Influenza virus(FLU)

Influenza virus is called influenza virus for short. It is divided into three types: A (A), B (B), and C (C), and influenza viruses discovered only in recent years will be classified as type D (D). Influenza viruses can cause infections and illnesses in various animals such as humans, birds, pigs, horses, and bats. They are the pathogens of human influenza, avian influenza, swine influenza, horse influenza, and other animal diseases.

The typical clinical symptoms of these diseases are acute high fever, systemic pain, significant fatigue, and respiratory symptoms. The influenza virus is mainly transmitted through droplets in the air, contact between susceptible and infected individuals, or contact with contaminated items. The general autumn and winter seasons are its high incidence periods. Human influenza is mainly caused by influenza A and influenza B viruses. The influenza A virus often undergoes antigen mutations and can be further divided into subtypes such as H1N1, H3N2, H5N1, H7N9 (where H and N represent the two surface glycoproteins of the influenza virus, respectively). The influenza virus has weak resistance to the outside world. Animal influenza viruses usually do not infect humans, and human influenza viruses usually do not infect animals, with pigs being an exception. Pigs can be infected with both human and avian influenza viruses, but they are mainly infected with the swine influenza virus. A few animal influenza viruses can cause a human influenza pandemic after adapting to humans.