Pandemics of contagious viruses are extreme infectious disease outbreaks. It is an explosive global event in which most, if not all, populations worldwide are at risk for infection and illness. In past pandemics, viruses have spread worldwide within months and are expected to spread even more quickly today given modern travel patterns.
A pandemic virus outbreak causes emerging fears due to the increase rate of illness and death among all age groups.
Although it is unpredictable when the next pandemic will occur and what strain may cause it, the continued and expanded spread of a highly contagious virus across several countries represents a significant pandemic threat.