Influenza is a contagious disease, which means that it spreads from person to person. The virus spreads in respiratory droplets caused by coughing and sneezing. Although person-to-person is the most common form of contagious, occasionally individuals may become infected by touching something with virus on it and then touching their mouth or nose.
It is important to be aware that adults may be able to infect others, not only when they are already sick but even the day before getting symptoms.
But how does the virus enter the body?