Synonyms: Teschovirus Encephalomyelitis, Teschen Disease, Teschen/Talfan Disease, Polioencephalomyelitis enzootica suum, Porcine Enterovirus Encephalomyelitis, Benign Enzootic Paresis
Teschen disease was first diagnosed in the Czech town of Teschen in 1929. In 1957 a PTV-1 virus with a milder clinical form was detected in Talfan (Wales).
Porcine Teschovirus A is an RNA virus belonging to the genus Teschovirus A of the family Picornaviridae. Previously, Teschoviruses were assigned to the group of enteroviruses with a total of 13 serotypes. Based on the cytopathic effect (CPE), replication properties in different cell lines of the host, serological test procedures and sequence data, the porcine enteroviruses (PEV) have been continuously reclassified and are currently divided into 3 groups: Teschovirus A (formerly Porcines Teschovirus), Sapelovirus A (formerly Porcines Enterovirus A, PEV-8) and Enterovirus G (formerly Porcines Enterovirus B, PEV-9 and PEV-10).
Infections with sapelovirus A (PSV-A), porcine enterovirus G (PEV-G), porcine parvovirus, PRRSV, Aujeszky's disease, European swine fever, African swine fever, colienterotoxaemia, selenium poisoning or other intoxications, spinal abscesses, trauma, bacterial meningoencephalitis can be diagnosed.
The first replication occurs in the tonsils as well as in the intestinal epithelium (especially ileum, colon). The enteral phase is not clinically significant and is accompanied by no morphological changes. The enteral phase is followed by viremia and invasion of the CNS with the typical picture of a non-purulent (encephalo)myelitis (inflammation of the brain or spinal cord). During the viremic phase, some serotypes show affinity to the uterus. Colonisation of the uterine tissue with the virus can lead to intrauterine death.
The infection occurs most frequently in weaned piglets due to the decrease in maternal immunity and the common housing of animals of different origins at this age. After 24 hours the virus is detectable in large quantities in the tonsils and cervical lymph nodes, after 48 hours in the mesenteric lymph nodes and in the faeces. Co-infection of Teschoviruses with other picornaviridae such as PSV-1 and PEV-G occurs.
Teschen disease (severe, fatal/lethal form)
- Pathogen: virulent strains of Porcines Teschovirus 1 (PTV-1)
- Occurrence: originally in Europe, sporadically Africa, China, Haiti, Brazil, Canada
- high morbidity (individuals in a population), high mortality (up to 90%), in all age groups
- Clinical signs: convulsions, opisthotonus, nystagmus, coma, death after 3-4 days, surviving patients show residual paralysis
Talfan disease (mild forms are predominant nowadays)
- Pathogen: Less virulent Teschovirus strains, including PTV-1
- Occurrence: worldwide and more frequently than Teschen disease
- Paresis, ataxias, rarely paralysis, often without symptoms, 95% of animals exposed to infection develop latent or inapparent infections