At a time when there is great concern over the risks of antibiotic resistance, researchers at Washington University in St. Louis have found a new way to distinguish between fevers in children caused by either bacteria or viruses.   In a study published in the Proceedings of the National Academy of Sciences, Hu, Yu, Crosby, and Storch measured utilization of genes for the immune response in febrile children, some of which turned out to be infected with bacteria or one of three different viruses, and in children without fevers.

They were able to find thousands of examples of increased or decreased gene utilization specifically related to either a viral or bacterial infection.   Of these, in most cases as few as eighteen to thirty-three markers could be utilized to accurately distinguish between a fever caused by a virus or bacteria.  Additionally, some of these markers were specific enough to distinguish between the three viruses used in this study, though they were unable to distinguish between bacteria.  The markers also found that an asymptomatic child infected by a virus was not able to be distinguished from a virus-negative child, indicating that the test showed specific immune response to these organisms.  The tests were much more accurate than traditional guidelines, such as white blood cell counts.

Unfortunately, the current assay takes too long to be clinically useful, but methods are being devised to limit the markers and speed the tests.  This would make clinical diagnosis of an active viral infection in children or adults easier and help to limit overprescription of antibiotics to individuals that are not undergoing bacterial infections.