Mammalian cells produce odor compounds in response to viral infection. Cristina E. Davis and colleagues at the University of California, Davis, USA, discovered that mammalian cells emit a specific set of “smells” upon being infected with influenza viruses. These odors are primarily composed of volatile organic compounds, which can be detected by using gas chromatography/mass spectrometry (GC/MS).
Specifically, circulating B-cells from our immune system are capable of producing chemical odors that appear after viral infection. Most of these compounds are specific to the strain of influenza, and they appear on a distinct time course post-infection. In some cases the researchers were able to detect flu just 6–8 hours after infection. Several of these chemicals appear to be generic influenza biomarkers.
This breakthrough may allow researchers to monitor for flu-associated compounds in exhaled human breath as an asymptomatic measure of viral infection—at a stage earlier than present clinical methods. It also appears that some of the compounds detected may be strain-specific, which could allow for further identification of the new infection.