, aided by the group’s clinical collaborators, is focused on developing the method into a medical diagnostic assay.

The work was carried out in the Department of Physics at the University of Oxford; the work was led by Dr Nicole Robb and Prof Achillefs Kapanidis at the University of Oxford in collaboration with researchers at the National Influenza Reference Laboratory of Southern Greece, Hellenic Pasteur Institute.

‘Rapid functionalization and detection of viruses via a novel Ca2+-mediated virus-DNA interaction’ by NC Robb et al was published Nature Scientific Reports and can be found here:
DOI: https://dx.doi.org/10.1038%2Fs41598-019-52759-5