Epizootic
Encyclopedia
In epizoology
, an epizootic (from Greek
epi- upon + zoion animal) is a disease
that appears as new cases in a given animal population, during a given period, at a rate that substantially exceeds what is "expected" based on recent experience (i.e. a sharp elevation in the incidence
rate). Epidemic
is the analogous term applied to human populations. High population density
is a major contributing factor to epizootics. Aquaculture
is an industry
sometimes plagued by disease because of the large number of fish
confined to a small area.
Defining an epizootic can be subjective, depending in part on what is "expected". An epizootic may be: a) restricted to a specific locale (an outbreak), b) general (an "epizootic") or c) widespread (panzootic
). Because it is based on what is "expected" or thought normal, a few cases of a very rare disease (like a TSE
outbreak in a Cervid population) might be classified as an "epizootic," while many cases of a common disease (like lymphocystis
in Esocids) would not.
Common diseases that occur at a constant but relatively high rate in the population are said to be "enzootic
." An example of an enzootic disease would be the influenza
virus in some bird populations http://www.cdc.gov/ncidod/EID/vol12no01/05-1024.htm or, at a lower incidence, the Type IVb strain of VHS
in certain Atlantic fish populations. http://www.michigan.gov/documents/dnr/Viral-Hemorrhagic-Septicemia-Fact-Sheet-11-9-2006_178081_7.pdf
An example of an epizootic would be the 1990 outbreak of Newcastle disease
virus in double-crested cormorant
colonies on the Great Lakes
that resulted in the death of some 10,000 birds. http://www.nwhc.usgs.gov/publications/field_manual/chapter_21.pdf
A more recent example ( may-August 2009 ) is the progressive disappearance of the common pigeons and Sea-Gull in Montréal ( Québec , Canada ),
this is still unexplained, although repeated advises to public services. For now called the JPD09 event.
-covered fish in River Zambezi
. The Agriculture Minister of Zambia
, Ben Kapita, asked experts to investigate the outbreak to probe the cause to find out if the disease can be transmitted to humans.
Epizoology
Epizoology, or veterinary epidemiology, is the study of disease patterns within animal populations. See epidemiology....
, an epizootic (from Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
epi- upon + zoion animal) is a disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
that appears as new cases in a given animal population, during a given period, at a rate that substantially exceeds what is "expected" based on recent experience (i.e. a sharp elevation in the incidence
Incidence (epidemiology)
Incidence is a measure of the risk of developing some new condition within a specified period of time. Although sometimes loosely expressed simply as the number of new cases during some time period, it is better expressed as a proportion or a rate with a denominator.Incidence proportion is the...
rate). Epidemic
Epidemic
In epidemiology, an epidemic , occurs when new cases of a certain disease, in a given human population, and during a given period, substantially exceed what is expected based on recent experience...
is the analogous term applied to human populations. High population density
Population density
Population density is a measurement of population per unit area or unit volume. It is frequently applied to living organisms, and particularly to humans...
is a major contributing factor to epizootics. Aquaculture
Aquaculture
Aquaculture, also known as aquafarming, is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the...
is an industry
Industry
Industry refers to the production of an economic good or service within an economy.-Industrial sectors:There are four key industrial economic sectors: the primary sector, largely raw material extraction industries such as mining and farming; the secondary sector, involving refining, construction,...
sometimes plagued by disease because of the large number of fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
confined to a small area.
Defining an epizootic can be subjective, depending in part on what is "expected". An epizootic may be: a) restricted to a specific locale (an outbreak), b) general (an "epizootic") or c) widespread (panzootic
Panzootic
A panzootic is an epizootic that spreads across a large region , or even worldwide...
). Because it is based on what is "expected" or thought normal, a few cases of a very rare disease (like a TSE
Transmissible spongiform encephalopathy
Transmissible spongiform encephalopathies , also known as prion diseases, are a group of progressive conditions that affect the brain and nervous system of many animals, including humans. According to the most widespread hypothesis they are transmitted by prions, though some other data suggest an...
outbreak in a Cervid population) might be classified as an "epizootic," while many cases of a common disease (like lymphocystis
Lymphocystis
Lymphocystis is a common viral disease of freshwater and saltwater fish.Aquarists often come across this virus when their fish are stressed such as when put into a new environment and the virus is able to grow....
in Esocids) would not.
Common diseases that occur at a constant but relatively high rate in the population are said to be "enzootic
Enzootic
Enzootic is the non-human equivalent of endemic and means, in a broad sense, "belonging to" or "native to", "characteristic of", or "prevalent in" a particular geography, race, field, area, or environment; native to an area or scope....
." An example of an enzootic disease would be the influenza
Influenza
Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae , that affects birds and mammals...
virus in some bird populations http://www.cdc.gov/ncidod/EID/vol12no01/05-1024.htm or, at a lower incidence, the Type IVb strain of VHS
Viral hemorrhagic septicemia
Viral hemorrhagic septicemia is a deadly infectious fish disease caused by theViral hemorrhagic septicemia virus...
in certain Atlantic fish populations. http://www.michigan.gov/documents/dnr/Viral-Hemorrhagic-Septicemia-Fact-Sheet-11-9-2006_178081_7.pdf
An example of an epizootic would be the 1990 outbreak of Newcastle disease
Newcastle disease
Newcastle disease is a contagious bird disease affecting many domestic and wild avian species. First found in Newcastle, United Kingdom in 1926, then by Burnet in 1943 in Australia in connection with laboratory infection where the virus was isolated from a ocular discharge of a patient to show the...
virus in double-crested cormorant
Double-crested Cormorant
The Double-crested Cormorant is a member of the cormorant family of seabirds. It occurs along inland waterways as well as in coastal areas, and is widely distributed across North America, from the Aleutian Islands in Alaska down to Florida and Mexico...
colonies on the Great Lakes
Great Lakes
The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...
that resulted in the death of some 10,000 birds. http://www.nwhc.usgs.gov/publications/field_manual/chapter_21.pdf
A more recent example ( may-August 2009 ) is the progressive disappearance of the common pigeons and Sea-Gull in Montréal ( Québec , Canada ),
this is still unexplained, although repeated advises to public services. For now called the JPD09 event.
Zambia EUS outbreak
On September 14, 2007, epizootic ulcerative syndrome (EUS), a mysterious disease killed hundreds of soreSore
Sore may refer to:* A mild pain or ache* A small skin ulcer, usually open from skin infection* A slang term for angry* Sore , an Indonesian rock band* Sore, Landes, a village in the Landes département of France* Sore , by Buzzov*en...
-covered fish in River Zambezi
Zambezi
The Zambezi is the fourth-longest river in Africa, and the largest flowing into the Indian Ocean from Africa. The area of its basin is , slightly less than half that of the Nile...
. The Agriculture Minister of Zambia
Zambia
Zambia , officially the Republic of Zambia, is a landlocked country in Southern Africa. The neighbouring countries are the Democratic Republic of the Congo to the north, Tanzania to the north-east, Malawi to the east, Mozambique, Zimbabwe, Botswana and Namibia to the south, and Angola to the west....
, Ben Kapita, asked experts to investigate the outbreak to probe the cause to find out if the disease can be transmitted to humans.
See also
- EpidemicEpidemicIn epidemiology, an epidemic , occurs when new cases of a certain disease, in a given human population, and during a given period, substantially exceed what is expected based on recent experience...
- EnzooticEnzooticEnzootic is the non-human equivalent of endemic and means, in a broad sense, "belonging to" or "native to", "characteristic of", or "prevalent in" a particular geography, race, field, area, or environment; native to an area or scope....
- EpizoologyEpizoologyEpizoology, or veterinary epidemiology, is the study of disease patterns within animal populations. See epidemiology....
- PanzooticPanzooticA panzootic is an epizootic that spreads across a large region , or even worldwide...
- Synzootic
- Equine Influenza for the Great Epizootic of 1872 in the US and Canada
- Mathematical modelling in epidemiologyMathematical modelling in epidemiologyIt is possible to mathematically model the progress of most infectious diseases to discover the likely outcome of an epidemic or to help manage them by vaccination...