The first decade of research advances in influenza D virus

Abstract

From its initial isolation in the USA in 2011 to the present, influenza D virus (IDV) has been detected in cattle and swine populations worldwide. IDV has exceptional thermal and acid stability and a broad host range. The virus utilizes cattle as its natural reservoir and amplification host with periodic spillover to other mammalian species, including swine. IDV infection can cause mild to moderate respiratory illnesses in cattle and has been implicated as a contributor to bovine respiratory disease (BRD) complex, which is the most common and costly disease affecting the cattle industry. Bovine and swine IDV outbreaks continue to increase globally, and there is increasing evidence indicating that IDV may have the potential to infect humans. This review discusses recent advances in IDV biology and epidemiology, and summarizes our current understanding of IDV pathogenesis and zoonotic potential.

Emergence of new phylogenetic lineage of Influenza D virus with broad antigenicity in California, United States

“…Orthomyxoviridae. Since its first identification in the United States, IDV and its antibody prevalence have been reported in North America, Europe, Asia, and Africa (1)(2)(3). IDV utilizes cattle as a primary reservoir with a broad host range.…”

“…IDV utilizes cattle as a primary reservoir with a broad host range. To date, IDV isolations are largely from cattle and to some extent, from pigs, while IDV RNA genomes and/or specific antibodies have been detected in multiple animal species including goats, sheep, horses, buffalo, camels and wild boars (1)(2)(3). IDV infection causes mild respiratory disease in cattle (4) and is associated with the bovine respiratory disease (BRD) complex (5-7) with a major economic impact to the cattle industry.…”

Tissue Microarrays to Visualize Influenza D Attachment to Host Receptors in the Respiratory Tract of Farm Animals

“…Staining was also observed in the submucosal glands, which could indicate the presence of receptors in mucus [ 25 , 36 ]. Pathogenesis in pigs is significantly lower compared to that in cattle, which could be due to infection being restricted to the upper respiratory tract of domestic pigs [ 5 , 13 ]. Another reason why IDV is much more prevalent in cattle could be because IDV has been suggested to contribute to, or even benefits from, bovine respiratory disease (BRD), as it is among the three most commonly found viral agents in dairy calves affected by BRD [ 4 , 37 , 38 ].…”

“…IDV strains can be categorized into two major clades, D/Oklahoma (D/OK) and D/660/Oklahoma (D/660), and two minor clades as D/China and D/Japan [ 12 , 13 , 14 ]. The original D/swine/Oklahoma/1334/2011 strain belongs to the D/Oklahoma clade and is the most widespread, being found in North America, Europe, Asia, Africa, and South America [ 3 , 12 , 15 , 16 , 17 , 18 ].…”

“…The D/660 clade was at first only isolated in North America, however, D/660 strains were recently also found in cattle herds in Ireland and Italy [ 3 , 6 , 19 , 20 ]. All IDV clades target the respiratory tract of their host, with rather mild clinical signs in cattle such as coughing, runny nose, and elevated temperature; no clinical signs have been observed in infected domestic pigs [ 13 ]. Differences in clinical signs between clades have thus far not been reported.…”