Survival of Aujeszky's disease virus in frozen pig meat.

The survival of Aujeszky's disease virus was studied in muscle, lymph node and bone marrow frozen at -18 degrees C, following infusion of a large dose of the virus into the hindquarter of a freshly killed pig. Previous attempts to induce an adequate viraemia for such studies, using intranasal and intravenous routes of inoculation of large doses of virus in live pigs, were unsuccessful. In frozen meat and marrow, the virus showed a biphasic inactivation curve with time, similar to that seen with cell-cultured virus. Most virus was rapidly inactivated initially but a small population of more stable virus persisted for a considerable period of time. In contrast, virus in lymph node showed a uniform inactivaton rate, like that of the more stable componet only. Virus was not detectable in any of the tissues after 35 days of storage at -18 degrees C.