Classical swine fever virus

Classical swine fever virus (CSFV) infects pigs and wild boar. It belongs to the genus Pestivirus in the family Flaviviridae, where only one serotype has been classified, but multiple strains exist which vary in virulence. CSFV is an enveloped virus that has a capsid and single stranded RNA genome.  

  • Classical swine fever is a notifiable disease and should be reported.
    Please see the Defra website for advice on how to spot and report the disease.

Associated diseases:

CSFV causes classical swine fever which is highly contagious. The severity of the disease can vary depending on the age of the pig, whether the pig has been exposed to the virus before and the virulence of the virus strain. Mortality in young pigs can approach 100% in the acute form of the disease.

Clinical signs:

Acute form (more virulent strains and/or younger pigs)

  • Fever
  • Anorexia, lethargy
  • Reddening/lesions of the skin
  • Conjunctivitis
  • Swollen lymph nodes
  • Blue colouring of the ears, limbs, tail, snout
  • Constipation followed by diarrhoea
  • Occasional vomiting
  • Laboured breathing, coughing
  • Movement problems
  • Birthing problems such as, mummification, stillbirth, abortion, birth of persistently infected litter
  • Death occurs 5–25 days after onset of illness

Chronic form (less virulent strains or partially immune herds)

  • Dullness, varied apetite, fever, diarrhoea for up to 1 month
  • Stunted growth
  • Apparent recovery with eventual relapse and death within about 3 months

Disease transmission:

CSF is spread mainly by the oral and oronasal routes and by direct contact with other infected animals. Indirect contact through objects such as vehicles, clothes, instruments and needles can also spread the virus as well as airborne transmission over short distances. In addition, transmission can occur through artificial insemination and from mother to piglet during pregnancy. Waste food fed to pigs that is cooked insufficiently is the most common means of entry into CSF free countries.

Disease prevalence:

CSF occurs in much of Asia, South America and Central America in addition to some Caribbean islands, Madagascar and Mauritius. This disease has been eradicated from the United States, Canada, New Zealand, Australia and most of western and central Europe.

Research papers

Hardy S, Jackson B, Goodbourn S, Seago J (2021)

Journal of Virology 95 (5) , e01136-01120.
Erickson A, Fisher M, Furukawa-Stoffer T, Ambagala A, Hodko D, Pasick J, King D P, Nfon C, Ortega Polo R, Lung O (2018)

Transboundary and Emerging Diseases 65 (2) , e272-e283
Wang J, Chen S, Liao Y, Zhang E, Feng S, Yu S, Li L-F, He W-R, Li Y, Luo Y, Sun Y, Zhou M, Wang X, Munir M, Li S, Qiu H-J (2016)

Journal of Virology 90 (22) , 10271-10283
Bautista M J, Ruiz-Villamor E, Salguero F J, Sanchez-Cordon P J, Carrasco L, Gomez-Villamandos J C (2002)

Veterinary Pathology 39 (1) , 84-91
Gomez-Villamandos J C, Ruiz-Villamor E, Bautista M J, Sanchez C P, Sanchez-Cordon P J, Salguero F J, Jover A (2001)

Journal of Comparative Pathology 125 (2-3) , 98-109


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