The average incubation period for flu type A is 1 to 4 days, according to the Centers for Disease Control and Prevention. Some people can remain infectious for up to 7 days.
Influenza is spread through respiratory droplet transmissions, such as coughing and sneezing. Symptoms of flu type A include coughing, sneezing, fever, body aches and chills. Some people experience more severe symptoms than others. The flu can last anywhere from 3 to 7 days, but if complications arise, a person can suffer from symptoms much longer. The elderly and young are at most risk for developing complications associated with any strain of influenza.