3. Arboviral infectious diseases

Question 1

What is Arboviral infectious diseases?

Answer 1

Viral infection caused by viruses from any family thats transmitted by arthropods (insects) as vectors, e.g. mosquitoes, ticksm flies.

Question 2

Why do they contain important group of viruses?

Answer 2

Cause many of them are both OIE listed and Zoonotic diseases

Question 3

Mention diseases belonging to this group of viruses with their family

Answer 3

• Togaviridae
  Eastern, Western and Venezuelan encephalitis –> man, equine: OIE and zoonotic
• Reoviridae
  1. African horse sickness –> equids: OIE
  2. Bluetongue disease –> sheep: OIE
  3. Colorado tick fever –> man,rodents: zoonotic
• Flaviviridae
  1. Classical swine fever –> suids: OIE
  2. Dengue fever –> man, primates: zoonotic
  3. West nile disease –> man, equid, birds: OIE + zoonotic
  4. Tick borne encephalitis –> man, ruminants: zoonotic (tick and unpasteurized milk)
  5. Yellow fever –> man, small mammals, monkey: zoonotic
• Bunyaviridae
  Rift valley fever –> man, ruminants: OIE + zoonotic

Question 4

What’s an important thing to mention about African horse sickness?

Answer 4

OIE listed

Question 5

What is the causative agent of African horse sickness?

Answer 5

African horse sickness virus belonging to Reoviridae family

Question 6

What is the susceptible host for AHS?

Answer 6

Equids (horse, mule, zebra)

Question 7

What does AHS cause to their host?

Answer 7

Respiratory and cardiac impairment

Question 8

How is African horse sickness transmitted?

Answer 8

Arthropod borne transmission, through midges

Question 9

What are the clinical signs for African horse sickness?

Answer 9

4 clinical forms
1. Pulmonary –> Full susceptible hosts, short course and high mortality
2. Cardiac or oedematous form –> Edema of head, 50% mortality
3. Mix –> Combined respiratory and cardiac signs, 70% mortality
4. Mild form –> Horse sickness fever, often overlooked. Seen in resistant equids

Infected horse might die

Question 10

How is African horse sickness diagnosed?

Answer 10

• Virus isolation by viral culture
• Virus detection by ELISA or PCR –> using blood or tissue samples

Question 11

What is treatment for African horse sickness?

Answer 11

No treatment!

Only supportive, but must be reported (OIE)

Question 12

How can spreading of African horse sickness be prevented?

Answer 12

• Vaccination in endemic areas
• Control of movement of animals
• General arthropod control
• Hygiene measures