Phylogenetic analysis and spatial distribution of bovine viral diarrhea virus (BVDV) in dairy cattle from Galicia (NW Spain)

Carmen Eiras,Ignacio Arnaiz,Francisco J Diéguez,Eduardo Yus,Manuel Cerviño

doi:10.5424/sjar/2019173-14814

Abstract

Aim of study: To examine the frequency and diversity of bovine viral diarrhea viruses infecting dairy cattleArea of study: The study was carried out in Galicia (NW Spain), the main dairy cattle area of SpainMaterial and methods: A total of 157 BVDV isolates (from 140 dairy herds) were typed. Typing was based on a 288-bp sequence from the 5′ untranslated region of viral RNA genome. Subsequently, to investigate whether the presence of herds diagnosed with a particular strain was higher in some areas or during some specific time period, data were tested using a Bernouille approachMain results: Of the 157 isolates, 137 (87.3%) were typed as BVDV-1b, 10 (6.4%%) as 1d, 7 (4.4%) as 1e and 2 (1.3%) as 1f. One isolate was assigned to type 1p. Three of the strains found in the study (the three belonging to type 1b) showed significant spatial clustering.Research highlights: This report indicates that BVDV-1b was the predominant species, although there was an important genetic diversity in the study population. Spatial analysis indicated important drawbacks in the application of biosecurity measures, especially as regards purchase of cattle or after the reintroduction of animals from cattle concentration points.

Highlights

Bovine viral diarrhea virus (BVDV) is a member of the genus Pestivirus, which comprises border disease virus and classical swine fever virus.The genera Pestivirus are included into the familyFlaviviridae
The only BVDV-1p strain came from a cow purchased in 2016 in the neighboring region of Castilla León
Spatial clustering was detected for three BVDV. This is the largest BVDV typing study ever reported for Spain and was carried out in the main dairy area of the country and the 9th in the European Union (Eurostat, 2018)

Summary

Introduction

Bovine viral diarrhea virus (BVDV) is a member of the genus Pestivirus, which comprises border disease virus and classical swine fever virus.The genera Pestivirus are included into the familyFlaviviridae. Bovine viral diarrhea virus (BVDV) is a member of the genus Pestivirus, which comprises border disease virus and classical swine fever virus. The genera Pestivirus are included into the family. BVDV cause bovine viral diarrhea, one of the most important diseases in cattle worldwide. It causes considerable economic losses in cattle, mainly attributable to reduced milk production, reduced reproductive performance, delayed growth, increased susceptibility to other diseases, early culling and increased mortality among young stock (Houe, 2003). As a consequence of their RNA genome, Pestiviruses display high mutation rates, which, in some cases, may lead to the emergence of new virus lineages. Thereby, genetic typing of BVDV isolates distinguishes two recognized species: BVDV-1 and BVDV-2, based on antigenic and genetic properties (Becher et al, 1997)

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