avian & livestock assay data sheet
Classical swine fever
NOTE: THIS TEST IS NOT PERFORMED
ON SAMPLES TAKEN FROM ANIMALS OWNED OR LOCATED IN THE STATE OF
CALIFORNIA.
Test code:
S0126 -
Ultrasensitive detection of classical swine fever virus by
reverse transcription coupled real time PCR
Classical
swine fever (CSF), also called hog cholera or swine fever, is
caused by a pestivirus within the flaviviridae family. Bovine
viral diarrhea virus and border disease virus are other members
of the pestivirus genus. Domestic pigs and wild boar are the
only natural reservoirs of CSF. Humans are not susceptible to
the CSF virus.
Infected
pigs can transmit the virus to susceptible pigs by direct or
indirect contact. Ingestion and inhalation are the most common
routes of infection, but transmission has also occurred via
conjunctival or mucous membrane contact, contamination of skin
abrasions, insemination, and transfer of blood.
Infected
animals can shed the virus in saliva, feces, blood, urine, and
nasal discharge. Contaminated equipment, vehicles, clothing, and
footwear can mechanically transmit the virus to susceptible
animals. Consumption of uncooked, infected pork scraps has
resulted in outbreaks of CSF. The CSF virus can survive in these
products for many months.
Transplacental infection with strains of low virulence can
produce chronically infected piglets. In addition, recovered
pigs can still shed the virus for a long period of time, making
them another potential source of infection and outbreaks.
CSF can
occur in acute or chronic forms. In the acute form of CSF,
affected animals exhibit a high fever, severe depression, and
anorexia. Blotchy, purple discoloration of the skin is
frequently observed. Affected pigs may stand with arched backs.
Abortions, still births, and weak litters are observed when
pregnant sows are infected with the CSF virus. Newborn piglets
frequently develop neurologic signs including tremors and
convulsions. Death usually occurs in 10 to 15 days.
The chronic
form of CSF results in similar clinical signs, but they are
intermittent and less severe. Anorexia, fever, hair loss, and
constipation alternating with diarrhea are usually observed.
This form can also result in “carrier-sow” syndrome, in which
chronically infected sows produce persistently infected piglets.
These animals become chronic carriers of the virus and transmit
infection when introduced into naïve herds. In some herds, the
only clinical sign observed when CSF viral infection is of low
virulence is poor reproductive performance. Congenital infection
with CSF virus of low virulence may result in tremors, runting,
poor growth, and death.
Serological
diagnosis and culture identification have been used to detect
this virus but they are not very specific, and culture is slow.
Molecular detection by PCR can provide rapid, specific and
sensitive results (Depner et al., 2007).
Utilities:
-
Help confirm the disease causing agent
-
Identify CSF virus carriers
-
Help ensure that animal colonies and populations are free of
CSF
-
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:
Depner, K., Hoffmann, B. and Beer, M. (2007) Evaluation of
real-time RT-PCR assay for the routine intra vitam diagnosis of
classical swine fever. Vet Microbiol. 121:338-43.
Specimen requirements: 0.2 ml whole blood in EDTA (purple top) tube, or 0.2 ml feces or urine, or 0.2 ml fresh or frozen
tissue, or rectal swab, or nasal swab.
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 reverse transcription coupled real time PCR
Normal range:
Nondetected
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