Know the Difference: Types of Flu Outbreaks
Seasonal Flu — A contagious respiratory illness caused by influenza (flu) viruses occurring every year. It affects an average of 5 percent to 20 percent of the U.S. population by causing mild to severe illness, and in some instances can lead to death.
Epidemic — The rapid spread of a disease that affects some or many people in a community or region at the same time.
Pandemic — An outbreak of a disease that affects large numbers of people throughout the world and spreads rapidly.
H1N1 Influenza (swine flu) — H1N1 influenza is a respiratory disease of pigs caused by type A influenza viruses that cause regular outbreaks in pigs. People do not normally get H1N1 influenza, but human infections can and do happen. H1N1 influenza viruses have been reported to spread from person-to-person.
Avian Influenza — Commonly known as bird flu, this strain of influenza virus is naturally occurring in birds. Wild birds can carry the virus and may not get sick from it; however, domestic birds may become infected by the virus and often die from it.