An outbreak of nephropathogenic avian infectious bronchitis in broiler flocks of Chhattisgarh region

Nephropathogenic avian infectious bronchitis (IB) was recorded during November, 2006 to February, 2007 in broiler flocks of Chhattisgarh region. A total of 7120 broiler birds from five commercial flocks were screened out. An average mortality of 6.8 per cent with 17.2 per cent morbidity was recorded. The moribund birds showed respiratory clinical signs, whereas, the dead birds showed lesions of visceral gout on necropsy. The tissue samples (trachea, lung and kidney), collected from dead birds (n=50), were inoculated in embryonated chicken eggs via allantoic cavity route. The infectious bronchitis virus (IBV) was isolated from all tissue samples which produced changes in chicken embryos characteristic of IB. Agar gel precipitation test was performed to detect IBV which detected the precipitating antigen in chorioallantoic membrane and allantoic fluid of inoculated embryos at third and fifth passage level, respectively. For detecting the IBV specific antibodies, serum samples (n=100) were randomly collected from moribund birds. Out of hundred serum samples, eighty five showed IBV specific antibodies in indirect enzyme linked immunosorbent assay. The findings in present study indicated that avian IBV was involved in disease outbreak that caused nephropathogenicity and visceral gout in broiler chickens.