Serological and molecular epidemiology of Japanese Encephalitis in Zhejiang, China, 2015-2018.

Background: Shifts have occurred in the epidemiological characteristics of Japanese encephalitis (JE), extending from the molecular level to the population level. The aim of this study was to investigate the seroprevalence of JE neutralizing antibodies in healthy populations from different age groups in Zhejiang Province, and to conduct mosquito monitoring to evaluate the infection rate of Japanese encephalitis virus (JEV) among vectors, as well as the molecular characteristics of the E gene of isolated JEV strains.

Methodology/principal Findings: A total of 1190 sera samples were screened by a microseroneutralization test, including 429 infants (28d-11m) and 761 participants (2y-82y).

Sero-molecular epidemiology of enterovirus-associated encephalitis in Zhejiang Province, China, from 2014 to 2017.

Background: Recently, both sporadic and outbreak aseptic meningitis caused by enteroviruses have been reported in Zhejiang Province based on a surveillance system.

Methods: This study analysed the epidemiologic features, phylogenetic characteristics and prevalence of enterovirus neutralizing antibodies (nAbs) from 2014 to 2017 in Zhejiang Province.

Results: A total of 584 samples were collected.

Sero-Molecular Epidemiology of Japanese Encephalitis in Zhejiang, an Eastern Province of China.

Background: Sporadic Japanese encephalitis (JE) cases still have been reported in Zhejiang Province in recent years, and concerns about vaccine cross-protection and population-level immunity have been raised off and on within the public health sphere. Genotype I (GI) has replaced GIII as the dominant genotype in Asian countries during the past few decades, which caused considerable concerns about the potential change of epidemiology characteristics and the vaccine effectiveness. The aim of this study was to investigate the prevalence of JE neutralizing antibody and its waning antibody trend after live attenuated JE vaccine immunization.

[Etiological and molecular-epidemiological analysis on enterovirus associated encephalitis in Zhejiang, 2008-2012].

Objective: In order to investigate etiology and molecular-epidemiological characteristics of enterovirus associated encephalitis (EAE) in Zhejiang, 2008-2012. Method Cerebrospinal fluid and stool specimens were collected from suspected EAE patients, who were admitted to our hospitals. RD and Hep-2 cell lines were used to isolate enterovirus (EV).

[Genomic sequences of human infection of avian-origin influenza A(H7N9)virus in Zhejiang province].

Objective: To analyze the etiology and genomic sequences of human infection of avian-origin influenza A(H7N9)virus from Zhejiang province.

Methods: Viral RNA was extracted from patients of suspected H7N9 influenza virus infection and real-time RT-PCR was conducted for detection of viral RNA. All 8 segments of influenza virus were amplified by one-step RT-PCR and genomic sequences were assembled using the sequencing data.

[Study on the complete sequence of CA24 variant isolated during the acute hemorrhagic conjunctivitis outbreaks in Zhejiang province during 2002 to 2010].

Objective: To analyze the genetic characteristics of the complete sequence of coxsackievirus A24 variant (CA24v) isolated from acute hemorrhagic conjunctivitis (AHC) outbreaks in Zhejiang province during 2002 to 2010.

Methods: Complete sequences of CA24v epidemic strains isolated in different years were amplified under the RT-PCR assay, while the sequences of whole genome, VP1, and 3C region of Zhejiang strains were compared with epidemic strains isolated in other areas of China and abroad.

Results: The whole genome of Zhejiang CA24v strains isolated in 2002 and 2010 was 7456 - 7458 bp in length, encoding a polyglutamine protein which containing 2214 amino acid residues.

[Identification of genotype III Japanese encephalitis virus isolated in Zhejiang province].

Objective: To investigate the molecular characteristics and genotype of Japanese encephalitis virus (JEV) found in vector mosquitoes in Zhejiang province from 1982 to 1983.

Methods: A total of 3188 mosquitoes were collected in Dinghai district and Yiwu city in Zhejiang province, during year 1982 and 1983. The virus was isolated by C6/36 cell, and then identified by hemagglutination inhibition test.

[Study on the molecular characteristics of Japanese encephalitis virus living in vector mosquitoes, in Zhejiang province, 2009 - 2010].

Objective: To investigate the molecular characteristics of Japanese encephalitis virus (JEV) living in vector mosquitoes, from Zhejiang province.

Methods: A total of 13 620 mosquitoes were collected from the monitoring stations located in Cixi city and Xianju county in Zhejiang province, in July and August, 2009 - 2010. Nucleic acid of JEV from the mosquitoes was monitored by using real-time RT-PCR.

[Study on the pathological and molecular characteristics of viral meningitis outbreaks in Linhai county, Zhejiang province, 2004].

Objective: In order to confirm the causes of viral meningitis outbreaks in Linhai county, Zhejiang province in 2004, and to analyze the relationship between hereditary variation and evolution of the pathogen.

Methods: 60 cerebrospinal fluid (CSF) specimens were collected from the suspected patients. Virus strains from the specimens were isolated with RD and Hep-2 cell lines, and identified through neutralization test.

[Study on the etiological and molecular characteristics of aseptic meningitis epidemic in Zhejiang Province in 2002-2004].

In order to confirm the cause of the outbreak of aseptic meningitis in Zhejiang Province in 2002-2004, trace the pathogen and analyze the molecular characteristics, 271 cerebrospinal fluid (CSF) and faeces specimens were collected from suspected patients. The virus strains from the specimens were isolated with RD and Hep-2 cell lines. The VP1 and VP4/VP2 genes of the isolated viruses were sequenced, and their phylogenetic and homology trees were also constructed.

[Study on the pathological and molecular characteristics of AHC epidemic in Zhejiang Province in 2010].

To identify and trace the pathogen of acute hemorrhagic conjunctivitis (AHC) epidemic in Zhejiang Province in 2010. Viral nucleic acid of Enterovirus (EV) and Coxsackievirus A24 variant (CA24v) were directly detected by real-time RT-PCR from the conjunctival swab collected from suspected patients. The virus was isolated from the swab samples using Hep-2 cell.

[Molecular characteristics of norovirus in 3 outbreak-episodes of gastroenteritis in Zhejiang from 2008 to 2009].

Objective: To study the molecular characteristic of norovirus in 3 outbreaks of gastroenteritis in Zhejiang province.

Methods: During January 2008 and December 2009, fecal specimens of patients were collected from 3 outbreaks of acute viral gastroenteritis. Noroviruses were detected by Real-time RT-PCR.

[Genetic variation of the hemagglutinin and neuraminidase of influenza B viruses isolated in Zhejiang province during 1999 - 2010].

Objective: To characterize the genetic diversity of hemagglutinin (HA) and neuraminidase (NA) of influenza B viruses isolated in Zhejiang province during 1999 - 2010.

Methods: Respiratory specimens were collected from patients with flu-like syndrome during the influenza outbreaks or from the hospitals which carrying out influenza surveillance project in Zhejiang province. Samples were detected by real-time RT-PCR and isolated for influenza virus.

[Diagnosis of a dengue fever outbreak in Yiwu city, Zhejiang province in 2009 and its molecular tracing of the pathogen].

Objective: To determine a dengue fever outbreak in Yiwu city, Zhejiang Province in 2009 and to trace the origin of the pathogen.

Methods: The dengue virus IgM, IgG antibodies and viral nucleic acid were detected and virus was isolated using 40 serum samples from the suspected patients. The viral RNA of the isolated virus strains was extracted and the E gene was amplified by RT-PCR.

[Traceability of the A/H3N2 virus borne influenza pandemic in Zhejiang province, 1998].

Objective: To trace back to the influenza pandemic caused by A/H3N2 virus happened in Zhejiang province, 1998.

Methods: The whole genome of three isolates related to Zhejiang influenza virus was amplified through RT-PCR, and the identified sequences were aligned with the sequences downloaded from GenBank of the H3N2 strains which were circulating in other regions during 1995 to 1998. The crossing HAI titers of the reference strains were measured by HAI test and antigenic ratios were calculated.

[Analysis on VP1 gene variation of Coxsackie virus B5 for aseptic meningitis isolated from Zhejiang Province in 2008].

Objective: Study meningoencephalitis virus isolated from the Coxsackie B5 virus(CVB5 virus) VP1 gene characteristics of Zhejiang Province in 2008 and compare with other countries CVB5 prototype isolates, and to explore the relationship of variation of the Virus VP1 areas and epidemic viral meningoencephalitis

Methods: Hep-2 and RD cells in cerebrospinal fluid and stool specimens for virus isolation, positive isolates combination with intestinal type of serum. On the separation of virus extracted RNA, and then RT-PCR amplified VP, gene CVB5 virus fragments, and purification of sequencing products, using DNAMAN and Bioedit analytical processing software.

Results: The VP1 gene of CVB5 isolated from Zhejiang province meningoencephalitis viral in 2008 was 735bp.

[Detection of unknown virus from 2 case of aseptic meningitis epidemic using random primer PCR assay].

Objective: To develop a molecular biology method which can be applied to detect unknown virus fast and accurately.

Methods: The samples were separated from human cerebrospinal fluid by infected human rhabdomyosarcoma cells. After centrifugation and discarding the cell debris, the samples were subjected to ultracentrifugation to precipitate viral particles.

[Comparative analysis of measles genome between vaccine strain and wild-type strain in Zhejiang province of China].

Objective: To explore the distinction between wild-type strain MVi/Zhejiang, CHN/7.05/4 and vaccine strain Shanghai-191 at genome level.

Methods: After sequencing of measles wild-stain MVi/Zhejiang.

[Molecular epidemiology of norovirus in outbreaks of gastroenteritis in Zhejiang from 2006 to 2007].

Objective: To study the molecular epidemiological characteristics of Norovirus gastroenteritis outbreaks in Zhejiang.

Methods: During January 2006 and December 2007, fecal specimens of patients collected from outbreaks of acute viral gastroenteritis were tested for Norovirus. Epidemiological data were also collected.

[Molecular characteristics and its evolution of the complete genome of avian influenza H5N1 virus isolated in Zhejiang province from 2002 to 2006].

Objective: To analyze the molecular characteristics and evolution reassortment of the complete genome of avian influenza H5N1 virus isolated in Zhejiang province in recent years.

Methods: Complete genomes of avian influenza H5N1 viruses isolated in Zhejiang province from 2002 to 2006 were sequenced. Molecular and evolution reassortment characterization of these virus strains were analyzed by Mega 3.

[Study on the genetic characteristics of the avian influenza virus strain A/Zhejiang/16/2006].

Objective: To study the genetic characteristics of avian influenza virus strain A/Zhejiang/ 16/2006 which was isolated from the case first reported in Zhejiang province.

Methods: Complete genome of A/Zhejiang/16/2006 including eight segments were sequenced and compared on the genetic homogeneity with sequences of the similar strains provided through domestic and overseas sources.

Results: There were 11 amino acids showing differences on HA between A/Zhejiang/16/2006 and the H5N1 isolates of neighboring countries, but these differences had not affected the stability of glycosylation sites.

[Study on the neutralization capacity of different types of human measles virus vaccine and the epidemic strains].

Objective: To explore the neutralization capacities of different types of human serum to measles virus epidemic strains and vaccine strain.

Methods: Neutralization antibody (NT) to Shanghai 191 and measles virus isolates in 2005 were tested using acute and convalescent serum samples from diagnosed measles patients, children serum samples collected before and after vaccination and serum samples of migrant residents, from 3 different regions. Additionally, animal immune serum referring to vaccine strain and 3 epidemic strains were prepared and used to undergo crossing neutralization test with corresponding strains mentioned-above.

[Genetic analysis on HA1 and NA regions of influenza virus subtype A3 isolates of Zhejiang province during 1998-2005].

Objective: To study the relationship between influenza epidemic and genetic characteristic on HA and NA regions of influenza virus subtype A3 isolates of Zhejiang province in the recent years.

Methods: RNA of 25 influenza virus subtype A3 isolates, circulated in Zhejiang province during 1998 to 2005, was extracted. HA1 and NA regions were amplified and sequenced.