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[[Image:Toxoplasma gondii.jpg|thumb|right|150px|''Toxoplasma gondii'' <br> Ke Hu and John Murray, WikiMedia Commons]]
 
[[Image:Toxoplasma gondii.jpg|thumb|right|150px|''Toxoplasma gondii'' <br> Ke Hu and John Murray, WikiMedia Commons]]
 
[[Image:Toxoplasma Life Cycle.jpg|thumb|right|150px|''Toxoplasma'' Life Cycle Diagram - Dennis Jacobs & Mark Fox RVC]]
 
[[Image:Toxoplasma Life Cycle.jpg|thumb|right|150px|''Toxoplasma'' Life Cycle Diagram - Dennis Jacobs & Mark Fox RVC]]
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==Life Cycle==
 
==Life Cycle==
The life cycle of ''T. gondii'' is cmplex, usually indirect and often referred to as '''facultatively heteroxenous'''. Intermediate host is not essential for completion of the life cycle. Gametogony (sexual stage) is host specific for felids.
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The life cycle of ''T. gondii'' is complex, usually indirect and often referred to as '''facultatively heteroxenous'''. Intermediate host is not essential for completion of the life cycle. Gametogony (sexual stage) is host specific for felids.
    
===Cats===
 
===Cats===
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===Other species===
 
===Other species===
 
When other, ‘’’non-feline, carnivores’’’ (such as dogs) or sheep consume tissue cysts or oocysts from cat faeces, ''Toxoplasma gondii'' initiates '''extraintestinal replication'''. This process is the same for all hosts, and does not vary with the form of the parasite ingested. '''Bradyzoites''' and '''sporozoites''', from cysts and oocysts respectively, are released in the intestine and infect the intestinal epithelium where they replicate - asexual reproduction by '''endodyogeny''' (budding) producing 8-16 '''tachyzoites'''. Tachyzoites are lunate in shape, about 6 microns in diameter and possess the ability to multiply in almost any cell type. The infected cell ruptures to release tachyzoites which then disseminate via blood and lymph to infect other tissues. Tachyzoites then replicate intracellularly and, if the cell does not burst, they eventually encyst and persist for the life of the host. Tissue cysts readily form in the CNS, muscles and visceral organs.  
 
When other, ‘’’non-feline, carnivores’’’ (such as dogs) or sheep consume tissue cysts or oocysts from cat faeces, ''Toxoplasma gondii'' initiates '''extraintestinal replication'''. This process is the same for all hosts, and does not vary with the form of the parasite ingested. '''Bradyzoites''' and '''sporozoites''', from cysts and oocysts respectively, are released in the intestine and infect the intestinal epithelium where they replicate - asexual reproduction by '''endodyogeny''' (budding) producing 8-16 '''tachyzoites'''. Tachyzoites are lunate in shape, about 6 microns in diameter and possess the ability to multiply in almost any cell type. The infected cell ruptures to release tachyzoites which then disseminate via blood and lymph to infect other tissues. Tachyzoites then replicate intracellularly and, if the cell does not burst, they eventually encyst and persist for the life of the host. Tissue cysts readily form in the CNS, muscles and visceral organs.  
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[[Image:Toxoplasmosis Life Cycle.jpg|thumb|right|300px| Life cycle of ''Toxoplasma gondii''. Source: Wikimedia Commons; Author: LadyofHats (2010)]]
    
==Transmission==
 
==Transmission==
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If a pregnant queen or human is naive to ''Toxoplasma gondii'' at the time of ingestion, '''transplacental infection''' can occur. The outcome of this depends on the stage of gestation. Infection during the first trimester usually has severe consequences, such as stillbirth or abortion; infections during the second or third trimesters are more likely to give rise to an infected foetus.
 
If a pregnant queen or human is naive to ''Toxoplasma gondii'' at the time of ingestion, '''transplacental infection''' can occur. The outcome of this depends on the stage of gestation. Infection during the first trimester usually has severe consequences, such as stillbirth or abortion; infections during the second or third trimesters are more likely to give rise to an infected foetus.
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==Prevention==
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''Toxoplasma'' infection could be controlled/prevented by testing for seropositive cats using [[ELISA testing|ELISA]], however, exposure to ''Toxoplasma'' without current infection may also n=be detected, and [[Toxoplasmosis - Small Animal#Treatment|treating]]. Human toxoplasmosis can be prevented by avoiding oocyst ingestion (safe handling of cat litter/faeces), tissue cyst ingestion (appropriate food preparation). Pregnant women should not be in contact with aborting sheep or cat faeces. Sheep can be vaccinated or given medicated feed.
      
For more information see:
 
For more information see:
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<big>'''[[Toxoplasmosis - Small Animal|Cat Toxoplasmosis]]
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<big>'''[[Toxoplasmosis - Cat and Dog|Cat Toxoplasmosis]]
    
'''[[Toxoplasmosis - Sheep|Sheep Toxoplasmosis]]
 
'''[[Toxoplasmosis - Sheep|Sheep Toxoplasmosis]]
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'''[[Toxoplasmosis - Human|Human Toxoplasmosis]]</big>
 
'''[[Toxoplasmosis - Human|Human Toxoplasmosis]]</big>
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==Literature Search==
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{{Learning
[[File:CABI logo.jpg|left|90px]]
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|literature search = [http://www.cabdirect.org/search.html?rowId=1&options1=AND&q1=%22toxoplasma+gondii%22&occuring1=title&rowId=2&options2=AND&q2=&occuring2=freetext&rowId=3&options3=AND&q3=&occuring3=freetext&publishedstart=2000&publishedend=yyyy&calendarInput=yyyy-mm-dd&la=any&it=any&show=all&x=47&y=7 ''Toxoplasma gondii'' publications since 2000]
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|flashcards = [[Tissue_Cyst_Forming_Coccidian_Flashcards|Tissue Cyst Forming Coccidian Flashcards]]
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|Vetstream = [https://www.vetstream.com/canis/search?s=protozoa Protozoa]
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}}
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==References==
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#Merck & Co (2008) '''The Merck Veterinary Manual (Eighth Edition)''' ''Merial''
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#'''OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals 2008''', Chapter 2.9.10, 1284-1293.
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#The Center for Food Security and Public Health, Iowa State University, College of Veterinary Medicine (2005). ''Toxoplasmosis Factsheet'', available at [http://www.cfsph.iastate.edu www.cfsph.iastate.edu]
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#Lappin, M R (2006) Toxoplasmosis. In '''North American Veterinary Conference Proceeeding 2006''', ''NAVC''.
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Use these links to find recent scientific publications via CAB Abstracts (log in required unless accessing from a subscribing organisation).
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<br><br><br>
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[http://www.cabdirect.org/search.html?rowId=1&options1=AND&q1=%22toxoplasma+gondii%22&occuring1=title&rowId=2&options2=AND&q2=&occuring2=freetext&rowId=3&options3=AND&q3=&occuring3=freetext&publishedstart=2000&publishedend=yyyy&calendarInput=yyyy-mm-dd&la=any&it=any&show=all&x=47&y=7 ''Toxoplasma gondii'' publications since 2000]
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==Test yourself with the Tissue Cyst Forming Coccidian Flashcards==
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[[Tissue_Cyst_Forming_Coccidian_Flashcards|Tissue Cyst Forming Coccidian Flashcards]]
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{{review}}
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{{OpenPages}}
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[[Category:Liver Protozoa]]
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[[Category:Respiratory Parasitic Infections]]
 
[[Category:Tissue_Cyst_Forming_Coccidia]]
 
[[Category:Tissue_Cyst_Forming_Coccidia]]
 
[[Category:Expert Review]]
 
[[Category:Expert Review]]
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