Tonsillar changes in pigs given pseudorabies (Aujeszky's disease) virus

Area of Science:

• Veterinary Pathology
• Virology
• Swine Infectious Diseases

Background:

• Pseudorabies virus (PRV), also known as Aujeszky's disease, is a significant pathogen in swine.
• Tonsillitis is a common manifestation of viral infections in pigs, impacting lymphoid tissues.

Purpose of the Study:

• To elucidate the histopathological changes and viral distribution in the tonsils of pigs following oral inoculation with pseudorabies virus.
• To characterize the early stages of PRV infection in porcine tonsils at the cellular and ultrastructural levels.

Main Methods:

• Oral inoculation of 5-day-old pigs with pseudorabies virus.
• Histopathological examination of tonsil tissues.
• Immunofluorescence staining to detect viral antigen.
• Ultrastructural analysis using electron microscopy.

Main Results:

• All inoculated pigs developed tonsillitis with characteristic necrosis in the subepithelial area, extending into lymphoid nodules and crypt epithelium.
• Specific immunofluorescence revealed PRV antigen initially in the nucleus and cytoplasm of subepithelial cells, spreading to lymphoid and epithelial cells.
• Ultrastructural examination identified enveloped virus particles within necrotic areas and degenerating epithelial cells, with subsequent release into the crypt lumen.

Conclusions:

• Pseudorabies virus infection initiates in the subepithelial region of porcine tonsils, leading to widespread necrosis and viral replication.
• The study provides detailed insights into the pathogenesis of PRV-induced tonsillitis, highlighting viral shedding dynamics.