Influenza - infectious evergreen

Influenza is a highly contagious viral di - sease of the respiratory tract. Influenza viruses infect humans as well as animals, especially birds and pigs. Over the last ten years, molecular biology methods have enabled us to explain the extraordinary mortality of the „Spanish flu“ epidemic of 1918 and other major pandemics of the 20th century. Although the so-called „pig flu“ epidemic of 2009 caus…