Diagnosis of Newcastle Disease

Present study was designed to investigate the clinico-pathological changes produced in broilers naturally infected with Newcastle Disease (ND) and to standardize the RT-PCR technique for confirmatory diagnosis of ND. A field survey of commercial broiler poultry farms (n=50) suspected of being infected with ND was carried out in district Faisalabad, Pakistan. The suspected birds either live or fresh mortality from each suspected infected premises were collected and pooled tissue samples were used for histopathological study, virus isolation identification and RT-PCR. Out of total 50 samples 33(66%) samples were found positive for NDV by HI assay. Thereafter, all the 50 samples were subjected to RT-PCR by using a set of oligonucleotide primers specific to the cleavage site of fusion protein gene (F). All the 33(66%) samples identified serologically (HI) as NDV, were also found positive through RT-PCR. Data obtained from the field study suggests a similar NDV detection rate with both of the antigen detection methods. But RT-PCR being a rapid and less laborious technique can be used as a method of choice for rapid and accurate diagnosis of ND during epidemic conditions.