| [influenza]. | influenza (flu) is an acute contagious viral infection characterized by inflammation of the respiratory tract that every winter affects more than 100 million people in europe, japan and the united states of america, also being responsible for several thousand of excess deaths (data from the united states reveal between 20,000 to 40,000 excess deaths annually). the mixovirus influenzae is the agent that causes influenza, commonly called flu. there are 3 types of influenza virus: a, b, c, and only ... | 2003 | 12806464 |