Frequent reassortment and potential recombination shape the genetic diversity of influenza D viruses

In 2011, a novel genus of influenza viruses was isolated from swine with influenza-like symptoms in the United States, named influenza D viruses (IDVs).1 IDVs have been reported in bovine and swine populations across North American and Eurasian countries, including France, Italy, Japan, and China,2 suggesting the potential global spread of this virus. Bovine was proposed to be the natural reservoir of IDVs due to its high seropositivity rate. Earlier studies have shown the cocirculation and frequent reassortment between two distinct genetic lineages of IDVs in the USA3, and a distinct genetic cluster in Japan.