Seroprevalence of Antibodies against Porcine Teschovirus 1 in Lithuania

The objective of the present work was to study the serological status and epidemiological situation of porcine teschovirus 1 (PTV-1) on swine farms in different Lithuanian regions by using virus neutralization test and virus isolation. Clinical, epidemiological, serological and virological examinations were performed for the diagnosis of Teschen disease (porcine enterovirus encephalomyelitis, TE). Swine blood serum samples (n = 1680) were collected on 28 farms (60 samples per farm) of 8 regions in 2003. For virus isolation 29 samples of pathological material were taken from the brains of pigs (2 - 4 months of age) that died suddenly on seven swine farms in five regions. Epidemiological and clinical examination revealed no signs of porcine enterovirus encephalomyelitis on 32 Lithuanian swine farms. PTV-1 was not isolated and identified in the PK-15 cell culture. Antibodies against PTV-1, detected by using VNT, were found on all investigated farms and in all age groups. Negative serum (2.3%, 39 from 1680) samples were found in 15.5% (16 from 103) of 2-4-month-old pigs and in 4.7% (23 from 494) of 4-6-month-old ones. The positive serological and negative epidemiological, clinical and virological results suggest that less virulent or avirulent PTV-1 strains were spread on Lithuanian swine farms.