Description of infectious agent and the disease
Classical swine fever (CSF) is a contagious disease of domestic and wild pigs with highly variable clinical signs and death rates. It is caused by an enveloped RNA virus that belongs to the genus Pestivirus within the family Flaviviridae. The virus is transmitted via direct (animal to animal) or indirect contact (e.g. transport vehicle, clothing) including pork and other products from infected pigs.
Three major genotypes (1, 2 and 3), comprising several sub-genotypes, have been described. Field infections of the last outbreaks within the European Union belonged to sub-genotype 2.3 (Latvia, 2012-2015) and to 2.1 (Lithuania, 2011).
Epidemiology of CSF
CSF remains endemic in Asia, South and Central America and the Caribbean. The whole African continent has no official OIE status.
So far, the OIE has listed over 30 countries that are CSF-free, including also large parts of the European Union. The most recent CSF outbreaks were confirmed in Japan, Korea, Colombia, Brazil, and Russia.
The risk of (re)introduction and spread of CSF increases by the intensified trade with pigs/ pig products and worldwide traffic and tourism as well as by the pig density.
Prevention, detection and control of CSF
Over the last decades the circulating CSF virus strains changed from highly virulent to moderate/ low virulent strains. The clinical diagnosis of the disease caused by these strains is challenging because typical clinical signs are missing and the virus spreads slowly within the pig herd.
Diagnostic procedures for antigen and antibody detection are described in the OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals and in the Manual of Diagnostic Tests for Detection of CSF.
In principle, prevention and control of CSF is performed by surveillance as well as stamping out and /or vaccination. Prophylactic vaccination with attenuated live vaccine is often applied in countries, where CSF is endemic and only little international trade is performed. In CSF- free countries, prophylactic vaccination is prohibited, but emergency vaccination strategies are important. To minimize the impact of trade the application of DIVA (differentiation of infected from vaccinated animals) vaccines will be ideal.
Additional information on CSF
Ganges et al., 2020. Classical swine fever virus: the past, present and future.
Postel et al., 2018. Epidemiology, diagnosis and control of classical swine fever: recent developments and future challenges.