62. Diseases of farm animals caused by orthoreoviruses and rotaviruses. Flashcards Preview

Epidemiology final Topic (1-102) > 62. Diseases of farm animals caused by orthoreoviruses and rotaviruses. > Flashcards

Flashcards in 62. Diseases of farm animals caused by orthoreoviruses and rotaviruses. Deck (9)
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1
Q

Causative agents?

A

Rotavirus infections in domestic animals

Causative agents

  • 9 species (A-J)
  • 11 genome segment, frequent reassortments

‣ A: most mammals and birds are susceptible, 90% of human cases

‣ B: human, swine, cattle, sheep, rat

‣ C: swine, rarely human

‣ D: bird

‣ E: swine

‣ F: bird

‣ G: bird

‣ H: swine

‣ I: cats

‣ J: bats

  • Resistant (pH 3), infectivity retained for months in environment
2
Q

History/ Occurrence?

A

History, occurrence:

  • First detection in calves w/enteritis(1969 USA)
  • World-wide distributed, frequent
3
Q

Epizootiology/ Pathogenesis?

A

Epizootiology, pathogenesis

  • Faecal ➝ oral route: faeces, environment
  • Not germinative, but present on the surface of egg
  • Multiplication in enterocytes of few day old animals
  • Mainly in the middle and distal regions of the small intestine ➝ shedding in faeces in high titres
  • Epithelial damage ➝ villus atrophy ➝ osmotic diarrhoea, exsiccosis
  • Simultaneous infections: parvovirus, coronavirus, astroviruses, E. coli, cryptosporidia
4
Q

Clinical signs?

A

Clinical signs

  • Mainly in 1 (2) weeks of age
  • 24-48 hour incubation period
  • Sudden massive diarrhoea
  • Loss of appetite, weakening, retarded body weight gain
  • Low mortality, mainly due to concomitant pathogens
  • Recovery by the end of the second week
  • If signs develop in older age ➝ usually more serious (immunosuppression in background)
5
Q

Pathology, Histopathology?

A

Pathology, histopathology:

  • Undigested, liquid content in the intestines, enlarged intestines
  • Inflammation in the enteric mucosa
  • Villus atrophy & blunting
6
Q

Diagnosis?

A

Diagnosis

  • Age (1st week of age), clinical signs ʹ suspicion
  • Virus detection: RT-PCR, AgELISA, cc immune-electrophoresis, IF, serology, EM, iEM (Mat immunity!)
  • Frequent simultaneous infectious with other pathogens!
7
Q

Treatment, prevention and control?

A

Treatment, prevention, control

  • Supportive/electrolyte therapy (possible parenteral)
  • AB against bacterial co-infections
  • Hygiene (parturition, hatching, litter, individual keeping)
  • Sufficient colostrum uptake
  • Inactivated, usually polyvalent vaccines (+corona, parvo, E. coli K99) - vaccination of pregnant cows
  • twice in the 3rd trimester
8
Q

Seadornavirus-associated diseases ʹ Reoviridae, Sedoreovirinae, Seadornavira genus ?

A

Seadornavirus-associated diseases ʹ Reoviridae, Sedoreovirinae, Seadornavira genus

  • Causative agents
  • S.E Asia dodeca RNA virus (Banna virus, kadipiro virus, Liao Ning virus)
  • 12 genome segment (dodeca)
  • Culicidae vectors
  • Occurrence: China, Java, Indonesia
  • Pathogenesis, symptoms
  • Human pathogen but detected in animals too
  • Influenza-like illness, fever, muscle & joint pains
  • Encephalitis
  • Zoonotic potential is unknown
9
Q

Orthoreovirus infections of domestic animals ʹ Reoviridae, Spinareovirinae?

A

Orthoreovirus infections of domestic animals ʹ Reoviridae, Spinareovirinae

Causative agents:

  • 5 sp. ʹ mammalian (4 serotypes), avian (11 serotypes), (baboon, bat, reptile)
  • 10 genome segment, reassortments
  • Mammalian orthoreovirus infections ʹ cattle & small Ru
  • CATTLE: world-wide occurrence
  • Shed in faeces & nasal discharge
  • PO, air-borne infections Æ viraemia
  • Mainly calves = mild enteritis, respiratory signs (pneumoenteriris)
  • Bacterial co-infections: complications! Chronic bovine resp disease complex
  • (contains reovirus also, Pasteurella multocida, Mannheimia, Histophilus somni)
  • Colostrum Abs can protect the calves until the age of ~5 months
  • Component of combined vaccines against respiratory disease of calves
  • SHEEP: in the background of resp & enteric diseases of lambs
  • HORSE: isolation from resp disease of foals, usually w/ bacterial co-infections ʹ coughing,
  • nasal discharge
  • SWINE: detection from diarrhoea & encephalitis cases ʹ zoonosis?
  • RABBIT: diarrhoea of young animals

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