Abstract
Influenza viruses have been known to be types A to C, including human seasonal influenza virus and avian influenza virus. In recent years, the influenza D virus, which possesses different characteristics from other types of influenza viruses, infecting livestock cattle and other domestic animals was discovered in the United States. Epidemiological surveys have revealed that influenza D viruses are prevalent throughout the world, including Japan, and are one of the causative agents of bovine respiratory disease complex (BRDC). In this review, we will describe the discovery of influenza D virus, its epidemiological status, its virological characters, and our researches on the epidemic status of influenza D in Japan.
