[Typing of 17 porcine enterovirus isolates from polio encephalomyelitis cases during the years 1983-1991]

Seventeen strains of porcine enteroviruses (PEV) were isolated from organs of 119 pigs with symptoms of polioencephalomyelitis submitted to the State Veterinary Institute Arnsberg/Westphalia between 1983 and 1991. 15 isolates originated from the central nervous system and 2 from organ suspensions made up of a brain-spleen-pool and a lung-spleen-lymph node-pool, respectively. Isolates were assigned to 7 PEV types which were present at the following frequencies: PEV1: 2x; PEV2: 6x; PEV4: 3x; PEV5: 1x; PEV6: 2x; PEV 12: 1x; PEV 13: 2x. Mortality rates of affected groups exhibited an age-dependent curvilinear relationship suggesting that the PEV involved possessed a rather similar low to medium grade neurovirulence, irrespective of type. Exceptions were 1 herd with 100% mortality at the age of 10-18 weeks from which PEV2 strain 6793/83 was isolated (described earlier) and a second herd with 18% mortality at the age of 14-18 weeks from which PEV types 1, 2 and 4 were recovered. Sensitivity of 5 cell lines for the isolation of PEV was compared. Rates of isolation from organ suspensions which had proved positive in any of the cell lines tested were as follows: PS-EK: 77%; IB-RS-2: 63%; ST: 56%; PK-15: 47%; BHK21 (CT): 10%.