1,593 bytes added
, 20:21, 21 October 2008
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{{toplink
|linkpage =Viruses
|linktext =VIRUSES
|sublink1=Flaviviridae
|subtext1=FLAVIVIRIDAE
|pagetype =Bugs
}}
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====Antigenicity====
*Isolates vary in virulence
*Some antigenic variation
*Best defined by monoclonal antibodies, but no serotypes
====Hosts====
*Pigs
*Wild boar
====Pathogenesis====
*Virus enters oropharynx and replicates in palatine tonsil
*Viremia 2-6 days post-infection
Two types of strain:
#Low Virulence:
#*Transplacental transmission causes abortion, cerebellar hypoplasia, or growth retardation
#*If piglets are born, they are carriers
#High Virulence:
#*Leukopenia
#*Thrombocytopenia
#*Generalized '''vasculitis'''
#*'''Hemorrhage''' of lymph nodes, spleen, bladder, larynx, and skin
#*Vasculitis in CNS causes tremors, incoordination and convulsions
Chronic disease:
*Infarction causes '''button ulcers''' over Peyer's Patches
====Epidemiology====
*Recovered animals are immune
*'''Highly contagious'''
*Transfer via '''contact''', '''aerosol''', or '''fomites'''
*Swine fever was once endemic worldwide but has now been '''eradicated''' from UK, Australia, NZ, USA, and Denmark following vaccination schemes
====Diagnosis====
*'''Immunofluorescence''' of tissues for virus isolation
*DD: Porcine circovirus 2, African swine fever, or bacterial septicemia
====Control====
*'''NOTIFIABLE''' disease
*'''Vaccination''' in endemic countries:
**Parts of EU are using vaccinated bait to control spread in wild boar population
**Vaccination does not curtail spread: marker vaccine needed to distinguish virus exposure from vaccine-induced antibody