Chinese researchers isolate IBV in chickens

Researchers from China recently isolated a virulent avian infectious bronchitis virus from 30-day-old broiler chickens that caused a high proportion of deaths in the country in 2005.

IBV is a member of the Coronaviridae family and causes highly contagious respiratory and occasional urogenital disease among chickens. The virus causes respiratory symptoms, nephropathologic lesions and reduced egg production and quality. The endemic pathogen leads to significant economic losses around the world.

The researchers determined that the isolated strain, designated YN, was the more severe of the two main genetic clusters of IBV isolates in China.

The YN isolate caused severe lesions and killed 65 percent of 30-day-old specific-pathogen-free chickens in experiments. All infected birds developed severe tracheal and kidney lesions.

The team demonstrated that YN-like viruses are a predominant strain in China and that the virus causes severe pathogenicity in chickens. The researchers suggest that more detailed analysis of the characteristics of the IBV isolate is needed to control the spread of the disease in China. The researchers also suggest that assessments are needed for the efficacy of current vaccines against YN IBV.

The study was published in the December issue of Emerging Infectious Diseases. The work was supported by the Beijing Research Group for Poultry Production Technology System.