Asfarviridae Flashcards
African swine fever
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
What species serve as a reservoir host in Africa?
- african wild boars
- bushpigs
- warthogs
What serves as a reservoir and transmission vector of ASF?
Soft ticks
- Ornithodoros erraticus
- Ornithodoros moubata
Geographic locations of ASF
Present in sub-Saharan countries of Africa, endemic in Sardinia
- is a reportable disease in US!
How does ASFV occur in ASFV-free areas?
Feeding pigs with contaminated garbage from international airports and seaports
- no vaccine available!
ASF clinical symptoms are similar to ______
Other hemorrhagic pig diseases
- especially Classical swine fever
What are the only methods of control for ASF?
Animal slaughter and area quarantine
What is the only known DNA arbovirus?
ASF virus
- also the only member of the asfarviridae family
Natural arthropod host of ASFV
Ornithodoros porcinus porcinus
_____ and _____ are required for maintenance of ASFV in the sylvatic cycle
Both vertebrate and arthropod hosts
- persistently infected ticks serve as a natural reservoir of the virus
T/F: ASFV transmission occurs from infected warthogs to domestic pigs
False, is rare
- occurs thru infected tick feeding on pigs
- transmission between domestic pigs is direct or indirect
Initial site of replication for ASFV
Midgut
Acute ASF
Characterized by disseminated intravascular coagulation with multiple hemorrhages in all tissues
- replicates in macrophages and monocytes
- leukopenia and severe impairment of lymphoid organs
What mediator contributes mainly to the pathogenesis of ASF
TNF-alpha
- induces vasodilation, increase in vascular permeability, and activation of vascular endothelium
- provides signals in apoptosis
Persistence of ASF
Virus resists inactivation
- persist in meat for 15 weeks, hams for 6 months, contaminated pens for 1 month
Is ASF clinical in warthogs?
No, serve as a reservoir
4 forms of ASF
- 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
ASF is clinically and postmortem similar to _____
Hog cholera
- aka: classical swine fever
