Endemic, epidemic, pandemic – what's the difference?
deepseek / deepseek-v4-flash
- The terms endemic, epidemic and pandemic are often confused, but in epidemiology they have precise meanings describing disease spread, not danger.
- An endemic disease occurs regularly in certain regions with a relatively constant number of cases, such as malaria affecting 300 million people annually in the tropics.
- An epidemic is an unusually frequent occurrence of a disease in a specific region over a limited period, often due to virus mutation or introduction to a new area.
- A pandemic is an epidemic that spreads across countries and continents, requiring cooperation among health systems for control.
- Pandemics are usually caused by new pathogens or viruses, such as zoonoses transmitted from animals to humans.
- An example of an epidemic is smallpox introduced to the Americas in the 16th century, killing up to 90% of the indigenous population.