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{{Taxobox
{{Taxobox
|name = ''Leucocytozoon caulleryi''
|name = ''Leucocytozoon caulleryi''
|kingdom = Protista
|kingdom = Protista
|sub-kingdom =
|sub-kingdom =
|phylum = Protozoa
|phylum = [[:Category:Protozoa|Protozoa]]
|sub-phylum = Apicomplexa
|sub-phylum = Apicomplexa
|super-class =
|super-class =
|species = ''L. caulleryi''
|species = ''L. caulleryi''
}}
}}
Also Known As: '''''Avian Haematozoa'''''
[[Category:To Do - Steph]]
Causes: '''''Leucocytozoonosis'''''
==Introduction==
[[File:Leucocytozoon smithi.jpg|thumb|200px|right|''L. smithi'' within an erythrocyte, distorting its appearance.]]
''Leucocytozoon caulleryi'' is a '''[[Protozoa|protozoan]] blood-borne parasite of birds.'''
This disease is not zoonotic.
==Lifecycle==
Chickens are infected through '''biting [[Ceratopogonidae|midges]]''', specifically ''Culicoides arakawae''. Other Leucocytozoon species are transmitted by '''[[Mosquitoes|mosquitoes]]'''.
'''Sporozoites''' are parasitic and can migrate to and affect the liver, spleen, lungs and kidneys, forming schizonts. '''Schizonts''' can then release '''merozoites''' or '''secondary schizonts''' in the '''endothelial cells''' of the blood vessels and in essentially any of the viscera. These secondary schizonts have a distinct protective capsule and contain many merozoites.
'''Gametogony''' (sexual reproduction) then occurs within the '''[[Erythrocytes|erythrocytes]]'''.
Other Leucocytozoon species can invade and replicate within the [[Leucocytes|leucocytes]].
==Signalment and Distribution==
''L. caulleryi'' has been reported in Thailand, India, Taiwan, Japan, Burma, Sri Lanka, the Philippines, Singapore, Malaysia, Indonesia, China, and Korea.<ref>Akiba, K (1970) '''Leucocytozoonosis of chickens'''. ''Natl. Inst. Anim. Quart.'', 10:131-147</ref>
Acute outbreaks of leucocytozoonosis have been reported in chickens, turkeys, waterfowl and wild birds worldwide.
Seasonality is dictated by presence of the insect vectors, so is usually in the Summer in temperate countries such as Japan but is present throughout the year where insects are active year-round such as in Southern Asia.
==Clinical Signs==
Infections range from '''subclinical to fatal''' and mortality can reach 100%. Mortalities are highest in young chicks due to marked haemorrhaging.
Leucocytozoonosis causes '''[[Anaemia|anaemia]]''' due to haemorrhages from damaged, ruptured blood vessels and affected [[Erythrocytes|erythrocytes]]. This can preset as '''pale mucous membranes, comb or wattle, petechiation and ecchymoses''', lethargy, weakness and neurological signs. '''Anorexia and [[Diarrhoea|diarrhoea]]''' often occur and '''soft, thin, defective eggs''' with reduced hatchability may be laid by infected hens.
Neurological signs can also be caused by parasite replication and invasion of nervous tissues.
==Diagnosis==
'''Large, poorly pigmented gametocytes''' can be identified within the host [[Erythrocytes|red blood cells]] distorting their appearance beyond recognition.
Antibodies and antigens can be detected serologically in serum using '''agar gel precipitation and [[ELISA testing|ELISA]]'''.<ref> Isobe, T., Suzuki, K (1986) '''Enzyme-linked immunosorbent assay for detection of antibody to ''Leucocytozoon caulleryi'''''. ''Avian Pathology'', 15(2):199-211; 14</ref>
On '''post-mortem, petechial haemorrhage and second generation schizonts''' are seen in various organs of dead chicks and also in oviducts of infected hens, when analysed histologically.<ref> Nakamura, K., Mitarai, Y., Tanimura, N., Hara, H., Ikeda, A., Shimada, J., Isobe, T (1997) '''Pathogenesis of reduced egg production and soft-shelled eggs in laying hens associated with ''Leucocytozoon caulleryi'' infection'''. ''J Parasitology'', 83(2):325-327; 11</ref> The shell glad of the reproductive tract and oviducts are most severely affected. Schizonts can cause inflammation, oedema and pressure atrophy of surrounding tissues. '''Granulomatous and lymphocytic lesions''' are seen in the lungs, heart, brain and peripheral nerves. Large gametocytes can block capillaries of the lungs.
==Treatment==
No treatment is usually effective.
==Control==
Preventative medication with '''pyrimethamine and sulfadimethoxine''' in the feed can be used.
Insect vector control is helpful but difficult.
{{Learning
|flashcards = [[Leucocytozoon caulleryi Flashcards|''L. caulleryi'' Flashcards]]
}}
==References==
<references/>
{{CABI source
|datasheet = [http://www.cabi.org/ahpc/?compid=3&dsid=77304&loadmodule=datasheet&page=2144&site=160 ''Leucocytozoon caulleryi''] and [http://www.cabi.org/ahpc/?compid=3&dsid=77305&loadmodule=datasheet&page=2144&site=160 leucocytozoonosis]
|date =1 July 2011
}}
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[[Category:CABI Expert Review]][[Category:CABI AHPC Pages]]
[[Category:Lymphoreticular and Haematopoietic Diseases - Birds]] [[Category:Neurological Diseases - Birds]]
[[Category:Avian Parasites]]
[[Category:Miscellaneous Protozoa]]