Surveillance analysis of influenza in Mainland China during 2016-2017 season / 中国人兽共患病学报

To analyze and summarize the surveillance results and epidemic situation of influenza in mainland China during 2016-2017 surveillance season,we collected ILI monitoring data and influenza outbreak data download from"China Influenza Surveillance Information System"and"Public Health Emergency Information Management System"in mainland China during 2016-2017 surveillance season.The results showed that influenza activity did not appear obvious summer peak in southern provinces,and the autumn and winter flu seasons were earlier than that during last season in both southern and northern prov-inces,while the epidemic peak level was lower than 2015-2016 surveillance season.Throughout the year,influenza predomi-nant viruses throughout the country underwent the alternation of type B,A (H3N2)and H1N1,respectively.The total num-ber of outbreaks of ILI reported in the country was less than that in 2015-2016.According the surveillance,we suggested that all regions continue to attach great importance to recent influenza virus activity,pay attention to the global epidemic situation and that of our country,strengthen the analysis and use of surveillance data,trace the activity levels,mutation and resistance change of influenza virus,carry out the flu outbreak investigation and disposal work timely.

Identification of crocus sativus and its adulterants from Chinese markets by using DNA barcoding technique

Background: saffron [Crocus sativus L.] is a common but very expensive herbal medicine. As an important traditional medicine, it has an outstanding effect in treating irregular and painful menstruation. Recently, the over-demand tendency of saffron results in an unusual phenomenon in the medicinal markets. Adulterants and saffron-like substitutes are intentionally mixed into medicinal markets and pharmacies or online stores, affecting drug safety and food quality

Objectives: Our study aimed to identify saffron from its adulterants via DNA barcoding

Materials and Methods: Samples [13 saffron + 4 others containing Carthamus tinctorius or Chrysanthemum x morifolium] obtained from 12 different provinces of China. Through DNA barcoding, samples were compared using three candidate markers, trnH-psbA, rbcL-a and ITS2

Results: trnH-psbA and rbcL-a were capable of distinguishing different accessions. ITS2 could identify samples even at intra-specific level. According to these three barcodes, four samples were identified saffron-like substitutes

Conclusions: the adulterant rate in Chinese markets reaches as high as 33.33% that may cause health risks and further may reduce saffron efficacy once is being used as herbal remedy. In order to make a distinction between C. sativus with other genera as adulterants, DNA barcoding is suggested

Selection pressure analysis of H3N2 influenza virus from China between 1992 and 2012 / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>In order to investigate the relationship between selection pressure and the prevalence of antigenic clusters, we sequenced and analyzed the H3N2 influenza virus from China between 1992 and 2012.</p><p><b>METHODS</b>The H3N2 influenza virus (n = 1206) in China from 1992 to 2012 was analyzed, include global selection pressure and sites positive selection pressure analysis.</p><p><b>RESULTS</b>Considering all the H3N2 influenza viruses during these 21 years, a total of four amino acid sites subject to positive selection. The global selection pressure varies with the variation of different antigenic clusters and three years with peak bottom selection pressure were identified.</p><p><b>CONCLUSION</b>The global selection pressure rise from the peak bottom, a new antigenic clusters will appear andprevalent in the population, indicating the best time to replace the vaccine strain.</p>

Reverse genetics platform construction of influenza pandemic virus strain / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>Reverse genetics was used to construct the platform of flu pandemic strain A/California/07/2009 (H1N1).</p><p><b>METHODS</b>Eight genes fragements were amplified and ligated with bidirectional vector, recombinant plasmids were co transfected to the 293 T cells and rescued the virus. Gene sequencing, antigenic analysis and growth property were used to evaluate the rescued virus.</p><p><b>RESULTS</b>Rescued virus show the genes sequence correct, keep the same antigenicity and similar growth property compared with wild type virus.</p><p><b>CONCLUSION</b>The pandemic virus reverse genetics platform of A/California/07/2009 (H1N1) were built. Based on this platform, rescued virus hold the similarity of antigenicity and growth ability with wild type virus.</p>

Emerged Pdm09 influenza virus increased purifying selection of seasonal H1N1 influenza virus / 病毒学报

Pdm09 virus outbreak occurred in Mainland China in May 2009, a few months later, the prevalence of seasonal H1N1(sH1N1) influenza virus that already circulated in human for tens of years began to decline and disappeared afterwards. To identify the reason for the rapid decline of sH1N1 in mainland China, we sequenced the HA1 of sH1N1 during 2006-2011, and then analyzed the selective pressure in different phases. Our results showed before Pdm09 outbreak, the omega value was 0. 36 while after Pdm09 outbreak the omega value was 0. 28 and significant difference (t test, P<0. 05) was identified. We concluded that sH1N1 obtained stronger purifying selection after Pdm09 outbreak in China. This might one of the major reasons causing the disappearance of sH1N1 in human.

Virological characterization of influenza B virus in mainland China during 2011-2012 / 病毒学报

In order to understand the prevalence and variation of influenza B viruses, the antigenic and genetic characteristics of influenza B viruses circulating in Mainland China during April, 2011 to March, 2012 were analyzed. The results showed the B Victoria lineage viruses were much more prevalent than B Yamagata lineage during this period, phylogenetic analysis showed vast majority of Victoria lineage viruses belong to genetic group 1, intra-clade reassortant between HA1 and NA gene was identified in a minor proportion of the viruses. 72.8% of the B/Victoria-lineage viruses were antigenically closely related to the vaccine strain B/Brisbane/60/2008. B Yamagata component was not included in the trivalent influenza vaccine in China during the study period, however vast majority of B Yamagata lineage viruses were antigenically and genetically closely related to the representative virus B/Hubei-Wujiagang/158/2009(97.8%) and B/Sichuan-Anyue/139/2011(85.2%) in China, reassortant between HA1 and NA was not identified in B Yamagata lineage viruses. Overall, the predominant circulating influenza B viruses in 2011-2012 season in China were matched by current influenza vaccine and the selected representative viruses were proved to represent the antigenic and genetic characteristics of the circulating viruses.

Development of a real-time reverse transcriptase PCR assay for detection of E119V amino acid change in neuraminidase of influenza A (H3N2) using the TaqMan-MGB probe / 中华预防医学杂志

<p><b>OBJECTIVE</b>To develop a rapid duplex Real-time reverse transcription PCR (rRT-PCR) method to detect E119V mutation on neuraminidase (NA) of influenza A(H3N2) subtype with drug resistance to oseltamivir.</p><p><b>METHODS</b>Twenty-six NA genes of influenza A(H3N2) virus between 2000 and 2012 in GenBank database were selected as the target genes, and specific TaqMan-MGB probe was designed to target the E119V amino acid change in neuraminidase protein. rRT-PCR was then performed and evaluated for the sensitivity, specificity and reproducibility using virus with E119V mutation and clinical samples.</p><p><b>RESULTS</b>This study described the validation of a highly sensitive and specific duplex rRT-PCR for detection of substitutions leading to the E119V amino acid change in NA protein of influenza A(H3N2). Fluorescence signals could be detected even when diluted a A (H3N2) virus (HA = 8) into 10(-5) and linear correlation between the logarithm of the viral titer with the Ct values was observed. In addition, the assay was highly specific in that there was no cross-react with other respiratory viruses, nor did two TaqMan-MGB probes. E119V substitution in quasispecies with both sensitive and resistant viruses could be detected as well. The limit of detection was 5% for quasispecies with high concentrations and 50% for quasispecies with low concentrations. The average coefficient of variation (CV) for within-run assays was 2.32% and 0.57% for H3N2-119E and H3N2-119V primer/probe sets separately, 1.77% and 0.97% for average CV of between-run assays, which exhibited good repeatability. Sequence analysis of twenty NA genes verified glutamic acid (E) at amino acid site 119, which was in consistent with the results from our rRT-PCR method.</p><p><b>CONCLUSION</b>The assay developed in this study is highly sensitive and specific, and easy to operate; thereby it could be used for identification of A(H3N2) virus with E119V amino acid change in NA protein.</p>

Virological characterization of influenza A(H3N2) virus in Mainland China during 2011-2012 / 病毒学报

To study the prevalence and variation of influenza A(H3N2) viruses, the antigenic and genetic characteristics of influenza A(H3N2) viruses circulating in Mainland China during April 2011 to March 2012 were analyzed. The results showed that influenza A(H3N2) viruses increased gradually since 2012 and became the dominant strain since March. The viruses were antigenically closely related to the vaccine strain A/PER/16/09 (87.2%) and the representative virus A/FJ/196/09 (76.0%) in Mainland China. The genetic characteristics analysis results showed that recently isolated viruses belonged to the Vic/208 clade, and most of the low reaction strains also fell into the same clade. Crystal structure analysis of HA protein found that, compared with the vaccine strain A/PER/16/09, the recently isolated viruses had amino acid substitutions in the antigenic site A, B and C areas, in addition to gaining potential glycosylation sites at the amino acid position of 45 of HA and 367 of NA. Although the majority of circulating influenza A (H3N2) viruses in 2011-2012 season in Mainland China were antigeniclly matched by current influenza vaccine strain and the selected representative viruses, low reaction strains have increased since 2012, therefore it is necessary to strengthen the surveillance on the variation of influenza virus and to provide solid information for the vaccine strain selection.

Study on the antigenicity and HA1 gene characteristics of influenza A viruses during 2004-2008 year in China / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To under stand influenza A viruses epidemic, antigenicity and genetic characteristics variation between the vaccine and Circulation strains during 2004-2008 year in China.</p><p><b>METHODS</b>The influenza A viruses (H1N1, H3N2) isolated from 2004-2008 year were under took antigenic and sequence analysis. Influenza A virus antigenicity and genetic characteristics were analyzed thought amino acid variation compassion of HA1 protein of influenza A virus isolates.</p><p><b>RESULTS</b>The antigenicity of influenza H1N1 subtype viruses isolated from 2004 to 2007 is very similar with vaccine strain A/New Caledonia/20/1999 (HIN1)-like virus. The influenza H1N1 viruses circulated in 2008 year had similar antigenic characteristics with A/Brisben/59/2007 (H1N1) which is component of influenza vaccines for northern hemisphere 2008-2009 year. The influenza H3N2 subtype viruses of 2004-2005 year had antigenic variation comparatively with vaccine strain A/Fujian/411/12002 (H3N2), The antigenicity of 2006-2007 H3N2 viruses and 2008 year's is A/Wiscansin/67/2006(H3N2) and A/ Brisben/10/2006(H3N2) respectively.</p><p><b>CONCLUSION</b>There is change of influenza A viruses (H1N1, H3N2) antigenic and genetic characteristics during 2004-2008 in China.</p>

Characteristic analysis of NA gene of human influenza viruses (H3N2) isolated from 1996 to 2005 in China / 病毒学报

The NA genes of 395 strains of human H3N2 influenza virus isolated from 1996 to 2005 in China were sequenced, analyzed with bioinformatics tools. The NA nucleotide sequence of phylogenetic tree showed a main evolution branch with multiple short side branches. The strains in the same year may be divided into several branches. There was an obvious lag between vaccine strains recommended by WHO and the Chinese circulating strains in phylogenetic tree of the NA nucleotide. The result also showed no amino acid deletion and insertion in the NA. In NA antigen sites, where including residues 197-199 aa, 431-434 aa and 339-347aa the mutation was higher, in contrast, the residues including 153 aa, 328-336 aa, 367-370aa and 400-403 aa, the mutation was lower. Besides the antigenic determinant sites, there also had the other amino acid mutated highly, such as 18, 23, 30, 93, 143, 208, 216, 221, 249, 265, 267, 307, 385 and 437 aa, among them 143 and 267 mutation were higher than that in antigenic determinant sites, their biological significance are not clear yet. The neuraminidase active-site residues in NA were highly conservative and the same were the disulphide bond and the glycosylation sites in NA. In conclusion, our analysis provides some information for influenza prevention and control and the NA inhibitor medicine application.

Study on the correlation of human influenza A/H3N2 hemagglutinin gene variation and the epidemic from 1995 to 2005 in China / 病毒学报

To study the correlation of human influenza A/H3N2 hemagglutinin gene variation and the epidemic from 1995 to 2005 in China, 550 HA1 sequences of H3N2 viruses isolated in China were analyzed with phylogenetic tree. The results showed that the evolution of HA1 represented a long trunk with short side branches. The animo acid changes of HA1 mostly located at the antigenic sites or aside of them, but also may occur at the other sites simultaneously. The analysis also showed three possibilities of HA1 variation to cause H3N2 epidemic, the first is multiple site mutations happened simultaneously; the second is mutation sites happened gradually and then accumulated to multiple sites; the third is a single antigenic site mutation occurred simultaneously with the receptor binding site variation.

Analysis of environmental factors and polycystic ovary syndrome / 中华妇产科杂志

Objective To investigate environmental risk factors associated with polycystic ovary syndrome(PCOS).Methods A retrospective study was carried out from Feb 2005 to Apr 2006.A total of 108 cases with PCOS and 108 patients without PCOS(control group)were interviewed using a designed questionnaire.Results Univariate analysis of environmental factors indicated that risk factors related to PCOS were:occupation,education,disposable plastic cup for drinking,cooking oil fume and indoor decoration,all of which were significantly related to PCOS(P