genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
parasitic
Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The ent ...
flatworm
Platyhelminthes (from the Greek language, Greek πλατύ, ''platy'', meaning "flat" and ἕλμινς (root: ἑλμινθ-), ''helminth-'', meaning "worm") is a Phylum (biology), phylum of relatively simple bilaterian, Segmentation (biology), ...
s belonging to the digenetictrematodes. It includes flukes which are mostly parasitising
livestock
Livestock are the Domestication, domesticated animals that are raised in an Agriculture, agricultural setting to provide labour and produce diversified products for consumption such as meat, Egg as food, eggs, milk, fur, leather, and wool. The t ...
ruminants
Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by Enteric fermentation, fermenting it in a specialized stomach prior to digestion, principa ...
, as well as some wild
mammals
A mammal () is a vertebrate animal of the class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three middle e ...
. They are responsible for the serious disease called paramphistomiasis, also known as amphistomosis, especially in
cattle
Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are calle ...
and
sheep
Sheep (: sheep) or domestic sheep (''Ovis aries'') are a domesticated, ruminant mammal typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to d ...
. Its
symptoms
Signs and symptoms are diagnostic indications of an illness, injury, or condition.
Signs are objective and externally observable; symptoms are a person's reported subjective experiences.
A sign for example may be a higher or lower temperature ...
include profuse
diarrhoea
Diarrhea (American English), also spelled diarrhoea or diarrhœa (British English), is the condition of having at least three loose, liquid, or watery bowel movements in a day. It often lasts for a few days and can result in dehydration d ...
,
anaemia
Anemia (also spelt anaemia in British English) is a blood disorder in which the blood has a reduced ability to carry oxygen. This can be due to a lower than normal number of red blood cells, a reduction in the amount of hemoglobin availab ...
,
lethargy
Lethargy is a state of tiredness, sleepiness, weariness, fatigue, sluggishness, or lack of energy. It can be accompanied by depression, decreased motivation, or apathy. Lethargy can be a normal response to inadequate sleep, overexertion, overw ...
, and often result in death if untreated. They are found throughout the world, and most abundantly in
livestock
Livestock are the Domestication, domesticated animals that are raised in an Agriculture, agricultural setting to provide labour and produce diversified products for consumption such as meat, Egg as food, eggs, milk, fur, leather, and wool. The t ...
farming
Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created ...
regions such as
Australia
Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...
,
Asia
Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...
,
Africa
Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...
,
Eastern Europe
Eastern Europe is a subregion of the Europe, European continent. As a largely ambiguous term, it has a wide range of geopolitical, geographical, ethnic, cultural and socio-economic connotations. Its eastern boundary is marked by the Ural Mountain ...
, and
Russia
Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...
.
The
generic
Generic or generics may refer to:
In business
* Generic term, a common name used for a range or class of similar things not protected by trademark
* Generic brand, a brand for a product that does not have an associated brand or trademark, other ...
name was introduced by F. Fischoeder in 1901 for the replacement of the then existing genus ''Amphistoma'' (Rudolphi, 1809). Under the new genus he redescribed both ''
Paramphistomum cervi
''Paramphistomum cervi'', the type species of ''Paramphistomum'', is a parasite, parasitic platyhelminthes, flat worm belonging to the class (biology), class Trematoda. It is a tiny trematoda, fluke mostly parasitism, parasitising livestock rumi ...
'' and ''P. bothriophoron'' and designated the former as the
type species
In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...
.
Species
Due to striking resemblance with each other and with other amphistomes, a number of described species are known to be synonymous. Some important species are:
*''
Paramphistomum cervi
''Paramphistomum cervi'', the type species of ''Paramphistomum'', is a parasite, parasitic platyhelminthes, flat worm belonging to the class (biology), class Trematoda. It is a tiny trematoda, fluke mostly parasitism, parasitising livestock rumi ...
''
*''
Paramphistomum cotylophorum
''Paramphistomum'' is a genus of parasitic flatworms belonging to the digenetic trematodes. It includes flukes which are mostly parasitising livestock ruminants, as well as some wild mammals. They are responsible for the serious disease called ...
''
*''
Paramphistomum cracile
''Paramphistomum'' is a genus of parasitic flatworms belonging to the digenetic trematodes. It includes flukes which are mostly parasitising livestock ruminants, as well as some wild mammals. They are responsible for the serious disease called ...
''
*''
Paramphistomum gotoi
''Paramphistomum'' is a genus of parasitic flatworms belonging to the digenetic trematodes. It includes flukes which are mostly parasitising livestock ruminants, as well as some wild mammals. They are responsible for the serious disease called ...
''
*''
Paramphistomum grande
''Paramphistomum'' is a genus of parasitic flatworms belonging to the digenetic trematodes. It includes flukes which are mostly parasitising livestock ruminants, as well as some wild mammals. They are responsible for the serious disease called ...
''
*''
Paramphistomum hiberniae
''Paramphistomum'' is a genus of parasitic flatworms belonging to the digenetic trematodes. It includes flukes which are mostly parasitising livestock ruminants, as well as some wild mammals. They are responsible for the serious disease called ...
''
*''
Paramphistomum ichikawai
''Paramphistomum'' is a genus of parasitic flatworms belonging to the digenetic trematodes. It includes flukes which are mostly parasitising livestock ruminants, as well as some wild mammals. They are responsible for the serious disease called ...
''
*''
Paramphistomum epiclitum
''Paramphistomum'' is a genus of parasitic flatworms belonging to the digenetic trematodes. It includes flukes which are mostly parasitising livestock ruminants, as well as some wild mammals. They are responsible for the serious disease called ...
''
*''
Paramphistomum explanatum
''Paramphistomum'' is a genus of parasitic flatworms belonging to the digenetic trematodes. It includes flukes which are mostly parasitising livestock ruminants, as well as some wild mammals. They are responsible for the serious disease called ...
Paramphistomum liorchis
''Paramphistomum'' is a genus of parasitic flatworms belonging to the digenetic trematodes. It includes flukes which are mostly parasitising livestock ruminants, as well as some wild mammals. They are responsible for the serious disease called ...
Greek
Greek may refer to:
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group
*Greek language, a branch of the Indo-European language family
**Proto-Greek language, the assumed last common ancestor of all kno ...
: ''para'' meaning "similar"
o ''Amphistoma''
O, or o, is the fifteenth letter and the fourth vowel letter of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''o'' (pronounced ), p ...
''amphi'' meaning "on both sides", and ''stoma'' for "mouth") is given due to the presence of an anterior oral sucker and a posterior larger ventral sucker in adult worms. The body is minute, measuring less than a
centimetre
upright=1.35, Different lengths as in respect to the electromagnetic spectrum, measured by the metre and its derived scales. The microwave is in-between 1 meter to 1 millimeter.
A centimetre (International spelling) or centimeter (American ...
. The body is covered with a highly folded tegument, which in turn is provided with sensory papillae. ''Paramphistomum'' are all
hermaphrodite
A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic.
The individuals of many ...
, having both male and female
reproductive system
The reproductive system of an organism, also known as the genital system, is the biological system made up of all the anatomical organs involved in sexual reproduction. Many non-living substances such as fluids, hormones, and pheromones are al ...
s in the posterior region of the body.
Life cycle
Their
life cycle
Life cycle, life-cycle, or lifecycle may refer to:
Science and academia
*Biological life cycle, the sequence of life stages that an organism undergoes from conception to reproduction
*Life-cycle hypothesis, in economics
*Erikson's stages of psy ...
is indirect, requiring a
definitive host
In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist ''guest'' (symbiont). The guest is typically provided with nourishment and shelter. Examples include ...
such as
ruminants
Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by Enteric fermentation, fermenting it in a specialized stomach prior to digestion, principa ...
, an
intermediate host
In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist ''guest'' (symbiont). The guest is typically provided with nourishment and shelter. Examples include ...
such as
snail
A snail is a shelled gastropod. The name is most often applied to land snails, terrestrial molluscs, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gas ...
, and a free-living of external phases in water and plants. The sexually mature
monoecious
Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system comparable with gynomonoecy, andromonoecy and trimonoecy, and contras ...
rumen
The rumen, also known as a paunch, is the largest stomach compartment in ruminants. The rumen and the reticulum make up the reticulorumen in ruminant animals. The diverse microbial communities in the rumen allows it to serve as the primary si ...
, and release the eggs along with
faeces
Feces (also known as faeces American and British English spelling differences#ae and oe, or fæces; : faex) are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the ...
. Eggs hatch in water into ciliated
miracidia
The miracidium is the second stage in the life cycle of trematodes. When trematode eggs are laid and come into contact with fresh water, they hatch and release miracidium. In this phase, miracidia are ciliated and free-swimming. This stage is comp ...
. The miracidia then enters the body of an intermediate host, which are snails belonging to the
genera
Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...
''
Bulinus
''Bulinus'' is a genus of small tropical freshwater snails, aquatic gastropod mollusks in the family Bulinidae, the ramshorn snails and their allies.MolluscaBase eds. (2020). MolluscaBase. Bulinus O. F. Müller, 1781. Accessed through: World R ...
'', ''
Planorbis
''Planorbis'' is a genus of air-breathing freshwater snails, aquatic animal, aquatic pulmonate gastropod molluscs in the family (biology), family Planorbidae, the sheep, ram's horn snails, or planorbids. All species in this genus have sinistral o ...
'', ''
Physa
''Physa'' is a genus of small, left-handed or sinistral, air-breathing freshwater snails, aquatic pulmonate gastropod molluscs in the subfamily Physinae of the family Physidae.MolluscaBase eds. (2021). MolluscaBase. Physa Draparnaud, 1801. Acces ...
'' ''
Stagnicola
''Stagnicola'' can refer to:
* ''Stagnicola'' (fungus), a fungus genus
* ''Stagnicola'' (gastropod), a freshwater snail genus
{{Genus disambiguation ...
'' and '' Pseudosuccinea''. Then the miracidia lost their cilia to become sporocysts. After a few days they develop up to 8 rediae, which are rapidly liberated. Each redia contains about 15-30
cercariae
A cercaria (plural cercariae) is a larval form of the trematode class of parasites. It develops within the germinal cells of the sporocyst or redia. A cercaria has a tapering head with large penetration glands. It may or may not have a long swim ...
. Mature cercariae are possess by two eyespots and a long slender tail, by which they find aquatic plants or other suitable substrata, to which they get attached and
encyst
A microbial cyst is a resting or dormant stage of a microorganism, that can be thought of as a state of suspended animation in which the metabolic processes of the cell are slowed and the cell ceases all activities like feeding and locomotion. ...
to become
metacercariae
Trematodes are parasitic flatworms of the class ''Trematoda'', specifically parasitic flukes with two Sucker (zoology), suckers: one ventral and the other Mouth, oral. Trematodes are covered by a Tegument (helminth), tegument, that protects the o ...
. The mammalian hosts ingest the infective larvae. Once inside the
duodenum
The duodenum is the first section of the small intestine in most vertebrates, including mammals, reptiles, and birds. In mammals, it may be the principal site for iron absorption.
The duodenum precedes the jejunum and ileum and is the shortest p ...
and
jejunum
The jejunum is the second part of the small intestine in humans and most higher vertebrates, including mammals, reptiles, and birds. Its lining is specialized for the absorption by enterocytes of small nutrient molecules which have been pr ...
, their
cyst
A cyst is a closed sac, having a distinct envelope and division compared with the nearby tissue. Hence, it is a cluster of cells that have grouped together to form a sac (like the manner in which water molecules group together to form a bubb ...
s are removed. They penetrate the intestinal wall by actively destroying the
mucosa
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It ...
, and then migrate to the rumen, where they grow into adults.
Pathogenicity and pathology
Paramphistomiasis causes enteritis and anaemia in livestock mammals and result in substantial production and economic losses. Pathological symptoms are produced by immature flukes. When the young flukes start to gather in the intestine, there is a watery and fetid diarrhoea which is often associated with high mortality (even up to 80-90%) in ruminants. At a given time, as many as 30,000 flukes may accumulate, fervently attacking the duodenal mucosa to induce acute enteritis. Adult flukes are relatively harmless. Liver tissue are generally damaged extensively, indicated by swelling,
haemorrhage
Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, vag ...
, discolouration,
necrosis
Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. The term "necrosis" came about in the mid-19th century and is commonly attributed to German pathologist Rudolf Virchow, who i ...
, bile duct
hyperplasia
Hyperplasia (from ancient Greek ὑπέρ ''huper'' 'over' + πλάσις ''plasis'' 'formation'), or hypergenesis, is an enlargement of an organ or tissue caused by an increase in the amount of Tissue (biology), organic tissue that results from ...
, and
fibrosis
Fibrosis, also known as fibrotic scarring, is the development of fibrous connective tissue in response to an injury. Fibrosis can be a normal connective tissue deposition or excessive tissue deposition caused by a disease.
Repeated injuries, ch ...
.
Diagnosis and treatment
Symptoms are easily indicated by infected sheep and cattle as they become severely
anorexic
Anorexia nervosa (AN), often referred to simply as anorexia, is an eating disorder characterized by Calorie restriction, food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin.
Individuals wit ...
or inefficiently digest food, and become unthrifty. Fetid diarrhoea is an obvious indication so that fluid faeces are examined for immature flukes.
Paramphistomiasis is considered a neglected
tropical disease
Tropical diseases are diseases that are prevalent in or unique to tropical and subtropical regions. The diseases are less prevalent in temperate climates, due in part to the occurrence of a cold season, which controls the insect population by forc ...
, with no prescription drug for treatment and control. Thus management of infection is based mainly on control of the snail population. Drugs shown to be effective are resorantel,
oxyclozanide
Oxyclozanide is a salicylanilide anthelmintic. It is used in the treatment and control of fascioliasis in ruminants, mainly domestic animals such as cattle, sheep, and goats. It mainly acts by uncoupling of oxidative phosphorylation in flukes. Al ...
, clorsulon,
ivermectin
Ivermectin is an antiparasitic drug. After its discovery in 1975, its first uses were in veterinary medicine to prevent and treat heartworm and acariasis. Approved for human use in 1987, it is used to treat infestations including head lice ...
,
niclosamide
Niclosamide, sold under the brand name Niclocide among others, is an anthelmintic medication used to treat tapeworm infestations, including diphyllobothriasis, hymenolepiasis, and taeniasis. It is not effective against other worms such as ...
, bithional and
levamisole
Levamisole, sold under the brand name Ergamisol among others, is a medication used to treat parasitic worm infections, specifically ascariasis and hookworm infections. It is taken by mouth.
Side effects may include abdominal pain, vomiting, ...