Simultaneous Detection of Bovine Rotavirus (BRV) and Bovine Viral Diarrhea (BVD) virus in Diarrheic Stool Samples: A Comparative Study of Molecular and Serological approaches

Calf scours (diarrhea) in unweaned calves play a major role in economic losses of animal farming industry worldwide. The present study was conducted to investigate and interpret the presence of BRV, BVDV, and Escherichia coli K99 by molecular and serological approaches simultaneously.

A total of 73 E. coli-negative diarrheic fecal samples were collected from one-week to less than one-month-old calves of Holstein dairy cattle herds of some provinces of Iran during autumn and winter. The samples were directed to antigen detection by ELISA (Enzyme Linked ImmunoSorbent Assay), RNA extraction by semi-manual approach, and cDNA synthesis for PCR amplification.

Out of 73 calves’ diarrheic  fecal samples, 28 (38.3%) and 1 (1.36%) were positive for BRV and BVDR by ELISA, respectively. However, 31 (42.4%) samples were positive for BRV and non for BVDV by RT-PCR. The Kappa coefficient showed significant differences in BRV and BVDR detection between ELISA and RT-PCR methods. The distribution of the BRV-positive samples among bovine diarrheic calves was 80, 52.6, and 50% in Eslamshahr, Qazvin, and Hamedan, respectively.

ELISA and RT-PCR indicated high prevalence rate of BRV in autumn and winter, respectively. The present study results showed that positive cases detected by RT-PCR were more than those detected by ELISA. Further studies are needed to achieve a comprehensive preventive and therapeutic strategy to address  diarrhea bovine pathogens.