A new assay for spotting the virus responsible for cold sores has been developed by scientists in Ireland.
It is estimated that between 60–95% of adults worldwide are infected with the herpes simplex virus-1 (HSV-1) and although the symptoms are usually limited to sores or blisters, in rare cases it can infect the central nervous system, which is fatal in 70% of untreated cases. If diagnosed early, antiviral therapy can lead to a positive outcome, thus emphasizing the need for rapid diagnostic methods.
At present, the most definitive HSV-1 test involves cell cultures but results can take up to a week to complete. Alternative assays have been proposed but they still remain time-consuming and introduce additional complications, like the need for specialist personnel.
The new test devised by Gil Lee and colleagues at University College Dublin uses beads, composed of iron oxide nanoparticles, coated with peptides that bind to the virus. As the nanoparticles are also superparamagnetic, a simple magnet can accelerate their aggregation and the way in which these aggregations scatter light is measured and used to indicate an infection. ‘We knew that a magnetic bead assay had the potential to be very sensitive based on our previous work with Dengue,’ explains Lee. ‘However, HSV is among the most difficult viruses to detect with this technique because it is a relatively large virus and has a complex and irregular membrane coat.’