Seroprevalence and Risk Factors of Bluetongue Virus Infection in Tibetan Sheep and Yaks in Tibetan Plateau, China.

Jian-Gang Ma,Dong-Hui Zhou,Gui-Xue Hu,Wen-Bin Zheng,Xing-Quan Zhu,Xiao-Xuan Zhang,Ying-Tian Xu

doi:10.1155/2017/5139703

Abstract

Bluetongue (BT), caused by bluetongue virus (BTV), is an arthropod-borne viral disease in ruminants. However, information about BTV infection in yaks in China is limited. Moreover, no such data concerning BTV in Tibetan sheep is available. Therefore, 3771 serum samples were collected from 2187 Tibetan sheep and 1584 yaks between April 2013 and March 2014 from Tibetan Plateau, western China, and tested for BTV antibodies using a commercially available ELISA kit. The overall seroprevalence of BTV was 17.34% (654/3771), with 20.3% (443/2187) in Tibetan sheep and 13.3% (211/1584) in yaks. In the Tibetan sheep group, the seroprevalence of BTV in Luqu, Maqu, Tianzhu, and Nyingchi Prefecture was 20.3%, 20.8%, 20.5%, and 19.1%, respectively. The seroprevalence of BTV in different season groups varied from 16.5% to 23.4%. In the yak group, BTV seroprevalence was 12.6%, 15.5%, and 11.0% in Tianzhu, Maqu, and Luqu counties, respectively. The seroprevalence in different seasons was 12.6%, 15.5%, 15.4%, and 9.0% in spring, summer, autumn, and winter, respectively. The season was the major risk factor concerning BTV infection in yaks (P < 0.05). The date of the BTV seroprevalence in Tibetan sheep and yaks provides baseline information for controlling BT in ruminants in western China.

Highlights

Bluetongue virus (BTV), a member of the genus Orbivirus, family Reoviridae, is the causative agent of bluetongue (BT), an infectious, noncontagious, arthropod-borne viral disease, which can infect a wide range of wild and domestic ruminants [1]
Six hundred and fifty-four (17.3%) out of 3771 serum samples were seropositive for BTV infection using an indirect ELISA test
According to conditional forward stepwise logistic regression, a significant difference was found between Tibetan sheep and yak groups (P < 0.05), for which the Odds ratios (ORs) was 1.653 (Table 2)

Summary

Introduction

Bluetongue virus (BTV), a member of the genus Orbivirus, family Reoviridae, is the causative agent of bluetongue (BT), an infectious, noncontagious, arthropod-borne viral disease, which can infect a wide range of wild and domestic ruminants [1]. The first case of BT in sheep in India was reported in 1964 [1]. This pathogen was firstly recorded in sheep in China in 1979 [2]. Transmission of BTV is mainly through biting of blood-feeding insect vectors of the genus Culicoides (Diptera: Ceratopogonidae). BTV infection in sheep and wild ruminants usually presents as symptoms of fever, nasal discharge, drooling of saliva, oral lesion, facial edema, depression, anorexia, and muscle weakness. Goats and cattle may be asymptomatic [3]

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