<div>The present study was conducted to evaluate and standardize direct fluorescent antibody technique (DFAT) in order to determine post-infection tissue dissemination pattern of hydropericardium syndrome (HPS) virus. The field isolated HPS virus was inoculated in chicken embryonated eggs for determining the egg infective dose 50 (EID50). The stock virus was utilized to standardize DFAT. A total of 50 birds were grouped as group A and Group B. The HPS virus was inoculated in experimental birds (group B), while group A birds were kept as control. Birds from both groups were slaughtered at 2<sup>nd</sup>, 6<sup>th</sup> and 8<sup>th</sup> day PI for virus detection by DFAT. Gross lesions, postmortem finding and mortality/morbidity status were also observed throughout the experiment. The specimens from experimentally inoculated birds when examined by DFAT indicated presence of virus in liver. The fluorescent nuclei indicated the presence of intranuclear inclusion bodies in the liver specimens at 2<sup>nd</sup>, 6<sup>th</sup> and 8<sup>th</sup> day post inoculation. The result of present study reveals that DFAT is a reliable method for early detection of HPS virus. As non-clinical HPS is apparently prevalent, significance of DFAT should be considered in conjunction with histological lesions to detect HPS in broilers.</div>


<div>Detection of hydropericardium syndrome virus by direct fluorescent antibody technique in broilers</div>


<div style="text-align: justify;">To understand the pathology of natural cases of rotavirus (RVA) in bovine calves, a total of 40 cases below 6 months died due to diarrhoea were studied, out of which 7 cases (17.5%) turned positive for RVA by RT-PCR. Histopathology of small intestine showed loss of villous enterocytes, blunting and fusion of villi, elongation of crypts and mononuclear cells infiltration in the lamina-propria. The mesenteric lymph nodes were severely depleted of lymphocytes. These changes were corroborated with presence of RVA antigen in sections by dFAT and nucleic acid by RT-PCR. The fluorescent signals were more in mesenteric lymph nodes than in intestine. Besides, 115 rectal fecal samples were also collected from calves for RVA detection by RT-PCR using VP6 gene specific sets of primers. Dead carcasses of calves (n= 40) belonged to organized dairy farm of Bareilly, while rectal fecal samples belonged to both organized (n= 38) and unorganized farms (n= 77) of Bareilly and Gwalior. The overall occurrence of RVA was 19.3% (30/155), comprising 5/37 cases (13.5%) from Gwalior (MP) and 25/118 cases (21.1%) from Bareilly (UP). These findings suggest the infection of RVA widely prevalent in calves and have potential to escape from the intestinal site to mesenteric lymph nodes.</div>

Detection of hydropericardium syndrome virus by direct fluorescent antibody technique in broilers

Rotavirus A associated pathology of intestine and mesenteric lymph nodes and occurrence in bovine calves of Gwalior and Bareilly regions