What is the Difference Between Epidemic and Endemic

The main difference between epidemic and endemic is that the epidemic is a disease that shows a rapid spread and causes devastation to a particular population whereas the endemic describes a disease regularly found in a population of a particular area. 

Epidemic and endemic are two terms that describe the diseases based on their patterns of occurrence. Epidemic diseases affect a significant amount of people within a short period of time while the endemic disease is common to a particular area. 

Key Areas Covered 

1. What is Epidemic
     – Definition, Characteristics, Examples
2. What is Endemic
     – Definition, Characteristics, Examples
3. What are the Similarities Between Epidemic and Endemic
     – Outline of Common Features
4. What is the Difference Between Epidemic and Endemic
     – Comparison of Key Differences

Key Terms 

Endemic Diseases, Endemic Steady State, Epidemic Diseases, Pandemic Disease

What is Epidemic 

Epidemic is a term that describes a disease which spreads fast to a large population within a short period of time. Therefore, an epidemic disease arises as an outbreak. The entry of a new pathogen or a mutated pathogen to a population can cause an epidemic disease. Also, an ecological change of the population such as a change in the population density can increase the risk of epidemic diseases. For example, increased stress due to the high population density of a particular area can raise this type of disease. The increased density of the vector can also cause an epidemic disease.  

Figure 1: Epidemic Ebola in West Africa 2014

Epidemic diseases are often restricted to a certain area but, sometimes, it can spread to another area. When an epidemic disease infects a large population in another region apart from its origin, it is called a pandemic disease. Some examples of epidemic diseases are influenza, smallpox, and Black Plague. 

What is Endemic 

Endemic is a term that describes a disease which has a habitual presence in a particular population. This type of diseases remains active for a long time. But, it does not show a sudden, exponential increase in the disease. That means this type of diseases exists in the endemic steady state. 

Figure 2: Malaria-Endemic Countries in the Eastern Hemisphere

As an example, chicken pox occurs among school children in a predictable cycle in the US. The common carriers of diseases are mosquitoes, ticks, fleas, and lice. Also, dengue is endemic in more than 100 countries. 

Similarities Between Epidemic and Endemic 

• Epidemic and endemic are two types of diseases which spread within populations. 
• Both cause damages to the individuals in the population. 

Difference Between Epidemic and Endemic 

Definition 

Epidemic refers to a widespread occurrence of an infectious disease in a community at a particular time while endemic refers to a regularly found disease among particular people or in a certain area. 

Significance 

Epidemic diseases cause a significant damage to the living organisms within a short period of time while endemic disease is prevalent in a certain region or population. This is the main difference between epidemic and endemic.

Rate of Infection 

Another difference between epidemic and endemic disease is that the rate of infection of an epidemic disease continuously increases while the rate of infection of an endemic disease is constant. 

Examples of Diseases 

Some examples of epidemic diseases are smallpox, H1N1, the black plague, etc. while some examples of endemic diseases are malaria, tuberculosis, chicken pox, etc. 

Conclusion 

The epidemic is a type of disease that occurs suddenly in a particular population, causing a severe damage. On the other hand, endemic is a type of disease that regularly exists in a particular population. Therefore, the main difference between epidemic and endemic is the type of occurrence of the disease.

Reference:

1. Green, M S, et al. “When Is an Epidemic an Epidemic?” IMAJ, U.S. National Library of Medicine, Jan. 2002, Available Here

Image Courtesy:

1. “2014 West Africa Ebola Epidemic – New Cases per Week” By Delphi234 – Own work (CC0) via Commons Wikimedia   
2. “Malaria-endemic countries eastern hemisphere-CDC” By Centers for Disease Control and Prevention –  (Public Domain) via Commons Wikimedia