Difference between revisions of "Theileriosis - Cattle"

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Also Known As '''''Bovine Theileriosis''''' '''''[[Theileria]]''''''''''[[East Coast Fever]]—'''''Egyptian fever''''''''''Tropical theileriosis—'''''Mediterranean Coast Fever'''''
+
Also Known As: '''''Bovine Theileriosis — [[Theileria]] — [[East Coast Fever]] — Egyptian Fever — Tropical Theileriosis — Mediterranean Coast Fever'''''
  
Caused By '''''Theileria parva''''' — '''''Theileria annulata'''''
+
Caused By: '''''Theileria parva''''' — '''''Theileria annulata'''''
 +
 
 +
==Introduction==
 
[[File:T_parva.gif|thumb|200px|right|Theileria sp inside erythrocytes of host]]
 
[[File:T_parva.gif|thumb|200px|right|Theileria sp inside erythrocytes of host]]
==Introduction==
+
Theileriosis is a disease of mammals and birds caused by a [[protozoa | '''protozoal''']] pathogen which resides within the [[Lymphocytes - Introduction |lymphocytes]] and [[Macrophages|macrophages]].
 
 
Theileriosis is a disease of mammals and birds caused by a [[protozoa | '''protozoal''']] pathogen which resides within the [[Lymphocytes - Introduction | lymphocytes]] and [[Macrophages | macrophages]]
 
  
''T. parva'' and ''T. annulata'' in cattle and ''T. Lestoguardi'' in sheep are the most economically important in domestic ruminants.
+
[[Theileria|''T. parva'' and ''T. annulata'']] in cattle and ''T. lestoguardi'' in sheep are the most economically important in domestic ruminants.
  
[[Theileria]] species are closely related to [[Babesia]] parasites.
+
''[[Theileria]]'' species are closely related to ''[[Babesia]]'' parasites.
  
 
==Signalment==
 
==Signalment==
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'''Native animals''' also appear to have a higher degree of '''innate tolerance''' in endemic areas than those that are imported, even if of the same breed.
 
'''Native animals''' also appear to have a higher degree of '''innate tolerance''' in endemic areas than those that are imported, even if of the same breed.
  
'''Friesians''' appear particularly susceptible to infection with [[Theileria]] species.
+
'''Friesians''' appear particularly susceptible to infection with ''[[Theileria]]'' species.
  
[[Parturition Endocrine Control - Anatomy & Physiology | Parturition]], [[Lactation - Anatomy & Physiology | lactation]] and stress can make an animal vulnerable to theileriosis, as they can any disease.
+
[[Parturition Endocrine Control - Anatomy & Physiology |Parturition]], [[Lactation - Anatomy & Physiology |lactation]] and stress can make an animal vulnerable to theileriosis, as they can to any disease.
  
 
Age linked tolerance may make younger calves more tolerant of disease than adults in some areas.
 
Age linked tolerance may make younger calves more tolerant of disease than adults in some areas.
  
 
==Distribution==
 
==Distribution==
Distribution of disease depends on the presence of [[Ticks | tick]] vectors and thus is primarily in '''tropical regions'''. Various species of [[Ticks | tick]] are implicated.
+
Distribution of disease depends on the presence of [[Ticks|tick]] vectors and thus is primarily in '''tropical regions'''. Various species of tick are implicated.
  
The distribution of anaplasmosis is increasing all the time.
+
<font color ="red">The distribution of anaplasmosis is increasing all the time.</font color>
  
 
==Transmission==
 
==Transmission==
 
[[File:Theileria_lifecycle.gif|thumb|200px|right|Theileria Lifecycle]]
 
[[File:Theileria_lifecycle.gif|thumb|200px|right|Theileria Lifecycle]]
 +
''[[Theileria]]'' species first invade the local '''[[Lymph Nodes - Anatomy & Physiology|lymph nodes]]''' of the hosts before forming schizonts and disseminating through the '''lymphoid tissues'''.
  
[[Theileria]] species first invade the local '''[[Lymph Nodes - Anatomy & Physiology|lymph nodes]]''' of the hosts before forming schizonts and disseminating through the '''lymphoid tissues'''.
+
'''Asexual''' reproduction in the '''host''' is followed by '''sexual reproduction''' within the '''tick''' vector. The parasite is then transmitted through the '''salivary glands''' of the tick into the mammalian host during bloodfeeding.
  
'''Asexual''' reproduction in the '''host''' is followed by '''sexual reproduction''' within the '''[[Ticks | tick]]''' vector.
+
For more information on ticks as vectors, see ''[[Theileria]]'' and [[Tick Disease Transmission]].
The parasite is then transmitted through the '''salivary glands''' of the tick into the mammalian host during bloodfeeding.
 
 
 
For more information on ticks as vectors, see [[Theileria]] and [[Tick Disease Transmission]]
 
  
 
In endemic areas, '''endemic stability''' is often reached, in which most or all cattle may be infected and be carriers and most ticks are also infected, but young calves gain solid immunity from their immune dams and therefore rarely show clinical disease. This state however takes time to stabilise and will cause significant economic losses in the process.
 
In endemic areas, '''endemic stability''' is often reached, in which most or all cattle may be infected and be carriers and most ticks are also infected, but young calves gain solid immunity from their immune dams and therefore rarely show clinical disease. This state however takes time to stabilise and will cause significant economic losses in the process.
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==Clinical Signs==
 
==Clinical Signs==
 
[[File:Theileriosis_diarrhoea.jpg|thumb|200px|right|Bloody diarrhoea often seen in Theileriosis cases]]
 
[[File:Theileriosis_diarrhoea.jpg|thumb|200px|right|Bloody diarrhoea often seen in Theileriosis cases]]
'''Marked pyrexia''', '''[[Lymph Nodes - Anatomy & Physiology | Lymph node enlargement]]''', '''dyspnoea''','''epistaxis''','''emaciation''', [[Diarrhoea | '''diarrhoea''']] and other GI signs.  
+
'''Marked pyrexia''', '''[[Lymph Nodes - Anatomy & Physiology |lymph node enlargement]]''', '''dyspnoea''', '''epistaxis''', '''emaciation''', [[Diarrhoea |'''diarrhoea''']] and other GI signs.  
  
 
'''Ocular signs''' and masses may develop.
 
'''Ocular signs''' and masses may develop.
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Pruritus and '''skin lesions/plaques''' are also seen.
 
Pruritus and '''skin lesions/plaques''' are also seen.
  
Neurological and Reproductive signs may develop in chronic or endemic disease.
+
Neurological and reproductive signs may develop in chronic or endemic disease.
  
 
The degree of pyrexia, pathogen load and host susceptibility will determine the severity of clinical signs at presentation.
 
The degree of pyrexia, pathogen load and host susceptibility will determine the severity of clinical signs at presentation.
  
 
==Diagnosis==
 
==Diagnosis==
Detection of parasite stages in thin '''blood smears''' with Giemsa staining.
+
Detection of parasite stages in thin '''blood smears''' with Giemsa staining. '''Schizonts''' should be looked for in thin smears from '''lymph node''' or '''liver''' biopsies.
 
 
'''Schizonts''' should be looked for in thin smears from '''lymph node''' or '''liver''' biopsies.
 
  
On '''post-mortem examination''', blood is watery and carcasses are [[Icterus| icteric]] and gelatinised. Numerous petechiae may be present within the mucous membranes, gut mucosae and heart. The [[Liver - Anatomy & Physiology | liver]] is often pale and friable and the [[Gall Bladder - Anatomy & Physiology | gall bladder]] distended with dark green bile. Ulcers are often evident in the [[Abomasum - Anatomy & Physiology | abomasum]] of ruminants and are surrounded by haemorrhagic zones. Urine is dark brown due to the presence of [[Bilirubin | bilirubin]] Pulmonary oedema may be present.
+
On '''post-mortem examination''', blood is watery and carcasses are [[Icterus|icteric]] and gelatinised. Numerous petechiae may be present within the mucous membranes, gut mucosae and heart. The [[Liver - Anatomy & Physiology |liver]] is often pale and friable and the [[Gall Bladder - Anatomy & Physiology |gall bladder]] distended with dark green bile. Ulcers are often evident in the [[Abomasum - Anatomy & Physiology |abomasum]] of ruminants and are surrounded by haemorrhagic zones. Urine is dark brown due to the presence of [[Bilirubin |bilirubin]]. [[Pulmonary Oedema|Pulmonary oedema]] may be present.
  
Indirect Fluorescent Antibody Tests (IFAT) and [[ELISA testing | ELISAs]] are also available and are useful for identifying carrier animals.
+
Indirect Fluorescent Antibody Tests (IFAT) and [[ELISA testing |ELISAs]] are also available and are useful for identifying carrier animals.
  
 
Sporozoites can also be detected within the '''salivary glands''' of ticks by staining with methyl-green pyronin and more recently with '''PCR'''.
 
Sporozoites can also be detected within the '''salivary glands''' of ticks by staining with methyl-green pyronin and more recently with '''PCR'''.
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Control of '''tick vectors''' and use of '''tick resistant''' host species such as zebu cattle in endemic areas is effective but expensive.
 
Control of '''tick vectors''' and use of '''tick resistant''' host species such as zebu cattle in endemic areas is effective but expensive.
  
Care should be taken when intensively dipping with [[Ectoparasiticides | ectoparasiticides]] to control ticks as upsurges in other tick borne diseases are not uncommon when programmes are interrupted.
+
Care should be taken when intensively dipping with [[Ectoparasiticides |ectoparasiticides]] to control ticks as upsurges in other tick borne diseases are not uncommon when programmes are interrupted.
  
 
'''Endemic stability''' can be encouraged by breeding indigenous or known carrier animals, although these are often still infective for ticks so '''separation''' from adult susceptible animals is essential to prevent further spread of disease.
 
'''Endemic stability''' can be encouraged by breeding indigenous or known carrier animals, although these are often still infective for ticks so '''separation''' from adult susceptible animals is essential to prevent further spread of disease.
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{{review}}
 +
[[Category:Alimentary Diseases - Cattle]][[Category:Reproductive Diseases - Cattle]][[Category:Neurological Diseases - Cattle]][[Category:Respiratory Diseases - Cattle]]
 +
[[Category:Dermatological Diseases - Cattle]]
 
[[Category:To Do - CABI review]]
 
[[Category:To Do - CABI review]]

Revision as of 13:04, 6 June 2011

Also Known As: Bovine Theileriosis — TheileriaEast Coast Fever — Egyptian Fever — Tropical Theileriosis — Mediterranean Coast Fever

Caused By: Theileria parvaTheileria annulata

Introduction

Theileria sp inside erythrocytes of host

Theileriosis is a disease of mammals and birds caused by a protozoal pathogen which resides within the lymphocytes and macrophages.

T. parva and T. annulata in cattle and T. lestoguardi in sheep are the most economically important in domestic ruminants.

Theileria species are closely related to Babesia parasites.

Signalment

Buffalo, both domestic and wild, appear less susceptible to theileriosis.

Native animals also appear to have a higher degree of innate tolerance in endemic areas than those that are imported, even if of the same breed.

Friesians appear particularly susceptible to infection with Theileria species.

Parturition, lactation and stress can make an animal vulnerable to theileriosis, as they can to any disease.

Age linked tolerance may make younger calves more tolerant of disease than adults in some areas.

Distribution

Distribution of disease depends on the presence of tick vectors and thus is primarily in tropical regions. Various species of tick are implicated.

The distribution of anaplasmosis is increasing all the time.

Transmission

Theileria Lifecycle

Theileria species first invade the local lymph nodes of the hosts before forming schizonts and disseminating through the lymphoid tissues.

Asexual reproduction in the host is followed by sexual reproduction within the tick vector. The parasite is then transmitted through the salivary glands of the tick into the mammalian host during bloodfeeding.

For more information on ticks as vectors, see Theileria and Tick Disease Transmission.

In endemic areas, endemic stability is often reached, in which most or all cattle may be infected and be carriers and most ticks are also infected, but young calves gain solid immunity from their immune dams and therefore rarely show clinical disease. This state however takes time to stabilise and will cause significant economic losses in the process.

Clinical Signs

Bloody diarrhoea often seen in Theileriosis cases

Marked pyrexia, lymph node enlargement, dyspnoea, epistaxis, emaciation, diarrhoea and other GI signs.

Ocular signs and masses may develop.

Pruritus and skin lesions/plaques are also seen.

Neurological and reproductive signs may develop in chronic or endemic disease.

The degree of pyrexia, pathogen load and host susceptibility will determine the severity of clinical signs at presentation.

Diagnosis

Detection of parasite stages in thin blood smears with Giemsa staining. Schizonts should be looked for in thin smears from lymph node or liver biopsies.

On post-mortem examination, blood is watery and carcasses are icteric and gelatinised. Numerous petechiae may be present within the mucous membranes, gut mucosae and heart. The liver is often pale and friable and the gall bladder distended with dark green bile. Ulcers are often evident in the abomasum of ruminants and are surrounded by haemorrhagic zones. Urine is dark brown due to the presence of bilirubin. Pulmonary oedema may be present.

Indirect Fluorescent Antibody Tests (IFAT) and ELISAs are also available and are useful for identifying carrier animals.

Sporozoites can also be detected within the salivary glands of ticks by staining with methyl-green pyronin and more recently with PCR.

Treatment

Buparvaquone and Halofuginone chemotherapeutics and/or Tetracyclines are the treatments of choice.

Control

Control of tick vectors and use of tick resistant host species such as zebu cattle in endemic areas is effective but expensive.

Care should be taken when intensively dipping with ectoparasiticides to control ticks as upsurges in other tick borne diseases are not uncommon when programmes are interrupted.

Endemic stability can be encouraged by breeding indigenous or known carrier animals, although these are often still infective for ticks so separation from adult susceptible animals is essential to prevent further spread of disease.

Vaccines are available involving attenuated schizont-infected cells and are the mainstay of tropical theleriosis in endemic countries with highly susceptible cattle breeds.

References

Animal Health & Production Compendium, Theileriosis datasheet, accessed 03/06/2011 @ http://www.cabi.org/ahpc/