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

Abstract

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.

Immunohistochemical and molecular detection of natural cases of bovine rotavirus and coronavirus infection causing enteritis in dairy calves

“…Among 45 deaths of cattle calves, 3 cases of enteritis were of due to rotavirus as demonstrated by the hallmark lesions of the shortening and fusion of villi, denudation, and the presence of cuboidal enterocytes, these lesions were very similar to those described by earlier workers in rotavirus infected calves [8,25,26]. Similarly, the extra-intestinal lesions in mesenteric lymph nodes (lymphocytes depletion and antigen detection by IHC) were also matched with the findings of previous workers, who described the depletion of lymphocytes from the germinal centers of lymphoid follicles of mesenteric lymph nodes and detection of rotavirus antigen by direct immunofluorescence technique in calves [27,28]: [29].…”

“…The tetrad of Rotavirus, Coronavirus, Cryptosporidium, and Escherichia coli accounts for 75-95% of infection in neonatal calves worldwide, of which especially rotavirus and coronavirus account for 27-36% and 20-26% infections, respectively [4][5][6][7]. Among all pathogens, rotaviruses are the leading cause of calf diarrhoea, and coronaviruses are a major contributor to it [4,5,8,9]. The coronavirus infect both small intestine and large intestine to cause severe disease [10].…”

Epidemiological study of naturally occurring bovine rotavirus infection in organized dairy farms, India

“…Then, this infection declined with advancing age of calves. The same has been described by previous workers for occurrence of rotaviral diarrhoea in neonatal calves (Radostits et al 2007;Dash et al 2011;Kashyap et al 2018a). The reason for high occurrence of rotaviral diarrhoea under 1 month of age could be due to less-developed immune system in neonates and the lack of adequate amount of maternal antibodies in the colostrum (Windeyer et al 2012), so the available free sites for attachment of rotavirus to sialic acid or galactosidase receptors of enterocytes remain open for viral attachment.…”

Prevalence of bovine coronavirus infection in organized dairy farms of Central and North regions, India

“…It possesses a single-stranded, non-segmented, positive sense RNA genome of 32 kb plus poly (A) tail in length (De Vries et al 1997). Three distinct clinical syndromes in cattle are described due to coronaviral infection: (a) diarrhoea in calves at 1-2 weeks of age; (b) winter dysentery with haemorrhagic diarrhoea in adult animals and (c) respiratory diseases including bovine respiratory disease complex (BRDC) in both young and adult cattle (Chi et al 2001;Liu et al 2006;Singh et al 2018;Kashyap et al 2018aKashyap et al , 2018b. The coronavirus results diarrhoea in calves up to 3 weeks of age, but disease may occurs up to three months of age.…”