Blog Marco

With all the news about the swine flu virus ravaging over the world plastered everywhere, I wonder what the difference is between an endemic, epidemic and a pandemic. (By the way, the photo has a random influenza virus illustrated in brown and the cilia from your lungs in blue)

An endemic is an infectious communicable disease (such as colds, influenza, measles, mumps, tuberculosis, pneumonia, smallpox) that exists permanently in a particular region or population. An epidemic occurs when this disease attack "a lot of" people at about the same time and may spread through one or several communities. A pandemic occurs when an epidemic spreads across the world.

The World Health Organisation has raised the pandemic alert level from phase four to phase five, signalling that a pandemic is "imminent". Here are the six different "pandemic influenza phases" defined by the WHO:

Phase 1: A virus circulates among animals but with no cases reported of infections in humans.

Phase 2: An animal flu virus is known to have caused infection in humans, and therefore considered a potential pandemic threat.