When patients present with symptoms such as a cough, runny nose, and fever, doctors are often unable to identify the source of their respiratory illness. However, a new technology developed by scientists at Duke University is able to accurately distinguish between viral and bacterial infections.

The new tool has been in the works for over a decade, and while it has been previously proven in a research setting, there remained a need for more rapid results in order to guide appropriate treatments. Now, the test can be performed right in a doctor’s office and results are available in less than an hour. This allows the physician to prescribe antibiotics if the source of infection is deemed bacterial, while simultaneously avoiding the same prescription if the source is determined to be viral. This is an important step as not only are antibiotics ineffective against viruses, but unnecessary treatment with antibiotics is a known contributing factor to the emergence of antibiotic-resistant bacterial strains.

Current diagnostic tests can only identify the specific pathogen they are targeted to detect, but this new method uses a different approach based on host gene expression. Our immune systems activate one set of genes when faced with bacterial infections, and a separate set of genes when responding to a viral infection. The new test looks for those unique signals to determine which type of infection the body is fighting.

In a multi-site study of more than 600 patients presenting to hospital emergency rooms (ER) with respiratory symptoms, the test was able to identify bacterial infections with 80% accuracy and viral infections with 87% accuracy. As a comparison, current standard tests have a 69% accuracy rate.

Additional studies are already underway to validate the tool in other groups of patients and to adapt the technology in order to provide more specific information.