Rotaviruses
 |
This article is still under construction. |
|
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