Histomoniasis
Encyclopedia
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...
of birds, particularly of chickens and turkeys, due to parasitic infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
of a protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
n, Histomonas meleagridis
Histomonas meleagridis
Histomonas meleagridis is species of parasitic protozoan that infects a wide range of birds including chickens, turkeys, peafowl, quail and pheasants, causing blackhead disease, infectious enterohepatitis, or histomoniasis. H. meleagridis can infect many birds but it is most deadly in turkeys...
. It is a form of blackhead disease
Blackhead disease
Blackhead disease is a commercially important avian disease that affects chickens, turkeys and other poultry birds. The disease carries a high mortality rate and primarily affects the liver and cecum. It is a form of histomoniasis which is transmitted by the protozoan parasite Histomonas meleagridis...
in poultry
Poultry
Poultry are domesticated birds kept by humans for the purpose of producing eggs, meat, and/or feathers. These most typically are members of the superorder Galloanserae , especially the order Galliformes and the family Anatidae , commonly known as "waterfowl"...
. The parasite specifically infects the cecum
Cecum
The cecum or caecum is a pouch, connecting the ileum with the ascending colon of the large intestine. It is separated from the ileum by the ileocecal valve or Bauhin's valve, and is considered to be the beginning of the large intestine. It is also separated from the colon by the cecocolic...
and liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
. Symptoms of the infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
include depression
Depression (mood)
Depression is a state of low mood and aversion to activity that can affect a person's thoughts, behaviour, feelings and physical well-being. Depressed people may feel sad, anxious, empty, hopeless, helpless, worthless, guilty, irritable, or restless...
, reduced appetite
Appetite
The appetite is the desire to eat food, felt as hunger. Appetite exists in all higher life-forms, and serves to regulate adequate energy intake to maintain metabolic needs. It is regulated by a close interplay between the digestive tract, adipose tissue and the brain. Decreased desire to eat is...
, poor growth, increased thirst, sulphur-yellow diarrhoea, listlessness and dry, ruffled feathers. The head may become cyanotic
Cyanotic
Cyanotic is a Chicago-based industrial rock collective fronted by Sean Payne that formed in 2002 and released its first full-length album in 2005. Cyanotic is known for its genre-blending work, which fuses traditional industrial beats and vocals with drum n bass, sampling and heavy metal to create...
(bluish in colour) and hence the common name of the disease, blackhead
Blackhead disease
Blackhead disease is a commercially important avian disease that affects chickens, turkeys and other poultry birds. The disease carries a high mortality rate and primarily affects the liver and cecum. It is a form of histomoniasis which is transmitted by the protozoan parasite Histomonas meleagridis...
; thus the name 'blackhead' is in all possibility a misnomer
Misnomer
A misnomer is a term which suggests an interpretation that is known to be untrue. Such incorrect terms sometimes derive their names because of the form, action, or origin of the subject becoming named popularly or widely referenced—long before their true natures were known.- Sources of misnomers...
for discoloration. It is particularly highly fatal
Fatal
Fatal may refer to:* Causing death* Fatal , an album by Hussein Fatal* Fatal Recordings, a feminist record label* Fatal, a rapper who collaborated with the band Therapy? on the song "Come and Die" from the Judgment Night film soundtrack...
in poultry birds
Poultry
Poultry are domesticated birds kept by humans for the purpose of producing eggs, meat, and/or feathers. These most typically are members of the superorder Galloanserae , especially the order Galliformes and the family Anatidae , commonly known as "waterfowl"...
, and less in other birds. Currently there is no prescription drug
Prescription drug
A prescription medication is a licensed medicine that is regulated by legislation to require a medical prescription before it can be obtained. The term is used to distinguish it from over-the-counter drugs which can be obtained without a prescription...
to treat this disease.
Etiology
A protozoan H. meleagridisHistomonas meleagridis
Histomonas meleagridis is species of parasitic protozoan that infects a wide range of birds including chickens, turkeys, peafowl, quail and pheasants, causing blackhead disease, infectious enterohepatitis, or histomoniasis. H. meleagridis can infect many birds but it is most deadly in turkeys...
is responsible for histomoniasis of gallinaceous birds
Galliformes
Galliformes are an order of heavy-bodied ground-feeding domestic or game bird, containing turkey, grouse, chicken, New and Old World Quail, ptarmigan, partridge, pheasant, and the Cracidae. Common names are gamefowl or gamebirds, landfowl, gallinaceous birds or galliforms...
ranging from chickens, turkeys, ducks, geese, grouse
Grouse
Grouse are a group of birds from the order Galliformes. They are sometimes considered a family Tetraonidae, though the American Ornithologists' Union and many others include grouse as a subfamily Tetraoninae in the family Phasianidae...
, guineafowl
Guineafowl
The guineafowl are a family of birds in the Galliformes order, although some authorities include the guineafowl as a subfamily, Numidinae, of the family Phasianidae...
, partridges, pheasants, and quails. The protozoan parasite is transmitted through the eggs of a nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
, Heterakis gallinarum
Heterakis gallinarum
Heterakis gallinarum is a nematode parasite that lives in the cecum of domestic fowl, particularly in ground feeders such as domestic chickens and turkeys. It causes infection that is mildly pathogenic. However it often carries a protozoan parasite Histomonas meleagridis which causes of...
. The eggs are highly resistant to environmental conditions, and H. meleagridis is in turn highly viable inside the eggs, even for years. Birds are infected once they ingest the eggs of the nematode in soil, or sometimes through earthworm
Earthworm
Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...
which had ingested the egg-contaminated soil. Outbreak
Outbreak
Outbreak is a term used in epidemiology to describe an occurrence of disease greater than would otherwise be expected at a particular time and place. It may affect a small and localized group or impact upon thousands of people across an entire continent. Two linked cases of a rare infectious...
can occur rapidly from the heavily infected bird in a flock
Flock
-Computing:* Flock , a defunct web browser* Flock system call, used for computer file locking* F-Lock, a function lock key on a computer keyboard-Entertainment:* Flock , a sculpture by Michael Christian...
readily through normal contact between uninfected and infected birds and their droppings in the total absence of cecal
Cecum
The cecum or caecum is a pouch, connecting the ileum with the ascending colon of the large intestine. It is separated from the ileum by the ileocecal valve or Bauhin's valve, and is considered to be the beginning of the large intestine. It is also separated from the colon by the cecocolic...
worm
Worm
The term worm refers to an obsolete taxon used by Carolus Linnaeus and Jean-Baptiste Lamarck for all non-arthropod invertebrate animals, and stems from the Old English word wyrm. Currently it is used to describe many different distantly-related animals that typically have a long cylindrical...
s. For this reason, infection can spread very quickly. Once inside the digestive system of the host, the protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
n is moved to the cecum
Cecum
The cecum or caecum is a pouch, connecting the ileum with the ascending colon of the large intestine. It is separated from the ileum by the ileocecal valve or Bauhin's valve, and is considered to be the beginning of the large intestine. It is also separated from the colon by the cecocolic...
along with the eggs of H. gallinarum.
Histopathology and Symptoms
Histomoniasis is characterized by blackhead in birds. H. meleagridis is released in the cecum where the eggs of the nematode undergo larval development. The parasite migrates to the mucosa and submucosaSubmucosa
In the gastrointestinal tract, the submucosa is the layer of dense irregular connective tissue or loose connective tissue that supports the mucosa, as well as joins the mucosa to the bulk of underlying smooth muscle .-Contents:Blood vessels, lymphatic vessels, and nerves will run through...
where they cause extensive and severe necrosis
Necrosis
Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...
of the tissue. Necrosis is initiated by inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
and gradual ulceration
Peptic ulcer
A peptic ulcer, also known as PUD or peptic ulcer disease, is the most common ulcer of an area of the gastrointestinal tract that is usually acidic and thus extremely painful. It is defined as mucosal erosions equal to or greater than 0.5 cm...
, causing thickening of the cecal
Cecum
The cecum or caecum is a pouch, connecting the ileum with the ascending colon of the large intestine. It is separated from the ileum by the ileocecal valve or Bauhin's valve, and is considered to be the beginning of the large intestine. It is also separated from the colon by the cecocolic...
wall. The lesions are sometimes exacerbated by other pathogens such as Escherichia coli
Escherichia coli
Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...
and coccidia
Coccidia
Coccidia is a subclass of microscopic, spore-forming, single-celled obligate parasites belonging to the apicomplexan class Conoidasida. Coccidian parasites infect the intestinal tracts of animals, and are the largest group of apicomplexan protozoa....
. Histomonads then gain entry into small veins of the blood stream from the cecal lesions and migrates to the liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
, where it again causes focal necrosis. Turkeys are noted to be most susceptible to the symptoms in terms of mortality
Mortality rate
Mortality rate is a measure of the number of deaths in a population, scaled to the size of that population, per unit time...
, sometimes approaching 100% of a flock. Diagnosis
Diagnosis
Diagnosis is the identification of the nature and cause of anything. Diagnosis is used in many different disciplines with variations in the use of logics, analytics, and experience to determine the cause and effect relationships...
can be easily performed by autopsy
Autopsy
An autopsy—also known as a post-mortem examination, necropsy , autopsia cadaverum, or obduction—is a highly specialized surgical procedure that consists of a thorough examination of a corpse to determine the cause and manner of death and to evaluate any disease or injury that may be present...
of the fresh or preserved carcass
Carcass
Carcass may refer to:*Cadaver of a human, or carrion of an animal.*Carcass , a death metal/grindcore band*Carcass , a type of incendiary ammunition designed to be fired from a cannon, three ships of the Royal Navy...
. Unusual lesions have been observed in other organs of turkey such as Bursa of Fabricius
Bursa of Fabricius
In birds, the bursa of Fabricius is the site of hematopoiesis, a specialized organ that, as first demonstrated by Bruce Glick and later by Max Cooper and Robert Good, is necessary for B cell development in birds...
, lungs and kidneys.
Symptoms appear within 7–12 days after infection and include depression, reduced appetite, poor growth, increased thirst, sulphur-yellow diarrhoea, listlessness, drooping wings, and unkempt feathers. Young birds have a more acute
Acute
Acute may refer to:* Acute accent* Acute angle* Acute * Acute * Acute toxicity...
disease and die within a few days after signs appear. Older birds may be sick for some time and become emaciated before death. The symptoms are highly fatal
Fatal
Fatal may refer to:* Causing death* Fatal , an album by Hussein Fatal* Fatal Recordings, a feminist record label* Fatal, a rapper who collaborated with the band Therapy? on the song "Come and Die" from the Judgment Night film soundtrack...
to turkeys, but affect less damage in chickens. However, outbreaks in chickens may result in high morbidity, moderate mortality, and extensive culling
Culling
Culling is the process of removing animals from a group based on specific criteria. This is done either to reinforce certain desirable characteristics or to remove certain undesirable characteristics from the group...
, leading to overall poor flock performance. Concurrence of Salmonella
Salmonella
Salmonella is a genus of rod-shaped, Gram-negative, non-spore-forming, predominantly motile enterobacteria with diameters around 0.7 to 1.5 µm, lengths from 2 to 5 µm, and flagella which grade in all directions . They are chemoorganotrophs, obtaining their energy from oxidation and reduction...
typhmurium and E. coli
Escherichia coli
Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...
was found to cause high mortality in broiler
Broiler
A broiler is a type of chicken raised specifically for meat production. Modern commercial broilers, typically known as Cornish crosses or Cornish-Rocks are specially bred for large scale, efficient meat production and grow much faster than egg or traditional dual purpose breeds...
chickens.
Prevention and Treatment
There are currently no therapeutic drugsDRUGS
Destroy Rebuild Until God Shows are an American post-hardcore band formed in 2010. They released their debut self-titled album on February 22, 2011.- Formation :...
prescribed for the disease. Therefore, prevention is the sole mode of treatment. Deworming
Deworming
Deworming is the giving of an anthelmintic drug to an animal to rid it of intestinal parasites, such as roundworm and tapeworm...
of birds with anthelmintics can reduce exposure to the cecal nematode that carry the protozoan. Good management of the farm
Farm
A farm is an area of land, or, for aquaculture, lake, river or sea, including various structures, devoted primarily to the practice of producing and managing food , fibres and, increasingly, fuel. It is the basic production facility in food production. Farms may be owned and operated by a single...
, including immediate quarantine
Quarantine
Quarantine is compulsory isolation, typically to contain the spread of something considered dangerous, often but not always disease. The word comes from the Italian quarantena, meaning forty-day period....
of infected birds and sanitation, is the main useful strategy for controlling the spread of the parasitic contamination. The only drug used for the control (prophylaxis) in the USA is nitarsone at 0.01875% of feed until 5 days before marketing. Natustat and nitarsone were shown to be effective therapeutic drugs
DRUGS
Destroy Rebuild Until God Shows are an American post-hardcore band formed in 2010. They released their debut self-titled album on February 22, 2011.- Formation :...
. Nifurtimox
Nifurtimox
Nifurtimox is a 5-nitrofuran and is used to treat diseases caused by trypanosomes including Chagas disease and sleeping sickness. It is given by mouth and not by injection.-Indications:...
(NFX), a compound with known antiprotozoal
Antiprotozoal agent
Antiprotozoal agents is a class of pharmaceuticals used in treatment of protozoan infection.Protozoans have little in common with each other and so agents effective against one pathogen may not be effective against another...
activity, was demonstrated to be significantly effective at 300–400 ppm
PPM
- Culture :*Peter, Paul and Mary, a 1960s folk music trio*Picture Postcard Monthly, a magazine for collectors of postcards*Please Please Me, the first album by The Beatles- Health :*Permanent pacemaker or artificial pacemaker...
, and well tolerated by turkeys.