15. Other retroviral infectious diseases

Question 1

Describe retroviral infections

Answer 1

Viral infections caused by family Retroviridae
RNA viruses

Question 2

Which diseases are retroviral infectious diseases

Answer 2

• Enzootic bovine leucosis- bovine leukemia (cattle) –> formation of lymphosarcoma
• Feline leukemia (cats) –> formation of lymphosarcoma
• Avian leukosis - avian leukemia (birds) –> formation of lymphosarcoma
• Maedi visna (sheep and goat) –> RT and CNS- OIE!
• Equine infectious anemia- (horse) –> anemia- OIE!

Question 3

What is important to mention about Maedia visna disease?

Answer 3

Contagious and OIE listed. Persistent infection!

Question 4

What are the agent responsible for causing Maedia visna disease

Answer 4

Lentivirus - Family Retroviridae

Question 5

What are susceptible host of Maedi virus

Answer 5

Sheep and goat

Question 6

What does Maedi visna cause in host?

Answer 6

RT and CNS infection. (Persistent infection)

Question 7

What is transmission of Maedia visna?

Answer 7

Horizontal - by contact
Vertical - colostrum and milk

Question 8

What are clinical signs of Maedi visna

Answer 8

• 2 forms of the disease:
• Maedi –> associated with RT infection –> chronic pneumonia and dyspnea
• Visna –> associated with CNS infection –> neurological signs- encephalitis

Question 9

How is Maedi visna diagnosed?

Answer 9

• Clinical signs and if over 2 y/o, wasting and slow progressive respiratory distress –> suspicion
• Serology if CNS signs- RT-PCR, ELISA

Question 10

How is Maedi visna treated?

Answer 10

No treatment. Slaughter of positive animals

Question 11

How can spread of Maedia visna be prevented?

Answer 11

By vaccination and frequent testing