An epidemic that spreads across multiple countries or continents and affects a large number of people.
A pandemic describes the broad geographic spread of a disease, usually an infectious disease, across countries or regions. The term focuses primarily on the scale and spread of an epidemic rather than how severe the disease is.
A pandemic can develop when an infectious agent spreads efficiently through populations with limited pre-existing immunity or other forms of protection. Not every disease that crosses an international border is a pandemic; the scale and pattern of sustained spread matter.
COMMONLY CONFUSED WITH
- Epidemic: disease occurrence above the expected level in a particular population, place, or period.
- Endemic: a disease that is consistently present at an expected or established level in a particular population or area.
- Outbreak: commonly used for a localized increase in cases.
SEE ALSO