Difference between revisions of "Theileria"

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[[Image:Theileria parva life cycle.jpg|thumb|right|150px|''Theileria parva'' Life Cycle Diagram - Dennis Jacobs & Mark Fox RVC]]
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[[Image:Lymph node smear East Coast Fever.jpg|thumb|right|150px|Lymph node smear of a cow with East Coast Fever - Drs. Elizabeth Howerth and Bruce LeRoy, Department of Pathology, UGA College of Veterinary Medicine]]
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[[Image:H and E stain brain East Coast Fever.jpg|thumb|right|150px|H and E stain of brain and meningal vessels of a cow with East Coast Fever - Drs. Elizabeth Howerth and Bruce LeRoy, Department of Pathology, UGA College of Veterinary Medicine]]
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[[Image:Theileria cervi.jpg|thumb|right|150px|''Theileria cervi'' (deer) - Drs. Elizabeth Howerth and Bruce LeRoy, Department of Pathology, UGA College of Veterinary Medicine]]
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*Main species of veterinary importance is ''Theileria parva''
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**Causes '''East Coast Fever'''
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***Severe, proliferative lymphatic disease of cattle
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***Central and Eastern Africa
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***Transmitted by [[Hard Ticks - Overseas|''Rhipicephalus appendiculatus'']]
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***[[Ticks#Disease Transmission|Trans-stadial]] transmission
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*Other ''Theileria'' species cause production losses in cattle and sheep in the Middle East, Mediterranean and in Northern Africa
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'''Life Cycle'''
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*Incubation phase lasts 1 week
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*Lymphoblast proliferation
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**Local [[Lymph Nodes - Anatomy & Physiology|lymph node]] first infected then spreads through body
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**Occurs in week two
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*Lymphoid depletion
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**[[Lymphocytes - WikiBlood|Lymphocytes]] killed
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**Decreases lymphopoiesis
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**Occurs in week 3
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*Total incubation period takes about 18 days
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'''Diagnosis'''
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*Clinical signs
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**Pyrexia
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**Enlarged local [[Lymph Nodes - Anatomy & Physiology|lymph node]]
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***Usually parotid [[Lymph Nodes - Anatomy & Physiology|lymph node]] as [[Hard Ticks - Overseas|''Rhipicephalus appendiculatus'']] feeds in the ear
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**Loss of condition
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*Examine Giemsa stained smears of:
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**Local [[Lymph Nodes - Anatomy & Physiology|lymph node]] aspirated for schizonts
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**Blood smears for piroplasms in red blood cells
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*Post-mortem
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**Pulmonary oedema
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**Gut mucosal haemorrhages
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**[[Lymph Nodes - Anatomy & Physiology|Lymph node]] and [[Spleen - Anatomy & Physiology|splenic]] cellular atrophy
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'''Control'''
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*Integrated control of both the [[Tick Control|tick vector]] and disease
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**[[Vaccines - WikiBlood|Vaccination]] and [[Ectoparasiticides]]
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*Current [[Vaccines - WikiBlood|vaccination]] is live unattentuated
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**Contains frozen stabilate of ground up tick gut containing infective sporozoites
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**Long lasting oxytetracycline administered at the same time to slow down schizogony giving the immune response time to develop[[Category:Piroplasmida]]

Revision as of 22:31, 9 April 2010

Theileria parva Life Cycle Diagram - Dennis Jacobs & Mark Fox RVC
File:Lymph node smear East Coast Fever.jpg
Lymph node smear of a cow with East Coast Fever - Drs. Elizabeth Howerth and Bruce LeRoy, Department of Pathology, UGA College of Veterinary Medicine
File:H and E stain brain East Coast Fever.jpg
H and E stain of brain and meningal vessels of a cow with East Coast Fever - Drs. Elizabeth Howerth and Bruce LeRoy, Department of Pathology, UGA College of Veterinary Medicine
Theileria cervi (deer) - Drs. Elizabeth Howerth and Bruce LeRoy, Department of Pathology, UGA College of Veterinary Medicine
  • Main species of veterinary importance is Theileria parva
  • Other Theileria species cause production losses in cattle and sheep in the Middle East, Mediterranean and in Northern Africa

Life Cycle

  • Incubation phase lasts 1 week
  • Lymphoblast proliferation
    • Local lymph node first infected then spreads through body
    • Occurs in week two
  • Lymphoid depletion
    • Lymphocytes killed
    • Decreases lymphopoiesis
    • Occurs in week 3
  • Total incubation period takes about 18 days

Diagnosis

  • Examine Giemsa stained smears of:
    • Local lymph node aspirated for schizonts
    • Blood smears for piroplasms in red blood cells
  • Post-mortem

Control

  • Current vaccination is live unattentuated
    • Contains frozen stabilate of ground up tick gut containing infective sporozoites
    • Long lasting oxytetracycline administered at the same time to slow down schizogony giving the immune response time to develop