First report of influenza D virus infection in Turkish cattle with respiratory disease.

Bovine respiratory infections are the most economically important diseases affecting the cattle industry worldwide including Turkey. Influenza D virus (IDV) could play an important role to trigger bovine respiratory disease (BRD) complex. Since, there is no data about the presence and genotypes of IDV in Turkish cattle herds; this study was performed to investigate IDV in cattle in Turkey. Animals analyzed in this study were from commercial cattle farms having respiratory disease in calves with significant mortality. Nasal swabs and tissue samples from cattle in Marmara, Inner Anatolia and Aegean region of Turkey were analyzed by real-time RT-PCR assay to detect IDV. Among 76 samples form 12 cattle herds, IDV was detected in 3 cattle in a herd. Sequencing and phylogenetic analysis of partial hemagglutinin esterase fusion (HEF) gene showed that the Turkish strain is 95% identical to its European and US counterparts, which suggest intercontinental spread of the virus. These findings highlight the need for future continuous surveillance on larger scale to determine the distribution pattern and evolution of this novel emerging pathogen in Turkish cattle industry.