The Epidemiological Investigation Of Bluetongue Infected Cattles And Sheep In Inner Mongolian Areas In 2015 And The Preliminary Separation And Identification Of Pathogeny

Bluetongue(BT) is an animal infectious diseases caused by bluetongue virus via culicoides biting animals, the cud chewers which are susceptible to bluetongue,include sheep,goat,cattle and deer etc. The live stocks infected virus usually manifest high temperature continued,high edema and erosion of oral mucosa etc. The lethality of bluetongue is 25%-30%,and could reach as high as 90% in particular cases. The animal products trade and agricultural and animal husbandry production have been caused heavy losses.We collected 2740 healthy sheep venous blood and 472 healthy cow venous blood from ALXA League,Wuhai,BayanNur,Ordos,Baotou,Hohhot, Ulanqab,xilinhot,Chifeng,Tongliao,Hinggan League Inner Mongolia. The results show 1017 positive sheep and the infection rate are 37.11%; 60 positive cow and the infection rate are 12.71%. Different breeding methods also affect the infection rate of BT. The infection rate of barn feeding animals affected by BT is 35.48% (532/1474),and that is 40.20% (509/1266)of free-ranging animals. We collected the blood samples of cud chewers in monitoring point to inoculate to chicken embryo of 10-11days,C6/36 cells,BHK-21 cells and isolated virus by the way of subculturing. Then we acquire RNA from the diseased cells culture and conducted RT-PCR with the specific oligonucleotides primers of NS1 gene. We confirmed that samplesb had been infected BT with the methods of morphological observation and phylogenetic analysis. Epidemic disease shows:bluetongue widely exists in livestocks in Inner Mongolia,both cattles and sheep could be infected,the infection rate of sheep is higher than cattles and goat; 6-9 months are optimum seasons for culicoides breeding and also the fastigium of bluetongue; Inner Mongolia is high-prevalence area of bluetongue positive serum and the detection rate of serum in western cities, such as Bayannur, Baotou,Hohhot etc is higher than eastern cities,such as tongliao,Hinggan league. In terms of all Inner Mongolia, the seroprevalence of bluetongue in low latitudes is higher than high latitudes.