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 the framework of the sampling programme 2020, 7,209 blood samples were tested for antibodies and 1,488 samples were tested for classical swine fever virus by PCR. In 2020, an additional 1,586 blood samples from domestic pigs were tested for antibodies and 353 samples from feral pigs were tested for classical swine fever virus. No classical swine fever virus or antibodies were detected in any sample.
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.
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.
Last updated: 04.05.2022