Abstract

Infectious Bursal Disease (IBD) is a highly contagious immunosuppressive disease of young chickens that constitutes a continuous scourge to the success of poultry production in Nigeria despite the availability of effective vaccines. Here, an outbreak of IBD in a small-scale commercial flock with high mortality is reported. Postmortem examination revealed haemorrhages on the thigh muscles and an inflamed bursa of Fabricius. Tissue samples were collected from the farm, and sera from free roaming chickens within the neighbouring villages in Jos south LGA, Plateau State. A total of 250 sera were collected from local birds within the five districts of the LGA using a random sampling method. The samples were analyzed using Agar Gel Immunodiffusion assay for the detection of antigen and serum antibodies against the IBD virus (IBDV). Results confirmed the presence of IBD antigen in the commercial poultry and high serological evidence of IBDV among local chickens in Jos South LGA, with a 78% average prevalence rate across the 5 districts assayed. The highest was observed in Zawan (88%), while the least was in Du (72%). These findings confirmed the level of exposure and endemicity of IBD in the sampled population. Detection of high levels of antibodies against IBDV in the studied population is an indication of natural infection among the local chickens as they are generally not routinely vaccinated against the disease. Thus, they may serve as reservoirs and a possible source of IBDV transmission to commercial poultry. Therefore, any effort towards controlling IBD should consider vaccinating rural chickens to prevent them from being reservoirs of the virus.

Key words: Antigen/Antibodies, Infectious Bursal Disease, Nigeria, Plateau State, Rural poultry