Pandemic

A pandemic (from Greek παν pan all + δήμος demos people) is an epidemic of infectious disease that spreads through populations across a large region; for instance a continent, or even worldwide. According to the World Health Organization (WHO), a pandemic can start when three conditions have been met: A disease or condition is not a pandemic merely because it is widespread or kills many people; it must also be infectious. For instance, cancer is responsible for many deaths but is not considered a pandemic