Difference between revisions of "Asfarviridae"

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(Redirected page to Category:Asfarviridae)
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#REDIRECT[[:Category:Asfarviridae]]
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{{unfinished}}
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{{toplink
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|linkpage =Viruses
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|linktext =VIRUSES
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|pagetype =Bugs
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}}
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<br>
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=Introduction=
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Asfarviridae receives it's name from '''A'''frican '''S'''wine '''F'''ever virus, which is derived from any of this family of viruses.  ASF is a serious exotic virus that should not be confused with [[Classical Swine Fever]].
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=Morphology=
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*Large, enveloped, icosahedral, '''cytoplasmic''' DNA virus
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=Virulence and Pathogenesis=
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*Infects either '''upper respiratory tract''' or '''skin''' via '''ticks'''
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*Enters bloodstream in [[Monocytes - WikiBlood|monocytes]]
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*Reaches viscera and bone marrow within days
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*Induces a '''clotting defect''' and '''hemolysis''' in red blood cells
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*Also affects lymphocytes:
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**Infects Th cells and causes them not to produce B-stimulating cytokines
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**Antigen-stimulated B-cells undergo apoptosis rather than producing antibody
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*General cell signal transduction is blocked, decreasing non-specific immunity
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''Acute Virus (Africa)''
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*Clinical Signs:
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**Nasal discharge, diarrhoea, reddening of the skin
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*Death within 7 days
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*PM: widespread internal hemorrhage
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''Subacute Virus (Europe)''
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*PM: Petechial hemorrhages may be seen under kidney capsule
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*Mortality: 30-70%
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*Survivors may lose body condition, have skin ulcers and joint swelling
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=Epidemiology=
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*Can persist on infected premises for months
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*Subacute recovered pigs become antibody-positive carriers
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*Transfer:
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**Africa: vertical transfer between '''soft ticks'''
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**Europe/Africa: '''direct contact''' with carrier pigs, '''aerosol''', infected swill, etc.
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=Diagnosis=
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*Mortalities with widespread hemorrhage, particularly in lymph nodes
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*Test to distinguish from  [[Classical Swine Fever]] and [[Porcine Circoviruses]]
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*Immunofluorescence
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*PCR
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=Control=
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*No vaccine is available
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Prevention:
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*Boiling swill
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*Isolation of sick pigs, domestic pigs from wild pigs
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*Keep pigs on concrete, not soil (to lessen tick contact)

Revision as of 17:39, 23 February 2010



Infectious agents and parasitesWikiBugs Banner.png
VIRUSES



Introduction

Asfarviridae receives it's name from African Swine Fever virus, which is derived from any of this family of viruses. ASF is a serious exotic virus that should not be confused with Classical Swine Fever.

Morphology

  • Large, enveloped, icosahedral, cytoplasmic DNA virus

Virulence and Pathogenesis

  • Infects either upper respiratory tract or skin via ticks
  • Enters bloodstream in monocytes
  • Reaches viscera and bone marrow within days
  • Induces a clotting defect and hemolysis in red blood cells
  • Also affects lymphocytes:
    • Infects Th cells and causes them not to produce B-stimulating cytokines
    • Antigen-stimulated B-cells undergo apoptosis rather than producing antibody
  • General cell signal transduction is blocked, decreasing non-specific immunity

Acute Virus (Africa)

  • Clinical Signs:
    • Nasal discharge, diarrhoea, reddening of the skin
  • Death within 7 days
  • PM: widespread internal hemorrhage

Subacute Virus (Europe)

  • PM: Petechial hemorrhages may be seen under kidney capsule
  • Mortality: 30-70%
  • Survivors may lose body condition, have skin ulcers and joint swelling

Epidemiology

  • Can persist on infected premises for months
  • Subacute recovered pigs become antibody-positive carriers
  • Transfer:
    • Africa: vertical transfer between soft ticks
    • Europe/Africa: direct contact with carrier pigs, aerosol, infected swill, etc.

Diagnosis

Control

  • No vaccine is available

Prevention:

  • Boiling swill
  • Isolation of sick pigs, domestic pigs from wild pigs
  • Keep pigs on concrete, not soil (to lessen tick contact)