Changes in
body odor are known to be a consequence of many diseases. Much of the published work on disease-related and
body odor changes has involved parasites and certain
cancers. Much less studied have been
viral diseases, possibly due to an absence of good animal model systems. Here we studied possible alteration of fecal odors in animals infected with
avian influenza viruses (AIV). In a behavioral study, inbred C57BL/6 mice were trained in a standard Y-maze to discriminate odors emanating from feces collected from mallard ducks (Anas platyrhynchos) infected with low-pathogenic
avian influenza virus compared to fecal odors from non-infected controls. Mice could discriminate odors from non-infected compared to infected individual ducks on the basis of fecal odors when feces from post-
infection periods were paired with feces from pre-
infection periods. Prompted by this indication of odor change, fecal samples were subjected to dynamic headspace and
solvent extraction analyses employing gas chromatography/mass spectrometry to identify chemical markers indicative of AIV
infection. Chemical analyses indicated that AIV
infection was associated with a marked increase of
acetoin (3-hydroxy-2-butanone) in feces. These experiments demonstrate that information regarding
viral infection exists via volatile metabolites present in feces. Further, they suggest that odor changes following
virus infection could play a role in regulating behavior of conspecifics exposed to infected individuals.