79. Diseases caused by Orthobunyaviruses (Zoon.).

Question 1

Orthobunyavirus: Summary

Answer 1

ZOONOTIC DISEASE

• Bunyaviridae family
• Segmented (into 3); Helical capsid; Enveloped
• Resistance: Not good; Sensitive to temp. & disinfectants
• Mosquito & tick vectors

Question 2

Orthobunyavirus: Antigenicity

Answer 2

• Enveloped glycoproteins - Good antigens
• Cross-reactions within genera - Serogroups

Question 3

Orthobunyavirus: Dx

Answer 3

• Direct: Virus isolation, IF, HA & PCR
• Indirect: VN, ELISA, HAI

Question 4

Orthobunyavirus: Serogroups

Answer 4

• Classification based on: VN & HI
• 18 serogroups

Question 5

Orthobunyavirus: Reservoir hosts

Answer 5

• Small rodents
• Birds
• Domesticated animals

Question 6

Orthobunyavirus: Epidemiology

Answer 6

ZOONOTIC DISEASE

• Simbu Serogroup: Worldwide
• Aino virus: Japan & Australia
• Schmallenburg: Europe

Question 7

List the notable Orthobunyaviruses

Answer 7

• Akabane virus
• Aino virus
• Schmallenberg virus

Question 8

Orthobunyavirus: Akabane virus: Summary

Answer 8

Causes Akabane Disease

• Vector: Mosquito; Affecting: Ru.
• Seen in Japan; Asia; Africa; Australia, Israel & Turkey

Question 9

Orthobunyavirus: Akabane virus: Pathogenesis

Answer 9

Bite → Incubation → Viraemia

Question 10

Orthobunyavirus: Akabane virus: CSx (adults)

Answer 10

• (May be subclinical)
• Fever
• CNS
• Death

Question 11

Orthobunyavirus: Akabane virus: CSx (during pregnancy)

Answer 11

• Abortion & miscarriage
• Premature birth
• Hydrocephaly
• Muscle dystrophy
• Foetal arthrogryposis

Question 12

Orthobunyavirus: Akabane virus: Dx

Answer 12

• Virus isolation (sickling mice)
• Serology: VN, IF & ELISA

Question 13

Orthobunyavirus: Akabane virus: DDx

Answer 13

• Aino virus
• Ephemeral fever
• Iberaki
• Blue tongue
• Japanese encephalitis
• BVD

Question 14

Orthobunyavirus: Akabane virus: Prevention

Answer 14

• Attenuated & inactivated vaccines
• Mosquito control

Question 15

Orthobunyavirus: Aino virus: Summary

Answer 15

• Foetal deformities in Bo. & Ov.
• Asia & Australia
• Mosquito & gnat vectors

Question 16

Orthobunyavirus: Aino virus: CSx

Answer 16

• Calves: Malformation (infection btw. day 120↔180 of gest.)
• Stillbirth; premature birth; birth defects
• Weakness; blindness; poor eyesight; CNS signs

Adults: Ø; ataxia & leukopenia in dairy cow

Question 17

Orthobunyavirus: Aino virus: Control

Answer 17

Inactivated, combined vaccine

Question 18

Orthobunyavirus: Schmallenberg virus: Notable serogroups

Answer 18

• Tete
• Turlock

Question 19

Orthobunyavirus: Schmallenberg virus: Tete serogroup

Answer 19

• Location: Europe; Asia; Africa
• Transmission: Ticks & mosquitos

Question 20

Orthobunyavirus: Schmallenberg virus: Turlock serogroup

Answer 20

• Location: Europe; Asia; Africa; America
• Transmission: Mosquito & birds

Question 21

Orthobunyavirus: Schmallenberg virus: Affected species

Answer 21

Bo.; Ov.; Cap.

Question 22

Orthobunyavirus: Schmallenberg virus: CSx (Bo.)

Answer 22

• Fever
• Anorexia
• Diarrhoea
• Poor condition
• ↓ Milk yield

Question 23

Orthobunyavirus: Schmallenberg virus: CSx (Ov.)

Answer 23

• Fever
• Congenital disorders:
  
  • Lambs are born alive, but non-viable
  • Arthrogryposis
  • Hydrocephaly
  • Ankylosis
  • Torticollis
  • Scoliosis
  • Brachygnathia

Question 24

Orthobunyavirus: Schmallenberg virus: Dx

Answer 24

RT-PCR

• Isolation on KC & BHK-21 cells
• VN & direct IF

Question 25

Orthobunyavirus: Schmallenberg virus: Epidemiology

Answer 25

POTENTIALLY ZOONOTIC DISEASE

• Import restrictions into certain countries