Epidemic disease

Epidemic disease refers to an increase, often sudden, in the number of cases of a disease above what is normally expected in that population in that area. It comes from the Greek words "epi", meaning "upon" and "demos", meaning "people".

Definition

An epidemic disease is defined by a sharp increase in the prevalence of a disease in a particular geographic region or population. This is often due to a lack of immunity to the disease among the population, or due to a change in the disease's pathogen.

Causes

Epidemics can be caused by several factors, including a change in the ecology of the host population (such as increased stress or increase in the density of a vector species), a genetic change in the pathogen reservoir or the introduction of a new pathogen to a host population (by movement of pathogen or host). Often, an epidemic occurs when host immunity to either an established pathogen or newly emerging novel pathogen is suddenly reduced below that found in the endemic equilibrium and the transmission threshold is exceeded.

Types of Epidemic Diseases

There are several types of epidemic diseases, including influenza, cholera, measles, and HIV/AIDS. These diseases can spread rapidly and cause widespread illness and death, particularly in populations with low immunity or poor access to healthcare services.

Prevention and Control

Prevention and control of epidemic diseases often involves a combination of public health interventions, including vaccination, quarantine, antibiotics, and health education. These interventions can help to reduce the spread of the disease and protect vulnerable populations.

See Also

• Pandemic
• Endemic (epidemiology)
• Outbreak
• Epidemiology