What virus causes the current influenza pandemic

Human influenza can cause morbidity in people of different ages, and each influenza pandemic has brought great disasters to human beings; since the avian influenza virus is considered to be the preservation host of the human influenza virus and the source of new influenza viruses, there is a traditional viewpoint that human beings will not be infected with avian influenza viruses, and even if human beings (volunteers) are inoculated with avian influenza viruses, they will not produce antibodies. However, the facts show that not only can people be infected with the avian influenza virus, but it can also cause morbidity and mortality. Symptoms of human infection with the bird flu virus range from the typical flu-like symptoms of fever, cough, sore throat and muscle aches to eye infections, pneumonia, acute respiratory distress, viral pneumonia and other serious, life-threatening complications.

Because influenza is so dangerous to humans and livestock, WHO has classified it as an infectious disease for which global surveillance is practiced. Animal influenza, especially avian influenza, is very closely related to human influenza and human health, and avian influenza is thought to be a source of new genes for the preservation and mutation of human influenza. A limited number of influenza virus subtypes are present in mammals, whereas all 15 hemagglutinin and 9 neuraminidase subtypes of influenza viruses are present in avian species, particularly waterfowl, that are now known. The ability of avian influenza viruses to break through the interspecies barrier and directly infect and kill humans or mammals has led to a renewed understanding of the public **** health significance of avian influenza.