Comparative study on biological material for molecular diagnosis of Gallid herpesvirus 2

The present study was intended to investigate the sensitivity of different tissues of tumorous and non-tumorous birds to the polymerize chain reaction-baseddiagnosis of Marek's disease. Tissue samples were collected from spleen, sciatic nerve, feather follicles and tumour parts (if any)of chickens during the routine necropsy examination. The presence of Marek's disease virus was examined using primers for 132 bp repeats of BamHI-H regionand positive samples were sequenced for 132 bp repeats and Meq gene. In the birds showing tumours, various samples such as the spleen, feather pulp, sciatic nerve and tumour tissue yielded positive results in 92.31%, 88.46%, 100% and 100% cases respectively. Amongst non-tumorous birds, 11.53% spleen, 23.07% feather pulp and 11.53% sciatic nerve were found positive. This is the first comparative study between nerve and other organs samples for molecular diagnosis of Marek's disease. Data generated shows that the probability of false negative in tumorous birds and false positive in non-tumorous birds was comparatively low while employing nerve tissue than spleen and feather follicles. Thus, it may be concluded from our study that nerves are a more reliable and robust diagnostic organ in comparison to the other organs used for conventional diagnosis.