37. Teschovirus encephalomyelitis.

Question 1

Teschovirus Encephalomyelitis:

1. Order
2. Family

Answer 1

1. Order: Picornavirales
2. Family: Picornaviridae

“RNA” because of its ssRNA genome

Question 2

Virus names within the family of Picornaviridae

Answer 2

1. Enterovirus
2. Hepatovirus
3. Avihepatovirus
4. Teschovirus
5. Tremovirus

Question 3

Picornaviridae family: General pathogenesis

Answer 3

PO → Asymptomatic replication in the gut → viraemia

Question 4

Are Picornaviridae viruses stenoxen or euryxen?

Answer 4

Stenoxen

Question 5

Teschovirus Encephalomyelitis is known by what other name?

Answer 5

Porcine Enteroviral Encephalomyelitis

Question 6

Teschovirus Encephalomyelitis: Variants

Answer 6

1. Teschen (more severe)
2. Talfan (milder & asymptomatic)

Question 7

Teschovirus Encephalomyelitis: Occurrence of Teschen variant

Answer 7

Endemic in middle-Europe & Madagascar

Question 8

Teschovirus Encephalomyelitis: Occurrence of Talfan variant

Answer 8

Europe, America & Australia

Question 9

Teschovirus encephalomyelitis: Causing agent

Answer 9

Porcine Teschovirus Serotype 1 (PTV-1)

Question 10

Teschovirus encephalomyelitis: Serotypes

Answer 10

• Serotype 1 = Very significant
• Serotypes 2 → 11 = Mild symptoms

Question 11

Teschovirus encephalomyelitis: Epidemiology

Answer 11

NOTIFIABLE DISEASE

• Only pigs are susceptible (stenoxen)
  
  • Teschen: All age groups
  • Talfan: <4mo of age
• Resistant in the environment for 3 weeks

Question 12

Teschovirus encephalomyelitis: Pathogenesis

Answer 12

2 different pathways:

1. PO infection→ Enteral phase → Viraemia → Fever; Depression; Anorexia
2. Nasal infection → Olfactory nerves → CNS → Meningitis; Encephalomyelitis; CNS signs

Question 13

Teschovirus encephalomyelitis: Enteral phase

Answer 13

• GI epithelium: Primary infection
• Asymptomatic infection is frequent. Seroconversion & shedding.
• Local immunity & end of virus shedding

Question 14

Teschovirus encephalomyelitis: Incubation & CSx (Teschen)

Answer 14

Incubation time: 1-4 weeks

• Mild fever & anorexia
• Piglet/grower: Vomiting, ataxia, convulsions & flaccid paralysis
• Adult: Flaccid HL paralysis

Some animals may recover but CSx still remain

Question 15

Teschovirus encephalomyelitis: CSx (Talfan)

Answer 15

• Ataxia, HL paralysis & opisthotonus
• Coma & death after 3 days

After recovery, ataxia may remain

Question 16

Teschovirus encephalomyelitis: Pathology

Answer 16

Ø Macroscopic lesions → HISTOLOGY

• Grey matter, brain stem, ventral horns & cerebellum:
  
  • Lymphocytic infiltration
  • Necrosis
  • Degeneration

Live piglet should be sent to lab to make a dx

Question 17

Teschovirus encephalomyelitis: Dx

Answer 17

• Epidemiology, CSx & histology
• Virus detection: RT-PCR, IF, IP, isolation of virus
• Antibody detection: VN^*

^<i></i>Increasing ABs proves the acute disease; solely seropositivity isn’t enough for dx*</i></sup>

Question 18

Teschovirus encephalomyelitis: DDx

Answer 18

• Classical Swine Fever
• African Swine Fever
• Aujeszky’s Disease (High fever)
• Rabies (CNS signs)
• Oedema disease (E.coli)
• Glasser’s disease
• Streptococcus suis (Hyperaesthesia)

Question 19

Teschovirus encephalomyelitis: Prevention & Control

Answer 19

NOTIFIABLE DISEASE

• Ø Vaccine
• Teschen: Movement restriction & stamping out
• Talfan: Seroconversion