Molecular characterization of the novel respiratory Influenza D virus detected in French calves

In 2011 in the United States an Influenza C-like virus was isolated from swine samples (Hause et al., 2013). Further studies better characterized this novel virus and discovered that it had only 50% of genetic identity with human infecting Influenza C virus and was not able to reassort not only with ICV but also with the other two genera of the Influenza viruses family, the Orthomyxoviridae. As a consequence of these discoveries, in 2014 the authors submitted the proposal to the International Committee on Taxonomy of Viruses (ICTV) for the insertion of a new genus in the Influenza virus family. The new genus is currently known as Influenza D virus, extending therefore the Orthomyxoviridae from six to seven genera. So far, IDV has been detected in different animal species and on almost all continents. In France, IDV was identified in 2011-2014 in cattle with respiratory clinical signs in Saone-et-Loire (Ducatez et al, 2015). However, the extent of IDV circulation in French cattle and small ruminants was not known. The aim of this work was therefore to detect and characterize IDV in French calves to assess the virus prevalence and genetic diversity and also evaluate IDV seroprevalence in cattle and small ruminants in 5 French departments (Vendée, Bretagne, Nord, Aveyron and Ariège).