scholarly journals Agricultural and geographic factors shaped the North American 2015 highly pathogenic avian influenza H5N2 outbreak

2019 ◽  
Author(s):  
Joseph T. Hicks ◽  
Dong-Hun Lee ◽  
Venkata R. Duvuuri ◽  
Mia Kim Torchetti ◽  
David E Swayne ◽  
...  
Keyword(s):  
United States ◽  
Avian Influenza ◽  
Highly Pathogenic Avian Influenza ◽  
The United States ◽  
Road Density ◽  
Highly Pathogenic ◽  
Geographic Factors ◽  
Pathogenic Avian Influenza ◽  
Viral Movement ◽  
Poultry Farms

ABSTRACTThe 2014 – 2015 highly pathogenic avian influenza (HPAI) H5NX outbreak represents the largest and most expensive HPAI outbreak in the United States to date. Despite extensive traditional and molecular epidemiological studies, factors associated with the spread of HPAI among midwestern poultry premises remain unclear. To better understand the dynamics of this outbreak, 182 full genome HPAI H5N2 sequences isolated from commercial layer chicken and turkey production premises were analyzed using evolutionary models modified to incorporate epidemiological and geographic information. Epidemiological compartmental models constructed in a phylogenetic framework provided evidence that poultry type acted as a barrier to the transmission of virus among midwestern poultry farms. Furthermore, after initial introduction, a continuous external source of virus was not needed to explain the propagation of HPAI cases within the commercial poultry industries. Discrete trait diffusion models indicated that within state viral transitions occurred more frequently than inter-state transitions. Distance, road density and proportion of water coverage were all supported as associated with viral transition between county groups (Bayes Factor > 3.0). Together these findings indicate that the midwestern poultry industries were not a single homogenous population, but rather, the outbreak was shaped by poultry sectors and geographic factors.AUTHOR SUMMARYThe highly pathogenic avian influenza outbreak among poultry farms in the midwestern United States appears to be influenced by agricultural and geographic factors. After initial introduction of the virus into the poultry industries, no further introductions (such as from a wild bird reservoir) were necessary to explain the continuation of the outbreak from March to June 2015. Additionally, evidence suggests that proximity increases the chances of viral movement between two locations. While many hypotheses have been proposed to explain the transmission of virus among poultry farms, the support for road density as an important driver of viral movement suggests human-mediated viral transportation played a key role in the spread of the highly pathogenic H5N2 outbreak in North America.

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 Pathogenesis and Transmission of Novel Highly Pathogenic Avian Influenza H5N2 and H5N8 Viruses in Ferrets and Mice

2015 ◽  
Vol 89 (20) ◽  
pp. 10286-10293 ◽  
Author(s):  
Joanna A. Pulit-Penaloza ◽  
Xiangjie Sun ◽  
Hannah M. Creager ◽  
Hui Zeng ◽  
Jessica A. Belser ◽  
...  
Keyword(s):  
Public Health ◽  
United States ◽  
Risk Assessment ◽  
Avian Influenza ◽  
Highly Pathogenic Avian Influenza ◽  
The United States ◽  
The Novel ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Asian Lineage

ABSTRACTA novel highly pathogenic avian influenza (HPAI) H5N8 virus, first detected in January 2014 in poultry and wild birds in South Korea, has spread throughout Asia and Europe and caused outbreaks in Canada and the United States by the end of the year. The spread of H5N8 and the novel reassortant viruses, H5N2 and H5N1 (H5Nx), in domestic poultry across multiple states in the United States pose a potential public health risk. To evaluate the potential of cross-species infection, we determined the pathogenicity and transmissibility of two Asian-origin H5Nx viruses in mammalian animal models. The newly isolated H5N2 and H5N8 viruses were able to cause severe disease in mice only at high doses. Both viruses replicated efficiently in the upper and lower respiratory tracts of ferrets; however, the clinical symptoms were generally mild, and there was no evidence of systemic dissemination of virus to multiple organs. Moreover, these influenza H5Nx viruses lacked the ability to transmit between ferrets in a direct contact setting. We further assessed viral replication kinetics of the novel H5Nx viruses in a human bronchial epithelium cell line, Calu-3. Both H5Nx viruses replicated to a level comparable to a human seasonal H1N1 virus, but significantly lower than a virulent Asian-lineage H5N1 HPAI virus. Although the recently isolated H5N2 and H5N8 viruses displayed moderate pathogenicity in mammalian models, their ability to rapidly spread among avian species, reassort, and generate novel strains underscores the need for continued risk assessment in mammals.IMPORTANCEIn 2015, highly pathogenic avian influenza (HPAI) H5 viruses have caused outbreaks in domestic poultry in multiple U.S. states. The economic losses incurred with H5N8 and H5N2 subtype virus infection have raised serious concerns for the poultry industry and the general public due to the potential risk of human infection. This recent outbreak underscores the need to better understand the pathogenesis and transmission of these viruses in mammals, which is an essential component of pandemic risk assessment. This study demonstrates that the newly isolated H5N2 and H5N8 viruses lacked the ability to transmit between ferrets and exhibited low to moderate virulence in mammals. In human bronchial epithelial (Calu-3) cells, both H5N8 and H5N2 viruses replicated to a level comparable to a human seasonal virus, but significantly lower than a virulent Asian-lineage H5N1 (A/Thailand/16/2004) virus. The results of this study are important for the evaluation of public health risk.

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 First detection of highly pathogenic avian influenza virus in Norway

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Knut Madslien ◽  
Torfinn Moldal ◽  
Britt Gjerset ◽  
Sveinn Gudmundsson ◽  
Arne Follestad ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Highly Pathogenic Avian Influenza ◽  
Wild Birds ◽  
Zoonotic Potential ◽  
Active Monitoring ◽  
Main Hypothesis ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Poultry Farms

Abstract Background Several outbreaks of highly pathogenic avian influenza (HPAI) caused by influenza A virus of subtype H5N8 have been reported in wild birds and poultry in Europe during autumn 2020. Norway is one of the few countries in Europe that had not previously detected HPAI virus, despite widespread active monitoring of both domestic and wild birds since 2005. Results We report detection of HPAI virus subtype H5N8 in a wild pink-footed goose (Anser brachyrhynchus), and several other geese, ducks and a gull, from south-western Norway in November and December 2020. Despite previous reports of low pathogenic avian influenza (LPAI), this constitutes the first detections of HPAI in Norway. Conclusions The mode of introduction is unclear, but a northward migration of infected geese or gulls from Denmark or the Netherlands during the autumn of 2020 is currently our main hypothesis for the introduction of HPAI to Norway. The presence of HPAI in wild birds constitutes a new, and ongoing, threat to the Norwegian poultry industry, and compliance with the improved biosecurity measures on poultry farms should therefore be ensured. [MK1]Finally, although HPAI of subtype H5N8 has been reported to have very low zoonotic potential, this is a reminder that HPAI with greater zoonotic potential in wild birds may pose a threat in the future. [MK1]Updated with a sentence emphasizing the risk HPAI pose to poultry farms, both in the Abstract and in the Conclusion-section in main text, as suggested by Reviewer 1 (#7).

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