What It Is
A pandemic is a global communicable disease outbreak (whereas an “epidemic” is regional in nature or otherwise confined to particular populations). An influenza pandemic occurs when a strain of influenza virus emerges:
• Which causes serious illness.
• For which there is limited immunity in the human population.
• Which is able to easily and quickly spread person-to-person – especially through saliva, coughing, or sneezing.
Infectious diseases are one of the leading cause of death worldwide. Because of air travel and international trade, infectious disease agents are carried across borders every day by humans, animals, insects, and food products.