First identified in 2011, influenza D virus (IDV) is now recognized as a pathogen of cattle and swine. The virus is able to infect and replicate in the same types of cell cultures that are typically used for the isolation of influenza viruses that affect humans. Studies in ferrets and guinea pigs, both of which are animal models for human influenza pathology and transmission, reveal that IDV successfully infects and replicates in their upper and lower respiratory tracts and is capable of being transmitted to close contacts. The predicted cell receptor binding protein structure of IDV is similar to that of human influenza C virus. Taken together, these observations suggest IDV has the potential to infect humans, and is a disease agent of humans.
EGH graduate student Sarah White, EGH associate professor John Lednicky, and their colleagues from Kansas State University, the CDC, and from Duke University hypothesized that cattle workers were at increased IDV exposure risk, and utilized a cross-sectional serological study to gain insights on the zoonotic potential of IDV to human adults with occupational exposure to cattle in north-central Florida. They found anti-IDV antibodies in about 90% of the cattle workers, suggesting they had been exposed to IDV or a very similar virus.
Their report can be accessed at: White SK, Ma W, McDaniel CJ, Gray GC, and Lednicky JA. 2016. Serologic evidence of exposure to influenza D virus among persons with occupational contact with cattle. Journal of Clinical Virology. http://dx.doi.org/10.1016/j.jcv.2016.05.017