Assessing the economic burden of avian infectious bronchitis on poultry farms in Brazil.

Avian infectious bronchitis (IB), caused by avian infectious bronchitis virus (IBV), is a worldwide endemic disease of chickens that affects all branches of the poultry industry. Multiple geno/serotypes occur, and lowvaccine cross-protection results from the highly divergent IBV types. In view of the lack of consistent data on the economic losses caused by IB and the poor protection resulting from the use of the Massachusetts type as a live vaccine in Brazil, this survey aimed to estimate the losses per 1000 birds in broiler and breeder flocks positive for IBV. Thirty-two different IBV genetic types were found. In breeders, the total loss per 1,000 birds was US $3567.4 and US $4210.8 at 25-26 and 42 weeks old, respectively, whereas in broilers (48 days old), the estimated loss was US $266.3 per 1,000 birds. Taken together, the results show a significant and measurable economic impact on the broiler and breeder industries, with an age-dependent increasing trend and an association with multiple genetic types of the virus.