Diagnostic techniques for infectious bovine rhinotracheitis: a review

Abstract

Infectious bovine rhinotracheitis (IBR) is a group of the bovine respiratory disease multifaceted pathogens and a key disease of cattle, leading to significant economic losses to the dairy industry globally. The causative agent of IBR is Bovine herpesvirus type-1 (BoHV-1), which is a member of the genus Varicellovirus in the Alphaherpesvirinae subfamily, which belongs to the family Herpesviridae, order Herpesvirales. BoHV-1 can be categorized into three subtypes (BoHV-1.1, BoHV-1.2a, and BoHV-1.2b) that belong to one single viral species, which is a serologically indistinguishable strain. Therefore, a more optimal method for the rapid diagnosis of BoHV-1 infection is highly needed. Hence, the objective of this paper is to review the appropriate diagnostic techniques for the IBR virus in infected cattle. In this review, various rapid and confirmatory diagnostic methods used for the diagnosis of BoHV-1 infection were briefly described. BoHV-1 can be routinely detected by virus neutralization tests and enzyme-linked immunosorbent assays (indirect or blocking ELISA). IBRgE-ELISA is the most specific serological test for BoHV-1 and is recommended for marker vaccine to differentiate wild infection from vaccination schemes. Furthermore, virus isolation from tissue or swab samples by cell culture and DNA detection with LAMP, PCR, and real-time PCR techniques are all used to detect infected cattle. Direct sequencing of the entire genome using the Sanger sequencing method recently allowed for the differentiation of BoHV-1 subspecies and the distinction of the BoHV-1 field strain from vaccine strains based on single nucleotide polymorphisms. As the gold standard diagnosis for IBR is virus isolation in cell culture, commonly followed by BoHV-1 gene sequencing, it is also recommended.