Author, Donkey, Bureaucrats, Administrators
53,803
edits
Changes
Created page with 'thumb|right|150px|''Sarcocytis'' Life Cycle Diagram - Dennis Jacobs & Mark Fox RVC [[Image:Sarcocystic.jpg|thumb|right|150px|''Sarcocytis'' -…'
[[Image:Sarcocystis Life Cycle.jpg|thumb|right|150px|''Sarcocytis'' Life Cycle Diagram - Dennis Jacobs & Mark Fox RVC]]
[[Image:Sarcocystic.jpg|thumb|right|150px|''Sarcocytis'' - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]]
[[Image:Sarcocystis in sheep oesophagus.jpg|thumb|right|150px|''Sarcocystis'' in sheep oesophagus - Adam Cuerden]]
[[Image:Equine protozoal myeloencephalitis.jpg|thumb|right|150px|Equine protozoal myeloencephalitis - Wikimedia Commons]]
[[Image:Sarcocystis cruzi.jpg|thumb|right|150px|''Sarcocystis cruzi'' - Courtesy of the Laboratory of Parasitology, University of Pennsylvania School of Veterinary Medicine]]
*Most infections are asymptomatic
*Heavy infections are causes of chronic wasting in large animals, hide condemnation and downgrading of carcasses
*''Sarcocystis'' should be differentiated from other tissue-cyst forming coccidia
*There are many species of ''Sarcocystis'' which differ in size from microscopic to several centimetres in length
**''S.neurona'' is an important equine pathogen in the USA
*Infective cyst in the intermediate host is called a '''sarcocyst'''
'''Life Cycle'''
*The individual life cycle of some species is incompletely understood
*Indirect life cycle
*Life cycle alternates between the final and the obligatory intermediate host
*Only '''one''' final and '''one''' intermediate host
*Sporulated oocyst has 2 sporocysts containing 4 sporozoites
**Naked sporocyst usually seen in faeces as the oocyst wall is very delicate
**Oocyst measures 15μm in length
*No schizogony in final host
*Gametogeny occurs deep in subepithelial tissue
*Faecal oocyst count is low
*Oocysts are sporulated when passed
**Difficult to find on faecal examination as the sporocysts are few in number and small
*Ingestion of sporocyst by intermediate host
**2 phases of rapid asexual reproduction in vascular endothelial cells
**Slow multiplication of bradyzoites in muscle tissue
**Sarcocyst forms with bradyzoites inside, surrounded by a cyst wall and divided into compartments
'''Epidemiology'''
*Final hosts are carnivores and omnivores
*Intermediate hosts are herbivores and omnivores
*Humans are the final host for some species and the intermediate hosts for others
**Final host for species infecting cattle and pigs
*Dogs are final hosts for species infecting cattle, sheep, goats, pigs and horses
*Cats are final hosts for species infecting cattle, sheep and pigs
'''Pathogenesis'''
*Widespread infection but mostly asymptomatic
*Cause meat inspection losses
*''Sarcocystis'' in [[Muscles Inflammatory - Pathology#Protozoa|myositis]]
*Experimental infections cause severe, acute pyrexic disease when the organism multiplies in the vascular endothelium
*Can cause chronic wasting disease in cattle and horses
**Causes abortion and post-natal disease in sheep
*Equine protozoal myeloencephalitis
**Necrotising encephalomyelitis affecting the grey and white matter of the CNS
**Caused by ''S.neurona''
**Opossum thought to be the definitive host
**Horses thought to be accidental hosts
**Natural intermediate hosts currently unknown
**Western Blotting shows 50% of horses in the USA are seropositive
**Risk factors poorly understood
**Causes spinal cord dysfunction
***Ataxia and paralysis[[Category:Tissue_Cyst_Forming_Coccidia]]
[[Image:Sarcocystic.jpg|thumb|right|150px|''Sarcocytis'' - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]]
[[Image:Sarcocystis in sheep oesophagus.jpg|thumb|right|150px|''Sarcocystis'' in sheep oesophagus - Adam Cuerden]]
[[Image:Equine protozoal myeloencephalitis.jpg|thumb|right|150px|Equine protozoal myeloencephalitis - Wikimedia Commons]]
[[Image:Sarcocystis cruzi.jpg|thumb|right|150px|''Sarcocystis cruzi'' - Courtesy of the Laboratory of Parasitology, University of Pennsylvania School of Veterinary Medicine]]
*Most infections are asymptomatic
*Heavy infections are causes of chronic wasting in large animals, hide condemnation and downgrading of carcasses
*''Sarcocystis'' should be differentiated from other tissue-cyst forming coccidia
*There are many species of ''Sarcocystis'' which differ in size from microscopic to several centimetres in length
**''S.neurona'' is an important equine pathogen in the USA
*Infective cyst in the intermediate host is called a '''sarcocyst'''
'''Life Cycle'''
*The individual life cycle of some species is incompletely understood
*Indirect life cycle
*Life cycle alternates between the final and the obligatory intermediate host
*Only '''one''' final and '''one''' intermediate host
*Sporulated oocyst has 2 sporocysts containing 4 sporozoites
**Naked sporocyst usually seen in faeces as the oocyst wall is very delicate
**Oocyst measures 15μm in length
*No schizogony in final host
*Gametogeny occurs deep in subepithelial tissue
*Faecal oocyst count is low
*Oocysts are sporulated when passed
**Difficult to find on faecal examination as the sporocysts are few in number and small
*Ingestion of sporocyst by intermediate host
**2 phases of rapid asexual reproduction in vascular endothelial cells
**Slow multiplication of bradyzoites in muscle tissue
**Sarcocyst forms with bradyzoites inside, surrounded by a cyst wall and divided into compartments
'''Epidemiology'''
*Final hosts are carnivores and omnivores
*Intermediate hosts are herbivores and omnivores
*Humans are the final host for some species and the intermediate hosts for others
**Final host for species infecting cattle and pigs
*Dogs are final hosts for species infecting cattle, sheep, goats, pigs and horses
*Cats are final hosts for species infecting cattle, sheep and pigs
'''Pathogenesis'''
*Widespread infection but mostly asymptomatic
*Cause meat inspection losses
*''Sarcocystis'' in [[Muscles Inflammatory - Pathology#Protozoa|myositis]]
*Experimental infections cause severe, acute pyrexic disease when the organism multiplies in the vascular endothelium
*Can cause chronic wasting disease in cattle and horses
**Causes abortion and post-natal disease in sheep
*Equine protozoal myeloencephalitis
**Necrotising encephalomyelitis affecting the grey and white matter of the CNS
**Caused by ''S.neurona''
**Opossum thought to be the definitive host
**Horses thought to be accidental hosts
**Natural intermediate hosts currently unknown
**Western Blotting shows 50% of horses in the USA are seropositive
**Risk factors poorly understood
**Causes spinal cord dysfunction
***Ataxia and paralysis[[Category:Tissue_Cyst_Forming_Coccidia]]