| preventing zoonotic influenza virus infection. | we evaluated 49 swine industry workers and 79 nonexposed controls for antibodies to swine influenza viruses. multivariate modeling showed that workers who seldom used gloves (odds ratio [or] 30.3) or who smoked (or 18.7) most frequently had evidence of previous h1n1 swine virus. these findings may be valuable in planning for pandemic influenza. | 2006 | 16707061 |
| a sensitive one-step real-time pcr for detection of avian influenza viruses using a mgb probe and an internal positive control. | avian influenza viruses (aivs) are endemic in wild birds and their introduction and conversion to highly pathogenic avian influenza virus in domestic poultry is a cause of serious economic losses as well as a risk for potential transmission to humans. the ability to rapidly recognise aivs in biological specimens is critical for limiting further spread of the disease in poultry. the advent of molecular methods such as real time polymerase chain reaction has allowed improvement of detection method ... | 2006 | 16725022 |
| genetic characterization of novel reassortant h1n2 influenza a viruses isolated from pigs in southeastern china. | in december 2004, three influenza h1n2 viruses were isolated from lung samples of pigs that had died from respiratory disease on a farm in southeastern china. to determine the genetic characterization and probable origin, one of the three isolates, a/swine/zhejiang/1/2004 (sw/zj/1/2004), was genetically analyzed. sw/zj/1/2004 was a reassortant with an na gene most closely related to the corresponding gene from a human-like h3n2 virus circulating in 1995. the remaining seven genes were most close ... | 2006 | 16755371 |
| [molecular genetic analysis of the biological properties of highly pathogenic influenza a/h5n1 virus strains isolated from wild birds and poultry during epizooty in western siberia (july 2005)]. | the full-size genomes of 2 highly pathogenetic avian influenza (hpai) virus strains isolated from a wild great-crested grebe (a/grebe/novosibirsk/29/05) and a domestic duck (a/duck/novosibirsk/56/05) in the tract of the chany hollow, barabino forest-steppe (novosibirsk region) during the epizootic outbreak in the summer of 2005. the reproductive properties of these strains successively increase in the series of cell lines bhk-2 --> leh --> vero-e6 --> mdck --> ps. a/grebe/novosibirsk/29/05 and a ... | 2006 | 16756172 |
| [in vitro effects of antiviral drugs on the reproduction of highly pathogenic influenza a/h5n1 virus strains that induce epizooty among poultry in the summer of 2005]. | commercial drugs, such as rimantadine, amantadine, rivabirine, and arbidole, are effective in suppressing the in vitro reproduction of highly pathogenic avian influenza a/h5n1 viruses. the study has used a porcine embryonic renal cell line and the highly pathogenic a/duck/novosibirsk/56/05 (h5n1) strain from a sick domestic duck (anas platyrhynchos domesticus) (chany lake environs, novosibirsk region). | 2006 | 16756173 |
| [christopher columbus flu. a hypothesis for an ecological catastrophe]. | when christopher columbus and his men embarked on the second colombian expedition to the new world (1493), the crew suffered from fever, respiratory symptoms and malaise. it is generally accepted that the disease was influenza. pigs, horses and hens acquired in gomera (canary islands) traveled in the same ship. the pigs may well have been the origin of the flu and the intermediary hosts for genetic recombination of other viral subtypes. the caribbean archipelago had a large population of birds, ... | 2006 | 16762260 |
| avian influenza h5n1 in viverrids: implications for wildlife health and conservation. | the asian countries chronically infected with avian influenza a h5n1 are 'global hotspots' for biodiversity conservation in terms of species diversity, endemism and levels of threat. since 2003, avian influenza a h5n1 viruses have naturally infected and killed a range of wild bird species, four felid species and a mustelid. here, we report fatal disseminated h5n1 infection in a globally threatened viverrid, the owston's civet, in vietnam, highlighting the risk that avian influenza h5n1 poses to ... | 2006 | 16790404 |
| characterization of an avian influenza virus of subtype h7n2 isolated from chickens in northern china. | an h7n2 avian influenza virus was isolated from chickens during routine surveillance in northern china in 2002. to understand the origin of this virus, we completely sequenced its genome. the pb1, pa, ha, and m genes of this virus were highly homologous with those of the wild bird virus a/africa starling/eng-q/983/79 (h7n1). the np and ns genes were closely related to those of two other wild bird viruses isolated 30 years ago. the closest relatives of the pb2 and na genes of the virus were those ... | 2006 | 16791426 |
| avian influenza in swine: a threat for the human population? | until recently, it was thought that pigs were required as intermediate hosts for the transmission of avian influenza viruses to humans and this hypothesis is based on three suppositions: (1) pigs are more susceptible to avian influenza viruses than humans. (2) pigs are the single animal species with receptors preferred by both avian (alpha 2-3 linked sialic acid to galactose) and human (alpha 2-6 linked sialic acid) influenza viruses, which supports their role as "mixing vessels" for reassortmen ... | 2006 | 16800240 |
| bird flu, influenza and 1918: the case for mutant avian tuberculosis. | influenza is italian for "influence", latin: influentia. it used to be thought that the disease was caused by a bad influence from the heavens. influenza was called a virus long, long before it was proven to be one. in 2005, an article in the new england journal of medicine estimated that a recurrence of the 1918 influenza epidemic could kill between 180 million and 360 million people worldwide. a large part of the current bird-flu hysteria is fostered by a distrust among the lay and scientific ... | 2006 | 16806732 |
| amantadine resistance among porcine h1n1, h1n2, and h3n2 influenza a viruses isolated in germany between 1981 and 2001. | this study was designed to gain insight into amantadine susceptibility of porcine influenza a viruses isolated in germany between 1981 and 2001. the 12 studied h1n1, h1n2, and h3n2 porcine influenza virus strains were isolated in chicken eggs and passaged once in mdck cells. plaque reduction assays were applied to examine virus susceptibility to amantadine. genotyping was used to confirm drug resistance. in the results of these antiviral studies, only 3 of the 12 isolates were shown to be amanta ... | 2006 | 16809934 |
| [application of single radial hemolysis technique for diagnosis of influenza a (h5n1)]. | to understand the optimal condition of single radial hemolysis (srh) for diagnosis of avian influenza a (h5n1) virus in order that srh could be performed in general laboratories. | 2006 | 16816850 |
| optimization of a sampling system for recovery and detection of airborne porcine reproductive and respiratory syndrome virus and swine influenza virus. | the objective of this research was to optimize sampling parameters for increased recovery and detection of airborne porcine reproductive and respiratory syndrome virus (prrsv) and swine influenza virus (siv). collection media containing antifoams, activated carbons, protectants, and ethylene glycol were evaluated for direct effects on factors impacting the detection of prrsv and siv, including virus infectivity, viability of continuous cell lines used for the isolation of these viruses, and perf ... | 2006 | 16820475 |
| [highly pathogenic influenza a/h5n1 virus-caused epizooty among mute swans (cygnus olor) in the lower estuary of the volga river (november 2005)]. | molecular virological studies of the field material collected in the epicenter of epizooty with high mortality among mute swans (cygnus olor) in the area of the lower estuary of the volga river (november 2005) could establish the etiological role of highly pathogenic influenza a (hpai) virus of the subtype h5n1. ten hpai/h5n1 strains deposited at the state collection of viruses of the russian federation with the priority dated december 1, 2005 were isolated from the cloacal/tracheal swabs and vi ... | 2006 | 16826750 |
| [population interactions in biological system: influenza virus a--wild and domestic animals--human; reasons and consequences of introduction high pathogenic influenza virus a/h5n1 on russian territory]. | own results and literature data under the analysis of variability of a influenza virus a and population interactions in biological system: influenza virus a--wild and domestic animals--human are presented. opportunities of virus reassortants appearance between viruses of animals and viruses of human and spreading the new pandemic variants are proved, in particular, at simultaneous infection of pigs with virus h5 and viruses of human influenza h1 and h3, circulating worldwide. blocks of preparati ... | 2006 | 16830601 |
| triple reassortant h3n2 influenza a viruses, canada, 2005. | since january 2005, h3n2 influenza viruses have been isolated from pigs and turkeys throughout canada and from a swine farmer and pigs on the same farm in ontario. these are human/classical swine/avian reassortants similar to viruses that emerged in us pigs in 1998 but with a distinct human-lineage neuraminidase gene. | 2006 | 16836834 |
| an overview of swine influenza. | swine influenza is a highly infectious viral disease of pigs, causing considerable economic impact. the causative agent is known as a type a orthomyxovirus with a segmented rna genome. influenza type a virus is a highly contagious pathogen among a limited number of birds and mammals. the objective of this review is to summarize the current knowledge in swine influenza infection in pigs with emphasizing on epidemiology, pathogenesis, diagnostic techniques and control measures. | 2006 | 16841566 |
| isolation and characterization of novel h3n1 swine influenza viruses from pigs with respiratory diseases in korea. | pigs can play an important role in the genetic reassortment of influenza viruses and as a reservoir for another lineage of influenza viruses that have the ability to reassort and be transmitted between species. in march and april 2006, novel h3n1 influenza a viruses were isolated from pigs with respiratory diseases at two different commercial swine farms in korea. genetic and phylogenetic analyses of the sequences of all eight viral rna segments showed that the novel h3n1 swine influenza viruses ... | 2006 | 16928961 |
| overcoming maternal antibody interference by vaccination with human adenovirus 5 recombinant viruses expressing the hemagglutinin and the nucleoprotein of swine influenza virus. | sows and gilts lack immunity to human adenovirus 5 (ad-5) vectored vaccines so immunogens of swine pathogens can be expressed with these vaccines in order to immunize suckling piglets that have interfering, maternally derived antibodies. in this study 7-day-old piglets, that had suckled h3n2 infected gilts, were sham-inoculated with a non-expressing ad-5 vector or given a primary vaccination with replication-defective ad-5 viruses expressed the h3 hemagglutinin and the nucleoprotein of swine inf ... | 2006 | 16939702 |
| vaccination of pigs against swine influenza viruses by using an ns1-truncated modified live-virus vaccine. | swine influenza viruses (siv) naturally infect pigs and can be transmitted to humans. in the pig, genetic reassortment to create novel influenza subtypes by mixing avian, human, and swine influenza viruses is possible. an siv vaccine inducing cross-protective immunity between different subtypes and strains circulating in pigs is highly desirable. previously, we have shown that an h3n2 siv (a/swine/texas/4199-2/98 [tx98]) containing a deleted ns1 gene expressing a truncated ns1 protein of 126 ami ... | 2006 | 16943300 |
| immunization with trivalent inactivated influenza vaccine in partially immunized toddlers. | children > or = 6 months of age who have previously received 1 dose of trivalent inactivated influenza vaccine are recommended to be given an additional single trivalent inactivated influenza vaccine dose the following fall. limited data exist documenting the immunogenicity of 2 doses of influenza vaccine given in separate years to young children, and it is not known if the antigen content of each of the 2 doses of vaccine must be identical or similar to optimally immunize children in this age g ... | 2006 | 16950949 |
| nonhomogeneous birth and death models for epidemic outbreak data. | in this paper, generalized nonlinear models are proposed in order to incorporate the following considerations in modeling an epidemic disease outbreak statistically. (1) the dependence of the data is handled with a nonhomogeneous death or a nonhomogeneous birth process. (2) the first stage of the outbreak is described with an epidemic susceptibles-infectives-removed (sir) model. soon the control measures taken will dominate the process. these measures are in addition to the natural epidemic remo ... | 2007 | 16957056 |
| evaluation of hemagglutinin subtype 1 swine influenza viruses from the united states. | swine influenza viruses (siv) of the hemagglutinin subtype 1 (h1) isolated from the united states (u.s.) have not been well-characterized in the natural host. an increase in the rate of mutation and reassortment has occurred in siv isolates from the u.s. since 1998, including viruses belonging to the h1 subtype. two independent animal studies were done to evaluate and compare the pathogenesis of 10 siv isolates dating from 1930 to currently circulating isolates. in addition, the hemagglutinin an ... | 2006 | 16962262 |
| review: molecular evolution and the feasibility of an avian influenza virus becoming a pandemic strain--a conceptual shift. | during recent years, a conceptual shift took place with respect to the genetic dynamics of influenza a viruses. in difference of the widely accepted approach that avian viral strains have the capacity to infect man only after undergoing genetic reassortment within pigs, it is now contended that direct transfection of man by intact avian-harbored viral genotypes is an actual, recurrent move, which may bring bout the generation of a new pandemic strain. this cardinal conceptual shift has been prop ... | 2006 | 16972025 |
| serological profiles after consecutive experimental infections of pigs with european h1n1, h3n2, and h1n2 swine influenza viruses. | swine influenza viruses (sivs) of h1n1, h3n2, and h1n2 subtypes, with antigenically different hemagglutinins, are currently cocirculating in pigs in europe. this study aimed to determine whether the hemagglutination inhibition (hi) test, which is the primary serological test for siv, is sufficiently specific to discriminate between infections with the three subtypes. in experiment 1, pigs were consecutively inoculated with european h1n1, h3n2, and h1n2 sivs by the intranasal route, or with the r ... | 2006 | 16987057 |
| a preliminary panorama of the diversity of n1 subtype influenza viruses. | n1 subtype influenza viruses have caused many epidemics and even a few pandemics in humans, pigs and fowls including 1918 human h1n1 pandemic, which killed 20-50 million people and the current avian h5n1 pandemic in the eastern hemisphere, which has caused great economic losses and posed a severe threat to human public health. to elucidate the whole diversity of n1 influenza viruses from a dynamic view, 202 neuraminidase (na) sequences of n1 subtype influenza isolates were selected and analyzed ... | 2007 | 17019634 |
| evidence of influenza a virus rna in siberian lake ice. | influenza a virus infects a large proportion of the human population annually, sometimes leading to the deaths of millions. the biotic cycles of infection are well characterized in the literature, including in studies of populations of humans, poultry, swine, and migratory waterfowl. however, there are few studies of abiotic reservoirs for this virus. here, we report the preservation of influenza a virus genes in ice and water from high-latitude lakes that are visited by large numbers of migrato ... | 2006 | 17035314 |
| [biological significance of amino acids deletion in na stalk of h5n1 avian influenza virus]. | it has been reported that na gene of some h1n1 influenza a virus strains isolated since 1933 is characterized by a deletion of 11 to 16 amino acids in the stalk. the spontaneous mutant in na stalk of h1n1 virus lacks enzyme activity with large substrate (fetuin) but not with small substrate (sialyllactose). recently, h5n1 virus also has been found that na has the same unique mutation in the stalk, a deletion of 15 to 20 amino acids. however, biological significance of this mutation has not yet b ... | 2006 | 17037051 |
| detection of porcine reproductive and respiratory syndrome virus, porcine circovirus type 2, swine influenza virus and aujeszky's disease virus in cases of porcine proliferative and necrotizing pneumonia (pnp) in spain. | proliferative and necrotizing pneumonia (pnp) is a severe form of interstitial pneumonia characterised by hypertrophy and proliferation of pneumocytes type 2 and presence of necrotic cells within alveoli lumen. many viral agents have been linked to pnp aetiology, with especial emphasis on porcine reproductive and respiratory syndrome virus (prrsv). to gain knowledge on pnp causality, a retrospective study on 74 pnp cases from postweaning pigs from spain was carried out. coupled with histopatholo ... | 2007 | 17070659 |
| immunostimulatory properties of a novel adjuvant administered with inactivated influenza virus vaccine. | the immunopotentiating activity of a new delivery system was investigated comparatively to alhydrogel adjuvant, as an antiviral inactivated vaccine after one injection. the efficiency of the new formulation (biomed) was evaluated with an inactivated porcine strain of influenza (a/sw/in/1726/88 h1n1) in the pig model. the first assessment criteria was the follow-up of selected immunological parameters such as, antibody levels, lymphoproliferation, double positive cd4+cd8+ t lymphocytes and cytoki ... | 2007 | 17074291 |
| the influenza viruses. | human epidemic influenza is caused by influenza type a and b viruses, which continually undergo antigenic change in their surface antigens, haemagglutinin (h) and neuraminidase (n). influenza epidemics are the consequence of small, ongoing antigenic changes known as "antigenic drift", which occurs in both influenza types. pandemic influenza occurs at irregular and unpredictable intervals, and is the result of a major antigenic change known as "antigenic shift", which occurs only in influenza a. ... | 2006 | 17115950 |
| pandemic preparedness: pigs, poultry, and people versus plans, products, and practice. | influenza pandemic preparedness planning is critical for reducing human suffering and negative effects on the economy and society. the centers for disease control and prevention (cdc) is working to ensure a rapid, efficient, and successful response to an outbreak if, when, and where it appears. the cdc's context for strategic planning is based on experiences with seasonal influenza and what is known about past influenza pandemics. from a public health perspective, pandemic preparedness can be ac ... | 2006 | 17163393 |
| genetic analysis of nonstructural genes (ns1 and ns2) of h9n2 and h5n1 viruses recently isolated in israel. | the avian influenza virus subtype h9n2 affects wild birds, domestic poultry, swine, and humans; it has circulated amongst domestic poultry in israel during the last 6 years. the h5n1 virus was recorded in israel for the first time in march 2006. nonstructural (ns) genes and ns proteins are important in the life cycle of the avian influenza viruses. in the present study, ns genes of 21 examples of h9n2 and of two examples of h5n1 avian influenza viruses, isolated in israel during 2000-2006, were ... | 2007 | 17171546 |
| isolation and phylogenetic analysis of h1n1 swine influenza virus isolated in korea. | a swine influenza h1n1 virus was isolated from a pig during a severe outbreak of respiratory disease in korea. all genes of the h1n1 isolate, including hemagglutinin (ha), neuraminidase (na), matrix (m), nucleoprotein (np), non-structural (ns), pa, pb1 and pb2, were of swine origin. also, all these genes showed a close phylogenic relationship with those of h1n1 viruses previously isolated from pigs in the united states. these results suggest that north american swine influenza virus has actually ... | 2007 | 17174433 |
| pb1-f2 gene in influenza a viruses of different hemagglutinin subtype. | the second orf frame (+1) of pb1 polymerase gene of influenza a virus (iav) encodes the pb1-f2 protein. the length of pb1-f2 encoded by the a/puerto rico/8/34 (h1n1) (pr8) virus is 87 aa. the analysis of nucleotide sequences of pb1 gene of 626 iav isolates available in genbank and influenza sequence database revealed that this gene has mostly the capacity to encode a putative protein of 90 aa. the predicted extra three amino acids in the 90-aa pb1-f2 are to a great extent conservative. some iav ... | 2006 | 17177613 |
| a naturally occurring variant of porcine mx1 associated with increased susceptibility to influenza virus in vitro. | mx1 has been implicated in resistance to the influenza virus. we have now identified four alleles of the mxl gene in domesticated breeds of pigs. two of the alleles encode deletion variants (a 3-bp deletion in exon 13 and an 11-bp deletion in exon 14), which might be expected to interfere with mx activity. the porcine mxl genes corresponding to wild type, the 3-bp deletion mutant, and the 11-bp deletion mutant were cloned and expressed in nih3t3 cells, and the antiviral activity for influenza vi ... | 2007 | 17203407 |
| serologic surveillance of swine h1 and h3 and avian h5 and h9 influenza a virus infections in swine population in korea. | influenza a is a respiratory disease common in the swine industry. three subtypes, h1n1, h1n2 and h3n2 influenza a viruses, are currently co-circulating in swine populations in korea. an outbreak of the highly pathogenic avian influenza h5n1 virus occurred in domestic bird farms in korea during the winter season of 2003. pigs can serve as hosts for avian influenza viruses, enabling passage of the virus to other mammals and recombination of mammalian and avian influenza viruses, which are more re ... | 2007 | 17223213 |
| epidemiologic assessment of porcine circovirus type 2 coinfection with other pathogens in swine. | to identify important pathogens and characterize their serologic and pathologic effects in porcine circovirus type 2 (pcv2)-infected pigs in relation to pig age and type of swine production system. | 2007 | 17223759 |
| prevalence of pb1-f2 of influenza a viruses. | pb1-f2 is a pro-apoptotic polypeptide of many influenza a virus (fluav) isolates encoded by an alternative orf of segment 2. a comprehensive genbank search was conducted to analyse its prevalence. this search yielded 2226 entries of 80 fluav subtypes. of these sequences, 87 % encode a pb1-f2 polypeptide greater than 78 aa. however, classic swine influenza viruses and human h1n1 isolates collected since 1950 harbour a truncated pb1-f2 sequence. while pb1-f2 of human h1n1 viruses terminates after ... | 2007 | 17251572 |
| avian and swine influenza viruses: our current understanding of the zoonotic risk. | the introduction of swine or avian influenza (ai) viruses in the human population can set the stage for a pandemic, and many fear that the asian h5n1 ai virus will become the next pandemic virus. this article first compares the pathogenesis of avian, swine and human influenza viruses in their natural hosts. the major aim was to evaluate the zoonotic potential of swine and avian viruses, and the possible role of pigs in the transmission of ai viruses to humans. cross-species transfers of swine an ... | 2007 | 17257572 |
| [expression and identification of h5 subtype hemagglutinin of avian influenza a virus in insect cells]. | to clone and express avian influenza a virus [a/hong kong/482/97(h5n1)] h5 subtype hemagglutinin in baculovirus-insect cell expression system and investigate the antigenicity and bioactivity of the recombinant protein. | 2007 | 17259136 |
| antigenic and genetic evolution of swine influenza a (h3n2) viruses in europe. | in the early 1970s, a human influenza a/port chalmers/1/73 (h3n2)-like virus colonized the european swine population. analyses of swine influenza a (h3n2) viruses isolated in the netherlands and belgium revealed that in the early 1990s, antigenic drift had occurred, away from a/port chalmers/1/73, the strain commonly used in influenza vaccines for pigs. here we show that italian swine influenza a (h3n2) viruses displayed antigenic and genetic changes similar to those observed in northern europea ... | 2007 | 17287258 |
| in vitro culture of porcine respiratory nasal mucosa explants for studying the interaction of porcine viruses with the respiratory tract. | the mucosal surface of the respiratory tract is a common site of entry of many viruses. molecular and cellular aspects of the interactions of respiratory viruses with the respiratory nasal mucosa are largely unknown. in order to be able to study those interactions in depth, an in vitro model was set up. this model consists of porcine respiratory nasal mucosa explants, cultured at an air-liquid interface. light microscopy, scanning electron microscopy and transmission electron microscopy, combine ... | 2007 | 17324473 |
| amino acid and codon use: in two influenza viruses and three hosts. | the aim of this study was to compare the use of amino acids and codons in influenza viruses a and b and in their common hosts, to highlight any relevant difference. | 2007 | 17336013 |
| [the spectrum of vetebrates' cell lines sensitive to highly pathogenic influenza a/tern/sa/61 (h5n3) and a/duck/novosibirsk/56/05 (h5n1) viruses]. | the reproduction of highly pathogenic avian influenza (hpai) a/tern/sa/61 h5n3 and a/ducklnovosibirsk/56/05 h5ni viruses was comparatively studied in 16 human and animal cell lines. the strain a/duck/novosibirsk/56/05 was shown to have a wider range of hosts. the most sensitive transplanted cell lines were found to be feline fibroblasts (cc-81), primarily trypsin-treated cells of chick embryonic fibroblasts (cef), the kidney of dogs (mdck), pigs (spev), monkeys (vero), the human conjunctiva (1-5 ... | 2007 | 17338234 |
| isolation and genetic analysis of human origin h1n1 and h3n2 influenza viruses from pigs in china. | influenza a viruses of subtypes h1n1 and h3n2 have been reported widely in pigs, associated with clinical disease. these mainly include classical swine h1n1, avian-like h1n1, and human-like or avian-like h3n2 viruses. from 2005 to 2006, we carried out swine influenza virus surveillance in eight provinces of china. here we report, for the first time, the isolation and genetic analysis of a human-like influenza h1n1 virus from a pig in a farm of guangdong province of southern china, a host suspect ... | 2007 | 17346674 |
| cases of swine influenza in humans: a review of the literature. | as the threat of a pandemic looms, improvement in our understanding of interspecies transmission of influenza is necessary. using the search terms "swine," "influenza," and "human," we searched the pubmed database in april 2006 to identify publications describing symptomatic infections of humans with influenza viruses of swine origin. from these reports, we extracted data regarding demographic characteristics, epidemiological investigations, and laboratory results. we found 50 cases of apparent ... | 2007 | 17366454 |
| the quail and chicken intestine have sialyl-galactose sugar chains responsible for the binding of influenza a viruses to human type receptors. | the receptor specificity of influenza viruses is one factor that allows avian influenza viruses to cross the species barrier. the recent transmissions of avian h5n1 and h9n2 influenza viruses from chickens and/or quails to humans indicate that avian influenza viruses can directly infect humans without an intermediate host, such as pigs. in this study, we used two strains of influenza a virus (a/pr/8/34, which preferentially binds to an avian-type receptor, and a/memphis/1/71, which preferentiall ... | 2007 | 17389652 |
| transmissibility of swine flu at fort dix, 1976. | the 1976 outbreak of a/new jersey/76 influenza in fort dix is a rare example of an influenza virus with documented human to human transmission that failed to spread widely. despite extensive epidemiological investigation, no attempt has been made to quantify the transmissibility of this virus. the world health organization and the united states government view containment of emerging influenza strains as central to combating pandemic influenza. computational models predict that it may be possibl ... | 2007 | 17412677 |
| genetic analysis of two influenza a (h1) swine viruses isolated from humans in thailand and the philippines. | influenza viruses a/philippines/341/2004 (h1n2) and a/thailand/271/2005 (h1n1) were isolated from two males, with mild influenza providing evidence of sporadic human infection by contemporary swine influenza. both viruses were antigenically and genetically distinct from influenza a (h1n1 and h1n2) viruses that have circulated in the human population. genetic analysis of the haemagglutinin genes found these viruses to have the highest degree of similarity to the classical swine h1 viruses circula ... | 2007 | 17429716 |
| neuraminidase inhibitor susceptibility of porcine h3n2 influenza a viruses isolated in germany between 1982 and 1999. | as an intermediate host of avian and human influenza a viruses (fluav) pigs may play a potential role in interspecies virus transmission and reassortment of viral genes including those conferring antiviral drug resistance. porcine fluav isolated in germany between 1989 and 2001 contains mutations in the m2 gene inducing amantadine resistance. no data exist on neuraminidase inhibitor (nai) susceptibility of these porcine fluav. we studied the antiviral activity of nai against seven selected h3n2 ... | 2007 | 17445913 |
| risk maps for the spread of highly pathogenic avian influenza in poultry. | devastating epidemics of highly contagious animal diseases such as avian influenza, classical swine fever, and foot-and-mouth disease underline the need for improved understanding of the factors promoting the spread of these pathogens. here the authors present a spatial analysis of the between-farm transmission of a highly pathogenic h7n7 avian influenza virus that caused a large epidemic in the netherlands in 2003. the authors developed a method to estimate key parameters determining the spread ... | 2007 | 17447838 |
| pandemic influenza planning: shouldn't swine and poultry workers be included? | recent research has demonstrated that swine and poultry professionals, especially those who work in large confinement facilities, are at markedly increased risk of zoonotic influenza virus infections. in serving as a bridging population for influenza virus spread between animals and man, these workers may introduce zoonotic influenza virus into their homes and communities as well as expose domestic swine and poultry to human influenza viruses. prolonged and intense occupational exposures of huma ... | 2007 | 17459539 |
| [effect of probiotic lactic acid bacteria strains on virus infection]. | the effect of probiotic lactic acid bacteria strains on viral infection was studied in experiments in vivo. it was shown that in investigations microbial substance based on living cells of l. plantarum and s. salivarius subsp. thermophilus strains manifested antiinfluenzal activity under administration of 0.3 ml of cultural medium per os at a dose of 3 x 10(8)/cfu mouse and antiherpetic activity at a dose of 0.3 x 10(9)/cfu mouse. the probiotic effectiveness was shown on the model of genital her ... | 2007 | 17494336 |
| practical problems in controlling h5n1 high pathogenicity avian influenza at village level in vietnam and introduction of biosecurity measures. | after a consultancy mission funded by a nongovernmental organization (ngo), information was collected on the dynamics of avian influenza (ai) infection at the rural level in a vietnamese province with several ongoing outbreaks. ai outbreaks are frequent at village level due to environmental, ecological, agroecological, physical, social, and cultural factors, the underlying factor being poor hygienic conditions. viral circulation is facilitated by the interactions of the integrated aquaculture, a ... | 2007 | 17494607 |
| the origin and virulence of the 1918 "spanish" influenza virus. | the "spanish" influenza pandemic of 1918-19 caused acute illness in 25-30 percent of the world's population and resulted in the death of up to an estimated 40 million people. using fixed and frozen lung tissue of 1918 influenza victims, the complete genomic sequence of the 1918 influenza virus has been deduced. sequence and phylogenetic analysis of the completed 1918 influenza virus genes shows them to be the most avian-like among the mammalian-adapted viruses. this finding supports the hypothes ... | 2006 | 17526158 |
| spatial clustering of swine influenza in ontario on the basis of herd-level disease status with different misclassification errors. | this approach maximizes sensitivity of serology-based monitoring systems by considering spatial clustering of herds classified as false positive by herd testing, allowing outbreaks to be detected in an early phase. the primary objective of this study was to determine whether swine herds infected with influenza viruses cluster in space, and if so, where they cluster. the secondary objective was to investigate the combining of a multivariate spatial scan statistic with herd test results to maximiz ... | 2007 | 17531333 |
| antigenic and genetic characterization of h9n2 swine influenza viruses in china. | as pigs are susceptible to infection with both avian and human influenza a viruses, they have been proposed to be an intermediate host for the generation of pandemic virus through reassortment. antigenic and genetic characterization was performed for five swine h9n2 influenza viruses isolated from diseased pigs from different farms. the haemagglutinin (ha) antigenicity of swine h9n2 viruses was different from that of chicken h9n2 viruses prevalent in northern china. genetic analysis revealed tha ... | 2007 | 17554038 |
| pathogenesis and inflammatory responses of swine h1n2 influenza viruses in pigs. | swine influenza viruses are an important pathogen in pig industry. in this study, we wanted to know whether swine h1n2 influenza viruses circulating in korean pigs would cause clinical signs in pigs when experimentally infected. when pigs were infected with swine h1n2 viruses isolated from korean pigs, pigs suffered from severe clinical signs of coughing, nasal discharge, labored breathing, facial edema, anorexia, and diarrhea. when the level of cytokine induction was measured using lung tissues ... | 2007 | 17570553 |
| investigation of exposure to swine influenza viruses in ontario (canada) finisher herds in 2004 and 2005. | the epidemiology of influenza in the north american swine population has changed since the emergence of a triple-reassortant h3n2 influenza virus. although seen previously in north america, the ontario swine population had likely been free of viruses of the reassortant h3n2 lineage until 2005. the objective of this study was to investigate the frequency and distribution of exposure to h1n1 and h3n2 subtypes in the ontario finisher pig population prior to and after the h3n2 outbreak that occurred ... | 2008 | 17604859 |
| cell culture (vero) derived whole virus (h5n1) vaccine based on wild-type virus strain induces cross-protective immune responses. | the rapid spread and the transmission to humans of avian influenza virus (h5n1) have induced world-wide fears of a new pandemic and raised concerns over the ability of standard influenza vaccine production methods to rapidly supply sufficient amounts of an effective vaccine. we report here on a robust and flexible strategy which uses wild-type virus grown in a continuous cell culture (vero) system to produce an inactivated whole virus vaccine. candidate vaccines based on clade 1 and clade 2 infl ... | 2007 | 17614165 |
| influenza virus a (h5n1): a pandemic risk? | influenza a subtype h5n1 has represented a growing alarm since its recent identification in asia. previously thought to infect only wild birds and poultry, h5n1 has now infected humans, cats, pigs and other mammals in an ongoing outbreak, often with a fatal outcome. in order to evaluate the risk factors for human infection with influenza virus h5n1, here we summarize 53 case patients confirmed with h5n1 infection during 2006. the review also compares the mortality rate among human cases from lat ... | 2007 | 17619249 |
| evolution and variation of the h3 gene of influenza a virus and interaction among hosts. | continual mutations to the hemagglutinin (ha) gene of influenza a virus generate novel antigenic strains that cause annual epidemics. the aim of this study was to evaluate evolution tendency of the h3 gene in a long period of time. | 2007 | 17622733 |
| evidence of the co-circulation of influenza h1n1, h1n2 and h3n2 viruses in the pig population of korea. | | 2007 | 17652438 |
| oligosaccharide specificity of influenza h1n1 virus neuraminidases. | a fluorescent neuraminidase (na) assay has been developed; 20 samples in five replicates could be analyzed at the same time, allowing us to study the kinetics of the enzyme-substrate interaction. the specificities of six influenza h1n1 virus nas for bodipy-labeled 3'sialac, 3'sialacnac, siale(c), siale(a), 6'sialac, and 6'sialacnac were evaluated. the duck virus na hydrolyzed 6'sialac and 6'sialacnac 50 times more slowly than 2-3 isomers. swine viruses digested siale(a) and 2-6 sialosides 20 tim ... | 2007 | 17680329 |
| serologic and genetic characterization of north american h3n2 swine influenza a viruses. | the h3n2 subtype of influenza a viruses isolated from pigs in the united states and canada has shown both genetic and antigenic diversity. the objective of this study was to determine the serologic and genetic characteristics of contemporary strains of these viruses. genetic analysis of 18 reference strains and 8 selected strains demonstrated differences in 1% to 9% of the nucleotides of the hemagglutinin (ha) gene. phylogenetic analysis of the ha gene revealed 3 genetic clusters, as well as div ... | 2007 | 17695595 |
| efficacy of swine influenza a virus vaccines against an h3n2 virus variant. | we compared the efficacy of 3 commercial vaccines against swine influenza a virus (siv) and an experimental homologous vaccine in young pigs that were subsequently challenged with a variant h3n2 siv, a/swine/colorado/00294/2004, selected from a repository of serologically and genetically characterized h3n2 siv isolates obtained from recent cases of swine respiratory disease. the experimental vaccine was prepared from the challenge virus. four groups of 8 pigs each were vaccinated intramuscularly ... | 2007 | 17695596 |
| snapshot: trouble in paradise. | | 2007 | 17700668 |
| human and avian influenza viruses target different cells in the lower respiratory tract of humans and other mammals. | viral attachment to the host cell is critical for tissue and species specificity of virus infections. recently, pattern of viral attachment (pva) in human respiratory tract was determined for highly pathogenic avian influenza virus of subtype h5n1. however, pva of human influenza viruses and other avian influenza viruses in either humans or experimental animals is unknown. therefore, we compared pva of two human influenza viruses (h1n1 and h3n2) and two low pathogenic avian influenza viruses (h5 ... | 2007 | 17717141 |
| the antibody responses to swine influenza virus (siv) recombinant matrix 1 (rm1), matrix 2 (m2), and hemagglutinin (ha) proteins in pigs with different siv exposure. | the influenza invariant matrix 2 (m2) protein is a potential subunit vaccine candidate to induce protective immunity against broader strains of influenza a viruses (iav). antibodies to m2 protein have not been well characterized in iav natural hosts. to characterize m2-specific antibodies in pigs, an elisa to the extracellular region of the m2 (m2e) protein was developed. sera from pigs experimentally infected with three different swine influenza virus (siv) subtypes, immunized with an siv inact ... | 2008 | 17719187 |
| failure of protection and enhanced pneumonia with a us h1n2 swine influenza virus in pigs vaccinated with an inactivated classical swine h1n1 vaccine. | two us swine influenza virus (siv) isolates, a/swine/iowa/15/1930 h1n1 (ia30) and a/swine/minnesota/00194/2003 h1n2 (mn03), were evaluated in an in vivo vaccination and challenge model. inactivated vaccines were prepared from each isolate and used to immunize conventional pigs, followed by challenge with homologous or heterologous virus. both inactivated vaccines provided complete protection against homologous challenge. however, the ia30 vaccine failed to protect against the heterologous mn03 c ... | 2008 | 17719188 |
| influenza vaccines and vaccination strategies in birds. | although it is well accepted that the present asian h5n1 panzootic is predominantly an animal health problem, the human health implications and the risk of human pandemic have highlighted the need for more information and collaboration in the field of veterinary and human health. h5 and h7 avian influenza (ai) viruses have the unique property of becoming highly pathogenic (hpai) during circulation in poultry. therefore, the final objective of poultry vaccination against ai must be eradication of ... | 2008 | 17889937 |
| purification and cdna cloning of a novel protease inhibitor secreted into culture supernatant by mdck cells. | the infectivity of influenza viruses to host cells depends on the activation of the viral glycoprotein hemagglutinin (ha) by proteases. starting from the observation that influenza virus replication in mdck (madin darby canine kidney) cells was impaired by inactivation of trypsin in the culture fluids, we demonstrated that the inhibitory activity was resolved into two trypsin-inactivating factors (tf), tf a (15 kda) and tf b (11 kda). n-terminal protein sequences of the factors revealed that tf ... | 2008 | 17892946 |
| comparative study of the hemagglutinin and neuraminidase genes of influenza a virus h3n2, h9n2, and h5n1 subtypes using bioinformatics techniques. | to investigate the genomic patterns of influenza a virus subtypes, such as h3n2, h9n2, and h5n1, we collected 1842 sequences of the hemagglutinin and neuraminidase genes from the ncbi database and parsed them into 7 categories: accession number, host species, sampling year, country, subtype, gene name, and sequence. the sequences that were isolated from the human, avian, and swine populations were extracted and stored in a mysql database for intensive analysis. the gc content and relative synony ... | 2007 | 17898838 |
| [transmission of agents of the porcine respiratory disease complex (prdc) between swine herds: a review. part 1--diagnosis, transmission by animal contact]. | knowledge on the different ways of transmitting prdc pathogens (prrsv, influenza virus a, pcv 2, m. hyopneumoniae, a. pleuropneumoniae) between swine herds is of special interest for the development of biosecurity measures or the retrospective risk analysis in the framework of activities of the consulting veterinarian. in this literature review the current knowledge of the transmission of prdc-pathogens is summarized. since the assessment of investigations into pathogen detection in detail is in ... | 2007 | 17927073 |
| a novel intranasal virus-like particle (vlp) vaccine designed to protect against the pandemic 1918 influenza a virus (h1n1). | we have prepared a virus-like particle (vlp) vaccine bearing the surface glycoproteins ha and na of the 1918 influenza a virus by infecting sf9 cells with a quadruple recombinant baculovirus that expresses the four influenza proteins (ha, na, m1, and m2) required for the assembly and budding of the vlps. the presence of ha and m1 in the purified vlps was confirmed by western blot, and that of na by a neuraminidase enzymatic assay. for in vivo studies, the 1918 vlp vaccine was formulated with or ... | 2007 | 17931114 |
| efficacy of intranasal administration of a truncated ns1 modified live influenza virus vaccine in swine. | in the u.s., despite available swine influenza virus (siv) vaccines, multiple influenza subtypes as well as antigenic and genetic variants within subtypes continue to circulate in the swine population. one of the challenges to control and eliminate siv is that the currently used inactivated influenza virus vaccines do not provide adequate cross-protection against multiple antigenic variants of siv in the field. we previously generated a recombinant h3n2 swine influenza virus (siv) based on the i ... | 2007 | 17933442 |
| evolutionary analyses of european h1n2 swine influenza a virus by placing timestamps on the multiple reassortment events. | a novel h1n2 swine influenza a virus emerged in europe since 1994. previous phylogenetic analyses revealed that its genome segments were derived from h1n1 human virus, h3n2 human virus and avian-like h1n1/h3n2 swine virus, indicating the possibility of multiple reassortments events. however, dates of these reassortment events have not been investigated systematically. in this study, we used both global and local molecular clock concepts in a maximum likelihood framework to extrapolate the times ... | 2008 | 17936394 |
| a naturally occurring deletion in its ns gene contributes to the attenuation of an h5n1 swine influenza virus in chickens. | in 2001 and 2003, we isolated two h5n1 viruses, a/swine/fujian/1/01 (sw/fj/01) and a/swine/fujian/1/03 (sw/fj/03), from pigs in fujian province, southern china. genetically, these two viruses are similar, although the ns gene of the sw/fj/03 virus has a 15-nucleotide deletion at coding positions 612 to 626. the sw/fj/01 virus is highly lethal for chickens, whereas the sw/fj/03 virus is nonpathogenic for chickens when administrated intravenously or intranasally. to understand the molecular basis ... | 2008 | 17942562 |
| discovery and characterization of the 1918 pandemic influenza virus in historical context. | the 2005 completion of the entire genome sequence of the 1918 h1n1 pandemic influenza virus represents both a beginning and an end. investigators have already begun to study the virus in vitro and in vivo to better understand its properties, pathogenicity, transmissibility and elicitation of host responses. although this is an exciting new beginning, characterization of the 1918 virus also represents the culmination of over a century of scientific research aiming to understand the causes of pand ... | 2007 | 17944266 |
| [transmission of agents of the porcine respiratory disease complex (prdc) between swine herds: a review. part 2--pathogen transmission via semen, air and living/nonliving vectors]. | the transmission of prdc-pathogens (prrsv, influenza virus a, pcv2, m. hyopneumoniae, a. pleuropneumoniae) between swine herds, which was summarized in the first part of the review, mainly occurs via pig movement. the risk of pathogen transmission by insemination with contaminated semen plays only a relevant role in the infection with prrsv and pcv2. a risk of the aerogen transmission of pathogens between herds within a distance of 2 to 3 km is described for m. hyopneumoniae and prrsv. evidence ... | 2007 | 17970334 |
| isolation and genetic characterization of avian influenza viruses and a newcastle disease virus from wild birds in barbados: 2003-2004. | zoonotic transmission of an h5n1 avian influenza a virus to humans in 2003-present has generated increased public health and scientific interest in the prevalence and variability of influenza a viruses in wild birds and their potential threat to human health. migratory waterfowl and shorebirds are regarded as the primordial reservoir of all influenza a viral subtypes and have been repeatedly implicated in avian influenza outbreaks in domestic poultry and swine. all of the 16 hemagglutinin and ni ... | 2007 | 17992942 |
| the importance of including swine and poultry workers in influenza vaccination programs. | sensing the threat of an influenza pandemic, many countries are developing influenza pandemic prevention and control strategies. such plans often focus efforts on detecting outbreaks and protecting leaders, health-care workers, and outbreak responders. considering recent research, we argue that prevention plans should also include swine and poultry workers. ignoring these workers could result in an increased probability of generating novel viruses, as well as the acceleration of a pandemic's mor ... | 2007 | 17998910 |
| genetic analysis of four porcine avian influenza viruses isolated from shandong, china. | a bayesian phylogenetic analysis of eight separate gene segments indicated a/swine/shandong/2/2003 (h5n1), a/swine/shandong/na/2003 (h9n2), a/swine/shandong/nb/2003 (h9n2) and a/swine/shandong/nc/2005 (h9n2) probably represent two multiple reassortant lineages, that had not been described before, with genes coming from h5n1, h9n2 and other lineages from poultry in asia. amino acid motifs within the haemagglutinin sequence of a/swine/shandong/nb/2003 suggested it may be able to infect people, whe ... | 2008 | 18000640 |
| [complex environmental and virological monitoring in the primorye territory in 2003-2006]. | the paper presents the results of monitoring of viruses of western nile (wn), japanese encephalitis (je), tick-borne encephalitis (tbe), geta, influenza a, as well as avian paramicroviruses type i (virus of newcastle disease (nd)) and type 6 (apmv-6) in the primorye territory in 2003-2006. totally throughout the period, specific antibodies to the viruses were detected by neutralization test in wild birds (7.3%, wn; 8.0%, geta; 0.7% batai; 2.8%, alpine hare (lepus timidus); by hemagglutination-in ... | 2007 | 18041224 |
| interspecies and intraspecies transmission of triple reassortant h3n2 influenza a viruses. | the triple reassortant h3n2 viruses were isolated for the first time from pigs in 1998 and are known to be endemic in swine and turkey populations in the united states. in 2004, we isolated two h3n2 triple reassortant viruses from two turkey breeder flocks in ohio and illinois. infected hens showed no clinical signs, but experienced a complete cessation of egg production. in this study, we evaluated three triple reassortant h3n2 isolates of turkey origin and one isolate of swine origin for their ... | 2007 | 18045494 |
| genetic and antigenic characterization of swine h1n2 influenza viruses isolated from korean pigs. | h1n2 influenza viruses are circulating in pigs worldwide and cause considerable economic losses to the pig industry. we genetically analyzed the genes of our isolates from korean pigs, and compared the antigenicity of our isolates with swine h1n2 viruses isolated from pigs in the u.s.a. in addition, we serologically surveyed the infection rate of swine h1n2 viruses in pigs. we found that h1n2 isolates from korean pigs are genetically more related to swine h1n2 viruses isolated from pigs in the u ... | 2007 | 18051312 |
| [genome sequence analysis of an h3n2 subtype swine influenza virus isolated from guangdong province in china]. | an h3n2 subtype swine influenza virus, a/swine/ guangdong/01/2005 (h3n2), was isolated from pigs with influenza-like signs in guangdong province in 2005. reverse transcription-polymerase chain reaction (rt-pcr) was used to amplify the gene segments for sequencing analysis. phylogenetic analysis showed that the hemagglutinin(ha) gene of a/swine/ guangdong/01/2005 shared high degree of sequence identity with those of h3n2 viruses isolated from swine in guangdong province from 2003 to 2004 and h3n2 ... | 2007 | 18062253 |
| novel reassortant of swine influenza h1n2 virus in germany. | european porcine h1n2 influenza viruses arose after multiple reassortment steps involving a porcine influenza virus with avian-influenza-like internal segments and human h1n1 and h3n2 viruses in 1994. in germany, h1n2 swine influenza viruses first appeared in 2000. two german h1n2 swine influenza virus strains isolated from pigs with clinical symptoms of influenza are described. they were characterized by the neutralization test, haemagglutination inhibition (hi) test and complete sequencing of ... | 2008 | 18089751 |
| [generation of cell culture high-yield recombinant h3n2 subtype swine influenza vaccine candidate by reverse genetics]. | high-yield h3n2 subtype swine influenza virus for large-scale vaccine production in cell culture was generated by reverse genetics. the rescued h3n2 (rh3n2) candidate virus contained hemagglutinin (ha) and neuraminidase (na) genes derived from a field isolate a/swine/henan/s4/01 (h3n2), pb2 gene from a/pr/8/34, and the other five internal genes from a/goose/dalian/3/01 (h9n2). the rh3n2 virus titer in mdck cell culture were measured by hemagglutination assay and the maximum virus titre of 1:512 ... | 2007 | 18092685 |
| identification of h2n3 influenza a viruses from swine in the united states. | although viruses of each of the 16 influenza a ha subtypes are potential human pathogens, only viruses of the h1, h2, and h3 subtype are known to have been successfully established in humans. h2 influenza viruses have been absent from human circulation since 1968, and as such they pose a substantial human pandemic risk. in this report, we isolate and characterize genetically similar avian/swine virus reassortant h2n3 influenza a viruses isolated from diseased swine from two farms in the united s ... | 2007 | 18093945 |
| [influenza virus]. | every year, especially during the cold season, many people catch an acute respiratory disease, namely flu. it is easy to catch this disease; therefore, it spreads very rapidly and often becomes an epidemic or a global pandemic. airway inflammation and other body ailments, which form in a very short period, torment the patient several weeks. after that, the symptoms of the disease usually disappear as quickly as they emerged. the great epidemics of flu have rather unique characteristics; therefor ... | 2007 | 18182834 |
| genetic evolution of swine influenza a (h3n2) viruses in china from 1970 to 2006. | pigs are susceptible to both human and avian influenza viruses and have been proposed to be intermediate hosts, or mixing vessels, for the generation of pandemic influenza viruses through reassortment or adaptation to the mammalian host. in this study, we summarize and report for the first time the coexistence of wholly human-like h3n2 viruses, double-reassortant h3n2 viruses, and triple-reassortant h3n2 viruses in pigs in china by analyzing the eight genes of swine influenza a (h3n2) viruses fo ... | 2008 | 18199784 |
| genetic and antigenic relatedness of h3 subtype influenza a viruses isolated from avian and mammalian species. | in 2004, we isolated triple reassortant h3n2 influenza viruses from turkey breeder hens in ohio and illinois. the illinois flock was vaccinated twice with an inactivated h3n2 vaccine containing a swine origin virus before the outbreak. additionally, a commercial inactivated vaccine containing an h3n4 virus of duck origin is being used in some turkey breeders. this prompted us to initiate a comparative study on the antigenic and genetic relatedness of various h3 subtype influenza viruses isolated ... | 2008 | 18206275 |
| prevalence of and risk factors for influenza in southern ontario swine herds in 2001 and 2003. | this research included 2 prevalence studies and a risk-factor investigation conducted in 2001 at 93 sites with sows only, finishers only, or both. in 2001, 1300 serum samples from sows in 65 herds and 720 serum samples from finisher pigs in 72 herds were tested for antibodies to swine influenzavirus (siv) of h1n1 subtype with an enzyme-linked immunosorbent assay (elisa). in 2003, 1140 serum samples from sows in 76 herds were tested for antibodies to siv of h3n2 subtype with a hemagglutination-in ... | 2008 | 18214156 |
| pandemic influenza: preventing the emergence of novel strains and countermeasures to ameliorate its effects. | influenza is a seasonal disease that peaks every year in the winter months. antigenic drift of the viral surface proteins, particularly the hemagglutinin (ha), is responsible for the virus's ability to evading the host's immune system, and for the severity of the disease. pandemic influenza arises when an influenza virus carrying a novel ha gene enters into the naive human population, resulting in excess morbidity and mortality. three major influenza pandemics were experienced in the last centur ... | 2007 | 18220962 |
| structural basis for the function and inhibition of an influenza virus proton channel. | the m2 protein from influenza a virus is a ph-activated proton channel that mediates acidification of the interior of viral particles entrapped in endosomes. m2 is the target of the anti-influenza drugs amantadine and rimantadine; recently, resistance to these drugs in humans, birds and pigs has reached more than 90% (ref. 1). here we describe the crystal structure of the transmembrane-spanning region of the homotetrameric protein in the presence and absence of the channel-blocking drug amantadi ... | 2008 | 18235504 |
| highly pathogenic rna viral infections: challenges for antiviral research. | a number of rna viruses can cause severe disease when transmitted to humans from an animal reservoir. one of them, the recently emerged h5n1 subtype of influenza a virus, has caused several hundred cases of severe disease when transferred directly from domestic poultry. this or another avian subtype could potentially evolve to a form more transmissible by the respiratory route or reassort with a circulating strain to initiate a pandemic. other zoonotic rna viruses cause sporadic single cases or ... | 2008 | 18243346 |
| swine influenza (h3n2) infection in a child and possible community transmission, canada. | an influenza a virus (h3n2) of probable swine origin, designated a/canada/1158/2006, was isolated from a 7-month-old hospitalized child who lived on a communal farm in canada. the child recovered uneventfully. a serosurvey that used a hemagglutination-inhibition assay for a/canada/1158/2006 was conducted on 54 of the 90 members of the farm. seropositivity was demonstrated in the index patient, 4 of 7 household members, and 4 of 46 nonhousehold members; none had a history of hospital admission fo ... | 2007 | 18258037 |
| swine workers and swine influenza virus infections. | in 2004, 803 rural iowans from the agricultural health study were enrolled in a 2-year prospective study of zoonotic influenza transmission. demographic and occupational exposure data from enrollment, 12-month, and 24-month follow-up encounters were examined for association with evidence of previous and incident influenza virus infections. when proportional odds modeling with multivariable adjustment was used, upon enrollment, swine-exposed participants (odds ratio [or] 54.9, 95% confidence inte ... | 2007 | 18258038 |