Endemic Epidemic Pandemic 101

Endemic, epidemic and pandemic are terms used to describe various infections in a population.

Endemic

An infection is said to be endemic in a population when the infection rate is constantly maintained at a baseline level in a geographic area year after year.

So we can say chickenpox is endemic in the UK as it's a common infection every year with relatively stable infection rates.

Epidemic

If there is a sudden increase in the infection rate of a disease in a given population it is deemed to be an epidemic, for example tuberculosis was considered to be almost eradicated in the UK by the 1980's but recent migration by some individuals with the condition has seen a spike in cases that we would call an epidemic.

Pandemic

When a disease is not localised to a specific area but has spread around the world it is known as a pandemic so an infection will suddenly appear in a new area, these can be serious as people are exposed to something their immune system has not encountered before.

These three terms can be used in conjunction depending on how common an illness is, how widely spread and if there has been any sudden rise in the number of infections.

The covid 19 virus that originated in China is new so obviously the large rise in the number of people infected makes it an epidemic, But now that it is being transmitted to people with no connection to China and is spreading globally we can say it is a pandemic epidemic.

The information released by the CCDC (Chinese Centre for Disease Control) suggests that most people that are infected only have mild symptoms and that complications and fatality is more common in the elderly.

This and the high transmission rate means covid 19 may become a regular seasonal infection as most people will contract it and survive to infect others, as we do with other common corona viruses, albeit a much more deadly one for the elderly and those with certain preconditions.

This would make it endemic and this is what the Harvard epidemiologist Marc Lipsitch said recently here

So as with all of these viruses the WHO (World Health Organisation) advice is the same, maintain good hygiene practices and avoid contact with potentially infected people.

Be prepared to self isolate and for the economic downturn that this is going to cause, China still has not returned to full production and this will affect the worlds economies and our interconnected global supply chains.

Take care

Roo