Objective: To gain detailed insights into the Borna disease virus infection and its genetic characteristics and phylogeny in Ningxia, China.
Methods: BDV p24 segment were detected by fluorescence quantitative nested RT-PCR from peripheral blood mononuclear cells of 119 patients with viral encephalitis, 205 cattle, 978 sheep, 46 patients with cerebrovascular diseases and 13 patients with multiple sclerosis. Data from phylogenetic analysis on BDV p24 positive samples together with those from the positive gene sequences of animals and patients in the previous studies in Ningxia, were compared to the 29 sequences provided by the GenBank from 7 animals in 5 countries. Both the sequence homologous similarity of the nucleotide and amino acid sequences were analyzed and gene phylogenetic tree was reconstructed.
Results: Data from 23 collections of positive test samples, together with the ones from early detection of gene sequence analysis, showed that the homologous similarity sequences of both nucleotide and amino acid was between 95.3% and 100.0% and highly homophylic with HE80 that detected from ill horses in Germany. One part of nucleotide sequences formed the 'Ningxia independent branch' while the other one belonged to the 'Germany-Ningxia-Japan mixed branch'. There was a high identity within the branch.
Conclusion: A Ningxia independent BDV strain from geographical origin might exist while the epidemic strains were imported with multiple sources.