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, 20:26, 14 October 2008
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{{toplink
|linkpage =Viruses
|linktext =VIRUSES
|sublink1=Reoviridae
|subtext1=REOVIRIDAE
|pagetype =Bugs
}}
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====Antigenicity====
*5 distinct antigenic groups: A to E
*A is the most commonly seen and studied
*A is further subdivided to G and P types
====Hosts====
*RVs are thought to be mostly species specific, but some transmission between species occurs
*Group A is present in all mammals
*Groups B and C are common in pigs but not fully understood
====Pathogenesis====
*Strains vary in virulence but are always confined to the gut
*Incubation: 1-4 days
*Target tissue: '''small intestine enteroycte'''
**Infected enterocytes are shed, villi shorten, and become covered with immature cuboidal epithelium
**As such, absorption is compromised
*Results in '''white scour'''
*NO viremia: confined to GIT
*Associated symptoms:
**Weight loss
**Depression
**Dehydration
*Can be fatal if unchecked
====Epidemiology====
*Occurs in neonates of most species, although the role of RVs in lamb and foal diarrhoea is less certain
*NOT associated with diarrhoea in dogs and cats
*Group A RVs are endemic in domestic animals worldwide
*Orofecal transmission, highly infectious
*Excreted in feces as maternal antibody wanes (calves: 2 weeks, piglets: post-weaning)
====Diagnosis====
*On feces:
**ELISA and Latex agglutination
*On sera:
**Rising antibody titres are not particularly helpful as most animals show high Ab levels from passive immunity
====Control====
*Ensure maternal antibody transfer through the reception of colostrum
*Hygiene and management strategies: all-in/all-out, isolation of sick animals, etc.
*Fluid therapy where necessary
*Dam vaccine:
**Boost and prolong Ab secretion during suckling
**Primarily for beef suckler herds as dairy calves receive batch milk after 24 hours