Introduction: Newcastle disease is major viral disease affecting all avian species. For diagnostic purposes different methods are available. Other than virus isolation as a gold standard, molecular detection is reliable assays. Rate of the virus shedding, long after the recovery, may not always be enormous. For tracking of the virus in the environment of breeder, hatchery, broiler and pullet farms and also recovery of the virus from the feces of captive birds, the industry desperately need a method to concentrate the virus for isolation and detection purposes. This study was designed to concentrate the virus using a novel approach, based on an old biological fact, the hemadsoroption phenomenon. In order to improve and increase sensitivity of the RT-PCR assay from fecal and environmental samples and as a non-invasive technique in captive birds, it was decided to concentration the virus using hemadsorption assay. Material and Methods: During the year 2013, fecal and tissue samples from 50 broiler flocks suspected to ND, submitted to Maad Professional Poultry Hospital, were used for this study. Tissue samples of brain, spleen and caecal tonsils from 4 carcasses of each flock were aseptically collected and pooled. In parallel to tissue sampling, two series of fecal samples from the same birds and flocks, were also collected and pooled separately. One series of fecal samples were processed for RNA extraction directly. But another series of fecal samples were processed for hemadsorption, followed by elution or without elution. RNA extraction was undertaken from all pooled samples, followed by RT-PCR assay. In all steps precaution were considered to avoid RNA degradation. Due to the widespread outbreak of velogenic Newcastle in the regions, a universal set of primers, based on the sequence data obtained in previous studies, were designed and used in the assay. Results and conclusion: An RT-PCR product with the expected size of 384 bp was detected in 37 out of 50 tissue samples examined. In fecal samples that were directly processed for RNA extraction, the amplicon was observed in 18 samples. In those fecal samples subjected to hemadsorption without elution step, RT-PCR assay was able to detect 34 cases out of all 50 fecal specimens. Collectively, NDV detection in the tissue, fecal and hemadsorbed fecal samples were 76%, 36% and 68%, respectively. It was confirmed that the concentration of the viruses from feces and the environment using hemadsorbtion is feasible for molecular detection and perhaps isolation of viruses with HA activity.

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