Endemics, Epidemics and Pandemics

Introduction

Infectious diseases are ever present in society but every once in a while there may be an outbreak, a new strain or a new disease that has a significant impact at either a local or global level. The spread and rate of new cases can be classified as:

Endemic - describes a disease that is present permanently in a region or population Epidemic - is an outbreak that affects many people at one time and can spread through one or several communities Pandemic - is the term used to describe the significant global spread of an epidemic.

Pandemic

An infectious disease can be spread by either bacterial or viral agent but in most cases a pandemic is the result of a transmissible infectious disease. Once an epidemic becomes global and affects a large percent of the population it becomes known as a pandemic. The terms pandemic and epidemic are used to describe the rate and distance of the spread of the disease and not the severity of the disease. Significant features of a pandemic are listed belows:

Affects a wider geographical area, often global Infects a large number of people Often caused by a new virus or a new strain of a virus that has been dormant for many years. Spreads quickly in humans as there is little to no immunity Can cause a high number of deaths Because of the need to control the spread of the disease there is often social disruption, unrest and economic loss

A pandemic will be declared by the World Health Organisation WHO (what criteria).