Molecular Epidemiological Of Borna Virus And West Nile Virus In The Animal Brain In Ili, Xinjiang

Borna disease virus (BDV) is a nonsegmented,negative single-stranded RNA virus and its replication and transcription occur in the cell nucleus.The BDV genome size is 8.9kb,which makes it the smallest of all known negative-stranded RNA viruses.The BDV genome contains six major open reading frames,which encoded nucleoprotein,phosphoprotein, transcriptional activator,matrix protein,surface glycoprotein and L-polymerase.The BDV p40 and p24 are present at high levels in infected cells and tissues,which is frequently used as serological assays and molecular methods.The BDV has a wide host range,including Horses,cattle,sheep,dogs,rats,rabbits.West Nile virus(WNV) is a nonsegmented,positive single-stranded RNA virus,a member of the genus Flavivirus,family Flaviviridae.It has a single open reading frame coding for three viral structural proteins(capsid C,premembrane M,envelope E) and seven non-structural proteins(NS1,NS2A,NS2B,NS3,NS4A,NS4B and NS5).The birds are the natural reservoir hosts.It can infect human,horses,birds and so on.WNV is maintained in the cycle involving birds and culicine mosquitoes,especially Culex pipiens.the person to person transmission also can occur through organ transplantation,blood and blood product transfusions,transplacentally and via breast milk.The BDV and WNV are both highly neurotropic.Persistent infection in brain could cause central nervous system(CNS) damage,such symtom as encephalitis, encephalomyelitis, epilepsy and etc,even to result in death.For the past several years,it broke out severe acute respiratory syndrome(SARS),"bird flu",H1N1 influenza viruses one after another in the world,and caused human exceeding panic,and resulted in hugeous economic loss.The virus was indigenous to Africa,Asia,Europe,and Australia,and especially in the Middle East.The Ili is in Xinjiang province, the frontier of our country,which is called'the silk road',and the important communication fortress in Eurasia.Nowadays, as China joining the WTO, trade exchange and the communication increasing,BDV and WNV was likely to be introduced from the neighboring countries to our country.Therefore, observing the epidemiology characterization of BDV and WNV in animals brain in Ili,Xingjiang,and preventing outbreaks were essential.While the detection of BDV and WNV in peripheral blood had been reported in Chongqing, Guizhou, Ningxia and other regions in China,but we lacked of large-scale research on animal brain infection.So,the BDV p24 gene and WNV E gene of animal brain tissues in Ili including 200 horses,75 donkeys and 100 shepherd dogs was detected by the fluorescence quantitative RT-PCR.Also,did the BDV p24 gene of 100 shepherd dogs in peripheral bloodThe result:1.The BDV p24 gene was found in 3 Ili horses, 4 Ili donkeys and 9 shepherd dogs,and the positive ratio is 1.5%,5.3% and 9%,respectively.The sequence of BDV p24 amplification production was totally the same as He/80 virus strain.2.There was no statistically significant difference between in peripheral blood and brain tissue in BDV p24 gene(P>0.05);3.No positive envelope gene fragment was detected in brain tissues.It was apparent that natural infection of BDV exist in the animals in Ili;the FQ-RT-PCR can be used to detect the BDV p24 gene segment in peripheral blood,which may reflect the infection of brain tissue,and was an effective method for the testing of the BDV infection in brain tissue in large-scale epidemiologic survey;the outbreak of West Nile virus infection would be impossible in Ili ,Xinjiang,in the near future.