Difference between outbreak, epidemic and pandemic

COVID-19 also widely known as Coronavirus has declared as a pandemic by the World Health Organization (WHO). The concept of pandemic, epidemic, and outbreak is not very clear to everyone. It’s just the scale of the severeness of a disease.

Outbreak

Outbreak happens to a small group of people. It is limited to a small geographic area.

Any disease can cause an outbreak. If a disease suddenly makes a spike and infects more than the average number of people in a shorter period then it is an outbreak. The outbreak is limited to a small geographic area.

Every pandemic or epidemic starts with an outbreak, as at the beginning it is limited to a small geographic area and the number of affected people is very small. The outbreak is controllable but if it becomes out of control then it goes to the next stage that is epidemic and if it further goes than it becomes pandemic.

example
An unusual spike in the number of children with food poisoning at a daycare. in a typical week, one or two sick kids might be normal, but if 20 children are having food-poisoning at the same time, then it is an outbreak

Epidemic

Bigger and spreading.

An epidemic is an outbreak, spreads over a larger geographic area in a shorter period. When the COVID-19 (widely known as Coronavirus) cases were limited to the small geographic area of Wuhan, it was an outbreak. As soon as the disease spread over the other parts of Wuhan and many areas of mainland China, it becomes out of control and declared as an epidemic.

An epidemic is a widespread case of uncontrollable disease limited to a single country or specific geographic area.

Pandemic

International and out of control.

A pandemic is an epidemic spreads to multiple countries or regions of the world. However, some epidemiologists classify a situation as a pandemic only once the disease is sustained in some of the newly affected regions through the local transmission.

An example, a COVID-19 infected traveler, who returns to Australia from China does not make a pandemic, but once he/she infects few other people like family members, friends or colleagues via local transmission than its a pandemic. When the efforts to control global spread have has failed then we call it a pandemic.

(263)