REOVIRIDAE

Question 1

Give the virion properties of Reoviridae.

Answer 1

• Nonenveloped ds RNA
• Cytoplasmic replication
• “Reo” - respiratory enteric orphan
• 10-12 segments genome

Question 2

Genus orbivirus is transmitted primarily by arthropod vectors such as ?

Answer 2

Species of Culicoides
midges, mosquitoes, black flies, sandflies, ticks

Question 3

What are the clinical signs of Blue tongue?

Answer 3

fever, salivation, frothing, nasal discharge, “blue tongue” (cyanotic through vascular compromise) weight loss, respiratory distress, edema, ulceration, reluctance to eat/drink, and muscle degeneration

Question 4

What is the transmission mode of Blue tongue virus?

Answer 4

1. Biting insects (Culicoides midges); biological vectors
2. Potential horizontal transmission
3. Wind-borne dispersal

Question 5

Describe the pulmonary form (Dunkop) of African horse sickness.

Answer 5

• Increased respiratory rate
• Affected animals may stand with their forelegs apart, head extended, nostrils dilated
• Spasmodic coughing accompanied by profuse sweating and a discharge of frothy fluid from the nostrils
• Most common in completely susceptible horses infected with a highly virulent virus

Question 6

Describe the cardiac form (Dikkop) of African horse sickness.

Answer 6

• Fever lasting for 3-6 days followed by edema involving the supraorbital fossae and eyelids, sometimes with accompanying congestion and hemorrhage in the conjunctiva
• Edema on lips, tongue, intermandibular space, laryngeal region
• 50% mortality rate
• Death occurs within 4-8 hours

Question 7

Describe the mixed form of African horse sickness.

Answer 7

• Intermediate severity
• 70% mortality rate

Question 8

Rotaviruses induces what disease?

Answer 8

• Causes gastroenteritis: responsible for causing diarrhea (scours) in newborn animals of all species

Question 9

Give the clinical signs of Orthoreoviruses in birds.

Answer 9

o Most frequent associated dss. syndrome: TENOSYNOVITIS and ARTHRITIS IN CHICKENS
o There’s inflammation within tendons and tendon sheath and around joints with possible necrosis and hemorrhage