Avian Poxvirus Study Guide

Overview and Clinical Importance

Avian poxvirus (Avipoxvirus) is one of the most significant viral diseases affecting domestic and wild birds worldwide. This slow-spreading DNA virus causes characteristic proliferative lesions and can result in significant morbidity and mortality, particularly in susceptible species like canaries and upland game birds. Understanding this disease is essential for the NAVLE, as it represents a classic example of viral pathology with pathognomonic histological findings.

Etiology

Virus Characteristics

Avipoxvirus belongs to the family Poxviridae, subfamily Chordopoxvirinae, genus Avipoxvirus. Key viral features include:

• Genome: Large double-stranded DNA virus (approximately 260-365 kbp)
• Morphology: Brick-shaped virions, approximately 200 nm x 270-350 nm
• Replication: Occurs entirely in the cytoplasm (NOT in the nucleus)
• Host Range: Cannot complete replication in non-avian species (mammalian cells)
• Environmental Stability: Highly stable; survives months to years in dried scabs and fomites

Recognized Avipoxvirus Species

There are 10 recognized species of avipoxvirus, each generally specific to certain bird groups: