Classical swine fever (CSF) is caused by classical swine fever virus (CSFV), a virus of the genus Pestivirus within the family Flaviviridae. Domestic pigs and wild boar are susceptible to the disease. CSF is also a notifiable disease under the World Organisation for Animal Health (WOAH) Terrestrial Animal Health Code. [1]

One of the difficulties with CSF is that the disease does not always look the same. The severity can vary with factors such as the virulence of the virus strain, the age of the pigs and their immune status. Some infections develop rapidly, while others may have less obvious clinical signs. [1,2]

Fever, loss of appetite, weakness and depression are common signs in affected pigs. Digestive problems such as constipation followed by diarrhoea may occur, and some animals develop an unsteady gait or other neurological signs. In more severe cases, purple discoloration can appear on areas such as the ears, abdomen and inner thighs. Low-virulence infections may present differently, including reproductive problems in breeding animals. [1]

These signs are not specific to CSF. Clinical observations can raise suspicion, but they cannot by themselves establish whether a herd is affected by classical swine fever. Laboratory testing is therefore an important part of CSF investigation and surveillance. [1,3]

Transmission Between Pigs

CSFV can spread through direct contact between infected and susceptible pigs. The virus can be present in saliva, nasal secretions, urine and faeces. Contaminated pens, vehicles, equipment, feed, clothing and other materials can also contribute to transmission. [1]

Animal movement is another factor that needs attention. Introducing pigs from a new source may introduce infection into a previously unaffected herd if their health status is unknown.

Wild boar can also be involved in CSFV epidemiology in some regions. Where domestic pigs and wild populations are present in the same area, maintaining farm biosecurity becomes particularly important. [1,2]

Looking at Antibodies

Antibodies provide information about the immune response of pigs following exposure to CSFV. For this reason, antibody detection can be used as part of serological surveillance and herd monitoring.

The background of the animals should be considered when interpreting an antibody result. Vaccination, maternal antibodies and previous exposure can all affect the result. WOAH also notes that antibodies to other pestiviruses may complicate the interpretation of CSFV serology, so positive findings may require further investigation. [2]

For routine monitoring, a rapid antibody test provides a convenient way to obtain serological information without making the testing process unnecessarily complicated.

J&G Classical Swine Fever Virus Antibody Test

The J&G Classical Swine Fever Virus Antibody Test is a rapid antibody test for pigs. It is designed to detect antibodies associated with CSFV and can be used for serological screening during herd monitoring.

The rapid format is suitable for situations where veterinary professionals need an accessible antibody screening option and want to obtain results within a practical testing workflow. It can be used as part of CSFV surveillance or when additional serological information is needed during herd health assessment.

Rapid antibody testing should be considered together with vaccination history, clinical observations and other available herd information. It is intended to provide useful serological information rather than replace the investigation required for suspected cases.

Research has also explored immunochromatographic test strips as a rapid approach for detecting CSFV antibodies, supporting the continued development of field-adaptable serological testing for swine disease surveillance. [4]

CSF Surveillance on the Farm

CSF management begins with prevention and continued surveillance. Controlling animal movement, maintaining farm hygiene and limiting opportunities for contact with potentially infected animals or contaminated materials are basic parts of farm biosecurity. [1]

Surveillance provides another layer of information. Where antibody monitoring is appropriate, rapid CSFV antibody testing can be used to check the serological status of pigs and identify situations that may require closer investigation.

For pig herds, disease monitoring is rarely based on a single observation. Clinical signs, animal history, vaccination information and testing results need to be considered together. This is particularly relevant for CSF because its clinical presentation can range from severe disease to relatively inconspicuous infection. [1,2]

References

1. World Organisation for Animal Health (WOAH). Classical swine fever. WOAH Disease Card.

2. World Organisation for Animal Health (WOAH). Terrestrial Animal Health Code, Chapter 15.2: Infection with classical swine fever virus. WOAH.

3. Beer, M., Goller, K. V., Staubach, C., & Blome, S. Genetic variability and distribution of classical swine fever virus. Veterinary Microbiology, 2015. [Background literature on CSFV epidemiology and diagnosis.]

4. Bai, Y., Jia, R., Wei, Q., et al. Development and application of a high-sensitivity immunochromatographic test strip for detecting classical swine fever virus antibodies. Transboundary and Emerging Diseases, 2022, 69(4): e788–e798. DOI: 10.1111/tbed.14367.