Outbreak Control and Clinical, Pathological, and Epidemiological Aspects and Molecular Characterization of a Bovine Herpesvirus Type 5 on a Feedlot Farm in São Paulo State.

Jane Megid,Marcos Bryan Heinemann,Acácia Ferreira Vicente,Clovis Reinaldo Silva Fonseca,Thaís Gasparini Baraldi,Vanessa Cristina Pelícia,Bruna Leticia Devidé Ribeiro,Susan Dora Allendorf,Edviges Maristela Pituco,Adriana Cortez,Mateus De Souza Ribeiro Mioni,Camila Michele Appolinario,Liria Hiromi Okuda

doi:10.1155/2015/981230

Abstract

This paper describes the control, epidemiological, pathological, and molecular aspects of an outbreak of meningoencephalitis in calves due to bovine herpesvirus 5 at a feedlot with 540 animals in São Paulo State, Brazil. The introduction of new animals and contact between the resident animals and the introduced ones were most likely responsible for virus transmission. Bovine herpesvirus 1 vaccine was used, resulting in the efficacy of the outbreak control, although two bovine herpesvirus 1 positive animals, vaccinated and revaccinated, presented meningoencephalitis, thereby characterizing vaccinal failure.

Highlights

Bovine herpesvirus type 5 (BoHV-5) belongs to the family Herpesviridae, subfamily Alphaherpesvirinae, and genus Varicellovirus [1] and is the etiological agent of nonsuppurative meningoencephalitis, which has been described worldwide but has a higher occurrence in Latin America [2]
Blood analysis were performed in two of the cases, and this analysis showed leukocytosis with neutrophilia, lymphocytosis, and monocytosis; serum protein, electrolytes, creatine kinase (CK), urea, and globulin were high in both animals; and GGT, AST, and creatinine were elevated in one of the animals
Polymerase chain reaction (PCR) was used to check BoHV-5 in samples from the three calves and it was positive for only the brain and serosanguineous cerebral fluid with negative results for the lung samples

Summary

Introduction

Bovine herpesvirus type 5 (BoHV-5) belongs to the family Herpesviridae, subfamily Alphaherpesvirinae, and genus Varicellovirus [1] and is the etiological agent of nonsuppurative meningoencephalitis, which has been described worldwide but has a higher occurrence in Latin America [2]. Outbreaks of meningoencephalitis caused by BoHV-5 have been reported mainly in South American countries such as Argentina [3, 4] and Uruguay [5]. The reason for the discrepancy in the prevalence between South America and the rest of the world is unknown. The absence of a specific tool for the detection and identification in vivo of BoHV-5 infected animals does not allow differentiation between BoHV-1 and/or BoHV5 positive animals; the true prevalence of the infection is unknown and the economic relevance remains to be determined [2]. The respiratory tract is a replication site for BoHV-5, and viral

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