Chicken Infectious Anemia Virus Markedly Enhances the Pathogenicity of Infectious Bronchitis Virus-Infected Chickens.

Area of Science:

• Veterinary Virology
• Poultry Pathology
• Infectious Disease Epidemiology

Background:

• Chicken Infectious Anemia Virus (CIAV) and Infectious Bronchitis Virus (IBV) are major economic threats to global poultry production.
• Increasing prevalence of CIAV and IBV coinfections necessitates understanding their synergistic pathogenicity.

Purpose of the Study:

• To establish a coinfection model for investigating pathogenic interactions between field-derived CIAV and IBV strains.
• To systematically analyze the synergistic effects of CIAV and IBV coinfection on disease severity, viral transmission, and pathology in chickens.

Main Methods:

• Development of a coinfection model using specific pathogen-free (SPF) chickens and field strains of CIAV and IBV.
• Assessment of clinical signs, survival rates, viral shedding, viral replication, and pathological lesions in monoinfected and coinfected groups.

Main Results:

• Coinfection led to significantly decreased survival rates (76%) and pronounced growth retardation compared to monoinfections.
• Viral shedding was markedly increased in coinfected chickens, with 100% detection rates in swabs by 14 days postinfection.
• Coinfection exacerbated pathological lesions, including thymus and bursa atrophy, splenomegaly, and increased inflammatory cell infiltration.

Conclusions:

• CIAV and IBV coinfection exhibit significant synergistic pathogenicity, worsening clinical disease and enhancing viral transmission potential.
• Findings provide a theoretical basis for understanding virus-virus interactions and underscore the need for integrated control strategies against both CIAV and IBV.