Outbreak, epidemic and pandemic (nouns, “OWT-BRAKE,” “EHP-ih-DEM-ick” and “PAN-dem-ick”)
When an infectious disease starts to spread,
experts can use several terms to describe this. An outbreak is an
unexpected number of cases. It can be limited to a single community. It might even
be just one case. Or it can spread across countries. It can last just a few
days or persist for years.
In March 2014, the World Health Organization
reported an outbreak of Ebola in west Africa. Then the disease spread to
several countries. Now it was as an epidemic. Epidemic diseases spread rapidly
and infect many people.
Some diseases spread to infect many people in
countries over several continents. These are known as pandemics. Ebola never
reached pandemic status because it was confined to one region of Africa. And pandemics
of new diseases are rare. But those rare cases can be devastating since no one
is immune to an illnesses that has never before infected people.
Influenza spreads around the world every year in
a pandemic. A very bad influenza pandemic developed in 1918 and 1919. It spread
to an estimated 500 million people. That was roughly one in every three people
alive at that time. This pandemic killed an estimated 50 million people.