Classical Swine Fever
Classical Swine Fever
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 2022, 1,448 samples from domestic pigs were tested for Classical Swine Fever virus and another 5,747 blood samples from domestic pigs were tested for antibodies against Classical Swine Fever. In addition, all feral pigs tested at AGES for African swine fever virus are also tested for classical swine fever virus, which totaled 1,809 in 2022. No classical swine fever virus or antibodies were detected in any sample.
Classical swine fever is a highly infectious general disease that occurs only in pigs. The disease is caused by a virus (CSFV, CSFV) from the genus Pestivirus, family Flaviviridae. CSF has been known as an infectious disease since 1933 (Ohio, USA) and occurs worldwide with the exception of Australia and New Zealand. Swine fever only affects animals of the family Suidae (true pigs or Old World pigs). Human infection is not known to occur. CSF virus is transmitted by direct (animal to animal) and indirect contact (e.g., shoes, clothing, work equipment, 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 feces begins later. Severely ill animals excrete CSF virus until death or until approximately 1 month after recovery. Chronically ill pigs and caretakers excrete the virus for more than half a year. The virus is absorbed through the digestive tract, less commonly through the conjunctiva or nasal mucosa. When epidemic, 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.
The CSF course depends on some factors (age, direction of use, viral virulence, infectious dose). Congenital infections with classical swine fever virus are manifested by weakness, "trembling piglet", groveling with dermatitis, leucopenia and incoordination. Three clinical pictures are distinguished:
- acute form of progression (classical form of progression)
- chronic form
- atypical form
The acute form manifests itself by high fever (40-41 °C), disturbance of general condition, lassitude, anorexia, hind hand weakness, trembling ("shivering piglet"), edema (eye), purulent nasal/ocular discharge, diphteroid coatings in the mouth/tongue, erythema, first constipation, then diarrhea, 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 diarrhea, fever, CNS disturbances are typical symptoms. CSF is a notifiable animal disease. Control of CSF is based on a) prevention of 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.
Suitable sample materials are:
- Whole blood or blood serum
- Organs (especially spleen, liver, kidney, lymph nodes, tonsils)
The detection of classical swine fever virus from the above materials is possible with the following methods:
- PCR (serum, organs)
- Virus isolation (serum, organs)
- ELISA (serum)
- Serum neutralization test (serum)
In all cases, the shipment of samples to the laboratory should ideally be carried out by an authorized logistics company with the addition of refrigerants and in compliance with the relevant transport regulations (UN3373).
Last updated: 26.05.2023