[Pathogenesis of Aujeszky's disease]

Area of Science:

• Veterinary Virology
• Immunology
• Pathology

Context:

• Aujeszky's disease, caused by Suid herpesvirus 1, poses a significant threat to swine health.
• Understanding viral localization and host response is crucial for effective disease control and vaccine development.

Purpose:

• To investigate the differential localization and pathological effects of an avirulent (MK strain) and a virulent (strain 2) Aujeszky's disease virus in experimentally infected pigs.
• To elucidate the host-pathogen interactions and immune responses associated with varying viral virulence.

Summary:

• Pigs infected orally with the avirulent MK strain showed limited virus presence in submandibular lymph nodes with low titers. Subcutaneous infection with MK strain did not yield virus.
• In contrast, pigs infected with the virulent strain 2 experienced high mortality (15/20 by day 7) with widespread virus detection across organs and high titers.
• Histopathology revealed severe nonsuppurative encephalitis, pneumonia, necroses, and inclusion bodies with the virulent strain, which were significantly milder and transient with the avirulent strain, suggesting an immunologic basis for the observed differences.

Impact:

• Findings highlight the distinct pathogenic potential and tissue tropism of different Aujeszky's disease virus strains.
• The study suggests that observed mild pathological changes with the avirulent strain are manifestations of an enhanced host immune response rather than direct toxic injury.
• This research contributes to understanding the pathogenesis of Aujeszky's disease and the host-immune interactions, informing future vaccine strategies.