47. Diseases caused by astroviruses. Flashcards
Astroviruses: Summary of the family
Astroviridae family
- Mamastrovirus genus
- Avastrovirus genus
Ø Envelope; ssRNA
Diseases caused by Astroviruses: Notable diseases
- Avian Nephritis
- Duck Hepatitis
- Astrovirus disease of Turkey
Astrovirus: Mamastrovirus - Summary
- Human; Swine; Cattle; Cat
- Gastroenteritis
Astrovirus: Avastrovirus - Summary
- Chicken astrovirus: Avian nephritis 1
- Duck Astrovirus
- Turkey Astrovirus
Astrovirus: Avian nephritis - Occurance
Japan; USA; Europe; N. Zealand
Astrovirus: Avian nephritis - Transmission
Faeces
Astrovirus: Avian nephritis - Epidemiology
- Only chickens are susceptible
- Infection can occur in all ages
- Mortality: 1-10% in the first week
Astrovirus: Avian nephritis - Pathogenesis
PO infection → Replicate in gut epithelium → Viraemia →
- Kidney: Epithelial cells of proximal tubules
Astrovirus: Avian Nephritis - CSx
Seen in the first 4 weeks of life (more severe in young)
- Acute: Non-specific; General CSx; Diarrhoea; ↓ Weight gain
- Death
Astrovirus: Avian Nephritis - Pathology
- Enteritis
- Nephrosis; Interstitial nephritis
- Chronic: Visceral urate deposition
Astrovirus: Avian Nephritis - Dx
Epidemiology; CSx; Pathology; Histology
- Direct: RT-PCR; IF; IHC; Isolation
- Indirect: ELISA; VN; IF
Astrovirus: Avian Nephritis - DDx
Nephropathogenic strains of infectious bronchitis
Astrovirus: Avian Nephritis - Prevention
- Epidemiological measures
- Ø Vaccine available
Astrovirus: Duck Hepatitis - CSx
Same as DVH caused by Picornavirus
Seen in young duckings
- Peracute: Large-scale death within hours
- Acute: Depression; Lethargy; Ataxia; Spasmodic padding; Death
Astrovirus: Duck Hepatitis - Pathology
Same as DVH caused by Picornavirus
- Liver: Enlarged; Yellow; Dystrophy; Necrosis; Haemorrhage
- Spleen: Enlarged; Mottled
- Kidney: Swollen; Plethoric; Nephrosis
Astrovirus: Duck Hepatitis - Dx
Same as DVH caused by Picornavirus
- Epidemiology; CSx; Pathology; Histopathology
- Direct: PCR; IF; Isolation
- Indirect: VN; ELISA
Astrovirus: Duck Hepatitis - Prevention
Same as DVH caused by Picornavirus
- Epidemiological measures → Isolation at 4 weeks old
- Vaccine:
- Inactivated: Layers → Booster
-
Attenuated:
- Layers & Day-old ducklings
- 7 Weeks old; 2-3 weeks before laying
- Attenuated + Inactivated vaccination
Astrovirus Disease of Turkey: Summary
- CSx
- Prevention
- Two Serotypes; Widespread
- CSx: Diarrhoea in 1-5 week-old animals
- Prevention: Epidemiological measures
Astrovirus Disease of Turkey: Dx
Same as Avian Nephritis
Epidemiology; CSx; Pathology; Histology
- Direct: RT-PCR; IF; IHC; Isolation
- Indirect: ELISA; VN; IF
