How does a flu pandemic occur
A pandemic influenza is a worldwide outbreak of disease that occurs when a new influenza virus appears in humans, causes serious illness and then spreads easily from person to person worldwide. pandemic is cause by a new virus that people have not been exposed to, so everyone is susceptible. Pandemic influenzas can cause more serious disease and many more deaths than the seasonal flu. Because of this, past pandemics have led to high levels of illness, death, disruption of society and economic loss.