Influenza

influenza is a highly contagious acute viral infection of the respiratory tract. it is caused by influenza a, b and c virus. infection occurs at all ages, but during epidemics the morbidity is higher at extremes of life. sick patients demand medical care and hospitalization, consuming limited resources, increasing length of hospital-days and eventually death. recently, in mexico a novel influenza a virus (h1n1) caused an epidemic. with the new virus surveillance, infections due also to seasonal virus were documented. this update highlights recommendations for prevention and treatment of influenza.