A survey of the prevalence of infectious bronchitis virus type 4/91 in Iran

Abstract
To evaluate the prevalence of infectious bronchitis virus (IBV) type 4/91 in Iran, tracheal swabs from 77 broiler flocks in 16 provinces were collected at the slaughterhouse. Swabs were subjected to RNA extraction and tested by RT-PCR, followed by a type-specific nested PCR. The viral RNA was detected in 33 samples (42.8%) from different provinces. The results indicate a relatively high prevalence of IBV type 4/91 in Iran and necessitate revising the vaccination programme against this disease.