Immunological and Molecular Evaluation of Newcastle Disease Virus in Tissue Specimens from Free-living Birds - Abstract
Newcastle disease (ND) is a viral disease that affects domestic and wild birds, highly contagious and can cause acute mortality in some species. Little is known about transmission and behaviour of the Newcastle Disease Virus (NDV) in avian species, particularly in free-living species and with the exception of commercial birds, which is extremely important owing to the possible ease of contact between free-living species and commercial birds. The purpose of ND diagnosis is to guide the decisions to control the disease and thus prevent the spread of the disease. The aim of the present study was to evaluate immunological (immunohistochemical) and molecular techniques Real Time RT PCR (rRT-PCR) in the diagnosis of Newcastle disease in free-living bird tissue samples. A total of 150 birds belonging to14orders and 46 avian species were evaluated. Positive immunoblotting for NDV in at least one of the evaluated tissues was found in 43 (28.6%) of the 150 birds tested and 110 (71.4%) were negative by Immunohistochemistry (IHC) for NDV. Regarding the results of Real Time RT PCR (rRT-PCR), only one positive sample was recorded for the class 2 NDV from the trachea of a specimen of striped owl (Asioclamator). Therefore, it is essential to carry out epidemiological monitoring, with a constant characterization of circulating viral samples in free-living birds, especially in regions of high poultry production, to identify possible biosecurity measures that could prevent outbreaks in commercial poultry.