简介：AbstractBackground:School closure is a common mitigation strategy during severe influenza epidemics and pandemics. However, the effectiveness of this strategy remains controversial. In this study, we aimed to explore the effectiveness of school closure on seasonal influenza epidemics in provincial-level administrative divisions (PLADs) with varying urbanization rates in China.Methods:This study analyzed influenza surveillance data between 2010 and 2019 provided by the Chinese National Influenza Center. Taking into consideration the climate, this study included a region with 3 adjacent PLADs in Northern China and another region with 4 adjacent PLADs in Southern China. The effect of school closure on influenza transmission was evaluated by the reduction of the effective reproductive number of seasonal influenza during school winter breaks compared with that before school winter breaks. An age-structured Susceptible-Infected-Recovered-Susceptible (SIRS) model was built to model influenza transmission in different levels of urbanization. Parameters were determined using the surveillance data via robust Bayesian method.Results:Between 2010 and 2019, in the less urbanized provinces: Hebei, Zhejiang, Jiangsu and Anhui, during school winter breaks, the effective reproductive number of seasonal influenza epidemics reduced 14.6% [95% confidential interval (CI): 6.2-22.9%], 9.6% (95% CI: 2.5-16.6%), 7.3% (95% CI: 0.1-14.4%) and 8.2% (95% CI: 1.1-15.3%) respectively. However, in the highly urbanized cities: Beijing, Tianjin and Shanghai, it reduced only 5.2% (95% CI: -0.7-11.2%), 4.1% (95% CI: -0.9-9.1%) and 3.9% (95% CI: -1.6-9.4%) respectively. In China, urbanization is associated with decreased proportion of children and increased social contact. According to the SIRS model, both factors could reduce the impact of school closure on seasonal influenza epidemics, and the proportion of children in the population is thought to be the dominant influencing factor.Conclusions:Effectiveness of school closure on the epidemics varies with the age structure in the population and social contact patterns. School closure should be recommended in the low urbanized regions in China in the influenza seasons.

简介：AbstractBackground:Understanding the global spatiotemporal pattern of seasonal influenza is essential for influenza control and prevention. Available data on the updated global spatiotemporal pattern of seasonal influenza are scarce. This study aimed to assess the spatiotemporal pattern of seasonal influenza after the 2009 influenza pandemic.Methods:Weekly influenza surveillance data in 86 countries from 2010 to 2017 were obtained from FluNet. First, the proportion of influenza A in total influenza viruses (PA) was calculated. Second, weekly numbers of influenza positive virus (A and B) were divided by the total number of samples processed to get weekly positive rates of influenza A (RWA) and influenza B (RWB). Third, the average positive rates of influenza A (RA) and influenza B (RB) for each country were calculated by averaging RWA, and RWB of 52 weeks. A Kruskal-Wallis test was conducted to examine if the year-to-year change in PA in all countries were significant, and a universal kriging method with linear semivariogram model was used to extrapolate RA and RB in all countries.Results:PA ranged from 0.43 in Zambia to 0.98 in Belarus, and PA in countries with higher income was greater than those countries with lower income. The spatial patterns of high RB were the highest in sub-Saharan Africa, Asia-Pacific region and South America. RWA peaked in early weeks in temperate countries, and the peak of RWB occurred a bit later. There were some temperate countries with non-distinct influenza seasonality (e.g., Mauritius and Maldives) and some tropical/subtropical countries with distinct influenza seasonality (e.g., Chile and South Africa).Conclusions:Influenza seasonality is not predictable in some temperate countries, and it is distinct in Chile, Argentina and South Africa, implying that the optimal timing for influenza vaccination needs to be chosen with caution in these unpredictable countries.

简介：由于连接增加，小世界现象在基于树的无线传感器网络存在。基于树的网络的小世界上的流行病被学习，并且流行病的爆发在发生的流行阀值是计算的。当感染概率比过滤阀值大时，流行病学的过程被分析。尽管不同流行病学的过程发生在内在的树拓扑学上，当感染传播，感染的节点的数字指数地增加。一致免疫过程在同类的小世界的网络被进行。尽管免疫有效地减少流行速度，感染仍然指数地延长。

简介：AbstractA novel bat-origin coronavirus emerged in Wuhan, China in December 2019 and continues to spread across China and the world. At the time of writing, a massive global response has been implemented to control the disease as it spreads from person to person. Yet the high-risk human-wildlife interactions and interfaces that led to the emergence of SARS-CoV and of 2019-nCoV continue to exist in emerging disease hotspots globally. To prevent the next epidemic and pandemic related to these interfaces, we call for research and investment in three areas: 1) surveillance among wildlife to identify the high-risk pathogens they carry; 2) surveillance among people who have contact with wildlife to identify early spillover events; and 3) improvement of market biosecurity regarding the wildlife trade. As the emergence of a novel virus anywhere can impact the furthest reaches of our connected world, international collaboration among scientists is essential to address these risks and prevent the next pandemic.

简介：严重流行性感冒为人在它的毒力仍然保持不平常。复杂并发症或最终，从这些感染产生的死亡经常与proinflammatorycytokine生产的hyperinduction被联系，它也作为‘被知道；cytokinestorm’；。为这疾病，immunomodulatory治疗可以改进结果，这被建议了，与或没有抗病毒的代理人的联合。这里，我们考察免疫系统的各种各样的受动器怎么开始cytokine暴风雨并且在主人加重病理学的损坏的当前的文学。我们也在严重流行性感冒为cytokine暴风雨的治疗考察一些当前的immunomodulatory策略，包括corticosteroids，peroxisome激活proliferator的受体收缩筋，sphingosine-1-phosphate受体1收缩筋，cyclooxygenase-2禁止者，抗氧化剂，anti-tumour-necrosis因素治疗，静脉内的免疫球蛋白治疗，statins，arbidol，植物，并且另外的潜在的治疗学的策略。

简介：AbstractAnti-influenza drugs are one of the most critical pathways for control of influenza virus infection. Drugs that have been developed or are developing may function via different mechanisms, and so far, inhibitors of influenza virus polymerase are among the most promising types of drugs. Favipiravir and Baloxavir, also named T-705 and Xofluza respectively, have been approved for influenza treatment in Japan and the United States. Favipiravir effectively and selectively inhibits the RNA-dependent RNA polymerase (RdRp) of RNA viruses while Baloxavir specifically targets the cap-dependent endonuclease PA of influenza viruses. These two drugs have been suggested as the first candidate drugs for influenza infection treatment, especially for strains resistant to other anti-influenza drugs. This review will focus on the pharmaceutical mechanisms and anti-influenza activity of these two drugs.

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简介：Anefficientmethodfortheidentificationofinfluentialspreadersthatcouldbeusedtocontrolepidemicswithinpopulationswouldbeofconsiderableimportance.Generally,populationsarecharacterizedbyitscommunitystructuresandbytheheterogeneousdistributionsofout-leavinglinksamongnodesbridgingovercommunities.Anewmethodforcommunitynetworkscapableofidentifyinginfluentialspreadersthatacceleratethespreadofdiseaseishereproposed.Inthismethod,influentialspreadersserveastargetnodes.Thisisbasedontheideathat,ink-shelldecompositionmethod,out-leavinglinksandinnerlinksareprocessedseparately.Themethodwasusedonempiricalnetworksconstructedfromonlinesocialnetworks,andresultsindicatedthatthismethodismoreaccurate.Itseffectivenessstemsfromthepatternsofconnectivityamongneighbors,anditsuccessfullyidentifiedtheimportantnodes.Inaddition,theperformanceofthemethodremainedrobustevenwhentherewereerrorsinthestructureofthenetwork.

简介：Spatiallyexplicitmodelshavebecomewidelyusedintoday'smathematicalecologyandepidemiologytostudythepersistenceofpopulations.Forsimplicity,populationdynamicsisoftenanalysedbyusingordinarydifferentialequations(ODEs)orpartialdifferentialequations(PDEs)intheone-dimensional(1D)space.Animportantquestionistopredictspeciesextinctionorpersistenceratebymeanofcomputersimulationbasedonthespatialmodel.Recently,ithasbeenreportedthatstableturbulentandregularwavesarepersistentbasedonthespatialsusceptible-infected-resistant-susceptible(SIRS)modelbyusingthecellularautomata(CA)methodinthetwo-dimensional(2D)space[Proc.Natl.Acad.Sci.USA101,18246(2004)].Inthispaper,weaddressotherimportantissuesrelevanttophasetransitionsofepidemicpersistence.Weareinterestedinassessingthesignificanceoftheriskofextinctionin1Dspace.Ourresultsshowthatthe2Dspacecanconsiderablyincreasethepossibilityofpersistenceofspreadofepidemicswhenthedegreedistributionoftheindividualsisuniform,i.e.thepatternof2Dspatialpersistencecorrespondingtoextinctionina1Dsystemwiththesameparameters.Thetrade-offsofextinctionandpersistencebetweentheinfectionperiodandinfectionrateareobservedinthe1Dcase.Moreover,nearthetrade-off(phasetransition)line,anindependentestimationofthedynamicexponentcanbeperformed,anditisinexcellentagreementwiththeresultobtainedbyusingtheconjecturedrelationshipofdirectedpercolation.Wefindthattheintroductionofashort-rangediffusionandalong-rangediffusionamongtheneighbourhoodscanenhancethepersistenceandglobaldiseasespreadinthespace.

简介：AbstractViral isolation in cell cultures has been regarded for decades as the "gold standard" for the laboratory diagnosis of influenza viral infections. Not all viral strains could be isolated from clinical samples. This study aimed to quantify the viral load in the samples before isolation to save working time and improve working efficiency. Four hundred samples from patients with influenza-like cases were confirmed pdmH1N1 positive (200 cases) and B Victoria (BV) positive (200 cases) by whole-genome sequencing and analyzed by ddPCR for viral load in samples before isolation, and isolation results were verified by hemagglutination (HA) assay and hemagglutination-inhibition (HI) tests. Probit regression analysis was used to calculate the isolation viral load limit with a 95% probability level by SPSS 19.0 software. The results showed that the isolation limit of viral load was 4.9 × 104 (95% CI: 2.5 × 104-9.0 × 104) copies/mL for pdmH1N1 and 1.9 × 104 (95% CI: 7.8 × 103-3.6 × 104) copies/mL for BV. The isolation rate of clinical samples is positively correlated with the viral load in clinical samples, which can be used for viral culture, providing important guidance for daily work.

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简介：流行性感冒的所有已知的子类型A病毒在野水鸟被维持，这些病毒的自然水库。流行性感冒A病毒被孤立从许多有改变病态和死亡率的动物种类。更重要地，流行性感冒A病毒与潜在地致命的结果在人引起呼吸疾病。在人的本地或全球的爆发被过量住院和死亡典型地描绘。在1997，H5N1子类型的高度病原的鸟的流行性感冒病毒在传给人的香港出现了，导致由鸟的流行性感冒病毒感染的人的死亡的首先记录的盒子。在越南，印度尼西亚，和泰国在家禽在2003年7月开始的新爆发，和高度病原的鸟的H5N1流行性感冒病毒后来在整个亚洲并且进欧洲和非洲传播了。这些病毒继续与高死亡率感染人并且引起隐约可见的世界范围的担心流行。而且，H5N1病毒爆发在整个亚洲在家禽工业上有破坏效果。因为H5N1病毒爆发看起来从南部的中国发源，我们这里在中国检验H5N1流行性感冒病毒，与他们的生物性质上的一个重音。

简介：AbstractAvian influenza remains a threat to human wellbeing. Hypochlorite derivatives are commonly used as disinfectants to prevent the spread of the disease. The World Health Organization (WHO) has listed chlorine dioxide (ClO2) as an A1-level, safe, and efficient disinfectant. In this study, we tested the efficacy of ClO2, in aqueous solution and gas forms, against avian influenza A (H7N9) virus. The virus suspension was mixed with ClO2 aqueous solutions of various concentrations and for various time intervals. Aliquots of the mixture were then serially diluted, and the 50% tissue culture infective dose (TCID50) was measured with a hemagglutination test on MDCK cells. ClO2 gas produced from generators was introduced in a chamber containing the virus suspension in a Petri dish. The infective activity of the surviving virus was measured by the hemagglutination test. An aqueous solution of ClO2 at 126 µg/mL for 15 s was effective given that no surviving virus was detected with the hemagglutination test. ClO2 gas at >5 µL/L sustained for 1 h inactivated the virus effectively, while at 2.5 µL/L for 1 h, it only partially inactivated the virus. ClO2 as gas or aqueous solution at a certain concentration is effective in inactivating the H7N9 virus, and can be applied for the decontamination and disinfection of environments.

简介：AbstractThe virulence of influenza viruses is a complex multigenic trait. Previous studies about the virulence determinants of influenza viruses mainly focused on amino acid sites, ignoring the influence of nucleotide mutations. In this study, we collected >200 viral strains from 21 subtypes of influenza A viruses with virulence in mammals and obtained over 100 mammalian virulence-related nucleotide sites across the genome by computational analysis. Fifty of these nucleotide sites only experienced synonymous mutations. Experiments showed that synonymous mutations in three high-scoring nucleotide sites, i.e., PB1–2031, PB1–633, and PB1–720, enhanced the pathogenicity of the influenza A(H1N1) viruses in mice. Besides, machine-learning models with accepted accuracy for predicting mammalian virulence of influenza A viruses were built. Overall, this study highlighted the importance of nucleotide mutations, especially synonymous mutations in viral virulence, and provided rapid methods for evaluating the virulence of influenza A viruses. It could be helpful for early warning of newly emerging influenza A viruses.

简介：AbstractBackground:The coronavirus disease 2019 (COVID-19) outbreak occurred during the flu season around the world. This study aimed to analyze the impact of influenza A virus (IAV) exposure on COVID-19.Methods:Seventy COVID-19 patients admitted to the hospital during January and February 2020 in Wuhan, China were included in this retrospective study. Serum tests including respiratory pathogen immunoglobulin M (IgM) and inflammation biomarkers were performed upon admission. Patients were divided into common, severe, and critical types according to disease severity. Symptoms, inflammation indices, disease severity, and fatality rate were compared between anti-IAV IgM-positive and anti-IAV IgM-negative groups. The effects of the empirical use of oseltamivir were also analyzed in both groups. For comparison between groups, t tests and the Mann-Whitney U test were used according to data distribution. The Chi-squared test was used to compare disease severity and fatality between groups.Results:Thirty-two (45.71%) of the 70 patients had positive anti-IAV IgM. Compared with the IAV-negative group, the positive group showed significantly higher proportions of female patients (59.38% vs. 34.21%, χ2 = 4.43, P = 0.035) and patients with fatigue (59.38% vs. 34.21%, χ2 = 4.43, P = 0.035). The levels of soluble interleukin 2 receptor (median 791.00 vs. 1075.50 IU/mL, Z = -2.70, P = 0.007) and tumor necrosis factor α (median 10.75 vs. 11.50 pg/mL, Z = -2.18, P = 0.029) were significantly lower in the IAV-positive group. Furthermore, this group tended to have a higher proportion of critical patients (31.25% vs. 15.79%, P = 0.066) and a higher fatality rate (21.88% vs. 7.89%, P = 0.169). Notably, in the IAV-positive group, patients who received oseltamivir had a significantly lower fatality rate (0 vs. 36.84%, P = 0.025) compared with those not receiving oseltamivir.Conclusions:The study suggests that during the flu season, close attention should be paid to the probability of IAV exposure in COVID-19 patients. Prospective studies with larger sample sizes are needed to clarify whether IAV increases the fatality rate of COVID-19 and to elucidate any benefits of empirical usage of oseltamivir.

简介：AbstractBackground:Dengue is the fastest spreading arboviral disease, posing great challenges on global public health. A reproduceable and comparable global genotyping framework for contextualizing spatiotemporal epidemiological data of dengue virus (DENV) is essential for research studies and collaborative surveillance.Methods:Targeting DENV-1 spreading prominently in recent decades, by reconciling all qualified complete E gene sequences of 5003 DENV-1 strains with epidemiological information from 78 epidemic countries/areas ranging from 1944 to 2018, we established and characterized a unified global high-resolution genotyping framework using phylogenetics, population genetics, phylogeography, and phylodynamics.Results:The defined framework was discriminated with three hierarchical layers of genotype, subgenotype and clade with respective mean pairwise distances 2-6%, 0.8-2%, and ≤ 0.8%. The global epidemic patterns of DENV-1 showed strong geographic constraints representing stratified spatial-genetic epidemic pairs of Continent-Genotype, Region-Subgenotype and Nation-Clade, thereby identifying 12 epidemic regions which prospectively facilitates the region-based coordination. The increasing cross-transmission trends were also demonstrated. The traditional endemic countries such as Thailand, Vietnam and Indonesia displayed as persisting dominant source centers, while the emerging epidemic countries such as China, Australia, and the USA, where dengue outbreaks were frequently triggered by importation, showed a growing trend of DENV-1 diffusion. The probably hidden epidemics were found especially in Africa and India. Then, our framework can be utilized in an accurate stratified coordinated surveillance based on the defined viral population compositions. Thereby it is prospectively valuable for further hampering the ongoing transition process of epidemic to endemic, addressing the issue of inadequate monitoring, and warning us to be concerned about the cross-national, cross-regional, and cross-continental diffusions of dengue, which can potentially trigger large epidemics.Conclusions:The framework and its utilization in quantitatively assessing DENV-1 epidemics has laid a foundation and re-unveiled the urgency for establishing a stratified coordinated surveillance platform for blocking global spreading of dengue. This framework is also expected to bridge classical DENV-1 genotyping with genomic epidemiology and risk modeling. We will promote it to the public and update it periodically.

简介：AbstractBackground:Healthcare workers (HCWs) were the priority group for influenza vaccination, in China during the 2020/2021 and 2021/2022 influenza seasons. However, vaccination rates in HCWs have always been low. This study investigated influenza vaccination status among Chinese HCWs and analyzed the factors driving vaccination.Methods:We provided electronic questionnaires to HCWs from January 27, 2022 to February 21, 2022, using the WeChat platform "Breath Circles". HCWs who received the link could also forward it to their colleagues. Binary logistic regression models were used to analyze vaccination-associated factors among HCWs.Results:Among the 1697 HCWs surveyed, vaccination coverage was 43.7% (741/1697) during the 2020/2021 influenza season, and 35.4% (600/1697) during the 2021/2022 influenza season, as of February 21, 2022. Additionally, 22.7% (385/1697) and 22.1% (358/1697) of HCWs reported that their workplaces implemented a free vaccination policy for all employees during the 2020/2021 and 2021/2022 influenza seasons. HCWs who were required to be vaccinated according to hospital regulations, and whose hospitals implemented the free influenza vaccine policy were more likely to be vaccinated (2020/2021 and 2021/2022; P < 0.05). In addition, the economic level of the HCWs' province (2021/2022, P < 0.05) and the HCWs’ knowledge about vaccination and willingness to get vaccinated, such as active learning about vaccines (2020/2021, P < 0.05), supportive attitude toward vaccination for all HCWs (2020/2021 and 2021/2022; P < 0.05), also had an impact on vaccine coverage.Conclusions:A free influenza vaccination policy and workplace required vaccination are effective in improving influenza vaccination coverage among HCWs. Influenza vaccination coverage of Chinese HCWs remained low and showed a downward trend after the COVID-19 outbreak. Further effective measures, such as advocacy campaigns, free vaccine policies, and on-site vaccination could be implemented to improve influenza vaccination coverage.

简介：ToexplorethepolysaccharidesfromselectedseaweedsofAtlanticCanadaandtoevaluatetheirpotentialanti-influenzavirusactivities,polysaccharideswereisolatedfromseveralAtlanticCanadianseaweeds,includingthreeredalgae(Polysiphonialanosa,Furcellarialumbricalis,andPalmariapalmata),twobrownalgae(AscophyllumnodosumandFucusvesiculosus),andonegreenalga(Ulvalactuca)bysequentialextractionwithcoldwater,hotwater,andalkalisolutions.Thesepolysaccharideswereana-lyzedformonosaccharidecompositionandothergeneralchemicalproperties,andtheywereevaluatedforanti-influenzavirusactivities.Totalsugarcontentsinthesepolysaccharidesrangedfrom15.4%(inU.lactuca)to91.4%(inF.lumbricalis);sulfationlevelwasashighas17.6%inapolysaccharidefromU.lactuca,whereasitcouldnotbedetectedinanalikali-extractfromP.palmaria.Forpolysaccharidesfromredseaweeds,themainsugarunitsweresulfatedgalactans(agarorcarrageenan)forP.lanosa,F.lumbricalis,andxylansforP.palmata.Inbrownseaweeds,thepolysaccharideslargelycontainedsulfatedfucans,whereasthepolysaccharidesingreenseaweedweremainlycomposedofheteroglycuronans.ScreeningforantiviralactivityagainstinfluenzaA/PR/8/34(H1N1)virusrevealedthatbrownalgalpolysaccharideswereparticularlyeffective.SeaweedsfromAtlanticCanadaareagoodsourceofmarinepolysaccharideswithpotentialantiviralproperties.

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简介：BackgroundAcuterespiratorydistresssyndrome(ARDS)causedbyH7N9influenzainpregnantwomanisalife-threateningeventwithanincreasedriskformaternalandbaby'sdeath.Theaimofthisstudywastoevaluatetheimpactofpoint-of-careultrasonography(POCUS)onthemanagementandprognosisofthesepatients.MethodsAcaseof31-yr-oldpregnantwomaninourhospital,whowasunderwentPOCUSforevaluatingcardiopulmonaryfunctions,volumestate,fluidresponsivenessandultrasound-guidedprocedureswasadmittedtoIntensiveCareUnit(ICU).Weperformedultrasonographydailyformonitoringorganfunctions.Reviewofrelatedliteratureswasalsoconducted.ResultsWiththehelpofPOCUS,wemadequicklydiagnosisofseverepneumoniaandARDScausedbyH7N9influenza.ThetherapieshadalsobeenchangedafterPOCUSexaminations,suchasrestrictfluidadministrationrelyingontheassessmentsoftheinferiorvenacava(IVC)toestimatepreloadandlungultrasoundmonitoringtoidentifytheearlypresenceofextravascularlungwater(EVLW)andavoidfluidoverresuscitation,ultrasound-guidedrecruitmentmaneuvertoimprovedrespiratorydistresssyndrome,andsoon.ConclusionsPOCUShasasignificantimpactondecision-makingandtherapeuticmanagementandshouldbecomeaclinicalroutineinthemanagementofARDSpatientscausedbyH7N9influenzainpregnancy.