Asfarviridae

Question 1

African swine fever

Answer 1

Contagious disease of swine caused by complex of DNA virus (asfivirus)

• economic loss due to high mortality of acute and peractue forms
• potential for rapid geographic spread
• domestic pigs and wild boars are susceptible

Question 2

What species serve as a reservoir host in Africa?

Answer 2

• african wild boars
• bushpigs
• warthogs

Question 3

What serves as a reservoir and transmission vector of ASF?

Answer 3

Soft ticks

• Ornithodoros erraticus
• Ornithodoros moubata

Question 4

Geographic locations of ASF

Answer 4

Present in sub-Saharan countries of Africa, endemic in Sardinia
- is a reportable disease in US!

Question 5

How does ASFV occur in ASFV-free areas?

Answer 5

Feeding pigs with contaminated garbage from international airports and seaports
- no vaccine available!

Question 6

ASF clinical symptoms are similar to ______

Answer 6

Other hemorrhagic pig diseases

- especially Classical swine fever

Question 7

What are the only methods of control for ASF?

Answer 7

Animal slaughter and area quarantine

Question 8

What is the only known DNA arbovirus?

Answer 8

ASF virus

- also the only member of the asfarviridae family

Question 9

Natural arthropod host of ASFV

Answer 9

Ornithodoros porcinus porcinus

Question 10

_____ and _____ are required for maintenance of ASFV in the sylvatic cycle

Answer 10

Both vertebrate and arthropod hosts

- persistently infected ticks serve as a natural reservoir of the virus

Question 11

T/F: ASFV transmission occurs from infected warthogs to domestic pigs

Answer 11

False, is rare

• occurs thru infected tick feeding on pigs
• transmission between domestic pigs is direct or indirect

Question 12

Initial site of replication for ASFV

Answer 12

Midgut

Question 13

Acute ASF

Answer 13

Characterized by disseminated intravascular coagulation with multiple hemorrhages in all tissues

• replicates in macrophages and monocytes
• leukopenia and severe impairment of lymphoid organs

Question 14

What mediator contributes mainly to the pathogenesis of ASF

Answer 14

TNF-alpha

• induces vasodilation, increase in vascular permeability, and activation of vascular endothelium
• provides signals in apoptosis

Question 15

Persistence of ASF

Answer 15

Virus resists inactivation

- persist in meat for 15 weeks, hams for 6 months, contaminated pens for 1 month

Question 16

Is ASF clinical in warthogs?

Answer 16

No, serve as a reservoir

Question 17

4 forms of ASF

Answer 17

• peracute: pigs found moribund with death
• acute: high fever after 1-2 days anorexia and recumbency, 100% mortality within 7 days of infection
• subacute: fever for 20 days with mild clinical signs
• chronic: transient recurring fever with stunting and emaciation

Question 18

ASF is clinically and postmortem similar to _____

Answer 18

Hog cholera

- aka: classical swine fever