Influenza virus
Influenza virus is divided into three types: A, B, and C. The influenza virus discovered in recent years will be classified as type D. Influenza viruses can cause infection and disease in a variety of animals such as humans, poultry, pigs, horses, and bats, and are the causative agent of human and animal diseases such as human influenza, avian influenza, swine influenza, and equine influenza.