OBJECTIVETo detect the relations between incidence rate of the epidemical encephalitis B and related factors, to provide a simple, valid and practical new method for forecasting encephalitis B eipdemics.

METHODSConnection number between the incidence rate of encephalitis B and the historical forecast factors was computed, before ranking the first, second and the third principal factor, to remove the factor with the smallest value in the light of the connection number before comparing the newest value of forecast factors with the same kind of history while the most nearly value becoming the forecasting factor value and to establish a forecasting equation according to the factor value and the consistent degree of the incidence rate of encephalitis B at that time. Finally, to put into the new factor value to get this forecast value under this equation. Assuming that there are n' (n' >or= 2) forecast factors, this time forecast value can then be directly obtained from the average of these estimate values.

RESULTSUsing above forecast method to forecast the incidence rate of encephalitis B at certain place and year, the predicting value is very much close to the actual incidence rate. Difference between the predicting value forecasted by the above-mentioned method and the actual incidence rate is only 0.0264/100 000 with an accurate rate of 97.94%.

CONCLUSIONThis principal factor analysis forecast method based on connection number in forecasting the incidence rate of encephalitis B prevention is acceptable.

China ; epidemiology ; Encephalitis Virus, Japanese ; Encephalitis, Viral ; epidemiology ; virology ; Factor Analysis, Statistical ; Forecasting ; Humans ; Incidence

The World Health Organization declared that a new strain of novel swine-origin influenza A (H1N1) virus was responsible for the pandemic infection in June 2009. We report a case of encephalitis diagnosed as the H1N1 virus infection. We describe a 17-year-old patient who had a seizure attack, diagnosed with a H1N1 virus infection via real time reverse-transcriptase polymerase chain reaction (RT-PCR). The H1N1 virus infection can be causative of the encephalitis, as with other influenza virus infections. Careful monitoring is essential for reducing complications.
Adolescent ; Animals ; Encephalitis, Viral/*diagnosis/*virology ; Humans ; Influenza A Virus, H1N1 Subtype/*pathogenicity ; Male ; Swine/*virology

Until the recent emergence/re-emergence of human-pathogenic viruses in ticks, tick-borne viruses have been neglected as causative agents of human disease (particularly in China). To gain insight into the diversity of tick-borne viruses in Xinjiang Uygur Autonomous Region (northwestern China), we conducted illumina deep sequencing-based screening for virus-derived small RNAs in field-collected Ixodes persulcatus ticks. We found 32, 631 unique virus-matched reads. In particular, 77 reads mapped to the tick-borne group within the genus of Flavivirus, and covered 3.8%-2.4% viral genomes. In addition, 32 unique reads were specific to the Siberian subtype of tick-borne encephalitis viruses (TBEV-Sib) which have never been reported in Chinese TBE loci. We confirmed the potential existence of TBEV-Sib by amplification (using reverse transcription-polymerase chain reaction) of genomic fragments from the envelope gene or 3' genomic terminus from the pools of examined ticks. Both sequences demonstrated high homology to TBEV-Sib strains attached geographically to southern Siberia with nucleotide identity of 97.2%-95.5% and aminoacid identity of 99.4%-98.3%, respectively. In conclusion, we report, for the first time, detection of TBEV-Sib in the natural TBE loci of China. These novel data may provide genetic information for further isolation and epidemiologic investigation of TBEV-Sib.
Animals ; Arachnid Vectors ; virology ; China ; Encephalitis Viruses, Tick-Borne ; classification ; genetics ; isolation & purification ; Encephalitis, Tick-Borne ; transmission ; virology ; Genome, Viral ; Humans ; Ixodes ; virology ; Molecular Sequence Data ; Phylogeny

OBJECTIVESequence and analysis the complete nucleotide of the Japanese encephalitis virus (JEV) newly strain SD08-10, isolated in 2008 in Shandong, China in order to understand the characterization of the virus.

METHODSOverlapping primers were designed according to the full-length genomes in GenBank. RT-PCR was used to amplify the fragments and the full-length genome was obtained by sequencing and splicing. Using the computer software to analysis the nucleic acid data, deduced amino acid sequence and phylogenetic tree, including Clustal X (1.8), DNASTAR, GENEDOC (3.2).

RESULTSThe result of sequence analysis shows that the genome of SD08-10 strain was 10 965 nucleotides long. An open reading frame from 96 to 10 392 including 10 296 nucleotides is capable of coding for a 3432 amino acid polyprotein. Compared with the live attenuated vaccine strain SA-14-14-2 in China, there was 1253 nucleotide difference and 82 amino acid divergence. Comparison of the complete genome sequences with 59 different JEV isolates showed a 0.7%-18.9% nucleotide sequence divergence among them, which resulted in 0.1%-5.2% amino acid sequence divergence. Phylogenetic analysis of full-length genome showed that the SD08-10 strain was belonging to genotype I.

CONCLUSIONAnalysis based on the complete genome sequences of different JEV isolates showed that the SD08-10 strain isolated in 2008 in Shandong was belonging to genotype I and close to SH17M-07 isolated in 2007 in China.

China ; Encephalitis Virus, Japanese ; classification ; genetics ; isolation & purification ; Encephalitis, Japanese ; virology ; Genome, Viral ; Molecular Sequence Data ; Phylogeny

Animals ; Encephalitis, Viral ; epidemiology ; transmission ; virology ; Humans ; Incidence ; Malaysia ; epidemiology ; Nipah Virus ; isolation & purification

OBJECTIVETo investigate the molecular basis of pathogenicity of Japanese encephalitis virus (JEV) by sequencing of complete nucleotide sequence and analyze the characteristics of full-length genome of genotype I Japanese encephalitis virus strains (GZ56) which was isolated from the first cerebrospinal fluid (CSF) of Japanese encephalitis patients.

METHODSThe complete nucleotide sequence was obtained by RT-PCR and sequencing was performed directly. Bioinformatics was used to analyze the nucleic acid data, deduced amino acid sequence and phylogenetic trees.

RESULTSThe result of sequence analysis showed that the genome of GZ56 strains had 10 965 nucleotides, which coded for a 3432-amino acid polyprotein. Phyolngenetic analysis based on full-length genome showed that GZ56 strains and M-28 strains which were the first isolated from mosquitoes in Yunnan in 1977 were in the same evolutionary branch. GZ56 strains belongs to genotype I of Japanese encephalitis virus, the homology of genome ranged from 96.2% to 98.6% in nucleotide and from 98.2% to 99.7% in amino acid sequences respectively when compared with selected genotype I of JEV strains in GenBank. There were 11 amino acid divergences in E protein when compared with the JEV inactivated P3 strain but they are not the key virulence sites. However, there were 14 amino acid divergences in E protein when compared with the JEV live attenuated vaccine SA14-14-2 strain and 8 amino acid divergences were the key virulence sites.

CONCLUSIONThis study indicated that the full length of genome GZ56 strains had no ignificant change. It can be hypothesized from genomic level that the currently available JEV vaccines(inactivated and live attenuated) can protect against GZ56 strains infection, meanwhile, the JEV live attenuated vaccine (SA14-14-2) formulation conferred higher levels of protection.

Computational Biology ; Encephalitis Virus, Japanese ; classification ; genetics ; isolation & purification ; Encephalitis, Japanese ; virology ; Enzyme-Linked Immunosorbent Assay ; Genome, Viral ; Genotype ; Japanese Encephalitis Vaccines ; immunology ; Phylogeny ; Sequence Analysis, DNA

OBJECTIVETo analyze the genetic characterization of the complete genome from a human coxsackievirus B3 strain A103/KM/09 isolated in Yunnan province, 2009.

METHODSBy using RT-PCR, all the eight fragments which containing about 1000 nucleotides and covering full viral genome, were sequenced. By using Mega 5.05,Geneious, RDP 3 and SimPlot 3.5.1 software, sequences were aligned with other enterovirus reference sequences. Phylogenetic and recombination analysis were also carried out.

RESULTSThe A103/KM/09 isolate genome showed 7389 nucleotides in length , encoding for 2185 amino acids. In the complete genome, the homology of nucleotide and amino acid among the seven coxsackievirus B3 isolates were 81.0%-88.0% and 95.7%-98.0%, respectively. There appeared 81.0% and 95.7% homology when compared with that of Nancy prototype strain. Results from the Phylogenetic analysis showed that the coxsackievirus B3 formed five distinct clades, I-V. Nucleotide divergence rates between clades were 16.2%-24.3% . The A103/KM/09 strain belonged to clade V. Clade V was further divided into four sub-clades,A-D. The nucleotide divergence between sub-clades was 4.3%-11.4%. Putative recombinant event for A103/ KM/09 was detected.

CONCLUSIONAll coxsackievirus B3 isolates could be divided into five clades, with A103/KM/09 strain belonged to Clade V-D. Evolution of coxsackievirus B3 had occurred in China.

Base Sequence ; Child, Preschool ; China ; epidemiology ; Encephalitis, Viral ; epidemiology ; virology ; Enterovirus B, Human ; genetics ; isolation & purification ; Enterovirus Infections ; epidemiology ; virology ; Genome, Viral ; Humans ; Male ; Phylogeny ; Viral Proteins ; genetics

OBJECTIVETo learn about the pathogen spectrum and genetic characterization of HFMD with encephalitis in Yantai city.

METHODSStool samples and cerebrospinal fluids (CSF) collected from HFMD with encephalitis cases in Yantai. Virus were isolated from stool samples and identified by fluorescence reverse transcription-polymerase chain reaction. The VPl region was amplified and sequenced from positive specimens. Genetic characterization was identified by sequence analysis.

RESULTSGetting 3 virus strains from 10 stool specimens and all of them belong to EV71. The nucleotide and amino acid homogeneity with the representative isolates of C4a were 98%-99% and 98.90%-99.45% respectively.

CONCLUSIONThe pathogen of HFMD with encephalitis in Yantai city were mainly EV71 wich belong to subgenogroup C4 cluster C4a.

Capsid Proteins ; genetics ; Encephalitis, Viral ; virology ; Enterovirus A, Human ; classification ; genetics ; isolation & purification ; Hand, Foot and Mouth Disease ; complications ; virology ; Humans ; Phylogeny

In order to reveal the phenotypic characteristics of 17 JE virus strains isolated from different years, plaque sizes, mice neurovirulence and mice neuroinvasiveness of the isolates were studied and compared. BHK21 cell monolayers were used for testing the plaque sizes. The virus neurovirulence was tested in 9-11g mice inoculated intracerebrally and the virus neuroinvasiveness was tested in 9-11g and 14-16g by subcutaneous inoculation. Results showed that all the viruses produced clear plaques on the BHK21 cell monolayers with different sizes and all the virus strains appeared high neurovirulence in the mice with higher than lg8. 0/0.03 mL virus titers, while no apparent difference among them. The neuroinvasiveness (subcutaneous virulence) tested in the 9-11g mice had shown a little difference, but when tested in the 12-14 g mice,the difference was apparent. The results demonstrated that JEV in nature were highly neurovirulent with no apparent difference. However the neuroinvasiveness of the JEV in nature was greatly different, which didn't relate to the years of isolation and genotypes, but most of the viruses isolated from patients showed higher neuroinvasiveness.
Animals ; Cell Line ; China ; Culicidae ; virology ; Encephalitis Virus, Japanese ; genetics ; isolation & purification ; pathogenicity ; Encephalitis, Japanese ; virology ; Genotype ; Humans ; Mice ; Phenotype ; Viral Plaque Assay ; Virulence

The biological and genetic characteristics of a highly neurovirulent JE virus strain SA4 were studied. Mice were inoculated intracerebrally with strain SA4 and SA14, and observed for 14 days, respectively. On different days, mice brains were harvested for titrations of the virus content in the brains. Full-length genome of SA4 was sequenced and compared with SA14 as well as other JE virus strains in the world. The results indicated that the mice inoculated by SA4 induced sickness and death more rapidly (24 hours faster) than those induced by the SA14. The virus titers in the brains of mice infected with SA4 were 0.5-1.0 lg PFU/mL higher than that infected with SA14. The sequence comparison indicated that the nucleotide and amino acid homology between SA4 and the other 21 JE strains were 84.6%-99.0% and 95.2%-99.7% respectively. Comparison with strain SA14 revealed that there were 17 amino acid differences between the two strains, of which 5 were in the E protein region. The results demonstrate that strain SA4 is a highly neurovirulent strain. The substitutions of the 17 amino acids in the SA4 strain can be the molecular basis for the biological characteristics of high neurovirulence.
Animals ; Brain ; virology ; Encephalitis Virus, Japanese ; classification ; genetics ; isolation & purification ; pathogenicity ; Encephalitis, Japanese ; mortality ; virology ; Genotype ; Humans ; Mice ; Sequence Analysis ; Viral Envelope Proteins ; genetics ; Virulence