Immunohistochemical demonstration of spread of Aujeszky's disease virus to the porcine central nervous system after intestinal inoculation.

Aujeszky's disease virus (ADV) was injected into the duodenal lumen of eight specific pathogen-free pigs aged 5 weeks. The infected pigs did not show any diarrhoea or nervous symptoms, but they developed characteristic necrotizing enteritis and myenteric plexitis, accompanied by follicular necrosis in the Peyer's patches. ADV antigen was detected in the submucosa of the dome area of Peyer's patches, lymphatic follicles, Meissner's and Auerbach's plexuses, solar ganglia and thoracic spinal ganglia. These findings suggest that ADV spreads from the intestinal mucosa to the central nervous system via the autonomic nerves.