Application of RT-PCR for Detection of Infectious bronchitis Disease in Laying Hens in Some Northern Provinces of Vietnam

Abstract

     Infectious bronchitis (IB) is one of the severe infectious disease causing tremendous economic losses in the poultry industry. In order to have an effective strategy for disease prevention and control, a method for rapid and accurate dectection of infectious bronchitis virus (IBV) is urgently needed. In this study, the tissue samples of lung, trachea and kidney collected from IB-suspected laying hens in three hen farms in Hanoi (Ba Vi District), Thai Nguyen and Bac Ninh have been diagnosed by the RT-PCR method. The diagnostic results showed that 34/71 (47,88%) samples were positive with the IBV. The common clinical signs of IBV-infected hens included fever, depression, loss of appetite, dyspnea, coughing, sneezing, tracheal rales, nasal discharge, diarrhea, fluid retention in the abdomen, facial swelling and conjunctivitis. The pathological signs in IBV-infected hens included kidney swelling (90%), tracheal hemorrhagea (77.5%), pulmonary hemorrhage and congestion (63,7%), inflammation of airsacculitis (60%) and upper respiratory tract (57,5%). Egg production and quality in IBV-infected laying hens decreased by 20,7 to 43%.