A survey of more than 11 years of neurologic diseases of ruminants with special reference to transmissible spongiform encephalopathies (TSEs) in Greece

The first cases of scrapie were detected in Greece in a flock of sheep in O ctober 1986. All the animals of the affected flock and all sheep in two flo cks that were in contact were killed and buried. A systematic investigation of all available cases with signs indicating a neurological disease starte d in sheep and goats in late 1986, as well as in cattle in 1989. The invest igation was based on clinical examination, necropsy or macroscopical examin ation of the brain and viscera, and histological examination of the brain i n all animals except those with coenurosis. Histological examinations of sp ecimens from the spinal cord and other tissues, and if considered necessary bacteriological, toxicological and serological examinations were also carr ied out. In October 1997, scrapie was diagnosed in sheep of a second flock (a mixed flock of sheep and goats), grazing in a pasture close to the place where scrapie was initially detected. All animals of the second flock were also killed and buried. Diagnosis in the first flock was based on clinical signs and histological lesions, and in the second immunoblotting was also used. Distinctive lesions of scrapie were found in the brain and/or the spi nal cord of eight sheep with clinical signs from the two flocks. The lesion s were revealed in the brain stem and/or in the cervical spinal cord, and t ended to be symmetrical. In one sheep, severe lesions in the cortex of cere bral hemispheres and of the cerebellum were also found. In the brain of two sheep from the second flock the pathological isoform of PrP protein was de tected. Despite the eradication scheme applied, scrapie in sheep reappeared after 11 years in a place close to where it occurred initially. This may i ndicate that the effectiveness of the eradication scheme implemented was no t adequate and additional approaches may be needed.