| protection against virulent h5 avian influenza virus infection in chickens by an inactivated vaccine produced with recombinant vaccinia virus. | a cloned cdna copy of the haemagglutinin (ha) gene of a/chicken/scotland/59 (h5n1) influenza virus has been expressed in vaccinia virus. this pox virus is poorly infectious or non-infectious for chickens. however, immunization of chickens with lysates of cell cultures infected with the recombinant vaccinia virus, that had been emulsified with adjuvant and which contained an estimated 0.5 microgram influenza ha, elicited a substantial neutralizing antibody response to influenza virus. challenges ... | 1988 | 3048009 |
| complete sequence of a cdna clone of the hemagglutinin gene of influenza a/chicken/scotland/59 (h5n1) virus: comparison with contemporary north american and european strains. | | 1988 | 3375087 |
| host range of a/chicken/pennsylvania/83 (h5n2) influenza virus. | the highly pathogenic a/chicken/penn./1370/83 (h5n2) avian influenza virus, which caused 80% mortality in chickens in pennsylvania, produced only mild transient illness in experimentally infected pheasants, little or no clinical signs in ring-billed gulls and pigs, and no clinical signs in pekin ducks. virus could be recovered from only the upper respiratory tract of gulls and pigs for 1-2 days. infection in ducks resulted in intestinal replication of virus in only 1 out of 12 ducks. by contrast ... | 1985 | 3985875 |
| deduced amino acid sequences at the haemagglutinin cleavage site of avian influenza a viruses of h5 and h7 subtypes. | the amino acid sequences at the haemagglutinin cleavage sites of 9 avian influenza a viruses of h5 subtype (5 high and 4 low pathogenicity for chickens) and 21 of h7 subtype (13 high and 8 low pathogenicity for chickens) were determined by direct rna sequencing, pcr amplification sequencing or both. none of the viruses of low pathogenicity had multiple basic amino acids at the cleavage site. all highly pathogenic viruses had an insert of basic amino acids at the cleavage site, except a/chicken/s ... | 1993 | 8503786 |
| cleavability of hemagglutinin from an extremely virulent strain of avian influenza virus containing a unique cleavage site sequence. | an avian influenza virus, a/turkey/england/50-92/91 (h5n1), showed extremely high virulence in chickens, although its hemagglutinin (ha) cleavage site sequence (r-k-r-k-t-r), having a nonbasic (thr) residue at the second position (p-2) from the carboxyl terminus of ha1, does not conform to the previously established consensus sequence motif, x-x-r/k-x-r/k-r (x = nonbasic residue), for highly virulent phenotype of the h5 virus. when we evaluated the ha cleavability of this strain in chicken embry ... | 1995 | 8593304 |
| neuropathological studies of chickens infected with highly pathogenic avian influenza viruses. | central nervous system lesions of chickens inoculated with three highly pathogenic avian influenza virus strains, a/chicken/victoria/1/85 (h7n7), a/turkey/england/50-92/91 (h5n1), and a/tern/south africa/61 (h5n3), were examined histologically and immunohistochemically. the chickens either died within 7 days of inoculation or were killed 2 weeks after inoculation. no significant differences were observed in the lesions induced by these three viruses. the lesions were divided into two types, diss ... | 1996 | 8920214 |
| characterization of an avian influenza a (h5n1) virus isolated from a child with a fatal respiratory illness. | an avian h5n1 influenza a virus (a/hong kong/156/97) was isolated from a tracheal aspirate obtained from a 3-year-old child in hong kong with a fatal illness consistent with influenza. serologic analysis indicated the presence of an h5 hemagglutinin. all eight rna segments were derived from an avian influenza a virus. the hemagglutinin contained multiple basic amino acids adjacent to the cleavage site, a feature characteristic of highly pathogenic avian influenza a viruses. the virus caused 87.5 ... | 1998 | 9430591 |
| human influenza a h5n1 virus related to a highly pathogenic avian influenza virus. | in may, 1997, a 3-year-old boy in hong kong was admitted to the hospital and subsequently died from influenza pneumonia, acute respiratory distress syndrome, reye's syndrome, multiorgan failure, and disseminated intravascular coagulation. an influenza a h5n1 virus was isolated from a tracheal aspirate of the boy. preceding this incident, avian influenza outbreaks of high mortality were reported from three chicken farms in hong kong, and the virus involved was also found to be of the h5 subtype. | 1998 | 9482438 |
| [influenza a(h5n1) in hong kong: forerunner of a pandemic or an only scientifically interesting phenomenon and a useful exercise in pandemiology?]. | from a three-year old boy in hong kong who died in may 1997 with an extensive influenza pneumonia an influenza a virus has been isolated which was, first at the national influenza centre of the netherlands, identified as belonging to subtype h5n1. presumably the patient had acquired the infection directly from an outbreak of fowl plague among chickens. as far as is known this is the first case of the isolation of an influenza virus belonging to one of the subtypes h4-h15 from a human influenza p ... | 1998 | 9602508 |
| comparisons of highly virulent h5n1 influenza a viruses isolated from humans and chickens from hong kong. | genes of an influenza a (h5n1) virus from a human in hong kong isolated in may 1997 were sequenced and found to be all avian-like (k. subbarao et al., science 279:393-395, 1998). gene sequences of this human isolate were compared to those of a highly pathogenic chicken h5n1 influenza virus isolated from hong kong in april 1997. sequence comparisons of all eight rna segments from the two viruses show greater than 99% sequence identity between them. however, neither isolate's gene sequence was clo ... | 1998 | 9658115 |
| [influenza remains an unpredictable infection]. | influenza virus a (h5n1) was isolated from the tracheal swab of a 3-year-old boy who died from influenza with the raye syndrome in hong kong in may, 1997. up to the present time, influenza viruses with hemagglutinin h5 were known to circulate only among birds. they caused a variety of diseases: from asymptomatic to epizootic with 100% mortality, particularly among chickens. the main difference between virulent and avirulent strains is as follows: virulent viruses are isolated from all tissues of ... | 1998 | 9702816 |
| [influenza a (h5n1) in hong kong: forerunner of a pandemic or just a scientifically interesting phenomenon and a useful exercise in pandemiology?]. | in 1997, 18 influenza patients were detected who were infected with influenza a(h5n1) virus. six patients died. presumably most of the patients had acquired the infection directly from chickens with the fowl plague prevalent in china in 1997. these are the first reported cases of isolation of influenza viruses belonging to one of the h4-h15 subtypes from human influenza patients. man-to-man transmission of the virus has not been demonstrated but cannot be excluded in every case. genetic analyses ... | 1998 | 9749297 |
| characterization of avian h5n1 influenza viruses from poultry in hong kong. | the transmission of avian h5n1 influenza viruses to 18 humans in hong kong in 1997 with six deaths established that avian influenza viruses can transmit to and cause lethal infection in humans. this report characterizes the antigenic and biological properties of the h5n1 influenza viruses isolated from chickens, ducks, and geese from farms and poultry markets in hong kong during 1997 and compares them with those of virus isolated from the index human case. each of the h5n1 viruses from hong kong ... | 1998 | 9878612 |
| the surface glycoproteins of h5 influenza viruses isolated from humans, chickens, and wild aquatic birds have distinguishable properties. | in 1997, 18 confirmed cases of human influenza arising from multiple independent transmissions of h5n1 viruses from infected chickens were reported from hong kong. to identify possible phenotypic changes in the hemagglutinin (ha) and neuraminidase (na) of the h5 viruses during interspecies transfer, we compared the receptor-binding properties and na activities of the human and chicken h5n1 isolates from hong kong and of h5n3 and h5n1 viruses from wild aquatic birds. all h5n1 viruses, including t ... | 1999 | 9882316 |
| characterization of the surface proteins of influenza a (h5n1) viruses isolated from humans in 1997-1998. | influenza a (h5n1) viruses infected humans in hong kong between may and december, 1997. sixteen viruses, including 6 from fatal cases, were isolated during this outbreak. molecular analysis of the surface proteins genes encoding the hemagglutinin (ha) and neuraminidase (na) of these h5n1 isolates, of a subtype not previously known to infect humans, are presented. the 16 human h5 ha sequences contain multiple basic amino acids adjacent to the cleavage site, a motif associated with highly pathogen ... | 1999 | 9927579 |
| dna vaccine encoding hemagglutinin provides protective immunity against h5n1 influenza virus infection in mice. | in hong kong in 1997, a highly lethal h5n1 avian influenza virus was apparently transmitted directly from chickens to humans with no intermediate mammalian host and caused 18 confirmed infections and six deaths. strategies must be developed to deal with this virus if it should reappear, and prospective vaccines must be developed to anticipate a future pandemic. we have determined that unadapted h5n1 viruses are pathogenic in mice, which provides a well-defined mammalian system for immunological ... | 1999 | 9971791 |
| biological heterogeneity, including systemic replication in mice, of h5n1 influenza a virus isolates from humans in hong kong. | an h5n1 avian influenza a virus was transmitted to humans in hong kong in 1997. although the virus causes systemic infection and is highly lethal in chickens because of the susceptibility of the hemagglutinin to furin and pc6 proteases, it is not known whether it also causes systemic infection in humans. the clinical outcomes of infection in hong kong residents ranged widely, from mild respiratory disease to multiple organ failure leading to death. therefore, to understand the pathogenesis of in ... | 1999 | 10074171 |
| rapid evolution of h5n1 influenza viruses in chickens in hong kong. | the h5n1 avian influenza virus that killed 6 of 18 persons infected in hong kong in 1997 was transmitted directly from poultry to humans. viral isolates from this outbreak may provide molecular clues to zoonotic transfer. here we demonstrate that the h5n1 viruses circulating in poultry comprised two distinguishable phylogenetic lineages in all genes that were in very rapid evolution. when introduced into new hosts, influenza viruses usually undergo rapid alteration of their surface glycoproteins ... | 1999 | 10074191 |
| recombinant influenza a virus vaccines for the pathogenic human a/hong kong/97 (h5n1) viruses. | recombinant reassortment technology was used to prepare h5n1 influenza vaccine strains containing a modified hemagglutinin (ha) gene and neuraminidase gene from the a/hong kong/156/97 and a/hong kong/483/97 isolates and the internal genes from the attenuated cold-adapted a/ann arbor/6/60 influenza virus strain. the ha cleavage site (ha1/ha2) of each h5n1 isolate was modified to resemble that of "low-pathogenic" avian strains. five of 6 basic amino acids at the cleavage site were deleted, and a t ... | 1999 | 10191214 |
| molecular characterization of h9n2 influenza viruses: were they the donors of the "internal" genes of h5n1 viruses in hong kong? | the origin of the h5n1 influenza viruses that killed six of eighteen infected humans in 1997 and were highly pathogenic in chickens has not been resolved. these h5n1 viruses transmitted directly to humans from infected poultry. in the poultry markets in hong kong, both h5n1 and h9n2 influenza viruses were cocirculating, raising the possibility of genetic reassortment. here we analyze the antigenic and genetic features of h9n2 influenza viruses with different epidemiological backgrounds. the resu ... | 1999 | 10430948 |
| avirulent avian influenza virus as a vaccine strain against a potential human pandemic. | in the influenza h5n1 virus incident in hong kong in 1997, viruses that are closely related to h5n1 viruses initially isolated in a severe outbreak of avian influenza in chickens were isolated from humans, signaling the possibility of an incipient pandemic. however, it was not possible to prepare a vaccine against the virus in the conventional embryonated egg system because of the lethality of the virus for chicken embryos and the high level of biosafety therefore required for vaccine production ... | 1999 | 10482580 |
| isolation of avian influenza viruses in central oklahoma. | aquatic birds are the natural hosts for influenza virus. it is established that avian influenza viruses provide the gene pool for the generation of new strains of human influenza virus, which can cause pandemic infections. the recent outbreak of an avian influenza virus (h5n1) in hong kong not only produced high mortality in chickens, but also resulted in six human fatalities. this outbreak indicates that avian influenza virus can be pathogenic for humans. we surveyed local waterfowl habitats by ... | 1999 | 10616258 |
| characterization of the pathogenicity of members of the newly established h9n2 influenza virus lineages in asia. | the reported transmission of avian h9n2 influenza viruses to humans and the isolation of these viruses from hong kong poultry markets lend urgency to studies of their ecology and pathogenicity. we found that h9n2 viruses from north america differ from those of asia. the north american viruses, which infect primarily domestic turkeys, replicated poorly in inoculated chickens. phylogenetic analysis of the hemagglutinin and nucleoprotein genes indicated that the asian h9n2 influenza viruses could b ... | 2000 | 10662623 |
| strategies for inducing protection against avian influenza a virus subtypes with dna vaccines. | the cross-species transfer of a h5n1 influenza virus from birds to humans, and the systemic spread of this virus in mice, has accelerated the efforts to devise protective strategies against lethal influenza viruses. dna vaccination with the highly conserved nucleoprotein gene appears to provide cross protection against influenza a viruses in murine models. whether such vaccines would protect human hosts against different influenza a viruses, including strains with pandemic potential, is unclear. ... | 2000 | 10775793 |
| interspecies transmission of influenza viruses: h5n1 virus and a hong kong sar perspective. | this account takes stock of events and involvements, particularly on the avian side of the influenza h5n1 'bird flu' incident in hong kong sar in 1997. it highlights the role of the chicken in the many live poultry markets as the source of the virus for humans. the slaughter of chicken and other poultry across the sar seemingly averted an influenza pandemic. this perspective from hong kong sar marks the coming-of-age of acceptance of the role of avian hosts as a source of pandemic human influenz ... | 2000 | 10799786 |
| characterization of the influenza a virus gene pool in avian species in southern china: was h6n1 a derivative or a precursor of h5n1? | in 1997, an h5n1 influenza virus outbreak occurred in chickens in hong kong, and the virus was transmitted directly to humans. because there is limited information about the avian influenza virus reservoir in that region, we genetically characterized virus strains isolated in hong kong during the 1997 outbreak. we sequenced the gene segments of a heterogeneous group of viruses of seven different serotypes (h3n8, h4n8, h6n1, h6n9, h11n1, h11n9, and h11n8) isolated from various bird species. the p ... | 2000 | 10864640 |
| continued circulation in china of highly pathogenic avian influenza viruses encoding the hemagglutinin gene associated with the 1997 h5n1 outbreak in poultry and humans. | since the outbreak in humans of an h5n1 avian influenza virus in hong kong in 1997, poultry entering the live-bird markets of hong kong have been closely monitored for infection with avian influenza. in march 1999, this monitoring system detected geese that were serologically positive for h5n1 avian influenza virus, but the birds were marketed before they could be sampled for virus. however, viral isolates were obtained by swabbing the cages that housed the geese. these samples, known collective ... | 2000 | 10864673 |
| precursor genes of future pandemic influenza viruses are perpetuated in ducks nesting in siberia. | influenza a viruses of different subtypes were isolated from fecal samples of ducks in their nesting areas in siberia in summer from 1996 to 1998. phylogenetic analysis of the np genes of the isolates in siberia and those in hokkaido, japan on their flyway of migration from siberia to the south in autumn revealed that they belong to the eurasian lineage of avian influenza viruses. it is noted that the genes of the isolates in siberia are closely related to those of h5n1 influenza virus strains i ... | 2000 | 10881676 |
| [development of influenza vaccines against newly emerging a/h5n1 virus]. | emergence of highly virulent influenza a/h5n1 viruses in hong kong in 1997 posed a threat of pandemic and brought an urgent need to develop a suitable seed virus for vaccine production. the virulence of the h5n1 viruses to chicken embryos should hamper the efficient production of the vaccine. in addition, potential virulence to humans raised safety issue in manufacturing vaccine. toward vaccine development, one approach is to use an avirulent avian influenza virus antigenically similar to the vi ... | 2000 | 10885322 |
| avian-to-human transmission of h9n2 subtype influenza a viruses: relationship between h9n2 and h5n1 human isolates. | in 1997, 18 cases of influenza in hong kong (bird flu) caused by a novel h5n1 (chicken) virus resulted in the deaths of six individuals and once again raised the specter of a potentially devastating influenza pandemic. slaughter of the poultry in the live bird markets removed the source of infection and no further human cases of h5n1 infection have occurred. in march 1999, however, a new pandemic threat appeared when influenza a h9n2 viruses infected two children in hong kong. these two virus is ... | 2000 | 10920197 |
| h9n2 influenza viruses possessing h5n1-like internal genomes continue to circulate in poultry in southeastern china. | the transmission of h9n2 influenza viruses to humans and the realization that the a/hong kong/156/97-like (h5n1) (abbreviated hk/156/97) genome complex may be present in h9n2 viruses in southeastern china necessitated a study of the distribution and characterization of h9n2 viruses in poultry in the hong kong sar in 1999. serological studies indicated that h9n2 influenza viruses had infected a high proportion of chickens and other land-based birds (pigeon, pheasant, quail, guinea fowl, and chukk ... | 2000 | 11000205 |
| h9n2 subtype influenza a viruses in poultry in pakistan are closely related to the h9n2 viruses responsible for human infection in hong kong. | following the outbreak of h5n1 "bird flu" in hong kong in 1997, the isolation of h9n2 subtype viruses from patients in southern china and hong kong sar once again raised the spectre of a possible influenza pandemic. h9n2 viruses have recently been responsible for disease in poultry in various parts of the world and preliminary studies of the h9 haemagglutinin (ha) genes of viruses isolated during 1998 and 1999 in germany, iran, pakistan, and saudi arabia showed a close relationship to the ha gen ... | 2000 | 11112478 |
| influenza virus (a/hk/156/97) hemagglutinin expressed by an alphavirus replicon system protects chickens against lethal infection with hong kong-origin h5n1 viruses. | venezuelan equine encephalitis virus replicon particles (vrp) containing the gene expressing hemagglutinin (ha) from the human hong kong influenza a isolate (a/hk/156/97) were evaluated as vaccines in chicken embryos and young chicks. expressed ha was readily detected in bird-tissue staining with anti-h5 ha antibody and in chicken cells infected with the replicon preparations following immunoprecipitation with monoclonal antibody. birds challenged with a dose of the lethal parent virus were prot ... | 2000 | 11112481 |
| pandemic threat posed by avian influenza a viruses. | influenza pandemics, defined as global outbreaks of the disease due to viruses with new antigenic subtypes, have exacted high death tolls from human populations. the last two pandemics were caused by hybrid viruses, or reassortants, that harbored a combination of avian and human viral genes. avian influenza viruses are therefore key contributors to the emergence of human influenza pandemics. in 1997, an h5n1 influenza virus was directly transmitted from birds in live poultry markets in hong kong ... | 2001 | 11148006 |
| cross-reactive, cell-mediated immunity and protection of chickens from lethal h5n1 influenza virus infection in hong kong poultry markets. | in 1997, avian h5n1 influenza virus transmitted from chickens to humans resulted in 18 confirmed infections. despite harboring lethal h5n1 influenza viruses, most chickens in the hong kong poultry markets showed no disease signs. at this time, h9n2 influenza viruses were cocirculating in the markets. we investigated the role of h9n2 influenza viruses in protecting chickens from lethal h5n1 influenza virus infections. sera from chickens infected with an h9n2 influenza virus did not cross-react wi ... | 2001 | 11222674 |
| efficacy of zanamivir against avian influenza a viruses that possess genes encoding h5n1 internal proteins and are pathogenic in mammals. | in 1997, an avian h5n1 influenza virus, a/hong kong/156/97 (a/hk/156/97), caused six deaths in hong kong, and in 1999, an avian h9n2 influenza virus infected two children in hong kong. these viruses and a third avian virus [a/teal/hk/w312/97 (h6n1)] have six highly related genes encoding internal proteins. additionally, a/chicken/hk/g9/97 (h9n2) virus has pb1 and pb2 genes that are highly related to those of a/hk/156/97 (h5n1), a/teal/hk/w312/97 (h6n1), and a/quail/hk/g1/97 (h9n2) viruses. becau ... | 2001 | 11257037 |
| pathobiology of a/chicken/hong kong/220/97 (h5n1) avian influenza virus in seven gallinaceous species. | direct bird-to-human transmission, with the production of severe respiratory disease and human mortality, is unique to the hong kong-origin h5n1 highly pathogenic avian influenza (hpai) virus, which was originally isolated from a disease outbreak in chickens. the pathobiology of the a/chicken/hong kong/220/97 (h5n1) (hk/220) hpai virus was investigated in chickens, turkeys, japanese and bobwhite quail, guinea fowl, pheasants, and partridges, where it produced 75-100% mortality within 10 days. de ... | 2001 | 11280371 |
| efficacy of vaccines in chickens against highly pathogenic hong kong h5n1 avian influenza. | in 1997, highly pathogenic (hp) h5n1 avian influenza virus (aiv) caused infections in poultry in hong kong and crossed into humans, resulting in a limited number of infections including 18 hospitalized cases and six associated deaths. the unique ability of this, aiv to infect both poultry and people raised a concern for the potential of humans to be biological as well as mechanical vectors of this aiv to poultry. the current study was undertaken to determine if existing vaccines and their techno ... | 2001 | 11417815 |
| characterization of h5n1 influenza viruses that continue to circulate in geese in southeastern china. | the h5n1 influenza virus, which killed humans and poultry in 1997, was a reassortant that possibly arose in one type of domestic poultry present in the live-poultry markets of hong kong. given that all the precursors of h5n1/97 are still circulating in poultry in southern china, the reassortment event that generated h5n1 could be repeated. because a/goose/guangdong/1/96-like (h5n1; go/gd) viruses are the proposed donors of the hemagglutinin gene of the h5n1 virus, we investigated the continued c ... | 2002 | 11739677 |
| h3n2 influenza viruses from domestic chickens in italy: an increasing role for chickens in the ecology of influenza? | in italy, multiple h3n2 influenza viruses were isolated from chickens with mild respiratory disease and were shown to replicate in the respiratory tracts of experimentally infected chickens; this finding is the first to show that h3n2 influenza viruses can replicate and cause disease in chickens. h3n2 influenza viruses in pigs on nearby farms seemed a likely source of the virus; however, antigenic and molecular analyses revealed that the gene segments of the viruses in chickens were mainly of eu ... | 2002 | 11807234 |
| pathogenicity of a hong kong-origin h5n1 highly pathogenic avian influenza virus for emus, geese, ducks, and pigeons. | the h5n1 type a influenza viruses that emerged in hong kong in 1997 are a unique lineage of type a influenza viruses with the capacity to transmit directly from chickens to humans and produce significant disease and mortality in both of these hosts. the objective of this study was to ascertain the susceptibility of emus (dramaius novaehollandiae), domestic geese (anser anser domesticus), domestic ducks (anas platyrhynchos), and pigeons (columba livia) to intranasal (i.n.) inoculation with the a/ ... | 2002 | 11924603 |
| outbreak of avian influenza a(h5n1) virus infection in hong kong in 1997. | the first outbreak of avian influenza a(h5n1) virus in humans occurred in hong kong in 1997. infection was confirmed in 18 individuals, 6 of whom died. infections were acquired by humans directly from chickens, without the involvement of an intermediate host. the outbreak was halted by a territory-wide slaughter of more than 1.5 million chickens at the end of december 1997. the clinical spectrum of h5n1 infection ranges from asymptomatic infection to fatal pneumonitis and multiple organ failure. ... | 2002 | 11938498 |
| protective cross-reactive cellular immunity to lethal a/goose/guangdong/1/96-like h5n1 influenza virus is correlated with the proportion of pulmonary cd8(+) t cells expressing gamma interferon. | a/goose/guangdong/1/96-like h5n1 influenza viruses now circulating in southeastern china differ genetically from the h5n1 viruses transmitted to humans in 1997 but were their precursors. here we show that the currently circulating h9n2 influenza viruses provide chickens with cross-reactive protective immunity against the currently circulating h5n1 influenza viruses and that this protective immunity is closely related to the percentage of pulmonary cd8(+) t cells expressing gamma interferon (ifn- ... | 2002 | 11967305 |
| characterization of a highly pathogenic h5n1 avian influenza a virus isolated from duck meat. | since the 1997 h5n1 influenza virus outbreak in humans and poultry in hong kong, the emergence of closely related viruses in poultry has raised concerns that additional zoonotic transmissions of influenza viruses from poultry to humans may occur. in may 2001, an avian h5n1 influenza a virus was isolated from duck meat that had been imported to south korea from china. phylogenetic analysis of the hemagglutinin (ha) gene of a/duck/anyang/avl-1/01 showed that the virus clustered with the h5 goose/g ... | 2002 | 12021367 |
| [differences in receptor specificity between the influenza a viruses isolated from the duck, chicken, and human]. | the affinity of the duck, chicken, and human influenza viruses to the host cell sialosides was determined, and considerable distinctions between duck and chicken viruses were found. duck viruses bind to a wide range of sialosides, including the short-stem gangliosides. most of the chicken viruses, like human ones, lose the ability to bind these gangliosides, which strictly correlates with the appearance of carbohydrate at position 158-160. the affinity of the chicken viruses to sialoglycoconjuga ... | 2002 | 12068641 |
| emergence of multiple genotypes of h5n1 avian influenza viruses in hong kong sar. | although a/hong kong/156/97 (h5n1/97)-like viruses associated with the "bird flu" incident in hong kong sar have not been detected since the slaughter of poultry in 1997, its putative precursors continue to persist in the region. one of these, goose/guangdong/1/96 (h5n1 gs/gd)-like viruses, reassorted with other avian viruses to generate multiple genotypes of h5n1 viruses that crossed to chickens and other terrestrial poultry from its reservoir in geese. whereas none of these recent reassortants ... | 2002 | 12077307 |
| influenza activity in china: 1998-1999. | during 1989-1999, influenza a h3n2 and h1n1 subtypes and b type viruses were still co-circulating in human population in china, while influenza a (h3n2) virus was predominant strain. the two antigenically and genetically distinguishable strains of influenza b virus were also still co-circulating in men in southern china. the antigenic analysis indicated that most of the h3n2 viruses were a/panama/2007/99 (h3n2)-like strain, the most of the h1n1 viruses were antigenically similar to a/beijing/262 ... | 2002 | 12110253 |
| influenza a (h5n1) in hong kong: an overview. | worldwide pandemics of human influenza virus caused extensive morbidity and mortality around the world had been documented in the 20th century. however, the mechanisms involved in the emergence of novel influenza virus and the epidemiological factors leading to pandemics are unpredictable. southern china is postulated as the epicentre of influenza epidemics due to its agricultural-based communities and high population density. pandemic influenza viruses are through to arise from avian viruses th ... | 2002 | 12110265 |
| h5n1 influenza in hong kong: virus characterizations. | in 1997, 18 people were infected in hong kong with an avian influenza a(h5n1) virus from chicken. this type of interspecies transmission was never detected before and could have resulted in the development of a pandemic strain. the occurrence suggests that the pig is not needed for the emergence of pandemic influenza virus strains. characteristics of the strains involved are discussed in relation to the question why, on the one hand, these strains were able to infect humans but on the other hand ... | 2002 | 12110266 |
| the invasion routes of neurovirulent a/hong kong/483/97 (h5n1) influenza virus into the central nervous system after respiratory infection in mice. | a/hong kong/483/97 (h5n1) influenza virus (hk483) isolated from the third patient during the outbreak of chicken and human influenza in hong kong in 1997 was shown to be neurovirulent in mice. hk483 was inoculated intranasally to mice, and the invasion routes of the virus in the central nervous system (cns) were investigated by immunohistochemical and in situ hybridization. the pathological changes consisted of bronchopneumonia, ganglionitis, and nonpurulent encephalomyelitis of the brain stem a ... | 2002 | 12111416 |
| susceptibility of laughing gulls (larus atricilla) to h5n1 and h5n3 highly pathogenic avian influenza viruses. | this investigation detailed the clinical disease, gross and histologic lesions, and distribution of viral antigen in juvenile laughing gulls (larus atricilla) intranasally inoculated with either the a/tern/south africa/61 (h5n3) (tern/sa) influenza virus or the a/chicken/hong kong/220/97 (h5n1) (chicken/hk) influenza virus, which are both highly pathogenic for chickens. neither morbidity nor mortality was observed in gulls inoculated with either virus within the 14-day investigative period. gros ... | 2002 | 12495048 |
| evaluation of a genetically modified reassortant h5n1 influenza a virus vaccine candidate generated by plasmid-based reverse genetics. | avian influenza a h5n1 viruses similar to those that infected humans in hong kong in 1997 continue to circulate in waterfowl and have reemerged in poultry in the region, raising concerns that these viruses could reappear in humans. the currently licensed trivalent inactivated influenza vaccines contain hemagglutinin (ha) and neuraminidase genes from epidemic strains in a background of internal genes derived from the vaccine donor strain, a/puerto rico/8/34 (pr8). such reassortant candidate vacci ... | 2003 | 12504552 |
| [genetic characterization of an avian influenza a (h5n1) virus isolated from a sick goose in china]. | genetic analysis of viral ha gene showed that there were 22 nucleotide differences in ha gene between goose and human h5n1 viruses. the sequence analysis of amino acid on viral protein molecules indicated that there were 7 and 9 position differences between goose and human, chicken h5n1 viruses, respectively. all the three viruses share multiple basic amino acids (r-e-r-r-r-k-k-r) at the cleavage site between ha1 and ha2 domain, that is associated with highly pathogenic h5 avian viruses. except ... | 1998 | 12526344 |
| comparison of nucleic acid-based detection of avian influenza h5n1 with virus isolation. | nucleic acid sequence-based amplification with electrochemiluminescent detection (nasba/ecl) of avian influenza virus was compared with viral culture in embryonated chicken eggs. virus was isolated from blood or anal swabs of chickens artificially infected with highly pathogenic avian influenza a/chicken/hong kong/1000/97 (h5n1). viral nucleic acid was detected in blood samples by nasba/ecl immediately prior to death, whilst nucleic acid extracted from anal swabs was detected from the day follow ... | 2003 | 12604358 |
| varied pathogenicity of a hong kong-origin h5n1 avian influenza virus in four passerine species and budgerigars. | this investigation assessed the ability of the zoonotic a/chicken/hong kong/220/97 (chicken/hong kong) (h5n1) highly pathogenic avian influenza virus to infect and cause disease in zebra finches (taeniopygia guttata), house finches (carpodacus mexicanus), house sparrows (passer domesticus), european starlings (sternus vulgaris), and budgerigars (melopsittacus undulatus) after intranasal administration. zebra finches were the most severely affected of the five species, demonstrating anorexia, dep ... | 2003 | 12627709 |
| the who update on influenza a (h5n1) in hong kong. | in may 1997 influenza a subtype h5n1 virus was isolated in the special administrative region of hong kong from a child who died. until then, the h5n1virus was known to infect only various species of birds, including chickens and ducks. after the first hum | 1998 | 12631776 |
| the next influenza pandemic: lessons from hong kong. | pandemic influenza is a zoonosis. studies on influenza ecology conducted in hong kong since the 1970s in which hong kong essentially functioned as an influenza sentinel post indicated that it might be possible, for the first time, to have influenza preparedness at the baseline avian level. this appreciation of influenza ecology facilitated recognition of the h5n1 'bird flu' incident in hong kong in 1997 in what was considered to be an incipient pandemic situation, the chicken being the source of ... | 2003 | 12675938 |
| protection of chickens against highly lethal h5n1 and h7n1 avian influenza viruses with a recombinant fowlpox virus co-expressing h5 haemagglutinin and n1 neuraminidase genes. | inactivated whole avian influenza virus (aiv) vaccine provides protection against homologous haemagglutinin (ha) subtype virus, but poor protection against a heterologous ha virus. moreover, it induces chickens to produce antibodies to cross-reactive antigens, especially nucleoprotein, which is limits aiv serological surveillance. in this study, a recombinant fowlpox virus co-expressing ha (h5 subtype) and na (ni subtype)genes of aiv was evaluated for its ability to protect chickens against intr ... | 2003 | 12745375 |
| neurotropism of the 1997 hong kong h5n1 influenza virus in mice. | the direct transmission of h5n1 influenza a viruses from chickens to humans in hong kong in 1997 emphasized the need to have information on the pathogenesis of avian influenza virus infection in mammals. h5n1 influenza viruses isolated from patients during the incident killed experimentally infected mice. the principal lesions of the mice were broncho-interstitial pneumonia and nonsuppurative encephalitis. infectious viruses and/or viral antigens were detected in the brain as well as in the trig ... | 2003 | 12860072 |
| h9n2 influenza viruses prevalent in poultry in china are phylogenetically distinct from a/quail/hong kong/g1/97 presumed to be the donor of the internal protein genes of the h5n1 hong kong/97 virus. | ten h9n2 influenza virus strains isolated from diseased chickens in different farms in china during 1995 to 1999 were antigenically and genetically characterized. the haemagglutinins of the isolates were not related to those of a/quail/hong kong/g1/97 (h9n2) (qa/hk/g1/97), but were closely related to that of a/chicken/hong kong/g9/97 (h9n2) (ck/hk/g9/97). the neuraminidase of these isolates had a deletion of three amino acid residues at positions 63 to 65 as compared with those of ck/hk/g9/97, w ... | 2003 | 14522712 |
| preparation of a standardized, efficacious agricultural h5n3 vaccine by reverse genetics. | options for the control of emerging and reemerging h5n1 influenza viruses include improvements in biosecurity and the use of inactivated vaccines. commercially available h5n2 influenza vaccine prevents disease signs and reduces virus load but does not completely prevent virus shedding after challenge with h5n1 virus. by using reverse genetics, we prepared an h5n3 vaccine whose hemagglutinin is 99.6% homologous to that of a/ck/hk/86.3/02 (h5n1). we used the internal genes of a/pr/8/34 and the h5 ... | 2003 | 14554086 |
| avian influenza in hong kong 1997-2002. | in 1997, a high-pathogenicity h5n1 avian influenza virus caused serious disease in both man and poultry in hong kong, china. eighteen human cases of disease were recorded, six of which were fatal. this unique virus was eliminated through total depopulation of all poultry markets and chicken farms in december 1997. other outbreaks of high-pathogenicity avian influenza (hpai) caused by h5n1 viruses occurred in poultry in 2001 and 2002. these h5n1 viruses isolated had different internal gene conste ... | 2003 | 14575073 |
| safety evaluation in chickens of candidate human vaccines against potential pandemic strains of influenza. | two candidate formalin-inactivated vaccines, made from high-growth reassortant viruses with the ha and na genes from avian viruses in a background of genes derived from a/puerto rico/8/34 (pr8), were prepared against h5n1 and h9n2 subtypes (designated as h5n1/pr8 and h9n2/pr8, respectively). these viruses bear the genotypes, antigenicity, and attenuation in mouse models that are desirable in candidate vaccines. the pathogenicity of the newly generated avian-human reassortant vaccine viruses was ... | 2003 | 14575088 |
| evaluation of a high-pathogenicity h5n1 avian influenza a virus isolated from duck meat. | the introduction of an influenza a virus possessing a novel hemagglutinin (ha) into an immunologically naive human population has the potential to cause severe disease and death. such was the case in 1997 in hong kong, where h5n1 influenza was transmitted to humans from infected poultry. because h5n1 viruses are still isolated from domestic poultry in southern china, there needs to be continued surveillance of poultry and characterization of virus subtypes and variants. this study provides molec ... | 2003 | 14575093 |
| comparative susceptibility of selected avian and mammalian species to a hong kong-origin h5n1 high-pathogenicity avian influenza virus. | seventeen avian species and two mammalian species were intranasally inoculated with the zoonotic a/chicken/hong kong/220/97 (chicken/hk) (h5n1) avian influenza (ai) virus in order to ascertain a relative range of susceptible hosts and the pathobiology of the resultant disease. a direct association was demonstrated between viral replication and the severity of disease, with four general gradations being observed among these species. these gradations included the following: 1) widespread dissemina ... | 2003 | 14575094 |
| an update on avian influenza in hong kong 2002. | an outbreak of highly pathogenic avian influenza caused by multiple genotypes of h5n1 virus occurred in hong kong, commencing in january 2002. infection in local chicken farms was preceded by the detection of virus in multiple retail markets and the main poultry wholesale market. the first case of this disease on a local farm was detected on february 1, 2002. by february 9, 2002, 15 farms were infected, and by late march a total of 22 infected farms had been identified. three main clusters of in ... | 2003 | 14575116 |
| differences between influenza virus receptors on target cells of duck and chicken and receptor specificity of the 1997 h5n1 chicken and human influenza viruses from hong kong. | to study whether influenza virus receptors in chickens differ from those in other species, we compared the binding of lectins and influenza viruses with known receptor specificity to cell membranes and gangliosides from epithelial tissues of ducks, chickens, and african green monkeys. we found that chicken cells contained neu5ac alpha(2-6)gal-terminated receptors recognized by sambucus nigra lectin and by human viruses. this finding explains how some recent h9n2 viruses replicate in chickens des ... | 2003 | 14575133 |
| wet markets--a continuing source of severe acute respiratory syndrome and influenza? | context: live-animal markets (wet markets) provide a source of vertebrate and invertebrate animals for customers in tropical and subtropical regions of the world. wet markets sell live poultry, fish, reptiles, and mammals of every kind. live-poultry markets (mostly chicken, pigeon, quail, ducks, geese, and a wide range of exotic wild-caught and farm-raised fowl) are usually separated from markets selling fish or red-meat animals, but the stalls can be near each other with no physical separation. ... | 2004 | 14738798 |
| avian influenza a virus (h7n7) associated with human conjunctivitis and a fatal case of acute respiratory distress syndrome. | highly pathogenic avian influenza a viruses of subtypes h5 and h7 are the causative agents of fowl plague in poultry. influenza a viruses of subtype h5n1 also caused severe respiratory disease in humans in hong kong in 1997 and 2003, including at least seven fatal cases, posing a serious human pandemic threat. between the end of february and the end of may 2003, a fowl plague outbreak occurred in the netherlands. a highly pathogenic avian influenza a virus of subtype h7n7, closely related to low ... | 2004 | 14745020 |
| the threat and prospects for control of an influenza pandemic. | influenza constitutes the most widespread and significant respiratory infectious disease in the world, resulting in increased morbidity, mortality and economic loss each epidemic year. pandemic influenza is a worldwide epidemic usually caused by a new virus variant to which the majority of the population has no immunity. as demonstrated in the devastating pandemic of 1918 to 1919, a pandemic virus may infect 30 to 50% of the worlds population and kill 1 to 2% of those infected. pandemic control ... | 2004 | 14761242 |
| pb2 amino acid at position 627 affects replicative efficiency, but not cell tropism, of hong kong h5n1 influenza a viruses in mice. | a single amino acid substitution, from glutamic acid to lysine at position 627 of the pb2 protein, converts a nonlethal h5n1 influenza a virus isolated from a human to a lethal virus in mice. in contrast to the nonlethal virus, which replicates only in respiratory organs, the lethal isolate replicates in a variety of organs, producing systemic infection. despite a clear difference in virulence and organ tropism between the two viruses, it remains unknown whether the dissimilarity is a result of ... | 2004 | 15016548 |
| the index influenza a virus subtype h5n1 isolated from a human in 1997 differs in its receptor-binding properties from a virulent avian influenza virus. | to gain insight into the events that occur when avian influenza viruses are transmitted to humans, the receptor-binding properties of the index h5n1 influenza virus isolated from a human in 1997 and the a/turkey/ontario/7732/66 (h5n9) virus were compared, by using a haemadsorption assay. cells expressing the haemagglutinin (ha) of the human isolate were adsorbed by both chicken red blood cells (rbcs) and human rbcs; those expressing the avian virus ha were only adsorbed by chicken rbcs. these re ... | 2004 | 15039542 |
| responsiveness to a pandemic alert: use of reverse genetics for rapid development of influenza vaccines. | in response to the emergence of severe infection capable of rapid global spread, who will issue a pandemic alert. such alerts are rare; however, on feb 19, 2003, a pandemic alert was issued in response to human infections caused by an avian h5n1 influenza virus, a/hong kong/213/03. h5n1 had been noted once before in human beings in 1997 and killed a third (6/18) of infected people. the 2003 variant seemed to have been transmitted directly from birds to human beings and caused fatal pneumonia in ... | 2004 | 15064027 |
| the evolution of h5n1 influenza viruses in ducks in southern china. | the pathogenicity of avian h5n1 influenza viruses to mammals has been evolving since the mid-1980s. here, we demonstrate that h5n1 influenza viruses, isolated from apparently healthy domestic ducks in mainland china from 1999 through 2002, were becoming progressively more pathogenic for mammals, and we present a hypothesis explaining the mechanism of this evolutionary direction. twenty-one viruses isolated from apparently healthy ducks in southern china from 1999 through 2002 were confirmed to b ... | 2004 | 15235128 |
| genesis of a highly pathogenic and potentially pandemic h5n1 influenza virus in eastern asia. | a highly pathogenic avian influenza virus, h5n1, caused disease outbreaks in poultry in china and seven other east asian countries between late 2003 and early 2004; the same virus was fatal to humans in thailand and vietnam. here we demonstrate a series of genetic reassortment events traceable to the precursor of the h5n1 viruses that caused the initial human outbreak in hong kong in 1997 (refs 2-4) and subsequent avian outbreaks in 2001 and 2002 (refs 5, 6). these events gave rise to a dominant ... | 2004 | 15241415 |
| continuing evolution of h9n2 influenza viruses in southeastern china. | h9n2 influenza viruses are panzootic in domestic poultry in eurasia and since 1999 have caused transient infections in humans and pigs. to investigate the zoonotic potential of h9n2 viruses, we studied the evolution of the viruses in live-poultry markets in hong kong in 2003. h9n2 was the most prevalent influenza virus subtype in the live-poultry markets between 2001 and 2003. antigenic and phylogenetic analysis of hemagglutinin (ha) showed that all of the 19 isolates found except one belonged t ... | 2004 | 15280470 |
| avian influenza virus infection of children in vietnam and thailand. | influenza viruses from chickens (h5n1) have caused outbreaks in children from both vietnam and thailand in 2004. all infected patients presented with fever and cough. striking laboratory findings included leukopenia and thrombocytopenia. all children who developed progressive pneumonia with acute respiratory distress syndrome died. however, very few children received antiviral therapy. | 2004 | 15295239 |
| generation of reassortant influenza vaccines by reverse genetics that allows utilization of a diva (differentiating infected from vaccinated animals) strategy for the control of avian influenza. | vaccination of poultry with inactivated influenza vaccine can be an effective tool in the control of avian influenza (ai). one major concern of using inactivated vaccine is vaccine-induced antibody interference with serologic surveillance and epidemiology. in the united states, low pathogenicity h5 and h7 subtype ai viruses have caused serious economic losses in the poultry industry. most of these viruses also have the accompanying n2 subtype and no h5n1 or h7n8 subtype ai viruses have been iden ... | 2004 | 15297071 |
| h5n1 chicken influenza viruses display a high binding affinity for neu5acalpha2-3galbeta1-4(6-hso3)glcnac-containing receptors. | to characterize differences in the receptor-binding specificity of h5n1 chicken viruses and viruses of aquatic birds, we used a panel of synthetic polyacrylamide (paa)-based sialylglycopolymers that carried identical terminal neu5acalpha2-3gal fragments but varied by the structure of the next saccharide residues. a majority of duck viruses irrespective of their ha subtype, bound with the highest affinity to trisaccharide neu5acalpha2-3galbeta1-3glcnac, suggesting that these viruses preferentiall ... | 2004 | 15302215 |
| molecular determinants within the surface proteins involved in the pathogenicity of h5n1 influenza viruses in chickens. | although it is established that the cleavage site and glycosylation patterns in the hemagglutinin (ha) play important roles in determining the pathogenicity of h5 avian influenza viruses, some viruses exist that are not highly pathogenic despite possessing the known characteristics of high pathogenicity (i.e., their ha contains multiple basic amino acids at the cleavage site and has glycosylation patterns similar to that of the highly pathogenic h5 viruses). currently little is known about the h ... | 2004 | 15331729 |
| avian h5n1 influenza in cats. | during the 2003 to 2004 outbreak of avian influenza a (h5n1) virus in asia, there were anecdotal reports of fatal infection in domestic cats, although this species is considered resistant to influenza. we experimentally inoculated cats with h5n1 virus intratracheally and by feeding them virus-infected chickens. the cats excreted virus, developed severe diffuse alveolar damage, and transmitted virus to sentinel cats. these results show that domestic cats are at risk of disease or death from h5n1 ... | 2004 | 15345779 |
| vaccination of chickens against h5n1 avian influenza in the face of an outbreak interrupts virus transmission. | vaccination of chickens with a commercially available killed h5n2 vaccine was being evaluated as an additional tool to enhanced biosecurity measures and intensive surveillance for control of highly pathogenic avian influenza subtype h5n1 disease in hong kong in 2002. in december 2002 to january 2003, there were outbreaks of h5n1 disease in waterfowl in two recreational parks, wild water birds, several poultry markets and five chicken farms. in addition to quarantine, depopulation of the affected ... | 2004 | 15370037 |
| [avian influenza virus]. | recent outbreaks of highly pathogenic avian influenza in chickens and ducks that occurred in 9 asian countries including japan alarmed to realize that there is no border for infections and gave a rise to great concern for human health as well as for agriculture. this h5n1 virus jumped the species barrier and caused severe disease with high mortality in humans in viet nam and thailand; 15 deaths of 22 cases and 8 of 12, respectively. a second concern was the possibility that the situation could g ... | 2004 | 15449909 |
| the genome sequence analysis of h5n1 avian influenza a virus isolated from the outbreak among poultry populations in thailand. | in this report, the genome of the thai avian influenza virus a (h5n1); a/chicken/nakorn-pathom/thailand/cu-k2/04, isolated from the thai avian influenza a (ai) epidemic during the early of 2004 was sequenced. phylogenetic analyses were performed in comparison to ai viruses from hong kong 1997 outbreaks and other ai (h5n1) isolates reported during 2001-2004. molecular characterization of the thai ai (h5n1) ha gene revealed a common characteristic of a highly pathogenic ai (hpai), a 20-codon delet ... | 2004 | 15464837 |
| investigation of outbreaks of highly pathogenic h5n1 avian influenza in waterfowl and wild birds in hong kong in late 2002. | outbreaks of highly pathogenic h5n1 avian influenza have occurred in hong kong in chickens and other gallinaceous poultry in 1997, 2001, twice in 2002 and 2003. high mortality rates were seen in gallinaceous birds but not in domestic or wild waterfowl or other wild birds until late 2002 when highly pathogenic h5n1 avian influenza occurred in waterfowl (geese, ducks and swans), captive greater flamingo (phoenicopterus ruber) and other wild birds (little egret egretta garzetta) at two waterfowl pa ... | 2004 | 15545029 |
| [severe acute respiratory syndrome and avian flu]. | severe acute respiratoru syndrome (sars) is a new disease that caused large ourbreaks in several countries in the first half of 2003, resulting in infection in more than 8.000 people and more than 900 deaths. the disease originated in southern china and a novel coronavirus (sars cov) has been implicated as the causative organism. we present an overview of the etiology, clinical presentation and diagnosis, based on the current state of knowledge derived from published studies and our experience i ... | 2004 | 15563119 |
| [discoveries of avian influenza a(h9n2) virus in chickens and men infected by h9n2 virus in guangzhou area]. | to understand the epidemic status of avian influenza a virus in chickens and men in guangzhou area and to prevent men suffering from avian influenza a (h5n1) virus. | 2004 | 15640850 |
| molecular characterization of the complete genome of human influenza h5n1 virus isolates from thailand. | the complete genomes of three human h5n1 influenza isolates were characterized, together with the haemagglutinin (ha) and neuraminidase (na) genes from two additional human isolates and one chicken isolate. these six influenza isolates were obtained from four different provinces of thailand during the avian influenza outbreak in asia from late 2003 to may 2004. all six thailand isolates contained multiple basic amino acids at the cleavage site in the ha gene. amino acid residues at the receptor- ... | 2005 | 15659762 |
| characterization of h5n1 influenza a viruses isolated during the 2003-2004 influenza outbreaks in japan. | in japan, between the end of december 2003 and march 2004, four outbreaks of acute, highly transmissible and lethal disease occurred in birds in three prefectures separated by 150-450 km, involving three chicken farms and a group of chickens raised as pets. the cause of each outbreak was an h5n1 influenza a virus-the first highly pathogenic virus to be isolated from the outbreaks in japan since 1925. the h5n1 virus was also isolated from dead crows, apparently infected by contact with virus-cont ... | 2005 | 15661149 |
| development of enzyme-linked immunosorbent assay with nucleoprotein as antigen for detection of antibodies to avian influenza virus. | during the avian influenza outbreak of 2003-04 in southeast asia, two avian influenza viruses (aiv), one of h5n1 subtype and the other h9n2 subtype, were isolated and identified from local farms. the nudeoprotein (np) gene of the h5n1 ai isolate was cloned, and the segment encoding amino acid 47-384, which covers its major antigenic domains, was subcloned and expressed in e. coli. subsequently, the np (47-384) expression product was purified and used as the diagnostic antigen to develop a np-bas ... | 2004 | 15666868 |
| probable person-to-person transmission of avian influenza a (h5n1). | during 2004, a highly pathogenic avian influenza a (h5n1) virus caused poultry disease in eight asian countries and infected at least 44 persons, killing 32; most of these persons had had close contact with poultry. no evidence of efficient person-to-person transmission has yet been reported. we investigated possible person-to-person transmission in a family cluster of the disease in thailand. | 2005 | 15668219 |
| lethality to ferrets of h5n1 influenza viruses isolated from humans and poultry in 2004. | the 2004 outbreaks of h5n1 influenza viruses in vietnam and thailand were highly lethal to humans and to poultry; therefore, newly emerging avian influenza a viruses pose a continued threat, not only to avian species but also to humans. we studied the pathogenicity of four human and nine avian h5n1/04 influenza viruses in ferrets (an excellent model for influenza studies). all four human isolates were fatal to intranasally inoculated ferrets. the human isolate a/vietnam/1203/04 (h5n1) was the mo ... | 2005 | 15681421 |
| genetic characterization of h5n1 avian influenza viruses isolated in southern china during the 2003-04 avian influenza outbreaks. | the recent h5n1 avian influenza outbreaks in asia spread over more than 8 countries. it has caused enormous economic loss and grand challenges for the public health. during these breakouts we isolated three strains of h5n1 avian influenza virus (aiv) from chickens and one from duck in different farms of southern china. we completely sequenced these four aivs. molecular characterization demonstrated that these strains retain the reported h5n1 aiv sequence properties relevant to virus virulence an ... | 2005 | 15717120 |
| characterization of highly pathogenic h5n1 avian influenza a viruses isolated from south korea. | an unprecedented outbreak of h5n1 highly pathogenic avian influenza (hpai) has been reported for poultry in eight different asian countries, including south korea, since december 2003. a phylogenetic analysis of the eight viral genes showed that the h5n1 poultry isolates from south korea were of avian origin and contained the hemagglutinin and neuraminidase genes of the a/goose/guangdong/1/96 (gs/gd) lineage. the current h5n1 strains in asia, including the korean isolates, share a gene constella ... | 2005 | 15731263 |
| pathogenicity of h5 influenza viruses for ducks. | four h5n1 highly pathogenic avian influenza (hpai) viruses and an avirulent reassortant h5n1 virus were tested for their pathogenicity in domestic ducks. a/chicken/yamaguchi/7/04 (h5n1) (ck/yamaguchi/04) isolated from a dead bird during the hpai outbreak in japan and a/duck/yokohama/aq-10/03 (h5n1) (dk/yokohama/03) isolated from duck meat at a quarantine inspection for importation from china replicated in multiple organs including the brain of ducks. the ducks infected with ck/yamaguchi/04 did n ... | 2005 | 15747052 |
| human disease from influenza a (h5n1), thailand, 2004. | influenza a (h5n1) is endemic in poultry across much of southeast asia, but limited information exists on the distinctive features of the few human cases. in thailand, we instituted nationwide surveillance and tested respiratory specimens by polymerase chain reaction and viral isolation. from january 1 to march 31, 2004, we reviewed 610 reports and identified 12 confirmed and 21 suspected cases. all 12 confirmed case-patients resided in villages that experienced abnormal chicken deaths, 9 lived ... | 2005 | 15752436 |
| isolation and characterization of avian influenza viruses, including highly pathogenic h5n1, from poultry in live bird markets in hanoi, vietnam, in 2001. | since 1997, outbreaks of highly pathogenic (hp) h5n1 and circulation of h9n2 viruses among domestic poultry in asia have posed a threat to public health. to better understand the extent of transmission of avian influenza viruses (aiv) to humans in asia, we conducted a cross-sectional virologic study in live bird markets (lbm) in hanoi, vietnam, in october 2001. specimens from 189 birds and 18 environmental samples were collected at 10 lbm. four influenza a viruses of the h4n6 (n = 1), h5n2 (n = ... | 2005 | 15767421 |
| [is avian influenza a risk for humans?]. | avian influenza is an infectious disease of birds, caused by type a strains of the influenza virus. the disease, which was first identified in italy more than 100 years ago, occurs worldwide. avian influenza viruses are mainly distributed by migratory birds. different mammals like swine, horse and finally humans are susceptible for avian influenza viruses. the high possibility of genomic changes like gene shift and drift is caused by the segmented rna genome. during the avian flu outbreak in eas ... | 2005 | 15812719 |
| latex agglutination test for monitoring antibodies to avian influenza virus subtype h5n1. | a latex agglutination test (lat) based on polystyrene beads sensitized with inactivated avian influenza virus h5n1 particles was developed. compared with the hemagglutination inhibition test, the sensitivity and specificity of the lat were 88.8 and 97.6%, respectively, in detecting 830 serum samples from vaccinated chickens. the test has application potential in field practice. | 2005 | 15815030 |
| dimeric zanamivir conjugates with various linking groups are potent, long-lasting inhibitors of influenza neuraminidase including h5n1 avian influenza. | the synthesis, antiviral and pharmacokinetic properties of zanamivir (zmv) dimers 8 and 13 are described. the compounds are highly potent neuraminidase (na) inhibitors which, along with dimer 3, are being investigated as potential second generation inhaled therapies both for the treatment of influenza and for prophylactic use. they show outstanding activity in a 1 week mouse influenza prophylaxis assay, and compared with zmv, high concentrations of 8 and 13 are found in rat lung tissue after 1 w ... | 2005 | 15828835 |