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New page: {{unfinished}} {{toplink |linkpage =Viruses |linktext =VIRUSES |sublink1=Reoviridae |subtext1=REOVIRIDAE |pagetype =Bugs }} <br> ====Antigenicity==== *24 serotypes of BTV have been descr...
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|linkpage =Viruses
|linktext =VIRUSES
|sublink1=Reoviridae
|subtext1=REOVIRIDAE
|pagetype =Bugs
}}
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====Antigenicity====
*24 serotypes of BTV have been described

====Hosts====
*Ruminants, including sheep, cattle, deer, goats, and camelids

====Pathogenesis====
*Transfer occurs through blood from viremic animals via biting midges ('''Culicodes spp.''')
*Replication in haematopoietic and endothelial cells of blood vessels
*Clinical signs vary between species, with sheep most severely affected
**Pyrexia
**Ocular and nasal discharge
**Drooling from mouth uclers
**Swelling of the mouth, head and neck
**Lameness
**Subdural hemorrhages
**Inflammation of the coronary band
*Cattle as the main reservoir
*A blue tongue is rarely seend as as a clinical sign of infection
*Resulting loss of condition, reduction in wool an meat production, which can be followed by death

====Diagnosis====
*Clinical signs can be confirmed through the lab:
**RT-PCR to detect viral RNA
**ELISA serology for Ab and rising Ab titres

====Current Relevance====
*August 2006: suspicious Dutch sheep confirmed as serotype 8
**Serotype 8 found in Belgium, Luxembourg, Germany, and north-eastern France
**Previously BTV-8 only seen in sub-Saharan Africa
*August 2007: increased outbreaks in same regions
*September 2007: first UK outbreak in Suffolk
*2008: Virus declared endemic and BTV-8 vaccine produced, voluntary vaccination strongly encouraged

====Control====
*BTV is '''NOTIFIABLE'''
*Vigilance in recognizing clinical signs
*Restriction of movement:
**Protection Zone: 100km radius around infected premises, movement within zone allowed but not in or out
***Vaccination within PZ using appropriate serotype is encouraged but still voluntary
**Surveillance Zone: 50km radius beyond PZ
*Vector control: ectoparasiticides, etc.
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