Definitive meanings of health-related words


An article in The Conversation (07 January 2015, 10.11pm AEDT) prompts writers and readers and experts to use health-related words correctly. This is an important part of public health education.

“Explainer: what’s the difference between an outbreak and an epidemic?” is authored by Arinjay Banerjee.   He’s a Ph.D. candidate in the Western College of Veterinary Medicine at the University of Saskatchewan, Canada.   Arinjay Banerjee reminds us to use the right words correctly. Many words used in the health sector have specific meanings which experts use to define public health situations and alert others about the seriousness of a health matter.  Selected paragraphs within this article are listed here for amplification because this is an important part of public health education:

“More than 8,000 people have died from Ebola in West Africa since February 2014 and it has spread beyond the three countries initially effected. So, it’s an epidemic, right? Or is it an outbreak?…

“It’s time to brush up on the vocabulary that can help you understand just what infectious disease experts are trying to tell us …”

Outbreaks, epidemics and pandemics

“An outbreak is the sudden occurrence of a disease in a community, which has never experienced the disease before or when cases of that disease occur in numbers greater than expected in a defined area…

“So what exactly is an epidemic? It is an occurrence of a group of illnesses of similar nature and derived from a common source, in excess of what would be normally expected in a community or region…

“A pandemic on the other hand refers to a worldwide epidemic, which could have started off as outbreak, escalated to the level of an epidemic and eventually spread to a number of countries across continents…”

Emerging and reemerging diseases

“We also come across words like “emerging” and “re-emerging.” An emerging disease is one that has appeared in a population for the first time or one which may have existed before, but is rapidly increasing in incidence. Examples of emerging infectious diseases are SARS, HIV and H1N1 …

Re-emerging diseases are those that have historically infected humans, but continue to appear in new locations or reappear after apparent control or elimination.”


“Although people use terms like outbreak and epidemic interchangeably, it would only be fair to understand the definitive meaning behind each word. An outbreak can take the form of an epidemic and eventually a pandemic, but that does not entitle us to use these words incorrectly.”

The article using this link was retrieved at 11.00 AEDT 07 January 2015:

Arinjay Banerjee can be reached at

Article published 08 January 2015, Canberra.
Updated 12 January 2015, Canberra.