Measures of tracheal lesions are more discriminatory and reproducible indications of chronic respiratory disease caused by Mycoplasma gallisepticum in poultry

Abstract

Mycoplasma gallisepticum is the primary causative agent of chronic respiratory disease in poultry, and vaccination is the measure most commonly used for its control. Pathological changes caused by M. gallisepticum are mainly observed in the trachea and air sacs, but assessment of air sac lesions is subjective. Standardized parameters for evaluation of pathological changes, and their reproducibility and discrimination in uninfected and infected groups, are critical when assessing the efficacy of M. gallisepticum vaccination. This study reviewed and critically appraised the published literature on evaluation of vaccine efficacy against pathological changes caused by M. gallisepticum in poultry..