Serological evidence of bluetongue virus infection and serotype distribution in dairy cattle in South Korea

Jeong-Min Hwang,Jung-Yong Yeh,Jae Geun Kim

doi:10.1186/s12917-019-2000-z

Abstract

BackgroundBluetongue is a vector-borne viral disease, and bluetongue virus (BTV) outbreaks can cause substantial economic losses. Even subclinical infection may carry significant associated costs, including a loss of condition, reduced milk yield, and infertility and abortion, and indirect costs, largely due to the export restrictions and surveillance requirements imposed to limit the spread of the virus. However, the BTV epidemiology in the Far East remains incompletely understood, especially in the cattle population in South Korea. In this study, the seroprevalence of BTV antibodies and distribution of BTV serotypes in dairy cattle in South Korea were evaluated to improve the understanding of the BTV epidemiological situation in the Asia-Pacific region.ResultsBetween 2012 and 2013, a total of 37 out of 171 dairy cattle herds (21.6%) and 85 out of 466 dairy cattle heads (18.2%) showed antibodies against BTV. Neutralizing antibodies to BTV-1, − 2, − 3, − 4, − 7, − 15, and − 16 serotypes were identified, and the RNAs of the BTV-1, − 2, − 3, − 15, and − 16 serotypes were detected, indicating that BTV was circulating in the dairy cattle population in South Korea.ConclusionsThese findings indicate that BTV is widespread and has circulated in dairy cattle in South Korea. This is the first report presenting evidence of circulating antibodies against BTV and the serotype distribution in bovine populations in South Korea.

Highlights

Bluetongue is a vector-borne viral disease, and bluetongue virus (BTV) outbreaks can cause substantial economic losses
The present study demonstrated that BTV infection was prevalent in the dairy cattle populations analyzed, in which approximately one in five dairy cattle herds and one in six dairy cattle were infected (Table 1)
Collectively, in this study, the significance of the serological evidence and the findings of BTV serotypes distributed in dairy cattle South Korea are discussed and further studies to isolate local BTV strains from sentinel animals, including dairy cattle, are proposed

Summary

Introduction

Bluetongue is a vector-borne viral disease, and bluetongue virus (BTV) outbreaks can cause substantial economic losses. Even subclinical infection may carry significant associated costs, including a loss of condition, reduced milk yield, and infertility and abortion [2], and indirect costs, which largely arise from the export restrictions and surveillance requirements imposed to limit the spread of the bluetongue virus (BTV) [3]. Because it can spread rapidly and cause serious economic consequences in affected countries, bluetongue. Bluetongue was recognized and described more than 100 years ago in southern Africa, BTV infection of ruminants, as an enzootic disease, and its vector, Culicoides (Diptera: Ceratopogonidae) genus insects are traditionally found in tropical and temperate regions of the world between the latitudes of approximately 40°

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