Etiology and molecular-epidemiological characteristics of viral meningoencephalitis of Zhejiang province in 2013 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate pathogens and molecular-epidemiology characteristics of viral meningoencephalitis in the monitoring sites of Zhejiang province, 2013.</p><p><b>METHODS</b>Cerebrospinal fluid and/or stool specimens were collected from suspected patients admitted to the monitoring hospitals in southern and northern Zhejiang province. Such specimen were subject to real-time qPCR for the detection of Human enterovirus (HEV), Japanese encephalitis virus (JEV), Mumps virus (MuV), Herpes simplex virus (HSV) and Cytomegalovirus (CMV). HEVs were isolated using the RD and Hep-2 cell lines, while VP1 genes from all HEV-positive isolates or RNA-positive specimen were amplified, sequenced, for homology and evolution analysis.</p><p><b>RESULTS</b>92 (38.5%) of the 239 samples collected from 229 patients were detected as virus nucleic acid positive, including 87 HEV positive samples, 1 MuV positive, 2 HSV positive, and 2 CMV positive; of the 87 HEV positive samples, 38 were further determined to be Coxsackievirus (CV) and 49 as Echovirus (E). 56 HEV strains were isolated from 239 (23.4%) samples. From the 31 cerebral fluid specimen of nucleic acid positive yet virus isolation negative, the most specimen were identified with E9 (9 specimen), followed by CVA9 (8 specimen); the viral serotype of Zhejiang province HEV were CVA9, CVB4, CVB5, E6, E7, E9, E11, E14, E16, E25 and E30, respectively. Predominant epidemic strains identified at southern and northern Zhejiang province were CVB5 and E6 respectively. The phylogenetic analysis of VP1 gene showed that all the HEV isolates in Zhejiang province were HEV-B.</p><p><b>CONCLUSION</b>The HEV-B was the main pathogen for viral meningoencephalitis in Zhejiang province in 2013, including 11 serotypes, while E7 was the first time to be isolated in Zhejiang province. The predominant isolates were CVB5 and E6 in southern and northern Zhejiang province respectively. The positive rate of viral nucleic acid detection was significantly higher than that of viral isolation. Regular EV isolation method was exposed to the risk of missing-detection of E9 and CVA9.</p>

Study on the genotypic characteristics of Japanese encephalitis virus and serology in the healthy population of Zhejiang province, 2012-2013 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the genotypic characteristics and the neutralizing antibody levels of Japanese encephalitis virus (JEV) and Japanese encephalitis (JE) in both vector mosquitoes and in healthy people of Zhejiang province.</p><p><b>METHODS</b>Virus was isolated from mosquitos sampled from the Monitoring Stations located in Xianju county during 2012 to 2013. Phylogenetic and homological studies were carried out on the E gene. A total of 1 263 blood specimens from 642 healthy people were collected before and after the seasons of JE epidemics. JEV neutralizing antibody was detected by the micro-neutralization test.</p><p><b>RESULTS</b>Twenty-five JEV strains were isolated from a total of 11 650 mosquitoes. The identity of nucleotide appeared as 87.8%-99.7% both from 2012 to 2013 and from 1982 to 2010 while as 87.7%-88.0% with vaccine strain SA14-14-2, in Zhejiang. The phylogeny tree of E gene indicated that the newly isolated virus belonged to genotype I but no mutation of amino acid sequence coding conformational epitope was identified in the envelop protein. Both positive rates and the geometric mean titer (GMT) of neutralizing antibody in healthy people were 31.5%-42.0% and 1 : 2.56-1 : 3.53 in Xianju county, during 2012 and 2013, respectively. Both of the two positive rates (χ(2)≤1.76, P > 0.05) and the two GMTs (u≤0.64, P > 0.5) for antibodies pre or post the epidemic season did not show significant differences.</p><p><b>CONCLUSION</b>JEV isolated in Xianju during 2012 and 2013 belonged to genotype I. The positive rates of JEV neutralizing antibody from healthy people in Xianju were less than 42.0%, which showed no significant differendes pre or post JE epidemic season.</p>

Study on the genotypic characteristics of Japanese encephalitis virus and serology in the healthy population of Zhejiang province,2012-2013 / 中华流行病学杂志

Objective To understand the genotypic characteristics and the neutralizing antibody levels of Japanese encephalitis virus(JEV)and Japanese encephalitis(JE)in both vector mosquitoes and in healthy people of Zhejiang province. Methods Virus was isolated from mosquitos sampled from the Monitoring Stations located in Xianju county during 2012 to 2013. Phylogenetic and homological studies were carried out on the E gene. A total of 1 263 blood specimens from 642 healthy people were collected before and after the seasons of JE epidemics. JEV neutralizing antibody was detected by the micro-neutralization test. Results Twenty-five JEV strains were isolated from a total of 11 650 mosquitoes. The identity of nucleotide appeared as 87.8%-99.7% both from 2012 to 2013 and from 1982 to 2010 while as 87.7%-88.0%with vaccine strain SA14-14-2,in Zhejiang. The phylogeny tree of E gene indicated that the newly isolated virus belonged to genotypeⅠ but no mutation of amino acid sequence coding conformational epitope was identified in the envelop protein. Both positive rates and the geometric mean titer(GMT)of neutralizing antibody in healthy people were 31.5%-42.0%and 1∶2.56-1∶3.53 in Xianju county,during 2012 and 2013,respectively. Both of the two positive rates(χ2≤1.76,P>0.05)and the two GMTs(u≤0.64,P>0.5)for antibodies pre or post the epidemic season did not show significant differences. Conclusion JEV isolated in Xianju during 2012 and 2013 belonged to genotypeⅠ. The positive rates of JEV neutralizing antibody from healthy people in Xianju were less than 42.0%,which showed no significant differendes pre or post JE epidemic season.

Study on the genotypic characteristics of Japanese encephalitis virus and serology in the healthy population of Zhejiang province,2012-2013 / 中华流行病学杂志

Objective To understand the genotypic characteristics and the neutralizing antibody levels of Japanese encephalitis virus(JEV)and Japanese encephalitis(JE)in both vector mosquitoes and in healthy people of Zhejiang province. Methods Virus was isolated from mosquitos sampled from the Monitoring Stations located in Xianju county during 2012 to 2013. Phylogenetic and homological studies were carried out on the E gene. A total of 1 263 blood specimens from 642 healthy people were collected before and after the seasons of JE epidemics. JEV neutralizing antibody was detected by the micro-neutralization test. Results Twenty-five JEV strains were isolated from a total of 11 650 mosquitoes. The identity of nucleotide appeared as 87.8%-99.7% both from 2012 to 2013 and from 1982 to 2010 while as 87.7%-88.0%with vaccine strain SA14-14-2,in Zhejiang. The phylogeny tree of E gene indicated that the newly isolated virus belonged to genotypeⅠ but no mutation of amino acid sequence coding conformational epitope was identified in the envelop protein. Both positive rates and the geometric mean titer(GMT)of neutralizing antibody in healthy people were 31.5%-42.0%and 1∶2.56-1∶3.53 in Xianju county,during 2012 and 2013,respectively. Both of the two positive rates(χ2≤1.76,P>0.05)and the two GMTs(u≤0.64,P>0.5)for antibodies pre or post the epidemic season did not show significant differences. Conclusion JEV isolated in Xianju during 2012 and 2013 belonged to genotypeⅠ. The positive rates of JEV neutralizing antibody from healthy people in Xianju were less than 42.0%,which showed no significant differendes pre or post JE epidemic season.

First confirmation of new bunyavirus-infected patients in Zhejiang province and molecular identification of the isolated virus / 中华微生物学和免疫学杂志

ObjectiveTo determine the potential natural foci of new bunyavirus,and isolate and identify the new bunyavirus strain in sera from suspected new bunyavirus-infected patients.MethodsImmunofluorescence assay was used to detect the antigens of new bunyavirus in different tissue specimens of wild rodent animals in Tiantai area of Zhejiang province.Fluorescence quantitative real-time RT-PCR was applied to detect the viral nucleic acid in sera of suspected new bunyavirus-infected patients and the amplification products were analyzed by sequencing.The new bunyavirus in the pateints'sera was isolated using Vero cells.Using nucleocapsid protein encoding gene of new bunyavirus as the target gene,the isolated suspected new bunyavirus strain was identified by RT-PCR and sequencing of the amplification product.Moreover,sequence identity of the amplification product of nucleocapsid protein encoding gene of new bunyavirus was analyzed and compared.ResultsOf the 70 wild rodent animals,5.71% were positive in the immunofluorescence assay.The fluorescence quantitative real-time RT-PCR confirmed that two of the four detected patients'serum specimens were positive.One suspected strain of new bunyavirus was isolated from one pf the two positive patients'serum specimens.The results of RT-PCR and sequencing confirmed that the viral strain exactly belongs to new bunyavirus with 92.2% sequence identity to that of the new bunyavirus isolates in Hubei province but distinct with the new bunyavirus isolates from other areas in China.ConclusionThe presence of natural foci of new bunyavirus and new bunyavirus-infected patients in Zhejiang province are firstly confirmed by this study.There is a geographical diversity of the distribution of new bunyavirus in different groups.

Severe acute respiratory syndrome-associated coronavirus genotype and its characterization / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To study the severe acute respiratory syndrome (SARS)-associated coronavirus genotype and its characteristics.</p><p><b>METHODS</b>A SARS-associated coronavirus isolate named ZJ01 was obtained from throat swab samples taken from a patient in Hangzhou, Zhejing province. The complete genome sequence of ZJ01 consisted of 29,715 bp (GenBank accession: AY297028, version: gi: 30910859). Seventeen SARS-associated coronavirus genome sequences in GenBank were compared to analyze the common sequence variations and the probability of co-occurrence of multiple polymorphisms or mutations. Phylogenetic analysis of those sequences was done.</p><p><b>RESULTS</b>By bioinformatics processing and analysis, the 5 loci nucleotides at ZJ01 genome were found being T, T, G, T and T, respectively. Compared with other SARS-associated coronavirus genomes in the GenBank database, an A/G mutation was detected besides the other 4 mutation loci (C:G:C:C/T:T:T:T) involved in this genetic signature. Therefore a new definition was put forward according to the 5 mutation loci. SARS-associated coronavirus strains would be grouped into two genotypes (C:G:A:C:C/T:T:G:T:T), and abbreviated as SARS coronavirus C genotype and T genotype. On the basis of this new definition, the ZJ01 isolate belongs to SARS-associated coronavirus T genotype, first discovered and reported in mainland China. Phylogenetic analysis of the spike protein gene fragments of these SARS-associated coronavirus strains showed that the GZ01 isolate was phylogenetically distinct from other isolates, and compared with groups F1 and F2 of the T genotype, the isolates of BJ01 and CUHK-W1 were more closely related to the GZ01 isolate. It was interesting to find that two (A/G and C/T) of the five mutation loci occurred in the spike protein gene, which caused changes of Asp to Gly and Thr to Ile in the protein, respectively.</p><p><b>CONCLUSION</b>Attention should be paid to whether these genotype and mutation patterns are related to the virus's biological activities,epidemic characteristics and host clinical symptoms.</p>