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It is an outbreak of disease that spreads quickly and affects many individuals at the same time. In this article, we are going to discuss the epidemic and its causes and types.

What is an Epidemic?

An epidemic is a disease that affects many people within a city, country, or large population area. It travels rapidly and affects many peoples at the same time. It is a process in which the disease continues to spread uncontrollably. An epidemic is an outbreak of a disease in a particular geographical area that affects a large population area.

Some of the examples of an epidemic in the past are as follows:

  • The Spanish flu came in 1981
  • The measles outbreak from 1981 to 1991
  • The case of whooping cough in 2014

Causes of Epidemic

The infectious epidemic may be caused by many factors, including change in the pathogen reservoir, change in the host's population ecology, and an emerging pathogen to a host population. Various changes may occur in an infectious disease that may cause an epidemic. Some of them are as follows:

  • Usually, an epidemic occurs when the existing pathogen's host immunity is unexpectedly lower than that found in the endemic equilibrium, and the transmission limit is exceeded.
  • Change in the ecology of the host population.
  • Many epidemics occur in certain seasons, like in the winter season, whooping cough, measles, and throat in winter seasons.
  • After exposure to chemicals or radioactive materials, epidemics can also occur. Minamata disease, for instance, is caused by mercury exposure.
  • Disease epidemics are generally caused by an infection that spread by person-to-person contact, animal-to-person contact, or through the environment or other media.
  • Epidemics could result from other disasters, including tropical storms, droughts, floods, earthquakes, etc.
  • Sometimes, the epidemic cause may be unknown even after various investigations.

Types of Epidemic

There are mainly two types of an epidemic:

  1. Common-Source Epidemics
  2. Propagated Epidemics

Common-Source Epidemics

  • Common-Source epidemics are caused due to an infectious person when he connects with another person.
  • They can occur from environmental contamination like air, water, food, and soil by industrial chemicals or pollutants.
  • For example, the Bhopal gas tragedy in India and the Minamata disease in Japan were caused by the ingestion of fish containing a high methyl mercury concentration.

Propagated Epidemics

  • A propagated epidemic happens when the infection is transmitted from one person to another via the air, contaminated water or food, vector, and many others.
  • The spread speed depends depends on the immunity of the herd, interaction opportunities, and secondary attack intensity.
  • Propagated epidemics are more likely to occur if many susceptible individuals are aggregated, or a constant supply of new susceptible individuals like birth and immigrants decreases herd immunity.
  • The epidemic typically has a steady rise and tails off for a much longer period of time.
  • Transmission occurs until the number of susceptible individuals is depleted, or the number of susceptible individuals is no longer exposed to infectious individuals or intermediate vectors.

Epidemics Response

There are various steps to use in the case of an epidemic. Some of them are as follows:

  • Create awareness
  • Advocate effective action
  • Experts suggest that a disease detection system is an excellent way to plan for an outbreak.
  • To be able to dispatch emergency workers quickly, particularly local emergency workers.
  • Have a legal way to ensure the safety and wellbeing of health staff.
  • Social mobilization focused on voluntary initiatives and funding for logistics like transport, warehouses, etc.

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