Dictionary > Zoonosis

Zoonosis

zoonosis definition

Zoonosis
n., ˌzoʊ.əˈnoʊ.sɪs
An infectious disease that can be transmitted from an animal to a human host. Example is the transmission of rabies from infected dog to a new human host.

Zoonosis Definition

Zoonosis is an infectious disease that can be transmitted from an animal to a human host. Originally a disease of an animal, a zoonosis has the potential to transmit the disease to humans. The transmission of the disease may occur directly or indirectly.

Etymology: zoo- + Greek ”nósos’ (“disease”). Synonyms: zoonotic disease.

Direct and Indirect

Zoonosis may be transmitted directly or indirectly. An example of direct transmission is when a dog with rabies transmits the disease to humans. Rabies is caused by a viral pathogen that is present in the nerves and the saliva of the infected animal. The virus enters the peripheral nervous system and subsequently to the central nervous system of the human host. The virus causes damage to these organs. Another example of the direct transmission of a disease from an animal to the human host is the transmission of the Ebola virus disease. The viral pathogen of Ebola infects primates and bats. Its spread to humans is presumed to be through direct contact with an infected animal (e.g. primates and monkeys) or with a fruit bat. Other zoonotic diseases that can be transmitted directly are HIV, taeniasis, balantidiasis, etc. Indirect transmission of a zoonotic disease is one in which the disease is spread via a vector. A vector is an intermediate species that serves as a pathogen-carrier but does not necessarily become infected with the pathogen. An example of zoonosis transmitted indirectly is tularemia (also called rabbit fever). The disease is caused by the bacterium Francisella tularensis. It can reach humans by insect vectors, e.g. ticks or deer flies. It may also be contracted by ingesting water containing the causative agent or by inhalation of dust contaminated with it. (Ref. 1)

Reverse Zoonosis

Humans infecting animals is possible and is referred to as anthroponosis (sometimes called reverse zoonosis). (Ref. 2)

See Also

References

  1. CDC. (2018, December 13). Tularemia. Centers for Disease Control and Prevention. https://www.cdc.gov/tularemia/index.html
  2. Messenger, A. M., Barnes, A.N., & Gray, G.C. (2014). “Reverse zoonotic disease transmission (zooanthroponosis): a systematic review of seldom-documented human biological threats to animals”. PLoS ONE. 9 (2): e89055. DOI:10.1371/journal.pone.0089055

Further reading

  • Investigating SARS-CoV-2 In Animals – BioTechniques. (2020, April 7). BioTechniques. https://www.biotechniques.com/coronavirus-news/from-bats-to-big-cats-how-are-animals-affected-by-covid-19/ (An example of zoonotic disease: SARS-CoV-2 apparently “jumped” from its animal host to humans)

©BiologyOnline. Content provided and moderated by BiologyOnline Editors.


You will also like...

Carbohydrates, fats and proteins - dietary sources
A Balanced Diet – Carbohydrates and Fat

Apart from vitamins, the human body also requires high energy sources such as carbohydrates and fats. If you want an ove..

green leaf - close up view
Leaves

Leaves are the major photosynthetic organ of a plant. Apart from that, they are also crucial to water movement. In this ..

Ecological Research Measuring & Analysis
Ecological Research: Measuring & Analysis

This lesson is about the methods used for ecological research, such as quadrat and transect sampling, canopy fogging, an..

Genetics – Lesson Outline & Worksheets
Genetics – Lesson Outline & Worksheets

  Topics Modules Quizzes/Worksheets Description Introduction to Genetics Genetics – Definition: Heredity and ..

Freshwater aquatic plankton
Freshwater Communities & Plankton

Planktons are microscopic organisms that live suspended in aquatic habitats. There are two groups: the phytoplanktons an..

Origins of Life on Earth
Origins of Life on Earth

Earth was created around 4.5 billion years ago and life began not long after. Primitive life likely possessed the elemen..