By Team Aakash Byju's | 27th December 2022
The sudden rise in the number of cases of a disease above what is normally expected in a particular area is called an Epidemic.
The three major types of epidemics are: – Common-source Epidemics – Propagated Epidemics – Mixed Epidemics
A common-source outbreak is when a group of people is exposed to an infectious agent or a toxin from the same source.
The epidemic of Leukemia cases in Hiroshima following the atomic bomb blast is one of the examples of a common-source epidemic.
The propagated epidemic is a transmission from one person to another by person-to-person contact or by sharing the same needles or by mosquitoes. E.g., Hepatitis B, HIV, Yellow Fever, etc.
Epidemics that have features of both common-source epidemics and propagated epidemics are called mixed epidemics.
For e.g., Shigellosis occurred among a group of women who attended a national music festival. Over the next few weeks, cases were propagated by person-to-person transmission from festival attendees.