avian
& livestock assay data sheet
African swine fever
NOTE: THIS TEST IS NOT PERFORMED
ON SAMPLES TAKEN FROM ANIMALS OWNED OR LOCATED IN THE STATE OF
CALIFORNIA.
Test code:
S0127
- Ultrasensitive detection of African swine fever virus by real time PCR
African
swine fever (ASF) is a highly contagious, generalized disease of
pigs caused by a DNA virus formerly classified as an iridovirus
(Iridoviridae) but recently re-classified into a newly created
family of viruses called Asfarviridae - a name derived from
"African Swine Fever And Related Viruses.” Within that family it
has been allocated to the Genus Asfivirus of which it is the
only member. Different strains of ASF virus exhibit varying
virulence. The virus is very resistant to inactivation, and can
persist up to one month in contaminated pens, in meat up to 15
weeks and in processed hams up to 6 months.
High
concentrations of ASF virus are shed in secretions and
excretions from acutely infected pigs. Because the virus
survives well in the environment and in meat, its spread can
occur via contaminated livestock pens or by feeding contaminated
garbage. The virus also spreads through pig to pig contact,
ticks and other biting insect vectors, contaminated injection
needles or mechanically by humans and equipment.
Infected
pigs usually have an incubation period of 5-15 days before the
disease may manifest itself in a number of forms:
•
Peracute - pigs
are found moribund with death following rapidly. •
Acute - high
fever (up to 42C.) after 1-2 days anorexia and recumbency, skin
blotching, diarrhea and abortion. Mortality close to 100% within
7 days. • Subacute
- fluctuating or continuous fever for up to 20 days, with milder
clinical signs. •
Chronic - transient recurring fever with
stunting and emaciation. Possible pneumonia, lameness, skin
lesions, and secondary infections.
Recovered
pigs may remain chronically infected and excrete the virus for 6
weeks after infection. Contaminated pens and garbage feeding,
particularly with material from international airports or
seaports, are documented methods of spread due to the resistance
of the virus to inactivation.
African
Swine Fever is clinically, and upon necropsy, very similar to
Hog Cholera (also known as "Classical Swine Fever"). Laboratory
tests are required to differentiate the two diseases.
Serological
diagnosis and culture identification have been used to detect
ASF but they are generally slow and not very specific. Molecular
detection by PCR can provide rapid, specific and sensitive
results (McKillen et al., 2007).
Utilities:
-
Help confirm the disease causing agent
-
Identify ASF virus carriers
-
Help ensure that animal colonies and populations are free of
ASF
-
Early prevention of spread of the virus among animals
-
Minimize human exposure to the virus
-
Safety monitoring of biological products that derive
from animals
References:
McKillen, J., Hjertner, B., Millar, A., McNeilly, F., Belák, S.,
Adair, B. and Allan, G. (2007) Molecular beacon real-time PCR
detection of swine viruses. J Virol Methods. 140:155-65.
Specimen requirements:
0.2 ml
whole blood in EDTA (purple top) tube, or 0.2 ml feces, or rectal swab, or 0.2 ml fresh, frozen or fixed
tissue.
Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.
For all
specimen types, if there will be a delay in shipping, or during
very warm weather, refrigerate specimens until shipped and ship
with a cold pack unless more stringent shipping requirements are
specified. Frozen specimens should be shipped so as to remain
frozen in transit. See
shipping instructions
for more information.
Turnaround time:
2 business days
Methodology:
Qualitative real time PCR
Normal range:
Nondetected
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