[Effect of low temperatures on the viability of Cysticercus bovis]

For investigations under laboratory conditions freezers specially prepared for this aim were used. The material for these investigations were alive Cysticercus bovis recovered from skeletal muscles of a bull infected with 500,000 eggs of Taenia saginata. The viability of C. bovis was determined on the basis of routine laboratory investigations. For investigations under conditions of an industrial cold storage plant 6 cattle carcasses intensively invaded by C. bovis were used, i.e. 5 animals infected under natural conditions and one bull specially infected with 500,000 eggs of T. saginata. The temperatures of cattle carcasses were measured with a thermograph. Every 24 hours sections of muscles were collected, from which C. bovis were recovered and examined on the viability by the above-mentioned method. It was found that at low temperatures the necrobiosis time of C. bovis isolated from skeletal muscles was 15 min. at -35 degrees C and as long as 10 hours at -5 degrees C. However, C. bovis died within 72-96 hours in muscles of cattle carcasses subjected to the activity of the temperatures minus 18-19 degrees C at a relative humidity of 86-90% under conditions of an industrial cold storage plant. From the obtained results the author concluded that the regulations hitherto obligatory in Poland, concerning the treatment of cattle carcasses with C. bovis by means of cooling or freezing, should be amended.