''Eimeria'' is a

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 ...

apicomplexa The Apicomplexa (also called Apicomplexia; single: apicomplexan) are organisms of a large phylum of mainly parasitic alveolates. Most possess a unique form of organelle structure that comprises a type of non-photosynthetic plastid called an ap ...

n parasites that includes various species capable of causing the disease

coccidiosis Coccidiosis is a parasitic disease of the intestinal tract of animals caused by coccidian protozoa. The disease spreads from one animal to another by contact with infected feces or ingestion of infected tissue. Diarrhea, which may become bloody ...

in animals such as

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 ...

poultry Poultry () are domesticated birds kept by humans for the purpose of harvesting animal products such as meat, Eggs as food, eggs or feathers. The practice of animal husbandry, raising poultry is known as poultry farming. These birds are most typ ...

and smaller

ruminant Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microb ...

s including

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 ...

and

goat The goat or domestic goat (''Capra hircus'') is a species of Caprinae, goat-antelope that is mostly kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the ...

s. ''Eimeria'' species are considered to be monoxenous because the life cycle is completed within a single host, and stenoxenous because they tend to be host specific, although a number of exceptions have been identified. Species of this genus infect a wide variety of hosts. Thirty-one species are known to occur in

bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

s (Chiroptera), two in turtles, and 130 named species infect fish. Two species (''E. phocae'' and ''E. weddelli'') infect seals. Five species infect llamas and alpacas: ''E. alpacae'', ''E. ivitaensis'', ''E. lamae'', ''E. macusaniensis'', and ''E. punonensis''. A number of species infect rodents, including ''E. couesii'', ''E. kinsellai'', ''E. palustris'', ''E. ojastii'' and ''E. oryzomysi''. Others infect poultry (''E. necatrix'' and ''E. tenella''), rabbits (''E. stiedai'') and cattle (''E. bovis'', ''E. ellipsoidalis'', and ''E. zuernii''). For full species list, see below. The most prevalent species of ''Eimeria'' that cause coccidiosis in cattle are ''E. bovis'', ''E. zuernii'', and ''E. auburnensis''. In a young, susceptible calf it is estimated that as few as 50,000 infective

oocysts Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism ...

can cause severe disease. ''Eimeria'' infections are particularly damaging to the poultry industry and costs the United States more than $1.5 billion in annual losses. The most economically important species among poultry are ''E. tenella'', ''E. acervulina'', and ''E. maxima''. The oocysts of what was later called ''Eimeria stiedai'' were first seen by the pioneering Dutch microscopist

Antonie van Leeuwenhoek Antonie Philips van Leeuwenhoek ( ; ; 24 October 1632 – 26 August 1723) was a Dutch microbiologist and microscopist in the Golden Age of Dutch art, science and technology. A largely self-taught man in science, he is commonly known as " ...

(1632–1723) in the

bile Bile (from Latin ''bilis''), also known as gall, is a yellow-green/misty green fluid produced by the liver of most vertebrates that aids the digestion of lipids in the small intestine. In humans, bile is primarily composed of water, is pro ...

of a

rabbit Rabbits are small mammals in the family Leporidae (which also includes the hares), which is in the order Lagomorpha (which also includes pikas). They are familiar throughout the world as a small herbivore, a prey animal, a domesticated ...

in 1674. The genus is named after the German

zoologist Zoology ( , ) is the scientific study of animals. Its studies include the structure, embryology, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. Zoology is one ...

Theodor Eimer Gustav Heinrich Theodor Eimer (22 February 1843 – 29 May 1898) was a German zoologist. He was a popularizer of orthogenesis, a form of directed evolution through mutations that made use of Lamarckian principles. Life and work Eimer was born ...

(1843–1898).

Life cycle

The ''Eimeria'' life cycle has an

exogenous In a variety of contexts, exogeny or exogeneity () is the fact of an action or object originating externally. It is the opposite of endogeneity or endogeny, the fact of being influenced from within a system. Economics In an economic model, an ...

phase, during which the oocysts are excreted into the environment, and an

endogenous Endogeny, in biology, refers to the property of originating or developing from within an organism, tissue, or cell. For example, ''endogenous substances'', and ''endogenous processes'' are those that originate within a living system (e.g. an ...

phase, where parasite development occurs in the host intestine. During the endogenous phase, several rounds of

schizogony Fission, in biology, is the division of a single entity into two or more parts and the regeneration of those parts to separate entities resembling the original. The object experiencing fission is usually a cell, but the term may also refer to ho ...

(asexual reproduction) take place, after which the

sexual differentiation Sexual differentiation is the process of development of the sex differences between males and females from an undifferentiated zygote. Sex differentiation is usually distinct from sex determination; sex determination is the designation of the de ...

gamete A gamete ( ) is a Ploidy#Haploid and monoploid, haploid cell that fuses with another haploid cell during fertilization in organisms that Sexual reproduction, reproduce sexually. Gametes are an organism's reproductive cells, also referred to as s ...

s and

fertilisation Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a zygote and initiate its development into a new individual organism or of ...

occurs. Parasite transmission occurs via the fecal-oral route. Infections are common in farming environments where many animals are confined in a small space. 450px, ''Eimeria'' life cycle

Oocysts

There are two forms of

oocyst Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism ...

: sporulated or late oocyst, and unsporulated or early oocyst. An infected host releases oocysts into the environment in their unsporulated form. These contain a multi-layered cell wall making them highly resistant to environmental pressures. Once released, the unsporulated oocysts undergo

meiosis Meiosis () is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, the sperm or egg cells. It involves two rounds of division that ultimately result in four cells, each with only one c ...

upon contact with oxygen and moisture. This process is known as

sporulation In biology, a spore is a unit of sexual (in fungi) or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plant ...

and the oocysts take approximately 2 to 7 days to become infectious. The sporulated oocyst is said to be tetrasporic meaning it contains four sporocysts, while each sporocyst is dizoic, i.e. it contains two sporozoites. Once ingested, the oocysts undergo a process called excystation, whereby thousands of sporozoites are released into lumen of the intestine. In the case of ''E. tenella'', this process is thought to occur due to the combination of enzymatic degradation and mechanical abrasion of the oocyst wall in the chicken's

gizzard The gizzard, also referred to as the ventriculus, gastric mill, and gigerium, is an organ found in the digestive tract of some animals, including archosaurs (birds and other dinosaurs, crocodiles, alligators, pterosaurs), earthworms, some gast ...

Sporozoites

The motile

sporozoites Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism ...

invade the

enterocyte Enterocytes, or intestinal absorptive cells, are simple columnar epithelial cells which line the inner surface of the small and large intestines. A glycocalyx surface coat contains digestive enzymes. Microvilli on the apical surface increase ...

s of small intestine, and migrate to their respective sites of development. Invasion is mediated through specialised membrane-bound structures on the surface of the parasite that release secretions. This results in the recognition of, and attachment to

host cell 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 ...

receptor Receptor may refer to: * Sensory receptor, in physiology, any neurite structure that, on receiving environmental stimuli, produces an informative nerve impulse *Receptor (biochemistry), in biochemistry, a protein molecule that receives and respond ...

s. This process is known as

gliding motility Gliding motility is a type of translocation used by microorganisms that is independent of propulsive structures such as flagella, pili, and fimbriae. Gliding allows microorganisms to travel along the surface of low aqueous films. The mechanisms ...

, which is conserved across all species of ''

Apicomplexa The Apicomplexa (also called Apicomplexia; single: apicomplexan) are organisms of a large phylum of mainly parasitic alveolates. Most possess a unique form of organelle structure that comprises a type of non-photosynthetic plastid called an ap ...

''. Membrane glyconjugates have been proposed as potential host cell receptors for ''Eimeria'' species. After invasion, the sporozoites develop into

trophozoite A trophozoite (G. ''trope'', nourishment + ''zoon'', animal) is the activated, feeding stage in the life cycle of certain protozoa such as malaria-causing ''Plasmodium falciparum'' and those of the ''Giardia'' group. The complementary form of the t ...

s, then into

schizont Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism ...

s, where they undergo several rounds of

asexual reproduction Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the f ...

. This results in many nuclei developing within the schizont. Each nucleus develops into a

merozoite Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism i ...

. Invasion requires the formation of a moving junction between parasite and host

cell membrane The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extr ...

s. In ''E. tenella'', this involves parasite

microneme Micronemes are secretory organelles, possessed by parasitic apicomplexans. Micronemes are located on the apical third of the protozoan body. They are surrounded by a typical unit membrane. On electron microscopy they have an electron-dense ma ...

s and

rhoptry A rhoptry is a specialized secretory organelle. They are club-shaped organelles connected by thin necks to the extreme apical pole of the parasite. These organelles, like micronemes, are characteristic of the motile stages of Apicomplexa protozoa ...

proteins including RON2, RON5 and AMA-2. It is unlikely that the host cell is completely passive in the invasion process, although evidence of host physical forces that assist in mediating parasite entry remains controversial.

Merozoites

When schizonts rupture, merozoites are released, which either go on to re-infect more

enterocytes Enterocytes, or intestinal absorptive cells, are simple columnar epithelial cells which line the inner surface of the small and large intestines. A glycocalyx surface coat contains digestive enzymes. Microvilli on the apical surface increase i ...

or develop into either male or female

gametes A gamete ( ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. The name gamete was introduced by the Ge ...

via the process of

gametogenesis Gametogenesis is a biological process by which diploid or haploid precursor cells undergo cell division and differentiation to form mature haploid gametes. Depending on the biological life cycle of the organism, gametogenesis occurs by meiotic d ...

. These gametes fuse to form an oocyst, which is then released in its non-infectious, unsporulated form through the faeces of the host. Merozoite invasion also requires the formation of a moving junction, however the

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

s involved in this process differs from those on sporozoites.

Rhoptry A rhoptry is a specialized secretory organelle. They are club-shaped organelles connected by thin necks to the extreme apical pole of the parasite. These organelles, like micronemes, are characteristic of the motile stages of Apicomplexa protozoa ...

proteins AMA-1 and RON4 are found exclusively on merozoites. There is also a greater diversity of variant surface antigens found on the surface of merozoites. It is hypothesised that this may be due to the fact that merozoites are short-lived and a greater

antigen In immunology, an antigen (Ag) is a molecule, moiety, foreign particulate matter, or an allergen, such as pollen, that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. ...

repertoire would permit faster binding and invasion.

Taxonomy

File : Apicomplexa tree..png, 350px, Evolutionary relationships among

The ''Eimeria'' lie within the family Eimeriidae. ''Eimeria'' accounts for close to 75% of the species within this family, and it is the most specious of the genera of the

with 1,700 described species. Attempts to subdivide this large taxonomic unit into separate genera have been made. The classification of eimeriid coccidian was largely based on morphological and life cycle details. More recently, classification has been done using rDNA and

mitochondrial genes Mitochondrial DNA (mtDNA and mDNA) is the DNA located in the mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the DNA contained in ...

, which indicate ''Eimeria'' may be

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

to ''

Isospora ''Isospora'' is a genus of internal parasites in the subclass Coccidia. It is responsible for the condition isosporiasis, which causes acute, non-bloody diarrhoea in immunocompromised individuals. Taxonomy At least 248 species were original ...

'' and ''

Cyclospora ''Cyclospora'' is a genus of apicomplexan parasites. It includes the species ''Cyclospora cayetanensis'', the causative agent of cyclosporiasis. Members of ''Cyclospora'' are characterized as having oocysts with two sporocysts, each containing ...

'' ''Eimeria'': These species are tetrasporocystic with dizoic, nonbivalved sporocysts with or without Stieda bodies. This new genus retains the majority of the species. ''

Goussia ''Goussia'' is a taxonomic genus, first described in 1896 by Labbé, containing parasitic protists which largely target fish and amphibians as their hosts. Members of this genus are homoxenous and often reside in the gastrointestinal tract of the ...

'' (Labbe 1896): These species are tetrasporocystic, dizoic, lack Stieda bodies, and have sporocyst walls consisting of two valves joined by a longitudinal suture. This genus contains about 20 species. '' Crystallospora'' (Thelohan 1893): The species in this genus is tetrasporocystic and dizoic, and have dodecahedral sporocysts composed of two hexagonal, pyrimidal valves joined at their bases by a suture. This genus contains a single species, ''Crystallospora cristalloides'' ''

Epieimeria ''Epieimeria'' is a genus of parasitic alveaolates of the phylum Apicomplexa. The genus was created in 1981 by Dyková and Lom. Species in this genus were earlier classified as ''Eimeria''. Taxonomy Species in this genus infect fish. Descript ...

'': The species in this genus are tetrasporocystic, dizoic, possess Stieda bodies, and undergo merogony and gametogony on the lumenal surface of the intestinal tract. Three species are in this genus.

Species identification

Methods for species identification are varied and among others, include

isozyme In biochemistry, isozymes (also known as isoenzymes or more generally as multiple forms of enzymes) are enzymes that differ in amino acid sequence but catalyze the same chemical reaction. Isozymes usually have different kinetic parameters (e.g. di ...

analysis, the use of

rRNA Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosomal ...

and rDNA probes,

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

assay An assay is an investigative (analytic) procedure in laboratory medicine, mining, pharmacology, environmental biology and molecular biology for qualitatively assessing or quantitatively measuring the presence, amount, or functional activity ...

s and

recombinant DNA Recombinant DNA (rDNA) molecules are DNA molecules formed by laboratory methods of genetic recombination (such as molecular cloning) that bring together genetic material from multiple sources, creating sequences that would not otherwise be fo ...

techniques. PCR has proven most useful for

outbreak In epidemiology, an outbreak is a sudden increase in occurrences of a disease when cases are in excess of normal expectancy for the location or season. It may affect a small and localized group or impact upon thousands of people across an entire ...

surveillance. Prior to these methods, species identification was based on

phenotypic In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology (physical form and structure), its developmental processes, its biochemical and physiological propert ...

characteristics such as the site of parasite development, the oocyst structure, the host species, cross

immunity Immunity may refer to: Medicine * Immunity (medical), resistance of an organism to infection or disease * ''Immunity'' (journal), a scientific journal published by Cell Press Biology * Immune system Engineering * Radiofrequence immunity ...

and the presence of lesions. Out of these, comparing oocyst structures was the most commonly used method.

Genomics

whole genome sequencing Whole genome sequencing (WGS), also known as full genome sequencing or just genome sequencing, is the process of determining the entirety of the DNA sequence of an organism's genome at a single time. This entails sequencing all of an organism's ...

project is in progress with chosen species, ''Eimeria tenella''. The genome is about 60

megabases A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA ...

in size and has a

GC-content In molecular biology and genetics, GC-content (or guanine-cytosine content) is the percentage of nitrogenous bases in a DNA or RNA molecule that are either guanine (G) or cytosine (C). This measure indicates the proportion of G and C bases out of ...

around 53%. The 14

chromosome A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...

s range in size from 1 to > 6 megabases. Since 2013, the sequencing and annotation of a further six avian ''Eimeria'' species genomes is in progress.

Pathology and symptoms

Coccidiosis typically results in

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 ...

, weight loss and

dehydration In physiology, dehydration is a lack of total body water that disrupts metabolic processes. It occurs when free water loss exceeds intake, often resulting from excessive sweating, health conditions, or inadequate consumption of water. Mild deh ...

. A combination of these factors may result in poor growth and death of the animal, particularly amongst young. Other clinical signs include

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 ...

, depression, and reduced normal grooming behaviour. Diarrhoea may be bloody due to

intestinal epithelium The intestinal epithelium is the single cell layer that forms the luminal surface (lining) of both the small and large intestine (colon) of the gastrointestinal tract. Composed of simple columnar epithelium its main functions are absorptio ...

dying off when a large number of oocysts and merozoites burst out of the cells. The severity of the disease is directly dependent on the number of infective ''Eimeria'' oocysts that are ingested. The

pathogenesis In pathology, pathogenesis is the process by which a disease or disorder develops. It can include factors which contribute not only to the onset of the disease or disorder, but also to its progression and maintenance. The word comes . Descript ...

of infection varies from mild to severe, and is largely dependent on the magnitude of infection. In light infections, the damage to the gut might only be minimal and be rapidly repaired as cells are rapidly replaced by the body. However, in heavy infections, it may only take two weeks for many intestinal epithelial cells to be infected with either ''Eimeria'' meronts or gametocytes. These cause the epithelial cells to burst, which causes significant damage to the intestine epithelial layer, resulting in the release of blood, fluid, and

electrolyte An electrolyte is a substance that conducts electricity through the movement of ions, but not through the movement of electrons. This includes most soluble Salt (chemistry), salts, acids, and Base (chemistry), bases, dissolved in a polar solven ...

s into the intestine.

Prevention and treatment

Good

animal husbandry Animal husbandry is the branch of agriculture concerned with animals that are raised for meat, animal fiber, fibre, milk, or other products. It includes day-to-day care, management, production, nutrition, selective breeding, and the raising ...

practices and

prophylactic Preventive healthcare, or prophylaxis, is the application of healthcare measures to prevent diseases.Hugh R. Leavell and E. Gurney Clark as "the science and art of preventing disease, prolonging life, and promoting physical and mental health a ...

application of anticoccidial drugs that target different stages of the parasite lifecycle, such as

sulfonamide In organic chemistry, the sulfonamide functional group (also spelled sulphonamide) is an organosulfur group with the Chemical structure, structure . It consists of a sulfonyl group () connected to an amine group (). Relatively speaking this gro ...

ionophore In chemistry, an ionophore () is a chemical species that reversibly binds ions. Many ionophores are lipid-soluble entities that transport ions across the cell membrane. Ionophores catalyze ion transport across hydrophobic membranes, such as l ...

s and

toltrazuril Toltrazuril is an antiparasitic medication used primarily to treat coccidiosis in animals. Coccidiosis is a parasitic disease caused by coccidia, which are microscopic, spore-forming, single-celled obligate intracellular parasites belonging to ...

, are the preferred methods of disease prevention, particularly in the poultry industry. The following drugs can be used for treatment of coccidiosis in cattle:

amprolium Amprolium is the organic compound sold as a coccidiostat used in poultry. It has many International Nonproprietary Names. __TOC__ Uses in coccidiosis treatment in poultry The drug is a thiamine analogue and blocks the thiamine transporter of '' ...

, sulfaquinoxaline, and sulfamethazine. However, it is often more effective to prevent this disease in cattle, which can be aided by the products

lasalocid Lasalocid is an antibacterial agent and a coccidiostat, which is produced by strains of ''Streptomyces ''Streptomyces'', from στρεπτός (''streptós''), meaning "twisted", and μύκης (''múkés''), meaning "fungus", is the larges ...

decoquinate Decoquinate is a quinolone coccidiostat used in veterinary medicine Veterinary medicine is the branch of medicine that deals with the prevention, management, medical diagnosis, diagnosis, and treatment of disease, disorder, and injury in non- ...

, and

monensin Monensin is a polyether antibiotic isolated from ''Streptomyces cinnamonensis''. It is widely used in ruminant animal feeds. The structure of monensin was first described by Agtarap et al. in 1967, and was the first polyether antibiotic to have i ...

. There is a growing problem of

drug resistance Drug resistance is the reduction in effectiveness of a medication such as an antimicrobial or an antineoplastic in treating a disease or condition. The term is used in the context of resistance that pathogens or cancers have "acquired", that is ...

, as well as possible drug residues in the meat once the animal is butchered. As a result, other avenues of control are being explored, particularly vaccine development, although several

live attenuated vaccines An attenuated vaccine (or a live attenuated vaccine, LAV) is a vaccine created by reducing the virulence of a pathogen, but still keeping it viable (or "live"). Attenuation takes an infectious agent and alters it so that it becomes harmless or les ...

have been in use since the 1950s. So far, the best practice is to vaccinate the chicks once they hatch from the egg so they are immune for life. Infection with ''Eimeria'' results in life-long

to that particular parasite species, but does not give cross protection against other species. For these reasons, vaccines for control seem promising, of which live attenuated vaccines are most effective. However, the search for highly

immunogenic Immunogenicity is the ability of a foreign substance, such as an antigen, to provoke an immune response in the body of a human or other animal. It may be wanted or unwanted: * Wanted immunogenicity typically relates to vaccines, where the injectio ...

s and overcoming

antigenic variation Antigenic variation or antigenic alteration refers to the mechanism by which an Pathogen, infectious agent such as a protozoan, bacterium or virus alters the proteins or carbohydrates on its surface and thus avoids a host (biology), host immune r ...

of the parasites remains a challenge. Immunity to the parasite varies depending on parasite and host species, as well as the site of invasion.

CD4+ T cell In molecular biology, CD4 (cluster of differentiation 4) is a glycoprotein that serves as a co-receptor for the T-cell receptor (TCR). CD4 is found on the surface of immune cells such as helper T cells, monocytes, macrophages, and dendritic c ...

s and

interferon gamma Interferon gamma (IFNG or IFN-γ) is a dimerized soluble cytokine that is the only member of the type II class of interferons. The existence of this interferon, which early in its history was known as immune interferon, was described by E. F. ...

(γ) are crucial components of

natural immunity In biology, immunity is the state of being insusceptible or resistant to a noxious agent or process, especially a pathogen or infectious disease. Immunity may occur naturally or be produced by prior exposure or immunization. Innate and adaptive ...

to infection.

Humoral immunity Humoral immunity is the aspect of immunity (medical), immunity that is mediated by macromolecules – including secreted antibodies, complement proteins, and certain antimicrobial peptides – located in extracellular fluids. Humoral immunity is ...

is thought to play little role in protection, and is most likely mediated through secretory

IgA IGA or IgA may refer to: Businesses and organizations * IGA (supermarkets) (initially Independent Grocers Alliance), a name used by many independent supermarkets throughout the world ** IGA (Australian supermarket group), the local Australian v ...

antibodies.

Host-parasite relations

Fish

* ''Eimeria aurati'' -

goldfish The goldfish (''Carassius auratus'') is a freshwater fish in the family Cyprinidae of the order Cypriniformes. It is commonly kept as a pet in indoor aquariums, and is one of the most popular aquarium fish. Goldfish released into the w ...

(''Carassius auratus'') * ''Eimeria baueri'' -

crucian carp The crucian carp (''Carassius carassius'') is a medium-sized member of the common carp family Cyprinidae. It occurs widely in northern European regions. Its name derives from the Low German ''karusse'' or ''karutze'', possibly from Medieval Lat ...

(''Carassius carassius'') * ''Eimeria lepidosirenis'' -

South American lungfish The South American lungfish (''Lepidosiren paradoxa''), also known as the American mud-fish and scaly salamanderfish, is the single species of lungfish found in swamps and slow-moving waters of the Amazon Basin, Amazon, Paraguay River, Paraguay, ...

(''Lepidosiren paradoxa'') * ''Eimeria leucisci'' -

common barbel The common barbel (''Barbus barbus'') is a species of freshwater fish belonging to the family Cyprinidae. It shares the common name 'barbel' with its many relatives in the genus ''Barbus'', of which it is the type species. In Great Britain it is ...

(''Barbus barbus bocagei'') * ''Eimeria rutili'' -

European chub ''Squalius cephalus'', the common chub, European chub or simply chub, is a species of freshwater ray-finned fish belonging to the family Leuciscidae, the daces, Eurasian minnows and related fishes. This species is found in Europe where it freq ...

(''Leuciscus cephalus cabeda''),

Iberian nase The Iberian nase (''Pseudochondrostoma polylepis'') is a species of freshwater ray-finned fish belonging to the family Leuciscidae, which includes the daces, Eurasian minnows and related species. This species is endemic to the Iberian Peninsula i ...

(''Chondrostoma polylepis polylepis'') * ''Eimeria vanasi'' - blue tilapia (''

Oreochromis aureus The blue tilapia (''Oreochromis aureus'') is a species of tilapia, a fish in the family Cichlidae. Native to Northern and Western Africa, and the Middle East, through introductions it is now also established elsewhere, including parts of the ...

'')

Reptiles

* ''Eimeria amphisbaeniarum'' - Mann's

worm lizard Amphisbaenia (called amphisbaenians or worm lizards) is a group of typically legless lizards, comprising over 200 extant species. Amphisbaenians are characterized by their long bodies, the reduction or loss of the limbs, and rudimentary eyes. As ...

('' Amphisbaena manni'') * ''Eimeria witcheri'' - Mann's worm lizard (''A. manni'') * ''Eimeria yemenensae'' - rock agama ('' Agama yemenensis'')

Birds

* '' Eimeria acervulina'' -

chicken The chicken (''Gallus gallus domesticus'') is a domesticated subspecies of the red junglefowl (''Gallus gallus''), originally native to Southeast Asia. It was first domesticated around 8,000 years ago and is now one of the most common and w ...

(''Gallus gallus domesticus'') * ''Eimeria adenoeides'' -

turkey Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...

(''Meleagris gallopavo'') * '' Eimeria brunetti'' - chicken (''G. g. domesticus'') * ''Eimeria colchici'' -

common pheasant The common pheasant (''Phasianus colchicus''), ring-necked pheasant, or blue-headed pheasant, is a bird in the pheasant family (biology), family (Phasianidae). The genus name comes from Latin ''phasianus'' 'pheasant'. The species name ''colchic ...

(''Phasianus colchicus'') * ''Eimeria curvata'' -

ruddy ground dove The ruddy ground dove (''Columbina talpacoti'') is a small New World tropical dove. It is a resident breeder from Mexico south to Brazil, Peru and Paraguay, and northern Argentina, and on Trinidad and Tobago. Individual birds can sometimes be see ...

(''Columbina talpacoti''),

scaled dove The scaled dove (''Columbina squammata''), also known as scaly dove, Ridgway's dove, mottled dove, and South American zebra dove, is found in Brazil, Bolivia, Argentina, Colombia, French Guiana, Paraguay, Trinidad and Tobago, and Venezuela. Its ...

(''Scardafella squammata'') * ''Eimeria dispersa'' - turkey (''M. gallopavo''), bobwhite quail (''

Colinus virginianus The northern bobwhite (''Colinus virginianus''), also known as the Virginia quail or (in its home range) bobwhite quail, is a ground-dwelling bird native to Canada, the United States, Mexico, and Cuba, with introduced populations elsewhere in th ...

'') * ''Eimeria duodenalis'' - pheasant (''Phasianus colchicus'') * '' Eimeria fraterculae'' - Atlantic puffin (''

Fratercula arctica The Atlantic puffin ('), also known as the common puffin, is a species of seabird in the auk family. It is the only puffin native to the Atlantic Ocean; two related species, the tufted puffin and the horned puffin being found in the northeast ...

'') * ''Eimeria gallopavonis'' - turkey (''M. gallopavo'') * ''Eimeria innocua'' - turkey (''M. gallopavo'') * ''Eimeria praecox'' - chicken (''G. g. domesticus'') * '' Eimeria maxima'' - chicken (''G. g. domesticus'') * '' Eimeria meleagridis'' - turkey (''M. gallopavo'') * ''Eimeria meleagrimitis'' - turkey (''M. gallopavo'') * ''Eimeria mitis'' - chicken (''G. g. domesticus'') * ''Eimeria muta'' -

rock ptarmigan The rock ptarmigan (''Lagopus muta'') is a medium-sized game bird in the grouse family. It is known simply as the ptarmigan in Europe. It is the official bird for the Canadian territory of Nunavut, where it is known as the ''aqiggiq'' (ᐊᕿ� ...

(''Lagopus muta islandorum'') * '' Eimeria necatrix'' - chicken (''G. g. domesticus'') * ''Eimeria phasiani'' - pheasant (''P. colchicus'') * ''Eimeria procera'' - grey partridges (''

Perdix perdix The grey partridge (''Perdix perdix'') is a bird in the pheasant family Phasianidae of the order Galliformes, gallinaceous birds. The scientific name is the Latin for "partridge". Taxonomy The grey partridge formally described in 1758 by the Sw ...

'') * ''Eimeria purpureicephali '' - red-capped parrot (''

Purpureicephalus spurius The red-capped parrot (''Purpureicephalus spurius'') is a species of broad-tailed parrot native to southwestern Australia. It was described by Heinrich Kuhl in 1820, with no subspecies recognised. It has long been classified in its own genus o ...

'') * ''Eimeria rjupa'' -

(''L. m. islandorum'') * ''

Eimeria tenella ''Eimeria tenella'' is a species of ''Eimeria'' that causes hemorrhagic cecal coccidiosis in young poultry. It is found worldwide. Description This species has a monoxenous life cycle with the only definitive host as chickens; it is extremel ...

'' - chicken (''G. g. domesticus'')

Mammals

* ''Eimeria ahsata'' - goat (''

Capra hircus The goat or domestic goat (''Capra hircus'') is a species of goat-antelope that is mostly kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the family Bo ...

''), sheep (''

Ovis aries 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 dom ...

'') * ''Eimeria alabamensis'' - cattle (''

Bos taurus 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 called ...

'') * ''Eimeria alijevi'' - goat (''C. hircus'') * ''Eimeria aspheronica'' - goat (''C. hircus'') * ''Eimeria arloingi'' - goat (''C. hircus'') * ''Eimeria arundeli'' - common wombat (''

Vombatus ursinus The common wombat (''Vombatus ursinus''), also known as the bare-nosed wombat, is a marsupial, one of three extant species of wombats and the only one in the genus ''Vombatus''. It has three subspecies: ''Vombatus ursinus hirsutus'', found on the ...

'') * ''Eimeria bakuensis'' - sheep (''O. aries'') * '' Eimeria bovis'' - cattle (''B. taurus'') * ''Eimeria cameli'' - camels (''

Camelus bactrianus The Bactrian camel (''Camelus bactrianus''), also known as the Mongolian camel, domestic Bactrian camel or two-humped camel, is a camel native to the steppes of Central Asia. It has two humps on its back, in contrast to the single-humped drome ...

'',''

Camelus dromedarius The dromedary (''Camelus dromedarius''), also known as the dromedary camel, Arabian camel and one-humped camel, is a large camel of the genus ''Camelus'' with one hump on its back. It is the tallest of the three camel species; adult males stan ...

'') * ''Eimeria caprina'' - goat (''C. hircus'') * ''Eimeria caprovina'' - goat (''C. hircus'') * ''Eimeria christenseni'' - goat (''C. hircus'') * ''Eimeria clethrionomyis'' - red-backed vole (''

Clethrionomys gapperi The southern red-backed vole or Gapper's red-backed vole (''Clethrionomys gapperi'') is a small slender vole found in Canada and the northern United States. It is closely related to the western red-backed vole (''Clethrionomys californius''), wh ...

'') * ''Eimeria coecicola'' - rabbit (''

Oryctolagus cuniculus The European rabbit (''Oryctolagus cuniculus'') or coney is a species of rabbit native to the Iberian Peninsula (Spain, Portugal and Andorra) and southwestern France. It is the only extant species in the genus '' Oryctolagus''. The European ra ...

'') * ''Eimeria contorta'' - mouse (''

Mus musculus The house mouse (''Mus musculus'') is a small mammal of the rodent family Muridae, characteristically having a pointed snout, large rounded ears, and a long and almost hairless tail. It is one of the most abundant species of the genus ''Mus (genu ...

'') * ''Eimeria couesii'' - rice rat (''

Oryzomys couesi ''Oryzomys couesi'', also known as Coues's rice rat, is a semiaquatic rodent in the family Cricetidae occurring from southernmost Texas through Mexico and Central America into northwestern Colombia. It is usually found in wet habitats, such as m ...

'') * ''Eimeria crandallis'' - sheep (''O. aries'') * ''Eimeria dammahensis'' - scimitar-homed oryx (''

Oryx dammah The scimitar oryx (''Oryx dammah''), also known as the scimitar-horned oryx and the Sahara oryx, is an ''Oryx'' species that was once widespread across North Africa and parts of West Africa and Central Africa. In 2000, it was declared extinct in ...

'') * ''Eimeria dowleri'' - eastern red bat ('' Lasiurus borealis'') * ''Eimeria exigua'' - rabbit (''O. cuniculus'') * ''Eimeria falciformis'' - mouse (''M. musculus'') * ''Eimeria farasanii'' - mountain gazelle ('' Gazella gazelle farasani'') * ''Eimeria ferrisi'' - mouse (''M. musculus'') * ''Eimeria flavescens'' - rabbit (''O. cuniculus'') * ''Eimeria gallatii'' - red-backed vole (''C. gapperi'') * ''Eimeria granulosa'' - goat (''C. hircus'') * ''Eimeria hirci'' - goat (''C. hircus'') * ''Eimeria intestinalis'' - rabbit (''O. cuniculus'') * ''Eimeria irresidua'' - rabbit (''O. cuniculus'') * ''Eimeria intricata'' - goat (''C. hircus'') * ''Eimeria jolchijevi'' - goat (''C. hircus'') * ''Eimeria krijgsmanni'' - mouse (''M. musculus'') * ''Eimeria larimerensis'' - Uinta ground squirrel (''

Spermophilus armatus The Uinta ground squirrel (''Urocitellus armatus''), commonly called a "chisler" and ''Potgut'' in northern Utah, is a species of rodent native to the western United States. Description The Uinta ground squirrel is a moderately sized ground squi ...

'') * ''Eimeria macusaniensis'' - llamas (''

Lama glama The llama (; or ) (''Lama glama'') is a domesticated South American camelid, widely used as a meat and pack animal by Andean cultures since the pre-Columbian era. Llamas are social animals and live with others as a herd. Their wool is so ...

''), guanacos (''

Lama guanicoe The guanaco ( ; ''Lama guanicoe'') is a camelid native to South America, closely related to the llama. Guanacos are one of two wild South American camelids; the other species is the vicuña, which lives at higher elevations. Etymology The gua ...

''), alpacas ('' Vicugna pacos''), vicunas (''

Vicugna vicugna ''Lama'' is a genus containing the South American camelids: the wild guanaco and vicuña and the domesticated llama, alpaca, and the extinct chilihueque. Before the Spanish conquest of the Americas, llamas, alpacas, and chilihueques were the o ...

'') * ''Eimeria magna'' - rabbit (''O. cuniculus'') * ''Eimeria marconii'' - red-backed vole (''Clethrionomys gapperi'') * ''Eimeria media'' - rabbit (''O. cuniculus'') * ''Eimeria melanuri'' - garden dormouse (''

Eliomys quercinus The garden dormouse (''Eliomys quercinus'') is a species of dormouse native to Europe. Characteristics The garden dormouse is gray or brown, with a whitish underside. It has black eye markings and large ears. Its hair is short, and its tail ha ...

'') * ''Eimeria myoxi'' - garden dormouse (''E. quercinus'') * ''Eimeria nagpurensis'' - rabbit (''O. cuniculus'') * ''Eimeria nieschulzi'' - brown rat (''R. norvegicus'') * ''Eimeria ninakohlyakimovae'' - goat (''C. hircus'') * ''Eimeria ovinoidalis'' - sheep (''O. aries'') * ''Eimeria pallida'' - goat (''C. hircus'') * ''Eimeria palustris'' - marsh rice rat (''

Oryzomys palustris The marsh rice rat (''Oryzomys palustris'') is a semiaquatic North American rodent in the family Cricetidae. It usually occurs in wetland habitats, such as swamps and salt marshes. It is found mostly in the eastern and southern United States, f ...

'') * ''Eimeria papillata'' - mouse (''M. musculus'') * ''Eimeria perforans'' - rabbit (''O. cuniculus'') * ''Eimeria phocae'' -

Sable Island Sable Island (, literally "island of sand") is a small, remote island off the coast of Nova Scotia, Canada. Sable Island is located in the North Atlantic Ocean, about southeast of Halifax, Nova Scotia, Halifax, and about southeast of the clo ...

harbour seals (''

Phoca vitulina The harbor (or harbour) seal (''Phoca vitulina''), also known as the common seal, is a true seal found along temperate and Arctic marine coastlines of the Northern Hemisphere. The most widely distributed species of pinniped (walruses, eared sea ...

'') * ''Eimeria pileata'' - red-backed vole (''Clethrionomys gapperi'') * ''Eimeria pipistrellus'' - Kuhl's pipistrelle ('' Pipistrellus kuhlii'') * ''Eimeria piriformis'' - rabbit (''O. cuniculus'') * ''Eimeria prionotemni'' - Bennett's wallaby (''

Macropus rufogriseus The red-necked wallaby or Bennett's wallaby (''Notamacropus rufogriseus'') is a medium-sized macropod marsupial (wallaby), common in the more temperate and fertile parts of eastern Australia, including Tasmania. Red-necked wallabies have been i ...

'') * ''Eimeria procyonis'' - raccoon (''

Procyon lotor The raccoon ( or , ''Procyon lotor''), sometimes called the North American, northern or common raccoon (also spelled racoon) to distinguish it from Procyonina, other species of raccoon, is a mammal native to North America. It is the largest ...

'') * ''Eimeria punctata'' - goat (''C. hircus'') * ''Eimeria roobroucki'' - rabbit (''O. cuniculus'') * ''Eimeria saudiensis'' - Arabian oryx (''

Oryx leucoryx The Arabian oryx or white oryx (''Oryx leucoryx'') is a medium-sized antelope with a distinct shoulder bump, long, straight horns, and a tufted tail. It is a bovid, and the smallest member of the genus ''Oryx'', native to desert and steppe areas ...

'') * ''Eimeria sealanderi'' - eastern red bat (''Lasiurus borealis'') * ''Eimeria separata'' - mouse (''M. musculus''), rat (''

Rattus rattus The black rat (''Rattus rattus''), also known as the roof rat, ship rat, or house rat, is a common long-tailed rodent of the stereotypical rat genus ''Rattus'', in the subfamily Murinae. It likely originated in the Indian subcontinent, but is ...

'') * ''Eimeria stiedai'' - rabbit (''O. cuniculus'') * ''Eimeria ursini'' - southern hairy-nosed wombat (''

Lasiorhinus latifrons The southern hairy-nosed wombat (''Lasiorhinus latifrons'') is one of three extant species of wombats. It is found in scattered areas of semiarid scrub and mallee (biogeographic region), mallee from the eastern Nullarbor Plain to the New South ...

'') * ''Eimeria vermiformis'' - mice (''M. musculus'') * ''Eimeria weybridgensis'' - sheep (''O. aries'') * ''Eimeria wobati'' - southern hairy-nosed wombat (''L. latifrons'') * ''

Eimeria zuernii ''Eimeria zuernii'' is a species of the parasite ''Eimeria'' that causes diarrheic disease known as eimeriosis in cattle (''Bos taurus''), and mainly affects younger animals. The disease is also commonly referred to as coccidiosis. The parasite c ...

'' - cattle (''B. taurus'')

List of species

* ''

Eimeria abramovi ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria acervulina'' * ''

Eimeria adenoides ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria ahsata'' * '' Eimeria airculensis'' * '' Eimeria alabamensis'' * '' Eimeria albigulae'' * '' Eimeria alijevi'' * '' Eimeria alpacae'' * '' Eimeria amphisbaeniarum'' * '' Eimeria anatis'' * '' Eimeria anguillae'' * ''

Eimeria ankarensis ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria anseris'' * '' Eimeria arizonensis'' * '' Eimeria arabukosokokensis'' * '' Eimeria arnyi'' * '' Eimeria arundeli'' * '' Eimeria anseris'' * '' Eimeria arkhari'' * '' Eimeria arloingi'' * '' Eimeria aspheronica'' * '' Eimeria auburnensis'' * ''

Eimeria augusta ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria aurati'' * '' Eimeria aythyae'' * ''

Eimeria azerbaidschanica ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria bactriani'' * '' Eimeria bakuensis'' * ''

Eimeria bareillyi ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria baueri'' * '' Eimeria battakhi'' * '' Eimeria beckeri'' * '' Eimeria beecheyi'' * '' Eimeria berkinbaevi'' * '' Eimeria brinkmanni'' * '' Eimeria bombaynsis'' * '' Eimeria bonasae'' * '' Eimeria boschadis'' * '' Eimeria bovis'' * '' Eimeria brantae'' * '' Eimeria brasiliensis'' * '' Eimeria brevoortiana'' * '' Eimeria brinkmanni'' * '' Eimeria brunetti'' * '' Eimeria bucephalae'' * '' Eimeria bufomarini'' * '' Eimeria bukidnonensis'' * '' Eimeria burdai'' * '' Eimeria callospermophili'' * '' Eimeria californicenis'' * '' Eimeria cameli'' * '' Eimeria canadensis'' * ''

Eimeria canis ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria caprina'' * '' Eimeria caprovina'' * '' Eimeria carinii'' * ''

Eimeria carpelli ''Eimeria'' is a genus of apicomplexa The Apicomplexa (also called Apicomplexia; single: apicomplexan) are organisms of a large phylum of mainly parasitic alveolates. Most possess a unique form of organelle structure that comprises a type of ...

'' * ''

Eimeria catostomi ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria catronensis'' * '' Eimeria caviae'' * '' Eimeria cerdonis'' * '' Eimeria citelli * '' Eimeria chelydrae'' * '' Eimeria christenseni'' * '' Eimeria clarkei'' * '' Eimeria clethrionomyis'' * '' Eimeria coecicola'' * '' Eimeria colchici'' * '' Eimeria columbae'' * ''

Eimeria columbarum ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria contorta'' * '' Eimeria coturnicus'' * ''

Eimeria couesii ''Eimeria couesii'' is an apicomplexan parasite of the genus ''Eimeria'' that infects the intestine of the rice rat ''Oryzomys couesi ''Oryzomys couesi'', also known as Coues's rice rat, is a semiaquatic rodent in the family Cricetidae occur ...

'' * '' Eimeria crandallis'' * ''

Eimeria crassa ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria curvata'' * '' Eimeria cylindrica'' * '' Eimeria cynomysis'' * '' Eimeria cyprini'' * '' Eimeria dammahensis'' * '' Eimeria danailovi'' * '' Eimeria danielle'' * '' Eimeria debliecki'' * ''

Eimeria deserticola ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * ''

Eimeria dispersa ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria dolichotis'' * '' Eimeria dromedarii'' * '' Eimeria duszynskii'' * '' Eimeria ellipsoidalis'' * '' Eimeria elongata'' * '' Eimeria etheostomae'' * '' Eimeria eutamiae'' * ''

Eimeria exigua ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria falciformis'' * '' Eimeria fanthami'' * '' Eimeria farasanii'' * '' Eimeria farra'' * '' Eimeria faurei'' * '' Eimeria fernandoae'' * '' Eimeria ferrisi'' * '' Eimeria filamentifera'' * '' Eimeria franklinii'' * '' Eimeria fraterculae'' * '' Eimeria freemani'' * '' Eimeria fulva'' * '' Eimeria funduli'' * '' Eimeria gallatii'' * '' Eimeria gallopavonis'' * '' Eimeria gasterostei'' * '' Eimeria gilruthi'' * ''

Eimeria glenorensis ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria gokaki'' * '' Eimeria gonzalei'' * '' Eimeria gorakhpuri'' * '' Eimeria granulosa'' * '' Eimeria grenieri'' * '' Eimeria guevarai'' * '' Eimeria hagani'' * '' Eimeria haneki'' * '' Eimeria hasei'' * '' Eimeria hawkinsi'' * '' Eimeria hermani'' * '' Eimeria hindlei'' * '' Eimeria hirci'' * '' Eimeria hoffmani'' * ''

Eimeria hoffmeisteri ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria hybognathi'' * '' Eimeria ictaluri'' * '' Eimeria illinoisensis'' * '' Eimeria innocua'' * '' Eimeria intestinalis'' * '' Eimeria intricata'' * '' Eimeria iroquoina'' * '' Eimeria irresidua'' * '' Eimeria ivitaensis'' * ''

Eimeria judoviciani ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * ''

Eimeria kinsellai ''Eimeria kinsellai'' is an apicomplexan parasite of the genus ''Eimeria'' that infects the marsh rice rat (''Oryzomys palustris''). It was discovered in 1970 at Paynes Prairie, Alachua County Alachua County ( ) is a county in the north cent ...

'' * '' Eimeria koganae'' * ''

Eimeria kotlani ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria krijgsmanni'' * '' Eimeria krylovi'' * '' Eimeria kunmingensis'' * '' Eimeria lagopodi'' * '' Eimeria lamae'' * '' Eimeria langebarteli'' * ''

Eimeria larimerensis ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria lateralis'' * '' Eimeria laureleus'' * '' Eimeria lepidosirenis'' * '' Eimeria leucisci'' * '' Eimeria ludoviciani'' * '' Eimeria macusaniensis'' * '' Eimeria magnalabia'' * ''

Eimeria marconii ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria maxima'' * '' Eimeria melanuri'' * '' Eimeria meleagridis'' * '' Eimeria menzbieri'' * ''

Eimeria micropteri ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria minasensis'' * '' Eimeria mitis'' * '' Eimeria monacis'' * '' Eimeria morainensis'' * '' Eimeria moronei'' * ''

Eimeria mulardi ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * ''

Eimeria muta ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria myoxi'' * ''

Eimeria myoxocephali ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria natricis'' * '' Eimeria necatrix'' * '' Eimeria neitzi'' * '' Eimeria nieschulzi'' * '' Eimeria nigricani'' * '' Eimeria nocens'' * '' Eimeria nyroca'' * '' Eimeria ojastii'' * '' Eimeria ojibwana'' * '' Eimeria onychomysis'' * ''

Eimeria oryzomysi ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria oryxae'' * ''

Eimeria os ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria osmeri'' * '' Eimeria ovata'' * '' Eimeria ovinoidalis'' * ''

Eimeria palustris ''Eimeria palustris'' is an apicomplexan parasite of the genus ''Eimeria'' that infects the marsh rice rat (''Oryzomys palustris''). It was discovered in 1970 at Tuskegee National Forest, Macon County, Alabama. A different ''Eimeria'', ''Eimeri ...

'' * ''

Eimeria papillata ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria parvula'' * '' Eimeria pigra'' * '' Eimeria pilarensis'' * '' Eimeria pileata'' * '' Eimeria pipistrellus'' * '' Eimeria phocae'' * '' Eimeria praecox'' * '' Eimeria prionotemni'' * '' Eimeria pseudospermophili'' * ''

Eimeria pulchella ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria pungitii'' * '' Eimeria punonensis'' * '' Eimeria ranae'' * '' Eimeria reedi'' * '' Eimeria reichenowi'' * '' Eimeria ribarrensis'' * '' Eimeria rjupa'' * '' Eimeria rutili'' * ''

Eimeria salvelini ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * ''

Eimeria saitamae ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria saudiensis'' * '' Eimeria separata'' * '' Eimeria schachdagica'' * ''

Eimeria sevilletensis ''Eimeria'' is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. ''Eimeria'' species are considered to be ...

'' * '' Eimeria sinensis'' * '' Eimeria sipedon'' * '' Eimeria somateriae'' * '' Eimeria spermophili'' * '' Eimeria squali'' * '' Eimeria stiedai'' * '' Eimeria stigmosa'' * '' Eimeria striata'' * '' Eimeria subepithelialis'' * '' Eimeria surki'' * '' Eimeria tamiasciuri'' * '' Eimeria tedlai'' * ''

'' * '' Eimeria truncata'' * '' Eimeria truttae'' * '' Eimeria uekii'' * '' Eimeria uniungulati'' * '' Eimeria ursini'' * '' Eimeria vilasi'' * '' Eimeria weddelli'' * '' Eimeria weybridgensis'' * '' Eimeria witcheri'' * '' Eimeria vanasi'' * '' Eimeria vermiformis'' * '' Eimeria volgensis'' * '' Eimeria wobati'' * '' Eimeria wyomingensis'' * '' Eimeria yemenensae'' * '' Eimeria yukonensis'' * ''

References

External links

An overview of ''Eimeria'' and coccidiosisThe Life Cycle of Coccidia
{{Authority control Apicomplexa genera Conoidasida Poultry diseases Veterinary protozoology Parasites of birds Parasites of equines