Classical Swine Fever

Classical Swine Fever

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Profile

Classical swine fever is a general disease that occurs only in pigs and is cyclical. It is not dangerous for humans.

Occurrence

Worldwide, except Australia and New Zealand

Host animals

All pigs, domestic pigs and wild boars

Infection route

Directly from animal to animal and indirectly via contaminated objects, e.g. shoes, clothing, work equipment, transport vehicles

Incubation time

3-8 days, in case of chronic and atypical classical swine fever 3-4 weeks

Symptoms

High fever (40-41 °C), disturbance of general condition, faintness, trembling ("shivering piglet"), bruising, purulent nasal/eye discharge, initially constipation, then diarrhoea, convulsions. The mortality rate varies between 30 % and 100 %.

Therapy

There is no therapy

Prevention

Prophylactic vaccinations are not allowed in the EU (in case of need only with an exemption from the EU).

Situation in Austria

Austria has been free of Classical Swine Fever in domestic pigs since 1997 and free of Classical Swine Fever in feral pigs since April 2003. In 2021, 1,517 samples from domestic pigs were tested for Classical Swine Fever virus and another 5,556 blood samples from domestic pigs were tested for antibodies against Classical Swine Fever virus. In addition, all feral pigs tested for African swine fever virus at AGES are also tested for classical swine fever virus, which totaled 1,813 in 2021. No classical swine fever virus or antibodies were detected in any sample.

Überwachung Klassische Schweinepest

Technical information

Classical swine fever is a general cyclical disease unique to pigs. The disease is caused by the European swine fever virus (ESP, CSF, CSF virus) of the genus Pestivirus, family Flaviviridae. ESP has been known as an infectious disease since 1933 (Ohio, USA) and occurs worldwide with the exception of Australia and New Zealand. Only animals of the family Suidae (true pigs or Old World pigs) are infected with swine fever. Human infection is not known to occur. The classical swine fever virus is transmitted by direct (animal to animal) and indirect contact (e.g. footwear, clothing, tools, transport vehicles). Virus excretors and slaughter and meat products containing virus are the most important factors for the outbreak of CSF. Virus excretion can begin as early as one day after infection in saliva, nasal, ocular and pharyngeal secretions. Excretion via urine and faeces starts later. Severely ill animals excrete classical swine fever virus until death or until about 1 month after recovery. Chronically diseased pigs and caretakers excrete the virus for more than half a year. The virus is absorbed via the digestive tract, less frequently via the conjunctiva or the nasal mucosa. In epidemic cases, classical swine fever virus is also transmitted by contact. The incubation period of acute CSF is 3-8 (12) days after natural infection, and 3-4 weeks for chronic and atypical CSF.

Symptomatology

The type of CSF course depends on several factors (age, direction of use, viral virulence, infectious dose). Congenital infections with KSP virus manifest themselves by weakness, "trembling piglets", groveling with dermatitis, leukopenia and incoordination. Three clinical pictures are distinguished:

  • acute form of progression (classical form of progression).
  • chronic form
  • atypical form

The acute form is manifested by high fever (40-41 °C), disturbance of the general condition, lassitude, anorexia, weakness of the hind hands, trembling ("shivering piglet"), oedema (eye), purulent nasal/ocular discharge, diphteroid coatings in the mouth/tongue, erythema, initially constipation, then diarrhoea, convulsions. The mortality rate varies from 30% to 100%. The chronic form is manifested by loss of appetite, emaciation, frequent alternation of diarrhea and constipation. The mortality rate is greatly reduced compared to the acute form. The atypical form runs a mild and protracted course; insatiable diarrhoea, fever, CNS disturbances are typical symptoms. Classical swine fever is a notifiable disease. The control of classical swine fever is based on a) the prevention of the introduction and spread of the pathogen and b) the "stamping out" method (= culling of infected and suspected animals). Prophylactic vaccination is prohibited in all EU countries except Romania.

Diagnostic

Detection methods:

  • Pathomorphological investigations
  • Detection of classical swine fever virus in organs using immunofluorescence sections
  • virus cultivation in cell culture
  • molecular biological methods (PCR)
  • detection of antibodies by ELISA
  • serum neutralisation test (SNT)

Contact

Institut für veterinärmedizinische Untersuchungen Mödling

Last updated: 16.11.2022

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