scholarly journals Surveillance for Asian H5N1 avian influenza in the United States

Fact Sheet ◽  
2006 ◽  
Author(s):  
Hon S. Ip ◽  
Paul G. Slota
Keyword(s):  
United States ◽  
Avian Influenza ◽  
The United States ◽  
H5n1 Avian Influenza

Should Tamiflu™ be stockpiled locally?

2006 ◽  
Vol 4 (3) ◽  
pp. 21
Author(s):  
Sandro Cinti, MD ◽  
Gerald Blackburn, DO
Keyword(s):  
United States ◽  
Avian Influenza ◽  
Hurricane Katrina ◽  
Local Governments ◽  
Influenza Pandemic ◽  
The United States ◽  
H5n1 Avian Influenza ◽  
Control And Prevention ◽  
Federal Response

The outbreak of H5N1 avian influenza in Asia raises serious concerns about an influenza pandemic of the kind seen in 1918. In addition, the recent federal response to Hurricane Katrina highlights the need for advanced local preparation for biological disasters. It is clear that there will not be enough vaccine early in an influenza pandemic. Without vaccine, the role of antivirals, especially oseltamivir (Tamiflu™), in treatment and prophylaxis becomes of paramount importance. It is unlikely that the Centers for Disease Control and Prevention (CDC) will be able to stockpile enough oseltamivir to protect every first responder in the United States. Thus, it is important that local governments and hospitals consider stockpiling oseltamivir for the treatment and/or prophylaxis of local first responders.

scholarly journals H5N2 Avian Influenza Outbreak in Texas in 2004: the First Highly Pathogenic Strain in the United States in 20 Years?

2005 ◽  
Vol 79 (17) ◽  
pp. 11412-11421 ◽  
Author(s):  
Chang-Won Lee ◽  
David E. Swayne ◽  
Jose A. Linares ◽  
Dennis A. Senne ◽  
David L. Suarez
Keyword(s):  
United States ◽  
Amino Acid ◽  
Avian Influenza ◽  
Cleavage Site ◽  
Basic Amino Acid ◽  
The United States ◽  
Influenza Viruses ◽  
Single Point Mutation ◽  
Highly Pathogenic

ABSTRACT In early 2004, an H5N2 avian influenza virus (AIV) that met the molecular criteria for classification as a highly pathogenic AIV was isolated from chickens in the state of Texas in the United States. However, clinical manifestations in the affected flock were consistent with avian influenza caused by a low-pathogenicity AIV and the representative virus (A/chicken/Texas/298313/04 [TX/04]) was not virulent for experimentally inoculated chickens. The hemagglutinin (HA) gene of the TX/04 isolate was similar in sequence to A/chicken/Texas/167280-4/02 (TX/02), a low-pathogenicity AIV isolate recovered from chickens in Texas in 2002. However, the TX/04 isolate had one additional basic amino acid at the HA cleavage site, which could be attributed to a single point mutation. The TX/04 isolate was similar in sequence to TX/02 isolate in several internal genes (NP, M, and NS), but some genes (PA, PB1, and PB2) had sequence of a clearly different origin. The TX/04 isolate also had a stalk deletion in the NA gene, characteristic of a chicken-adapted AIV. By analyzing viruses constructed by in vitro mutagenesis followed by reverse genetics, we found that the pathogenicity of the TX/04 virus could be increased in vitro and in vivo by the insertion of an additional basic amino acid at the HA cleavage site and not by the loss of a glycosylation site near the cleavage site. Our study provides the genetic and biologic characteristics of the TX/04 isolate, which highlight the complexity of the polygenic nature of the virulence of influenza viruses.

scholarly journals Large-Scale Avian Influenza Surveillance in Wild Birds throughout the United States

PLoS ONE ◽  
2014 ◽  
Vol 9 (8) ◽  
pp. e104360 ◽  
Author(s):  
Sarah N. Bevins ◽  
Kerri Pedersen ◽  
Mark W. Lutman ◽  
John A. Baroch ◽  
Brandon S. Schmit ◽  
...  
Keyword(s):  
United States ◽  
Avian Influenza ◽  
Large Scale ◽  
The United States ◽  
Wild Birds ◽  
Influenza Surveillance

scholarly journals Pathobiology of Clade 2.3.4.4 H5Nx High-Pathogenicity Avian Influenza Virus Infections in Minor Gallinaceous Poultry Supports Early Backyard Flock Introductions in the Western United States in 2014-2015

2017 ◽  
Vol 91 (21) ◽  
Author(s):  
Kateri Bertran ◽  
Dong-Hun Lee ◽  
Mary J. Pantin-Jackwood ◽  
Erica Spackman ◽  
Charles Balzli ◽  
...  
Keyword(s):  
United States ◽  
Avian Influenza ◽  
Japanese Quail ◽  
Evolutionary Dynamics ◽  
Highly Pathogenic Avian Influenza ◽  
The United States ◽  
Guinea Fowl ◽  
Highly Pathogenic ◽  
Backyard Poultry ◽  
Pathogenic Avian Influenza

ABSTRACT In 2014 and 2015, the United States experienced an unprecedented outbreak of Eurasian clade 2.3.4.4 H5 highly pathogenic avian influenza (HPAI) virus. Initial cases affected mainly wild birds and mixed backyard poultry species, while later outbreaks affected mostly commercial chickens and turkeys. The pathogenesis, transmission, and intrahost evolutionary dynamics of initial Eurasian H5N8 and reassortant H5N2 clade 2.3.4.4 HPAI viruses in the United States were investigated in minor gallinaceous poultry species (i.e., species for which the U.S. commercial industries are small), namely, Japanese quail, bobwhite quail, pearl guinea fowl, chukar partridges, and ring-necked pheasants. Low mean bird infectious doses (<2 to 3.7 log10) support direct introduction and infection of these species as observed in mixed backyard poultry during the early outbreaks. Pathobiological features and systemic virus replication in all species tested were consistent with HPAI virus infection. Sustained virus shedding with transmission to contact-exposed birds, alongside long incubation periods, may enable unrecognized dissemination and adaptation to other gallinaceous species, such as chickens and turkeys. Genome sequencing of excreted viruses revealed numerous low-frequency polymorphisms and 20 consensus-level substitutions in all genes and species, but especially in Japanese quail and pearl guinea fowl and in internal proteins PB1 and PB2. This genomic flexibility after only one passage indicates that influenza viruses can continue to evolve in galliform species, increasing their opportunity to adapt to other species. Our findings suggest that these gallinaceous poultry are permissive for infection and sustainable transmissibility with the 2014 initial wild bird-adapted clade 2.3.4.4 virus, with potential acquisition of mutations leading to host range adaptation. IMPORTANCE The outbreak of clade 2.3.4.4 H5 highly pathogenic avian influenza (HPAI) virus that occurred in the United States in 2014 and 2015 represents the worst livestock disease event in the country, with unprecedented socioeconomic and commercial consequences. Epidemiological and molecular investigations can identify transmission pathways of the HPAI virus. However, understanding the pathogenesis, transmission, and intrahost evolutionary dynamics of new HPAI viruses in different avian species is paramount. The significance of our research is in examining the susceptibility of minor gallinaceous species to HPAI virus, as this poultry sector also suffers from HPAI epizootics, and identifying the biological potential of these species as an epidemiological link between the waterfowl reservoir and the commercial chicken and turkey populations, with the ultimate goal of refining surveillance in these populations to enhance early detection, management, and control in future HPAI virus outbreaks.

scholarly journals From sporadic to global: The changing face of H5N8

2015 ◽  
Author(s):  
Andrew Dalby
Keyword(s):  
United States ◽  
Avian Influenza ◽  
Highly Pathogenic Avian Influenza ◽  
The United States ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Viral Subtype ◽  
History Of ◽  
Different Characteristics

The H5N8 influenza subtype is a relatively new highly pathogenic avian influenza. Until the recent Korean outbreak of H5N8 the viral subtype had only been detected sporadically. This paper looks at the multiple reassortment events between H5 hemagglutinin and N8 neuraminidase segments that explain the breaks in the history of the H5N8 subtype, especially in the United States and that show that the recent reassortment has produced an outbreak that has very different characteristics to previous H5N8 outbreaks.

scholarly journals Genetic Evidence Supports Sporadic and Independent Introductions of Subtype H5 Low-Pathogenic Avian Influenza A Viruses from Wild Birds to Domestic Poultry in North America

2018 ◽  
Vol 92 (19) ◽  
Author(s):  
Lei Li ◽  
Andrew S. Bowman ◽  
Thomas J. DeLiberto ◽  
Mary L. Killian ◽  
Scott Krauss ◽  
...  
Keyword(s):  
United States ◽  
Avian Influenza ◽  
Influenza A ◽  
The United States ◽  
Wild Birds ◽  
Influenza A Viruses ◽  
Pathogenic Avian Influenza ◽  
Live Bird Markets ◽  
Domestic Poultry ◽  
Live Bird

ABSTRACTWild-bird origin influenza A viruses (IAVs or avian influenza) have led to sporadic outbreaks among domestic poultry in the United States and Canada, resulting in economic losses through the implementation of costly containment practices and destruction of birds. We used evolutionary analyses of virus sequence data to determine that 78 H5 low-pathogenic avian influenza viruses (LPAIVs) isolated from domestic poultry in the United States and Canada during 2001 to 2017 resulted from 18 independent virus introductions from wild birds. Within the wild-bird reservoir, the hemagglutinin gene segments of H5 LPAIVs exist primarily as two cocirculating genetic sublineages, and our findings suggest that the H5 gene segments flow within each migratory bird flyway and among adjacent flyways, with limited exchange between the nonadjacent Atlantic and Pacific Flyways. Phylogeographic analyses provided evidence that IAVs from dabbling ducks and swans/geese contributed to the emergence of viruses among domestic poultry. H5 LPAIVs isolated from commercial farm poultry (i.e., turkey) that were descended from a single introduction typically remained a single genotype, whereas those from live-bird markets sometimes led to multiple genotypes, reflecting the potential for reassortment with other IAVs circulating within live-bird markets. H5 LPAIVs introduced from wild birds to domestic poultry represent economic threats to the U.S. poultry industry, and our data suggest that such introductions have been sporadic, controlled effectively through production monitoring and a stamping-out policy, and are, therefore, unlikely to result in sustained detections in commercial poultry operations.IMPORTANCEIntegration of viral genome sequencing into influenza surveillance for wild birds and domestic poultry can elucidate evolutionary pathways of economically costly poultry pathogens. Evolutionary analyses of H5 LPAIVs detected in domestic poultry in the United States and Canada during 2001 to 2017 suggest that these viruses originated from repeated introductions of IAVs from wild birds, followed by various degrees of reassortment. Reassortment was observed where biosecurity was low and where opportunities for more than one virus to circulate existed (e.g., congregations of birds from different premises, such as live-bird markets). None of the H5 lineages identified were maintained for the long term in domestic poultry, suggesting that management strategies have been effective in minimizing the impacts of virus introductions on U.S. poultry production.

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