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influenza viruses in adult dogs raised in rural and urban areas in the state of são paulo, brazil.in 1970, searching for the interspecies transmission of influenza viruses led to the first study on influenza viruses in domestic animals. birds and mammals, including human beings, are their natural hosts; however, other animals may also play a role in the virus epidemiology. the objective was to investigate the incidence of influenza viruses in adult dogs raised in rural (9, 19.56%) and urban (37, 80.43%) areas in the state of são paulo, brazil. dog serum samples were examined for antibodies t ...201223152313
incidence and epidemiology of hospitalized influenza cases in rural thailand during the influenza a (h1n1)pdm09 pandemic, 2009-2010.data on the burden of the 2009 influenza pandemic in asia are limited. influenza a(h1n1)pdm09 was first reported in thailand in may 2009. we assessed incidence and epidemiology of influenza-associated hospitalizations during 2009-2010.201223139802
microwave assisted synthesis and anti-influenza virus activity of 1-adamantyl substituted n-(1-thia-4-azaspiro[4.5]decan-4-yl)carboxamide derivatives.a microwave-assisted three-component one-pot cyclocondensation method was applied for the synthesis of novel n-(1-thia-4-azaspiro[4.5]decan-4-yl)carboxamide compounds carrying an adamantyl moiety. the structures of the compounds were confirmed by spectral and elemental analysis. all compounds were evaluated for antiviral activity against influenza a (h1n1 and h3n2) and influenza b virus in mdck cell cultures. the compounds displayed a confined structure-activity relationship. the n-(2,8-dimethyl ...201223117173
randomized comparative study of the serum antihemagglutinin and antineuraminidase antibody responses to six licensed trivalent influenza vaccines.serum antibody to the hemagglutinin (ha) surface protein of influenza virus induced by influenza vaccination is a correlate of protection against influenza. the neuraminidase (na) protein is also on the surface of the virus; antibody to it has been shown to impair virus release from infected cells and to reduce the intensity of influenza infections in animal models and in humans challenged with infectious virus. recently we have shown that na inhibiting antibody can independently contribute to i ...201223107591
[influenza viruses--a challenge for vaccinations].the clinical picture of influenza may vary from mild respiratory infection to pneumonia requiring intensive care. annual epidemics are most commonly caused by h3n2 or h1n1 type influenza a or influenza b viruses. the population's immune protection against a new virus type is low, whereupon morbidity and mortality may be high. vaccinations are the most important means to decrease influenza morbidity. annual variation and quick intercontinental migration of influenza viruses, combined with the pos ...201223088004
epidemiological characteristics, clinical presentation and diagnosis at point-of-care during the first wave of the h1n1 influenza pandemic in cambodia.we conducted clinic-based surveillance for influenza virus among cases with acute febrile illness at 9 medical clinics in south-central cambodia during 2006-2009. patients greater than or equal to 24 months old presenting with acute fever (> 38 degrees c) were enrolled. in late july 2009, the study identified its first case of pandemic h1n1 (ph1n1) influenza virus infection. the prevalence of ph1n1 infections increased rapidly during august and september and by october, ph1n1 infections had peak ...201223082556
[development of duplex real-time pcr assay for identification of influenza viruses of subtype a(h1)pdm09 and a(h3)].among different laboratory techniques used in influenza surveillance, methods based on molecular biology, such as real-time pcr, play increasingly important role. they allow detection and identification of viruses currently circulating in human population and responsible for infections and diseases. the aim of the study was to develop duplex real-time pcr assay for detection and differentiation of influenza virus subtype a(h1n1) pdm09 and a(h3n2).201223072058
kinetics of the antibody response to seasonal influenza vaccination among the elderly.influenza vaccination, which has been targeted to the elderly and those at serious risk of complications, is recommended. the purpose of this study was to determine antibody responses after influenza vaccination among thai elderly persons living in the community. a total of 591 subjects consisting of 308 vaccinees and 283 non-vaccinees were enrolled in the study. antibodies to h1n1, h3n2, and b viruses were detected by hemagglutination inhibition (hi) testing. the numbers of subjects who had pro ...201223061793
full genomic analysis of an influenza a (h1n2) virus identified during 2009 pandemic in eastern india: evidence of reassortment event between co-circulating a(h1n1)pdm09 and a/brisbane/10/2007-like h3n2 strains.during the pandemic [influenza a(h1n1)pdm09] period in 2009-2010, an influenza a (inf-a) virus with h1n2 subtype (designated as a/eastern india/n-1289/2009) was detected from a 25 years old male from mizoram (north-eastern india).201223057530
molecular characterization of avian-like h1n1 swine influenza a viruses isolated in eastern china, 2011.currently, three predominant subtypes of influenza virus are prevalent in pig populations worldwide: h1n1, h3n2, and h1n2. european avian-like h1n1 viruses, which were initially detected in european pig populations in 1979, have been circulating in pigs in eastern china since 2007. in this study, six influenza a viruses were isolated from 60 swine lung samples collected from january to april 2011 in eastern china. based on whole genome sequencing, molecular characteristics of two isolates were d ...201223055004
multiple distinct forms of cd8+ t cell cross-reactivity and specificities revealed after 2009 h1n1 influenza a virus infection in mice.influenza primed mice are protected against lethal infection with h1n1 a/ca/04/e3/09 virus, and t depletion and serum transfer studies suggest a t-dependent mechanism. we therefore set out to investigate the quality of the cross-reactive t cell response to ca/e3/09 in mice primed with h3n2 influenza a/hong kong/x31 virus. sequences of the immunodominant nucleoprotein (np) np366-374 and acid polymerase (pa) pa224-233 cd8 epitopes from x31 each differ from the ca/e3/09 virus by one amino acid: an ...201223029425
influenza a/h1n1 2009 pandemic and respiratory virus infections, beijing, 2009-2010.to determine the role of the pandemic influenza a/h1n1 2009 (a/h1n1 2009pdm) in acute respiratory tract infections (artis) and its impact on the epidemic of seasonal influenza viruses and other common respiratory viruses, nasal and throat swabs taken from 7,776 patients with suspected viral artis from 2006 through 2010 in beijing, china were screened by real-time pcr for influenza virus typing and subtyping and by multiplex or single pcr tests for other common respiratory viruses. we observed a ...201223029253
heterosubtypic antibody recognition of the influenza virus hemagglutinin receptor binding site enhanced by avidity.continual and rapid mutation of seasonal influenza viruses by antigenic drift necessitates the almost annual reformulation of flu vaccines, which may offer little protection if the match to the dominant circulating strain is poor. s139/1 is a cross-reactive antibody that neutralizes multiple ha strains and subtypes, including those from h1n1 and h3n2 viruses that currently infect humans. the crystal structure of the s139/1 fab in complex with the ha from the a/victoria/3/1975 (h3n2) virus reveal ...201223027945
molecular evidence for interspecies transmission of h3n2pm/h3n2v influenza a viruses at an ohio agricultural fair, july 2012.evidence accumulating in 2011-2012 indicates that there is significant intra- and inter-species transmission of influenza a viruses at agricultural fairs, which has renewed interest in this unique human/swine interface. six human cases of influenza a (h3n2) variant (h3n2v) virus infections were epidemiologically linked to swine exposure at fairs in the united states in 2011. in 2012, the number of h3n2v cases in the midwest had exceeded 300 from early july to september, 2012. prospective influen ...201226038404
virulence and transmissibility of h1n2 influenza virus in ferrets imply the continuing threat of triple-reassortant swine viruses.efficient worldwide swine surveillance for influenza a viruses is urgently needed; the emergence of a novel reassortant pandemic h1n1 (ph1n1) virus in 2009 demonstrated that swine can be the direct source of pandemic influenza and that the pandemic potential of viruses prevalent in swine populations must be monitored. we used the ferret model to assess the pathogenicity and transmissibility of predominant korean triple-reassortant swine (trsw) h1n2 and h3n2 influenza viruses genetically related ...201223019374
influenza a (h3n2) variant virus-related hospitalizations: ohio, 2012.since july 2012, 305 cases of infection with influenza a (h3n2) variant (h3n2v) virus containing the influenza a (h1n1)pdm09 m gene have occurred in multiple u.s. states, primarily associated with swine exposure at agricultural fairs. in ohio, from july 28 to september 25, 2012, a total of 106 confirmed h3n2v cases were identified through enhanced surveillance. whereas most h3n2v patients experienced mild, self-limited influenza-like illness (ili), 11 of the ohio patients were hospitalized, repr ...201223013722
prevalence and risk factors for h1n1 and h3n2 influenza a virus infections in minnesota turkey premises.influenza virus infections can cause respiratory and systemic disease of variable severity and also result in economic losses for the turkey industry. several subtypes of influenza can infect turkeys, causing diverse clinical signs. influenza subtypes of swine origin have been diagnosed in turkey premises; however, it is not known how common these infections are nor the likely routes of transmission. we conducted a cross-sectional study to estimate the prevalence of influenza viruses and examine ...201223050464
excess mortality associated with influenza a and b virus in hong kong, 1998-2009.although deaths associated with laboratory-confirmed influenza virus infections are rare, the excess mortality burden of influenza estimated from statistical models may more reliably quantify the impact of influenza in a population.201223045622
quantitative analysis of four rapid antigen assays for detection of pandemic h1n1 2009 compared with seasonal h1n1 and h3n2 influenza a viruses on nasopharyngeal aspirates from patients with influenza.data on analytical sensitivity of rapid diagnostic assays are important for clinical management of influenza, especially during a pandemic. four rapid antigen detection assays were compared for detection of pandemic influenza a h1n1 2009, seasonal h1n1 and h3n2 in 96 patients with influenza a infection confirmed by real-time rt-pcr. these rapid antigen tests appeared to have lower sensitivity (55.8%) for the diagnosis of pandemic influenza a h1n1 2009 as compared with seasonal h3n2 (71.0%) or h1 ...201222989408
sentinel surveillance of influenza-like illness in two hospitals in maracay, venezuela: 2006-2010.limited information exists on the epidemiology of acute febrile respiratory illnesses in tropical south american countries such as venezuela. the objective of the present study was to examine the epidemiology of influenza-like illness (ili) in two hospitals in maracay, venezuela.201222984519
tracking oseltamivir-resistance in new zealand influenza viruses during a medicine reclassification in 2007, a resistant-virus importation in 2008 and the 2009 pandemic.oseltamivir (tamiflu®) is an important pharmaceutical intervention against the influenza virus. the importance of surveillance for resistance to oseltamivir has been highlighted by two global events: the emergence of an oseltamivir-resistant seasonal influenza a(h1n1) virus in 2008, and emergence of the influenza a(h1n1)pdm09 virus in 2009. oseltamivir is a prescription medicine in new zealand, but more timely access has been provided since 2007 by allowing pharmacies to directly dispense oselta ...201223908945
respiratory virus laboratory pandemic planning and surveillance in central viet nam, 2008-2010.laboratory capacity is needed in central viet nam to provide early warning to public health authorities of respiratory outbreaks of importance to human health, for example the outbreak of influenza a(h1n1) pandemic in 2009. polymerase chain reaction (pcr) procedures established as part of a capacity-building process were used to conduct prospective respiratory surveillance in a region where few previous studies have been undertaken.201223908924
[analysis on pathogen detection for 53 influenza outbreaks].in order to provide a scientific basis for influenza prevention and control, analyzing the epidemic characteristics and laws of influenza outbreaks in xuzhou area during 2005-2011.201223627018
[etiological analysis of influenza surveillance data in xuzhou from 2005 to 2011].to investigate the prevalence and subtypes of influenza viruses in xuzhou city from 2005 to 2011 and to provide the scientific supports for influenza prevention and control in this religion.201223627016
[characterization of influenza virus reassortants based on new donor strain a/hk/1/68/162/35(h3n2)].influenza reassortant viruses a/spb/hk/09(h1n1), a/astana/hk/2009 (h5n1), a/otar/hk/2010(h3n8), and a/perth/ hk/2011(h3n2), carrying surface antigens of different subtypes, were constructed on the basis of new potential unified donor strain a/hk/1/68/162/35(h3n2). the virulence and reproduction activity of the obtained reassortants were tested. the safety of the candidate live and inactivated influenza vaccines produced from the reassortant viruses was demonstrated. the study demonstrates that a ...201223477254
[genetic diversity and molecular evolution of the influenza a viruses in russia during 2006-2012].the results of molecular genetic analysis of more than 280 strains of influenza a virus subtypes h1n1 and h3n2 circulating in russia in 2006-2012 are presented. the genetic changes underlying the evolution of the virus strains and sensitivity to antiviral drugs were analyzed. significant changes in the genetic structure of influenza a viruses circulating in the russian federation and their phylogenetic affiliation are shown to occur within the studied period. the studies identifying codons under ...201223477253
[development of influenza surveillance in russia in the system of the who national influenza center].analysis of development influenza activity season 2010-2011 is presented. significant participation of influenza a(h1n1)pdm09 virus and influenza b of victoria lineage virus in the epidemic morbidity structure with minor participation ofa(h3n2) virus was revealed. the influenza viruses isolated in russia according to antigenic properties were similar to the strains included in the vaccine composition. drift variants of influenza a(h1n1)pdm09 viruses isolated in astrakhan and st.-petersburg were ...201223477249
[characterization of cold-adapted influenza strain a/hongkong/1/68/162/35 as a potential donor of attenuation and high reproduction].live and inactivated vaccines are currently produced using virus reassortants originating from various gene donors of internal proteins. based on the pandemic virus a/hong kong/1/68 (h3n2), a cold-adapted thermo-sensitive strain a/hong kong/1/68/162/35 was generated. it is distinguished for its high reproductive capacity (9-9.5 lg eid50), and hemagglutinating activity (1:1024-1:2048). the strain has ts and ca phenotype: reproductive capacity at t = 39 degrees c is 1.0 lg eid50; at t = 26 degrees ...201223477248
effect of statin treatments on highly pathogenic avian influenza h5n1, seasonal and h1n1pdm09 virus infections in balb/c mice.statins are used to control elevated cholesterol or hypercholesterolemia, but have previously been reported to have antiviral properties. aims: to show efficacy of statins in various influenza virus mouse models. materials & methods: balb/c mice were treated intraperitoneally or orally with several types of statins (simvastatin, lovastatin, mevastatin, pitavastatin, atorvastatin or rosuvastatin) at various concentrations before or after infection with either influenza a/duck/ mn/1525/81 h5n1 vir ...201223420457
genetic analysis of avian influenza viruses: cocirculation of avian influenza viruses with allele a and b nonstructural gene in northern pintail (anas acuta) ducks wintering in japan.the pandemic influenza virus strains of 1918 (h1n1), 1957 (h2n2), 1968 (h3n2), and 2009 (h1n1) have genes related to avian influenza viruses (aivs). the nonstructural (ns) gene of aivs plays a significant role in host-viral interaction. however, little is known about the degree of diversity of this gene in northern pintail (anas acuta) ducks wintering in japan. this study describes characteristics of pintail-originated h1n1, h1n2, h1n3, h5n2, h5n3, h5n9, and h7n7 viruses. most of the viruses wer ...201223320157
replication of swine and human influenza viruses in juvenile and layer turkey hens.since the first reported isolation of swine influenza viruses (sivs) in turkeys in the 1980s, transmission of sivs to turkeys was frequently documented. recently, the 2009 pandemic h1n1 virus, that was thought to be of swine origin, was detected in turkeys with a severe drop in egg production. in this study, we assessed the infectivity of different mammalian influenza viruses including swine, pandemic h1n1 and seasonal human influenza viruses in both juvenile and layer turkeys. in addition, we i ...201223305617
components of selection in the evolution of the influenza virus: linkage effects beat inherent selection.the influenza virus is an important human pathogen, with a rapid rate of evolution in the human population. the rate of homologous recombination within genes of influenza is essentially zero. as such, where two alleles within the same gene are in linkage disequilibrium, interference between alleles will occur, whereby selection acting upon one allele has an influence upon the frequency of the other. we here measured the relative importance of selection and interference effects upon the evolution ...201223300444
phylodynamic inference and model assessment with approximate bayesian computation: influenza as a case study.a key priority in infectious disease research is to understand the ecological and evolutionary drivers of viral diseases from data on disease incidence as well as viral genetic and antigenic variation. we propose using a simulation-based, bayesian method known as approximate bayesian computation (abc) to fit and assess phylodynamic models that simulate pathogen evolution and ecology against summaries of these data. we illustrate the versatility of the method by analyzing two spatial models descr ...201223300420
efficacy of influenza vaccination in patients with cirrhosis and inactive carriers of hepatitis b virus infection.influenza can causes morbidity and mortality that are greatly enhanced in patients with underlying chronic diseases such as cirrhotic patients. this study was performed to assess the immunogenicity of influenza vaccination in patients with cirrhosis and inactive carriers of hepatitis b virus infection.201223285414
robust immunity and heterologous protection against influenza in mice elicited by a novel recombinant np-m2e fusion protein expressed in e. coli.the 23-amino acid extracellular domain of matrix 2 protein (m2e) and the internal nucleoprotein (np) of influenza are highly conserved among viruses and thus are promising candidate antigens for the development of a universal influenza vaccine. various m2e- or np-based dna or viral vector vaccines have been shown to have high immunogenicity; however, high cost, complicated immunization procedures, and vector-specific antibody responses have restricted their applications. immunization with an np- ...201223285063
susceptibility of human h3n2 influenza virus to oseltamivir in south korea, 2009-2011.during the 2009-2011 influenza seasons, 10.26% of the specimens isolated from patients in south korea were subtyped as h3n2 viruses. some oseltamivir-sensitive h3n2 samples exhibited different plaque morphologies, and were found to have novel mutations in the neuraminidase gene. in a subsequent analysis using na mutant viruses, viral compensation against oseltamivir treatment was observed only in the n2 mutant virus. all things considered, these novel mutations may account for the exclusive char ...201223274998
influenza a virus nucleoprotein derived from escherichia coli or recombinant vaccinia (tiantan) virus elicits robust cross-protection in mice.immunity to conserved viral antigens is an attractive approach to develop a universal vaccine against epidemic and pandemic influenza. a nucleoprotein (np)-based vaccine has been explored and preliminary studies have shown promise. however, no study has explored the immunity and cross-protective efficacy of recombinant np derived from escherichia coli compared with recombinant vaccinia virus (tiantan).201223272943
comparative study of pandemic (h1n1) 2009, swine h1n1, and avian h3n2 influenza viral infections in quails.quail has been proposed to be an intermediate host of influenza a viruses. however, information on the susceptibility and pathogenicity of pandemic h1n1 2009 (ph1n1) and swine influenza viruses in quails is limited. in this study, the pathogenicity, virus shedding, and transmission characteristics of ph1n1, swine h1n1 (swh1n1), and avian h3n2 (dkh3n2) influenza viruses in quails was examined. three groups of 15 quails were inoculated with each virus and evaluated for clinical signs, virus sheddi ...201223271181
immune responses and protective efficacy of a recombinant swinepox virus co-expressing ha1 genes of h3n2 and h1n1 swine influenza virus in mice and pigs.the recombinant swine poxvirus rspv/h3-2a-h1 co-expressing ha1 genes of h3n2 and h1n1 subtype siv has been constructed and identified. inoculations of rspv/h3-2a-h1 yielded elisa and neutralization antibodies against siv h1n1 and h3n2, and elicited potent h1n1 and h3n2 siv-specific inf-γ response from t-lymphocytes in mice and pigs in this study. complete protection against siv h1n1 or h3n2 challenge in pigs was observed.201223265244
induction of anti-influenza immunity by modified green fluorescent protein (gfp) carrying hemagglutinin-derived epitope structure.the development of vaccination methods that can overcome the emergence of new types of influenza strains caused by escape mutations is desirable to avoid future pandemics. here, a novel type of immunogen was designed that targeted the conformation of a highly conserved region of influenza a virus hemagglutinin (ha) composed of two separate sequences that associate to form an anti-parallel β-sheet structure. our previous study identified this β-sheet region as the structural core in the epitope o ...201223264630
a reduced dose seasonal trivalent influenza vaccine is safe and immunogenic in adult and elderly patients - a randomized controlled trial.background: with the recent pandemic of influenza a (h1n1) and vaccine shortages, there has been a considerable interest of developing influenza vaccines with reduced doses, allowing for increased production capacity.design: here we report a prospective, randomized, double-blind, single-center clinical trial of a reduced-dose whole-virion inactivated, adjuvanted influenza vaccine in adult and elderly volunteers.methods: a total of 234 subjects including 120 adults (18-60 years of age) and 114 el ...201222219315
use of a human influenza challenge model to assess person-to-person transmission: proof-of-concept study.background. influenza transmission in humans remains poorly understood. in particular, the relative contribution of contact, large droplet, and aerosol transmission is unknown. the aims of this proof-of-concept study were to determine whether an experimentally induced influenza infection is transmissible between humans and whether this would form a viable platform for future studies. methods. in a quarantine facility, healthy volunteers ("donors") were inoculated with a/wisconsin/67/2005 (h3n2) ...201222131338
Identification of novel virus inhibitors by influenza A virus specific reporter cell based screening.As influenza viruses have developed resistance towards current drugs, it is urgent to find potential novel antiviral inhibitors. Here we generated an influenza virus reporter cell line in which the luciferase gene was driven by the influenza virus promoter and screened a small compound library (NCI Diversity Set II). Ten compounds were identified to have inhibitory activity against influenza A virus H1N1. Among them, four compounds blocked influenza virus replication through inhibiting the activ ...201222057306
Characterization of neutralizing antibodies in adults after intranasal vaccination with an inactivated influenza vaccine.The levels and properties of neutralizing antibodies in nasal wash and serum collected from five healthy adults were examined after intranasal administration of an A/Uruguay/716/2007 (H3N2) split vaccine (45?µg hemagglutinin (HA) per dose; five doses, with an interval of 3 weeks between each dose). Prior to the assays, nasal wash samples were concentrated so that the total amount of antibodies was equivalent to about 1/10 of that found in the natural nasal mucus. Vaccination induced virus-specif ...201222170556
intracytoplasmic trapping of influenza virus by a lipophilic derivative of aglycoristocetin.we report on a new anti-influenza virus agent, sa-19, a lipophilic glycopeptide derivative consisting of aglycoristocetin coupled to a phenylbenzyl-substituted cyclobutenedione. in madin-darby canine kidney cells infected with influenza a/h1n1, a/h3n2, or b virus, sa-19 displayed a 50% antivirally effective concentration of 0.60 μm and a selectivity index (ratio of cytotoxic versus antiviral concentration) of 112. sa-19 was 11-fold more potent than unsubstituted aglycoristocetin and was active i ...201222740402
a novel small molecule inhibitor of influenza a viruses that targets polymerase function and indirectly induces interferon.influenza viruses continue to pose a major public health threat worldwide and options for antiviral therapy are limited by the emergence of drug-resistant virus strains. the antiviral cytokine, interferon (ifn) is an essential mediator of the innate immune response and influenza viruses, like many viruses, have evolved strategies to evade this response, resulting in increased replication and enhanced pathogenicity. a cell-based assay that monitors ifn production was developed and applied in a hi ...201222577360
inhibitory effects of an m2-specific monoclonal antibody on different strains of influenza a virus.new approaches to the treatment of influenza have been designed based on the highly conserved antigenicity of the m2 envelope protein among influenza a virus strains. the present study examined the anti-viral activities of an anti-m2 ectodomain (m2e) monoclonal antibody (clone rm2ss23), which binds to the m2 proteins of the influenza a virus strains a/ aichi/2/68 (h3n2) (aichi) and a/pjr/8/34 (h1n1) (pr8). the results showed that rm2ss23 bound to both aichi and pr8 m2 proteins expressed on the c ...201223094582
immunization with m2e-displaying t7 bacteriophage nanoparticles protects against influenza a virus challenge.considering the emergence of highly pathogenic influenza viruses and threat of worldwide pandemics, there is an urgent need to develop broadly-protective influenza vaccines. in this study, we demonstrate the potential of t7 bacteriophage-based nanoparticles with genetically fused ectodomain of influenza a virus m2 protein (t7-m2e) as a candidate universal flu vaccine. immunization of mice with non-adjuvanted t7-m2e elicited m2e-specific serum antibody responses that were similar in magnitude to ...201223029232
lgp2 downregulates interferon production during infection with seasonal human influenza a viruses that activate interferon regulatory factor 3.lgp2, a member of the rig-i-like receptor family, lacks the amino-terminal caspase activation recruitment domains (cards) required for initiating the activation of interferon regulatory factor 3 (irf3) and interferon (ifn) transcription. the role of lgp2 in virus infection is controversial, and the only lgp2 experiments previously carried out with mammalian influenza a viruses employed an attenuated, mouse-adapted h1n1 a/pr/8/34 (pr8) virus that does not encode the ns1 protein. here we determine ...201222837208
[development of sybr green i real-time rt-pcr for the detection of ebola virus].in order to establish a rapid and accurate method for the detection of ebola virus (ebov), the primers used in sybr green i real-time rt-pcr were designed based on the ebov np gene sequences published in genbank. the sybr green i real-time rt-pcr was established and optimized for the detection of ebov. the ebov rna that was transcribed in vitro was used as a template. the sensitivity of this method was found to reach 1.0 x 10(2) copies/microl and the detection range was 10(2) - 10(10). no cross ...201223233935
induction of protective immune responses against ev71 in mice by baculovirus encoding a novel expression cassette for capsid protein vp1.ev71 is a major causative agent of hand, foot and mouth disease (hfmd) and is responsible for large outbreaks in various asian pacific countries. in the present study, we generated the recombinant baculovirus (bac-vp1) encoding vp1 in a novel expression cassette. the transmembrane domain of hemagglutinin of the h3n2 influenza virus was included in the cassette as a minimal membrane anchor for vp1. the protective immunity of bac-vp1 was investigated in a mouse model. the results showed that mice ...201222691220
design of escherichia coli-expressed stalk domain immunogens of h1n1 hemagglutinin that protect mice from lethal challenge.the hemagglutinin protein (ha) on the surface of influenza virus is essential for viral entry into the host cells. the ha1 subunit of ha is also the primary target for neutralizing antibodies. the ha2 subunit is less exposed on the virion surface and more conserved than ha1. we have previously designed an ha2-based immunogen derived from the sequence of the h3n2 a/hk/68 virus. in the present study, we report the design of an ha2-based immunogen from the h1n1 subtype (pr/8/34). this immunogen (h1 ...201223015722
in contrast to conventional inactivated influenza vaccines, 4xm2e.hsp70c fusion protein fully protected mice against lethal dose of h1, h3 and h9 influenza a isolates circulating in iran.ideal vaccines against influenza viruses should elicit not only a humoral response, but also a cellular response. mycobacterium tuberculosis hsp70 (mhsp70) have been found to promote immunogenic apcs function, elicit a strong cytotoxic t lymphocyte (ctl) response, and prevent the induction of tolerance. moreover, it showed linkage of antigens to the c-terminus of mhsp70 (mhsp70c) can represent them as vaccines resulted in more potent, protective antigen specific responses in the absence of adjuv ...201222595444
synthesis and biological evaluation of sialic acid derivatives containing a long hydrophobic chain at the anomeric position and their c-5 linked polymers as potent influenza virus inhibitors.conversions of the c-5 acetamide group in sialic acid into two kinds of cc double bond substituents were accomplished under shotten-baumann conditions. the polymerizable glycomonomers also contain a hydrophobic chain or hydroxyl group at the anomeric position. radical polymerizations of the fully protected glycomonomers were carried out with acryl amide in the presence of ammonium persulfate (aps) and n,n,n',n'-tetramethylethylenediamine (temed), followed by deprotection to furnish water-soluble ...201222100261
public health impact of including two lineages of influenza b in a quadrivalent seasonal influenza vaccine.the annual trivalent influenza vaccine (tiv) includes viruses representing three influenza strains - one a/h1n1, one a/h3n2, and one b, although two antigenically distinct lineages of influenza b (victoria and yamagata) co-circulate annually in the united states. predicting which lineage of influenza b will predominate during a season is challenging, and cross-protection by immunization against the other lineage is expected to be low. one proposed alternative is to produce a quadrivalent influen ...201222226861
surveillance in eastern india (2007-2009) revealed reassortment event involving ns and pb1-f2 gene segments among co-circulating influenza a subtypes.abstract: background: influenza a virus encodes for eleven proteins, of which ha, na, ns1 and pb1-f2 have been implicated in viral pathogenicity and virulence. thus, in addition to the ha and na gene segments, monitoring diversity of ns1 and pb1-f2 is also important. methods: 55 out of 166 circulating influenza a strains (31 h1n1 and 24 h3n2) were randomly picked during 2007-2009 and ns and pb1-f2 genes were sequenced. phylogenetic analysis was carried out with reference to the prototype strain ...201222217077
cloned cdna of a/swine/iowa/15/1930 internal genes as a candidate backbone for reverse genetics vaccine against influenza a viruses.reverse genetics viruses for influenza vaccine production usually utilize the internal genes of the egg-adapted a/puerto rico/8/34 (pr8) strain. this egg-adapted strain provides high production yield in embryonated eggs but does not necessarily give the best yield in mammalian cell culture. in order to generate a reverse genetics viral backbone that is well-adapted to high growth in mammalian cell culture, a swine influenza isolate a/swine/iowa/15/30 (h1n1) (rg1930) that was shown to give high y ...201222230579
Identification of H5N1-Specific T-Cell Responses in a High-risk Cohort in Vietnam Indicates the Existence of Potential Asymptomatic Infections.Background. Most reported human H5N1 viral infections have been severe and were detected after hospital admission. A case ascertainment bias may therefore exist, with mild cases or asymptomatic infections going undetected. We sought evidence of mild or asymptomatic H5N1 infection by examining H5N1-specific T-cell and antibody responses in a high-risk cohort in Vietnam. Methods. Peripheral blood mononuclear cells were tested using interferon-? enzyme-linked immunospot T assays measuring the respo ...201222080094
Antiviral activity of arbidol, a broad-spectrum drug for use against respiratory viruses, varies according to test conditions.The therapeutic activity of arbidol was investigated against representatives of seven different virus families. Its 50% median effective concentration (EC(50) ) was 0.22-11.8?µg/ml (0.41-22?nM). Therapeutic indices of 91 were obtained for type 1 poliovirus and 1.9-8.5 for influenza A and B, human paramyxo-3, avian infectious bronchitis-, and Marek's disease viruses. Arbidol was more inhibitory for influenza A/Aichi/2/68 (H3N2) virus than rimantadine or amantadine (EC(50) 10 vs. >15 and >31.6?µg/ ...201222028179
molecular and antigenic evolution of human influenza a/h3n2 viruses in quebec, canada, 2009-2011.a/h3n2 variability leads to poor vaccine effectiveness when the vaccine strain is not well matched to the circulating virus.201222036039
Boosting Heterosubtypic Neutralization Antibodies in Recipients of 2009 Pandemic H1N1 Influenza Vaccine.Background. A mass vaccination has been implemented to prevent the spread of 2009 pandemic influenza virus in China. Highly limited information is available on whether this vaccine induces cross-reactive neutralization antibodies against other subtypes of influenza viruses. Methods. We employed pseudovirus-based assays to analyze heterosubtypic neutralization responses in serum samples of 23 recipients of 2009 pandemic influenza vaccine. Results. One dose of pandemic vaccine not only stimulated ...201222052887
Host genetic background and the innate inflammatory response of lung to influenza virus.Many studies of influenza severity have focused on viral properties that confer virulence, whereas the contributory role of the host genetic background on infection severity remains largely unexplored. In this study, we measure the impact of inoculation with influenza virus in four strains of inbred mice - BALB/cByJ, C57BL/6J, A/J, and DBA/2J. To evaluate the extent to which responses are inherent to lung per se, as opposed to effects of the systemic response to lung infection, we also measured ...201221920449
impaired wound healing predisposes obese mice to severe influenza virus infection.(see the editorial commentary by beck, on pages 172-3, and the article by kim et al, on pages 244-51.) for the first time, obesity appeared as a risk factor for developing severe 2009 pandemic influenza infection. given the increase in obesity, there is a need to understand the mechanisms underlying poor outcomes in this population. in these studies, we examined the severity of pandemic influenza virus in obese mice and evaluated antiviral effectiveness. we found that genetically and diet-induce ...201222147799
vaccination with ns1-truncated h3n2 swine influenza virus primes t cells and confers cross-protection against an h1n1 heterosubtypic challenge in pigs.the diversity of contemporary swine influenza virus (siv) strains impedes effective immunization of swine herds. mucosally delivered, attenuated virus vaccines are one approach with potential to provide broad cross-protection. reverse genetics-derived h3n2 siv virus with truncated ns1 (ns1δ126 tx98) is attenuated and immunogenic when delivered intranasally in young pigs. we analyzed t-cell priming and cross-protective efficacy in weanling piglets after intranasal inoculation with ns1δ126 tx98 ve ...201222067263
respiratory syncytial virus (rsv) community-acquired pneumonia (cap) in a hospitalized adult with human immunodeficiency virus (hiv) mimicking influenza a and pneumocystis (carinii) jiroveci pneumonia (pcp).respiratory syncytial virus (rsv) is an important cause of lower respiratory tract infections in young children, the elderly, and immunocompromised hosts, but rsv is a rare cause of community-acquired pneumonia (cap) in hospitalized adults with human immunodeficiency virus (hiv). in patients with hiv, cap is most frequently attributable to the usual bacterial respiratory pathogens that cause cap in immunocompetent hosts, eg, streptococcuspneumoniae or hemophilus influenzae. adults with hiv are a ...201222005289
Intranasal administration of a flagellin-adjuvanted inactivated influenza vaccine enhances mucosal immune responses to protect mice against lethal infection.The influenza virus, a mucosal pathogen that infects the respiratory tract, is a major global health issue. There have been attempts to mucosally administer inactivated influenza vaccines to induce both mucosal and systemic immune responses. However, mucosally administered inactivated influenza vaccine has low immunogenicity, which is partially due to the lack of an effective mucosal adjuvant. The development of a safe and effective mucosal adjuvant is a prerequisite to the practical use of a mu ...201222051136
Genetic analysis and antigenic characterization of swine origin influenza viruses isolated from humans in the United States, 1990-2010.Swine influenza viruses (SIV) have been recognized as important pathogens for pigs and occasional human infections with swine origin influenza viruses (SOIV) have been reported. Between1990 and 2010, a total of twenty seven human cases of SOIV infections have been identified in the United States. Six viruses isolated from1990 to 1995 were recognized as classical SOIV (cSOIV) A(H1N1). After 1998, twenty-one SOIV recovered from human cases were characterized as triple reassortant (tr_SOIV) inherit ...201222078166
inefficient splicing of segment 7 and 8 mrnas is an inherent property of influenza virus a/brevig mission/1918/1 (h1n1) that causes elevated expression of ns1 protein.influenza a virus encodes two segments (7 and 8) that produce mrnas that can be spliced. we have investigated if naturally occurring sequence polymorphisms in the influenza a virus family affects splicing of these viral mrnas, as that could potentially alter the ns1/ns2- and/or m1/m2-protein ratios. we compared splicing efficiency of segment 7 and 8 mrnas of a/brevig mission/1918/1 (h1n1) and a/netherlands/178/95 (h3n2), as well as various h5n1 avian strains. results revealed that both segment 7 ...201222036312
constrained evolution drives limited influenza diversity.h3n2 influenza a viruses have been widely circulating in human populations since the pandemic of 1968. a striking feature of the evolutionary development of this strain has been its 'canalized' nature, with narrow evolutionary trees dominated by long trunks with few branching, or bifurcation events and a consequent lack of standing diversity at any single point. this is puzzling, as one might expect that the strong human immune response against the virus would create an environment encouraging m ...201222613866
age-dependent prevalence of antibodies cross-reactive to the influenza a(h3n2) variant virus in sera collected in norway in 2011.antibody cross-reactivity to the influenza a(h3n2) variant virus recently reported in the united states, was investigated in norwegian sera. seroprevalence was 40% overall, and 71% in people born between 1977 and 1993. the most susceptible age groups were children and people aged around 50 years. the high immunity in young adults is likely to be due to strong priming infection with similar viruses in the 1990s. more research is needed to explain the poor immunity in 45–54 year-olds.201222607964
immune responses and protection efficacy of a recombinant swinepox virus expressing ha1 against swine h3n2 influenza virus in mice and pigs.swine influenza virus (siv) is not only an important respiratory pathogen in pigs but also a potent threat to human health. even though immunization with recombinant vaccinia poxviruses expressing protective antigens as a vaccination strategy has been widely used for many infectious diseases, development of recombinant swinepox virus (rspv) vector for this purpose has been less successful. here, we report the construction of a recombinant swinepox virus (rspv) expressing hemagglutinin (ha1) of h ...201222584406
strain-dependent effects of pb1-f2 of triple-reassortant h3n2 influenza viruses in swine.the pb1-f2 protein of the influenza a viruses (iavs) can act as a virulence factor in mice. its contribution to the virulence of iav in swine, however, remains largely unexplored. in this study, we chose two genetically related h3n2 triple-reassortant iavs to assess the impact of pb1-f2 in virus replication and virulence in pigs. using reverse genetics, we disrupted the pb1-f2 orf of a/swine/wisconsin/14094/99 (h3n2) (sw/99) and a/turkey/ohio/313053/04 (h3n2) (ty/04). removing the pb1-f2 orf led ...201222815274
live attenuated influenza vaccine provides superior protection from heterologous infection in pigs with maternal antibodies without inducing vaccine-associated enhanced respiratory disease.control of swine influenza a virus (iav) in the united states is hindered because inactivated vaccines do not provide robust cross-protection against the multiple antigenic variants cocirculating in the field. vaccine efficacy can be limited further for vaccines administered to young pigs that possess maternally derived immunity. we previously demonstrated that a recombinant a/sw/texas/4199-2/1998 (tx98) (h3n2) virus expressing a truncated ns1 protein is attenuated in swine and has potential for ...201222811541
tenacity of low-pathogenic avian influenza viruses in different types of poultry litter.to determine the risk of infection associated with exposure to low-pathogenic avian influenza (ai) virus-contaminated poultry litter, the tenacity of low pathogenic a/ck/ca/431/00(h6n2), a/mallard/mn/355779/00(h5n2), and a/turkey/ohio/313053/04(h3n2) was evaluated. viral stocks were incubated with poultry litter from commercial flocks at 25°c. three types of poultry litter, wood shavings, shavings plus gypsum, and shavings plus peanut hulls, from commercial broiler flocks were used. the 3 low-pa ...201222802163
synthesis of c-4-modified zanamivir analogs as neuraminidase inhibitors and their anti-aiv activities.with the introduction of bioisosteres of the guanidinium group together with scaffold hopping, 35 zanamivir analogs with c-4-modification were synthesized, and their inhibitory activities against both group-1 and group-2 neuraminidase (h5n1 and h3n2) were determined. compound d26 exerts the most potency, with ic(50) values of 0.58 and 2.72 μm against n2 and n1, respectively. further preliminary anti-avian influenza virus (aiv, h5n1) activities against infected mdck cells were evaluated, and d5 e ...201222795831
neurological picture. sub-acute hydrocephalus in a patient with influenza a (h3n2) virus-related cerebellitis. 201222773858
surface glycoproteins of influenza a h3n2 virus modulate virus replication in the respiratory tract of ferrets.the hemagglutinin (ha) genes of the influenza a h3n2 subtype viruses isolated from 1968 to 2010 have evolved substantially but their neuraminidase (na) genes have been relatively less divergent. the h3n2 viruses isolated since 1995 were found to replicate in the lower respiratory tract of ferrets less efficiently than the earlier isolates. to evaluate whether the ha or/and na or the internal protein gene segments of the h3n2 virus affected viral replication in the respiratory tract of ferrets, r ...201222743127
highly conserved influenza a virus epitope sequences as candidates of h3n2 flu vaccine targets.this study focused on identifying the conserved epitopes in a single subtype a (h3n2)-as candidates for vaccine targets. we identified a total of 32 conserved epitopes in four viral proteins [22 ha, 4pb1, 3 na, 3 np]. evaluation of conserved epitopes in coverage during 1968-2010 revealed that (1) 12 ha conserved epitopes were highly present in the circulating viruses; (2) the remaining 10 ha conserved epitopes appeared with lower percentage but a significantly increasing trend after 1989 [p<0.00 ...201222698979
alkaloids from the root of isatis indigotica.seventeen new alkaloids (1-17) and 14 known analogues have been isolated from an aqueous extract of the root of isatis indigotica. the structures and absolute configurations of these compounds were determined by extensive spectroscopic data analysis, including 2d nmr, single-crystal x-ray crystallography using anomalous scattering of cu kα radiation, and electronic circular dichroism spectra calculations based on the quantum-mechanical time-dependent density functional theory. compounds 1, 2, an ...201222694318
annual influenza vaccination affects the development of heterosubtypic immunity.annual vaccination of healthy children >6 months of age against seasonal influenza has been recommended by public health authorities of some countries. however, currently used seasonal vaccines provide only limited protection against (potentially) pandemic influenza viruses. furthermore, we recently hypothesized that annual vaccination may hamper the development of cross-reactive immunity against influenza a viruses of novel subtypes, that would otherwise be induced by natural infection. here we ...201222643217
prophylactic and therapeutic combination effects of rimantadine and oseltamivir against influenza virus a (h3n2) infection in mice.the combined effect of rimantadine and oseltamivir in a prophylactic context (therapy beginning 4 h pre-virus infection) and therapeutic context (therapy started at 24 h post-viral inoculation) course on influenza h3n2 virus infection in mice was studied. in the prophylactic course 5 and 10 mg/kg/day rimantadine with 0.2 and 0.4 mg/kg/day (25:1 dose ratio) oseltamivir showed a protection index (pi) of 79.6% and 75%, respectively and a mean survival time (mst) of 13.1 and 12.9 days. the individua ...201222617756
rescue of a h3n2 influenza virus containing a deficient neuraminidase protein by a hemagglutinin with a low receptor-binding affinity.influenza viruses possess at their surface two glycoproteins, the hemagglutinin and the neuraminidase, of which the antagonistic functions have to be well balanced for the virus to grow efficiently. ferraris et al. isolated in 2003-2004 viruses lacking both a na gene and protein (h3na- viruses) (ferraris o., 2006, vaccine, 24(44-46):6656-9). in this study we showed that the hemagglutinins of two of the h3na- viruses have reduced affinity for saα2.6gal receptors, between 49 and 128 times lower th ...201222563453
high-yield production of a stable vero cell-based vaccine candidate against the highly pathogenic avian influenza virus h5n1.highly pathogenic avian influenza (hpai) viruses pose a global pandemic threat, for which rapid large-scale vaccine production technology is critical for prevention and control. because chickens are highly susceptible to hpai viruses, the supply of chicken embryos for vaccine production might be depleted during a virus outbreak. therefore, developing hpai virus vaccines using other technologies is critical. meeting vaccine demand using the vero cell-based fermentation process has been hindered b ...201222554519
canalization of the evolutionary trajectory of the human influenza virus.since its emergence in 1968, influenza a (h3n2) has evolved extensively in genotype and antigenic phenotype. however, despite strong pressure to evolve away from human immunity and to diversify in antigenic phenotype, h3n2 influenza shows paradoxically limited genetic and antigenic diversity present at any one time. here, we propose a simple model of antigenic evolution in the influenza virus that accounts for this apparent discrepancy.201222546494
severe coinfection with seasonal influenza a (h3n2) virus and staphylococcus aureus--maryland, february-march 2012.on march 5, 2012, the maryland department of health and mental hygiene (dhmh) and the calvert county health department were notified of three deaths following respiratory illness among members of a maryland family. one family member (patient a) experienced upper-respiratory symptoms and died unexpectedly at home. two others (patients b and c) sought medical care for fever, shortness of breath, and cough productive of bloody sputum and died during their hospitalizations. all three family members ...201222534762
the human h3n2 influenza viruses a/victoria/3/75 and a/hiroshima/52/2005 preferentially bind to α2-3-sialylated monosialogangliosides with fucosylated poly-n-acetyllactosaminyl chains.among influenza a viruses, subtype h3n2 is the major cause of human influenza morbidity and is associated with seasonal epidemics causing annually half million deaths worldwide. influenza a virus infection is initiated via hemagglutinin that binds to terminally sialylated glycoconjugates exposed on the surface of target cells. gangliosides from human granulocytes were probed using thin-layer chromatography overlay assays for their binding potential to h3n2 virus strains a/victoria/3/75 and a/hir ...201222534568
excess mortality among the elderly in 12 european countries, february and march 2012.in february and march 2012, excess deaths among the elderly have been observed in 12 european countries that carry out weekly monitoring of all-cause mortality. these preliminary data indicate that the impact of influenza in europe differs from the recent pandemic and post-pandemic seasons. the current excess mortality among the elderly may be related to the return of influenza a(h3n2) virus, potentially with added effects of a cold snap.201222516003
influenza outbreaks in nursing homes with high vaccination coverage in navarre, spain, 2011/12.in the 2011/12 season, three influenza outbreaks were studied in nursing homes with high vaccination coverage in navarre, spain. attack rates ranged from 2.9% to 67%. influenza a/stockholm/18/2011(h3n2) virus strain was isolated from the three outbreaks. vaccination should be complemented with other hygiene measures in nursing homes. early detection of influenza outbreaks in nursing homes can aid in their control.201222516002
evaluation of influenza virus a/h3n2 and b vaccines on the basis of cross-reactivity of postvaccination human serum antibodies against influenza viruses a/h3n2 and b isolated in mdck cells and embryonated hen eggs.the vaccine strains against influenza virus a/h3n2 for the 2010-2011 season and influenza virus b for the 2009-2010 and 2010-2011 seasons in japan are a high-growth reassortant a/victoria/210/2009 (x-187) strain and an egg-adapted b/brisbane/60/2008 (victoria lineage) strain, respectively. hemagglutination inhibition (hi) tests with postinfection ferret antisera indicated that the antisera raised against the x-187 and egg-adapted b/brisbane/60/2008 vaccine production strains poorly inhibited rec ...201222492743
early estimates of the effectiveness of the 2011/12 influenza vaccine in the population targeted for vaccination in spain, 25 december 2011 to 19 february 2012.we present early estimates of influenza vaccine effectiveness (ve) in the population targeted for vaccination, during 25 december 2011 to 19 february 2012. the adjusted ve was 55% (95% ci: 3 to 79) against any type of influenza virus and 54% (95% ci: 1 to 79) against influenza a(h3n2) virus. this suggests a moderate protective effect of the vaccine in the targeted population in a late influenza epidemic with limited match between vaccine and circulating strains.201222490308
influenza transmission in a community during a seasonal influenza a(h3n2) outbreak (2010-2011) in mongolia: a community-based prospective cohort study.knowledge of how influenza viruses spread in a community is important for planning and implementation of effective interventions, including social distancing measures. households and schools are implicated as the major sites for influenza virus transmission. however, the overall picture of community transmission is not well defined during actual outbreaks. we conducted a community-based prospective cohort study to describe the transmission characteristics of influenza in mongolia.201222427943
doxycycline treatment attenuates acute lung injury in mice infected with virulent influenza h3n2 virus: involvement of matrix metalloproteinases.acute respiratory distress syndrome, a severe form of acute lung injury (ali), is a major cause of death during influenza pneumonia. we have provided evidence for the involvement of recruited neutrophils, their toxic enzymes such as myeloperoxidase and matrix metalloproteinases (mmps), and neutrophil extracellular traps in aggravating alveolar-capillary damage. in this study, we investigated the effects of doxycycline (dox), an inhibitor of mmps, on influenza-induced ali. balb/c mice were infect ...201222421441
suppression of the antiviral response by an influenza histone mimic.viral infection is commonly associated with virus-driven hijacking of host proteins. here we describe a novel mechanism by which influenza virus affects host cells through the interaction of influenza non-structural protein 1 (ns1) with the infected cell epigenome. we show that the ns1 protein of influenza a h3n2 subtype possesses a histone-like sequence (histone mimic) that is used by the virus to target the human paf1 transcription elongation complex (hpaf1c). we demonstrate that binding of ns ...201222419161
fatal cases of influenza a(h3n2) in children: insights from whole genome sequence analysis.during the northern hemisphere winter of 2003-2004 the emergence of a novel influenza antigenic variant, a/fujian/411/2002-like(h3n2), was associated with an unusually high number of fatalities in children. seventeen fatal cases in the uk were laboratory confirmed for fujian/411-like viruses. to look for phylogenetic patterns and genetic markers that might be associated with increased virulence, sequencing and phylogenetic analysis of the whole genomes of 63 viruses isolated from fatal cases and ...201222412998
genetic and pathobiologic characterization of h3n2 canine influenza viruses isolated in the jiangsu province of china in 2009-2010.the newly emerging canine influenza virus (civ) causes considerable concerns for both veterinary and public health. during 2009-2010, six strains of h3n2 influenza virus were isolated from dogs in jiangsu province, china. sequence and phylogenetic analysis of eight gene segments revealed that the six viruses were most similar to a recent canine-derived subtype h3n2 influenza virus isolated in cats from south korea, which originated from avian strain. by comparing the deduced amino acid sequences ...201222397933
critical role of constitutive type i interferon response in bronchial epithelial cell to influenza infection.innate antiviral responses in bronchial epithelial cells (becs) provide the first line of defense against respiratory viral infection and the effectiveness of this response is critically dependent on the type i interferons (ifns). however the importance of the antiviral responses in becs during influenza infection is not well understood. we profiled the innate immune response to infection with h3n2 and h5n1 virus using calu-3 cells and primary becs to model proximal airway cells. the susceptibil ...201222396801
generation of reassortant influenza viruses within the non-industrial poultry system.we compared the genetic and biologic characteristics of 35 influenza viruses of different epidemiological backgrounds in korea, including h3n2 canine influenza virus (civ). phylogenetic analysis revealed that chicken adapted h9n2 viruses (a/chicken/korea/96006/96 [ck/kor/96006-like]) have acquired aquatic avian gene segments through reassortment, and these reassorted h9n2 viruses were more frequently detected from minor poultry species than from industrial poultry. conversely, gene segments from ...201222386854
age as a determinant for dissemination of seasonal and pandemic influenza: an open cohort study of influenza outbreaks in östergötland county, sweden.an understanding of the occurrence and comparative timing of influenza infections in different age groups is important for developing community response and disease control measures. this study uses data from a scandinavian county (population 427.000) to investigate whether age was a determinant for being diagnosed with influenza 2005-2010 and to examine if age was associated with case timing during outbreaks. aggregated demographic data were collected from statistics sweden, while influenza cas ...201222384066
multifunctional adaptive ns1 mutations are selected upon human influenza virus evolution in the mouse.the role of the ns1 protein in modulating influenza a virulence and host range was assessed by adapting a/hong kong/1/1968 (h3n2) (hk-wt) to increased virulence in the mouse. sequencing the ns genome segment of mouse-adapted variants revealed 11 mutations in the ns1 gene and 4 in the overlapping nep gene. using the hk-wt virus and reverse genetics to incorporate mutant ns gene segments, we demonstrated that all ns1 mutations were adaptive and enhanced virus replication (up to 100 fold) in mouse ...201222363747
pathogenesis and transmission of swine origin a(h3n2)v influenza viruses in ferrets.recent isolation of a novel swine-origin influenza a h3n2 variant virus [a(h3n2)v] from humans in the united states has raised concern over the pandemic potential of these viruses. here, we analyzed the virulence, transmissibility, and receptor-binding preference of four a(h3n2)v influenza viruses isolated from humans in 2009, 2010, and 2011. high titers of infectious virus were detected in nasal turbinates and nasal wash samples of a(h3n2)v-inoculated ferrets. all four a(h3n2)v viruses possesse ...201222355116
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