Abstract
In Saudi Arabia, infectious bursal disease (IBD), commonly known as Gumboro Disease, poses a significant threat to the poultry industry. The disease suppresses the immune system of young chicks, leading to increased morbidity, mortality, reduced productivity, and heightened susceptibility to secondary infections. The rapid spread of IBD in commercial poultry farms has resulted in substantial economic losses, further aggravated by the emergence of mutant and variant strains, environmental stressors, and inadequate biosecurity measures. This review aims to provide a comprehensive overview of the epidemiology, clinical manifestations, diagnostic approaches, vaccination strategies, and control measures of infectious bursal disease in Saudi Arabia. A narrative review of published literature, surveillance reports, and field observations related to IBD in Saudi Arabia was conducted. Emphasis was placed on disease prevalence, circulating strains, diagnostic tools such as ELISA, PCR, and next-generation sequencing, and the effectiveness of existing vaccination and biosecurity strategies. IBD has spread rapidly across commercial poultry farms in Saudi Arabia, leading to immune suppression and significant financial losses. The presence of novel mutant and variant strains, combined with environmental stressors and suboptimal biosecurity, has exacerbated disease severity. Diagnostic techniques, including ELISA, PCR, and next-generation sequencing, have improved detection capabilities, although their implementation is constrained by resource limitations. Vaccination protocols have shown variable efficacy due to co-infections, improper vaccination management, and differences in farming practices. Nutritional interventions, particularly phytogenic feed additives and probiotics, have demonstrated potential in enhancing vaccine efficacy and improving overall avian health. Effective control of infectious bursal disease in Saudi Arabia requires an integrated approach combining advanced diagnostic tools, robust vaccination programs, strict biosecurity measures, and supportive nutritional strategies. Future priorities should focus on continuous monitoring of emerging strains, field evaluation of vaccine performance, and the development of novel vaccine platforms to ensure sustainable disease control.

Key words: Infectious bursal disease; Epidemiology; Vaccination strategies; Molecular characterization; Saudi Arabia.