Classical Swine Fever

Unique identifier / Notation

BI0303

Synonyms

Hog cholera CSF

Classical swine fever, also known as hog cholera, is a contagious viral disease of domestic and wild swine. It is caused by a virus of the genus Pestivirus of the family Flaviviridae (WOAH, no date).

Primary reference(s)

WOAH, no date. Classical Swine Fever (CSF). World Organisation for Animal Health (WOAH). Accessed 28 May 2025.

Annotations

Additional scientific description

Classical swine fever (CSF) remains one of the most important transboundary viral diseases of swine worldwide. Classical Swine Fever (CSF) is a contagious viral disease of domestic and wild swine. It is caused by a virus of the genus Pestivirus of the family Flaviviridae (WOAH, 2022). The disease is preventable through control measures, including vaccination. The CSF vaccine provides a good example of solid immunity. Each country typically maintains a list of registered veterinary vaccines approved for use. For specific regulations, consult the country's veterinary authorities.

The disease has acute and chronic forms and can range from severe, with high mortality, to mild or even unapparent. In the acute form of the disease, in all age groups, there is fever, huddling of sick animals, loss of appetite, dullness, weakness, conjunctivitis, constipation followed by diarrhoea, and an unsteady gait. Several days after the onset of clinical signs, the ears, abdomen and inner thighs may show purple discolouration. Animals with acute disease die within one to two weeks. Severe cases of the disease appear very similar to African swine fever. With low virulence strains, the only expression may be poor reproductive performance and the birth of piglets with neurological defects such as congenital tremors. The most common method of transmission is through direct contact between healthy swine and those infected with classical swine fever virus (CSFV). The virus is shed in saliva, nasal secretions, urine, and faeces. Contact with contaminated vehicles, pens, feed, or clothing may spread the disease. Animals that are chronic carriers of the disease (persistently infected) may show no clinical signs of illness but may shed the virus in their faeces. Offspring of infected sows can become infected in the uterus and once born can shed the virus for months. CSFV can survive in pork and processed pork products for months when meat is refrigerated and for years when it is frozen. Pigs can become infected by eating CSF-infected pork meat or products.

CSF is found in Central and South America, Europe, Asia, and parts of Africa. North America, Australia and New Zealand are currently free of the disease. In the 1990s large CSF outbreaks occurred in the Netherlands, Germany, Belgium and Italy. The World Organisation for Animal Health standards for surveillance have helped eradicate CSF from North America and much of Western Europe. It has been proven that in parts of Europe; the wild boar population may play a role in the epidemiology of the disease. The disease has been spread through legal and illegal transport of animals, and by feeding swill containing infective tissues to pigs. When an outbreak occurs, many actions must be set in place urgently: slaughter of all pigs on affected farms; safe disposal of carcasses, bedding, etc.; thorough disinfection; designation of infected zone, with control of pig movements; detailed epidemiological investigation, with tracing of possible sources (up-stream) and surveillance of the infected zone, and the surrounding area. In disease-free areas, a stamping-out policy is applied consisting of early detection, movement control, proper disposal of carcasses, and cleaning and disinfection. This policy has led to the elimination of CSF from North America, and much of Western Europe (WOAH, no date).

In areas where the disease is endemic, vaccination can prevent the spread of the disease. Vaccines used should be produced in accordance with the OIE standards for vaccine production (WOAH, 2024a). As the disease is brought under control, vaccination ceases, with continued surveillance. The WOAH Terrestrial Animal Health Code defines the requirements for a country or a zone to be considered free of the disease. CSF is one of the World Organisation for Animal Health (WOAH) listed diseases (WOAH, 2024b). The disease is not a zoonosis, i.e. it does not infect humans.

Metrics and numeric limits

CSF is one of the World Organisation for Animal Health (WOAH) listed diseases (WOAH, 2024b). Reports are available on organisations such as the World Organisation for Animal Health map of CSF official status (WOAH) website (WOAH, 2024c) and the Swine Health Information Center (SHIC, 2024),

Key relevant UN convention / multilateral treaty

WTO Agreement on the Application of Sanitary and Phytosanitary Measures (SPS Agreement) (WTO, 1994). Available from: https://www.wto.org/english/res_e/booksp_e/agrmntseries4_sps_e.pdf

United Nations. 2023. UN Recommendations on the Transport of Dangerous Goods - UN Model Regulations. Available from: https://unece.org/transport/dangerous-goods/un-model-regulations-rev-23

Drivers

Lack of biosecurity, swill feeding. CSF easily spreads in areas experiencing storms, flooding, civil conflict, insecurity, displacement of people, and greater need to remain mobile, due to difficulties in maintaining high biosecurity. Pork products for food aid may introduce CSF to CSF-free areas when uncooked food waste is fed to raise pigs.

Impacts

Death of infected animals, spread of infection, trade ban. An outbreak in the Netherlands in 1997 led to the destruction of 11 million pigs and cost USD 2.3 billion (WOAH, 2024a).

Multi-hazard context

The virus is shed in saliva, nasal secretions, urine, and faeces. Contact with contaminated vehicles, pens, feed, or clothing may spread the disease. Animals that are chronic carriers of the disease (persistently infected) may show no clinical signs of illness but may shed the virus in their faeces. It has been proven that in parts of Europe, the wild boar population may play a role in the epidemiology of the disease. The disease has been spread through legal and illegal transport of animals, and by feeding swill containing infective tissues to pigs (WOAH, no date).

Risk Management

Vaccination programme, movement control, depopulating infected herds, improvement of biosecurity at farms. CSF disease prevention and control states that treatment if not attempted, affected pigs must be slaughtered and the carcases buried or incinerated. The first barrier preventing a CSF outbreak is to apply strict and rigorous sanitary prophylaxis, as defined in the WOAH Terrestrial Animal Health Code (WOAH, 2024b). Good communication between veterinary authorities, veterinary practitioners and pig farmers, a reliable disease reporting system, and hygiene measures protecting domestic pigs from contact with wild boar are the most effective measures to prevent the disease.

Monitoring

The section and the table below offer an overview of monitoring for classical swine fever. This information can be used for forecasting within a national early warning system (EWS). Since EWS capacities and processes differ across countries, the most current and specific information regarding EWS should be obtained from the appropriate national or regional agency/authority responsible for disaster management.

Which institution(s) produce(s) Disaster Risk Data/Information?

FAO Reference Centres, WOAH Reference Centres,

How is the Hazard Observed/Monitored/Forecast?

FAO empres-i+ https://empres-i.apps.fao.org/diseases

WOAH WAHIS https://wahis.woah.org/#/event-management