African Swine Fever

Question 1

what is referred to epidemic 1 of ASF

Answer 1

In 60s, endemic in Sardinia- Genotype 1

Question 2

What is referred as Epidemic 2 of ASF?

Answer 2

07, Caucasus region- genotype 2

Question 3

ASF found in which animals

Answer 3

wild boars & domestic pigs

Question 3

ASFV name

Answer 3

Asfaviridae, asfavirus

Question 4

ASF virus physical aspect

Answer 4

at least 24 genotypes, very big, many genes = many antigens

Question 5

asfavirus way of infection

Answer 5

• some genes block interferon production & antiviral defense mechanism
• encodes prot of eukaryotic origin (difficult to differentiate from somatic cells)
  -multiplication in macrophages (block of the IS)
• prot: induction of Ab BUT none neutralizing ones!

Question 6

what are the main problem the body encounters against ASFV

Answer 6

• interferon are blocked
• hidden from IS
• no neutralizing anitbodies

Question 7

ASFV genome

Answer 7

Ds linear DNA: cytoplasmic inclusion body despite being DNA virus

Question 8

ASFV polymerase

Answer 8

its own, can rep in vector AND swine

Question 9

ASFV resistancy

Answer 9

enveloped BUT high resistance

60° for 30mins

Question 10

what is the vector of ASFV

Answer 10

tick (biological vector)

Question 11

Africa: transmission of ASFV

Answer 11

• tick-tick (vertical)
• tick-warthog (dead end host)
• tick-domestic swine

Question 12

europe & asia, transmission of ASFV

Answer 12

Boar-pig, pig-pig, boar-boar, tick-pig

Question 13

spreading of ASFV in europe & Asia

Answer 13

inf: saliva, nasal discharge (tick) shedding before CS (48hrs)
spreading: airport, raw meat, transport

lesser importance of tick in europe

Question 14

mortality in acute ASF

Answer 14

100%

Question 15

mortality in chronic ASF

Answer 15

<30%

Question 16

what kind of cycle can be found between warthog- ticks and ticks-ticks?

Answer 16

Sylvatic cycle

both asymptomatic carriers (doesnt do anything)

Question 17

which genotype does O. moubata caries?

Answer 17

genotype 1

Question 18

What genotype of ASF does O. erraticus can carrie ?

O: Ornithodorus

Answer 18

Genotype 1

Question 19

which genotype of ASF Ornithodorus verrucosus can carry

Answer 19

genotype 2

Question 20

ASFV pathogenesis

Answer 20

PO/Tick
tonsils, regional Ln
Viraemia (macrophages)
Spleen, lymphatic T., endothel

Question 21

when does the virus of ASF start shedding

Answer 21

even 48hrs before start of CS

Question 22

Consequence of a persistent viraemia of ASF?

Answer 22

immunosupppression

Question 23

Abs against ASFV

Answer 23

6-8 days postinfection
non neutralizing
virus wears membrane of macrophage like a raincoat (Abs can’t reach it)
persistent
immune complex formation

Question 24

Obvious clinical sign of ASF

Answer 24

**Abortion** ## Footnote in case of DD for abortion => ASF should be said first

Question 25

ASF incubation time

Answer 25

4-19 dys (usually 2-7dys)

Question 26

Peracute CS of AFS

Answer 26

rapid death without rapid fever, CS or patho changes

Question 27

Acute ASF CS

Answer 27

fever 40-42° no appetite dyspnea (bloody serous discharge) conjunctivitis diarrhoea (with coagulated blood) CNS signs skin haemorrhages, cyanotic ears lung oedema

Question 28

Subacute ASF CS

Answer 28

mild symptoms (milder acute form) longer course (4wks) more frequent CNS symptoms death within 14-30dys

Question 29

chronic ASF CS

Answer 29

recurrent fever, athritis focal skin necrosis & ulcers in protuding parts resp signs | death as late as 2-15 mths

Question 30

# T/F chronic case of ASF easy to diagnose

Answer 30

false

Question 31

Patho of ASF

Answer 31

acute course: damage of blood vessels gallbladder and choleductus region show gelatinous inflitration oedematous lung

Question 33

muscle necrosis is a patho finding of ASF?

Answer 33

Yes, chronic form

Question 34

how to differantiate between ASF & CSF

Answer 34

RT-PCR can

Question 35

diag methods for ASF

Answer 35

RT-PCR Hemadsorption

Question 36

DD of ASF

Answer 36

CSF acute paratypus PDNS swine erysipelas

Question 37

difference between CSF & ASF

Answer 37

- ASF has more serious haemorrhagic appearance - Higher mortality - Enlarged spleen - Oedema in the wall of the gall bladder

Question 38

Prevention of ASF

Answer 38

no spe prevention (animals WILL die) preventive zone 3km Observation zone 10km (can be resolved after 45 dys) ban on import of live pigs, airports, ports & border station

Question 39

Treatment of ASF

Answer 39

no vaccine | (2 ASF vaccine dvlped in vietnam but not to WOAH standards)