Research on the association between Borna disease virus infection and the viral encephalitis

Objective To investigate the infection of Borna disease virus(BDV)in unidentified viral encephalitis patients in Ningxia in order to explore if the nucleotide sequence and amino acid sequence in BDV p24 were homophylic with the overseas standard strain.We also intended to investigate the correlation between BDV infection and the unidentified viral encephalitis patients from Ningxia to lay an experimental basis for etiological diagnosis,prevention and treatment on certain human neuropsychiatric disorders.Methods BDV p24 gene fragment was detected by nested reverse transcriptase polymerase chain reaction with fluorescence quantitative PCR(FQ-nRT-PCR)in peripheral blood mononuclear cells(PBMCs).Samples were from 59 unidentified viral encephalitis patients and 60 normal controls.For those positive products,gene sequence and amino acid sequence were then analyzed by BLAST and DNAsist 5.0.Results The positive rate of the BDV p24 gene fragment in PBMCs from the unidentified viral encephalitis(10.17%)was significantly higher than from the controls(0%)(P＜0.05).Data from the gene sequence on those positive products showed BDV p24 fragment in the patients with unidentified viral encephalitis from Ningxia was homophylic with strain H3915 detected from ill horses(97.67%),as well as with the strain H1766(96.51%)and strain V(95.35%).However,their amino acid sequences remained the same.Conclusion BDV infection might probably have existed in the unidentified viral encephalitis patients of Ningxia.The gene sequence seemed to be homophylic with that of standard strain H1766 and strain V,especially with strain H3915. Key words: Borna disease virus; Viral encephalitis; Fluorescence quantitative nested reverse transcriptase PCR