The pathogenesis of mucosal disease

Area of Science:

• Veterinary Pathology
• Virology
• Immunology

Background:

• Mucosal disease (MD) pathogenesis in cattle is complex and not fully understood.
• Persistent infection with noncytopathic Bovine viral diarrhea virus (BVDV) is a prerequisite for MD.
• Cytopathic BVDV is associated with MD and likely triggers the cellular destruction leading to clinical signs.

Purpose of the Study:

• To elucidate the complex pathogenesis of Mucosal Disease (MD) in cattle.
• To investigate the role of cytopathic and noncytopathic BVDV in disease development.
• To explore the mechanisms of cellular destruction and the involvement of immunotolerance.

Main Methods:

• Analysis of existing research on MD pathogenesis.
• Review of viral characteristics (cytopathic vs. noncytopathic BVDV).
• Examination of the role of persistent infection and immune tolerance.

Main Results:

• Cytopathic BVDV is the likely trigger for cellular destruction in MD.
• Noncytopathic BVDV is the probable source of cytopathic BVDV through spontaneous mutation.
• MD outbreaks can result from spontaneous mutation or exposure to heterologous cytopathic BVDV in persistently infected cattle.

Conclusions:

• MD pathogenesis involves complex interactions between noncytopathic and cytopathic BVDV.
• Spontaneous mutation of noncytopathic to cytopathic BVDV within persistently infected animals is a likely cause of MD outbreaks.
• Further research is required to clarify the precise mechanisms of cellular destruction and the role of immunotolerance in MD.