scholarly journals Comparative Virological and Pathogenic Characteristics of Avian Influenza H5N8 Viruses Detected in Wild Birds and Domestic Poultry in Egypt during the Winter of 2016/2017

Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 990 ◽  
Author(s):  
Yassmin Moatasim ◽  
Ahmed Kandeil ◽  
Basma Emad Aboulhoda ◽  
Rabeh El-Shesheny ◽  
Maha Alkhazindar ◽  
...  
Keyword(s):  
Avian Influenza ◽  
A549 Cells ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Multiple Introductions ◽  
Domestic Poultry ◽  
Growth Properties ◽  
Reassortant Viruses

The surveillance and virological characterization of H5N8 avian influenza viruses are important in order to assess their zoonotic potential. The genetic analyses of the Egyptian H5N8 viruses isolated through active surveillance in wild birds and domestic poultry in the winter of 2016/2017 showed multiple introductions of reassortant viruses. In this study, we investigated and compared the growth kinetics, infectivity, and pathogenicity of the three reassortant forms of H5N8 viruses detected in wild birds and domestic poultry in Egypt during the first introduction wave in the winter of 2016/2017. Three representative H5N8 viruses (abbreviated as 813, 871, and 13666) were selected. The 871/H5N8 virus showed enhanced growth properties in vitro in Madin Darby canine kidney (MDCK) and A549 cells. Interestingly, all viruses replicated well in mice without prior adaptation. Infected C57BL/6 mice showed 20% mortality for 813/H5N8 and 60% mortality for 871/H5N8 and 13666/H5N8, which could be attributed to the genetic differences among the viruses. Studies on the pathogenicity in experimentally infected ducks revealed a range of pathogenic effects, with mortality rate ranging from 0% for 813/H5N8 and 13666/H5N8 to 28% for 871/H5N8. No significant differences were observed among the three compared viruses in infected chickens. Overall, different H5N8 viruses had variable biological characteristics, indicating a continuous need for surveillance and virus characterization efforts.

scholarly journals Genesis and spread of multiple reassortants during the 2016/2017 H5 avian influenza epidemic in Eurasia

2020 ◽  
Vol 117 (34) ◽  
pp. 20814-20825 ◽  
Author(s):  
Samantha J. Lycett ◽  
Anne Pohlmann ◽  
Christoph Staubach ◽  
Valentina Caliendo ◽  
Mark Woolhouse ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Severe Disease ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Highly Pathogenic ◽  
Time Resolved ◽  
Bird Populations ◽  
Pathogenic Avian Influenza ◽  
Reassortant Viruses

Highly pathogenic avian influenza (HPAI) viruses of the H5 A/goose/Guangdong/1/96 lineage can cause severe disease in poultry and wild birds, and occasionally in humans. In recent years, H5 HPAI viruses of this lineage infecting poultry in Asia have spilled over into wild birds and spread via bird migration to countries in Europe, Africa, and North America. In 2016/2017, this spillover resulted in the largest HPAI epidemic on record in Europe and was associated with an unusually high frequency of reassortments between H5 HPAI viruses and cocirculating low-pathogenic avian influenza viruses. Here, we show that the seven main H5 reassortant viruses had various combinations of gene segments 1, 2, 3, 5, and 6. Using detailed time-resolved phylogenetic analysis, most of these gene segments likely originated from wild birds and at dates and locations that corresponded to their hosts’ migratory cycles. However, some gene segments in two reassortant viruses likely originated from domestic anseriforms, either in spring 2016 in east China or in autumn 2016 in central Europe. Our results demonstrate that, in addition to domestic anseriforms in Asia, both migratory wild birds and domestic anseriforms in Europe are relevant sources of gene segments for recent reassortant H5 HPAI viruses. The ease with which these H5 HPAI viruses reassort, in combination with repeated spillovers of H5 HPAI viruses into wild birds, increases the risk of emergence of a reassortant virus that persists in wild bird populations yet remains highly pathogenic for poultry.

scholarly journals Pathogenesis and Transmission Assessments of Two H7N8 Influenza A Viruses Recently Isolated from Turkey Farms in Indiana Using Mouse and Ferret Models

2016 ◽  
Vol 90 (23) ◽  
pp. 10936-10944 ◽  
Author(s):  
Xiangjie Sun ◽  
Jessica A. Belser ◽  
Joanna A. Pulit-Penaloza ◽  
Hui Zeng ◽  
Amanda Lewis ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Domestic Poultry ◽  
Commercial Turkey

ABSTRACTAvian influenza A H7 viruses have caused multiple outbreaks in domestic poultry throughout North America, resulting in occasional infections of humans in close contact with affected birds. In early 2016, the presence of H7N8 highly pathogenic avian influenza (HPAI) viruses and closely related H7N8 low-pathogenic avian influenza (LPAI) viruses was confirmed in commercial turkey farms in Indiana. These H7N8 viruses represent the first isolation of this subtype in domestic poultry in North America, and their virulence in mammalian hosts and the potential risk for human infection are largely unknown. In this study, we assessed the ability of H7N8 HPAI and LPAI viruses to replicatein vitroin human airway cells andin vivoin mouse and ferret models. Both H7N8 viruses replicated efficientlyin vitroandin vivo, but they exhibited substantial differences in disease severity in mammals. In mice, while the H7N8 LPAI virus largely remained avirulent, the H7N8 HPAI virus exhibited greater infectivity, virulence, and lethality. Both H7N8 viruses replicated similarly in ferrets, but only the H7N8 HPAI virus caused moderate weight loss, lethargy, and mortality. The H7N8 LPAI virus displayed limited transmissibility in ferrets placed in direct contact with an inoculated animal, while no transmission of H7N8 HPAI virus was detected. Our results indicate that the H7N8 avian influenza viruses from Indiana are able to replicate in mammals and cause severe disease but with limited transmission. The recent appearance of H7N8 viruses in domestic poultry highlights the need for continued influenza surveillance in wild birds and close monitoring of the potential risk to human health.IMPORTANCEH7 influenza viruses circulate in wild birds in the United States, but when the virus emerges in domestic poultry populations, the frequency of human exposure and the potential for human infections increases. An H7N8 highly pathogenic avian influenza (HPAI) virus and an H7N8 low-pathogenic avian influenza (LPAI) virus were recently isolated from commercial turkey farms in Indiana. To determine the risk that these influenza viruses pose to humans, we assessed their pathogenesis and transmissionin vitroand in mammalian models. We found that the H7N8 HPAI virus exhibited enhanced virulence, and although transmission was only observed with the H7N8 LPAI virus, the ability of this H7 virus to transmit in a mammalian host and quickly evolve to a more virulent strain is cause for concern. Our findings offer important insight into the potential for emerging H7 avian influenza viruses to acquire the ability to cause disease and transmit among mammals.

Biologic Characterization of H4, H6, and H9 Type Low Pathogenicity Avian Influenza Viruses from Wild Birds in Chickens and Turkeys

2009 ◽  
Vol 53 (4) ◽  
pp. 552-562 ◽  
Author(s):  
Antonio C. Morales ◽  
Deborah A. Hilt ◽  
Susan M. Williams ◽  
Mary J. Pantin-Jackwood ◽  
David L. Suarez ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Biologic Characterization

scholarly journals Preferential selection and contribution of non-structural protein 1 (NS1) to the efficient transmission of the panzootic avian influenza H5N8 2.3.4.4 clades A and B viruses in chickens and ducks

2021 ◽  
Author(s):  
Claudia Blaurock ◽  
Angele Breithaupt ◽  
David Scheibner ◽  
Ola Bagato ◽  
Axel Karger ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Ns1 Protein ◽  
Structural Protein ◽  
Evolutionary Trajectory ◽  
C Terminus ◽  
Clade B ◽  
Efficient Transmission

Highly pathogenic avian influenza viruses H5N8 clade 2.3.4.4 caused outbreaks in poultry at an unprecedented global scale. The virus was spread by wild birds in Asia in two waves: clade-2.3.4.4A in 2014/2015 and clade-2.3.4.4B since 2016 up to today. Both clades were highly virulent in chickens, but only clade-B viruses exhibited high virulence in ducks. Viral factors which contribute to virulence and transmission of these panzootic H5N8 2.3.4.4 viruses are largely unknown. The NS1 protein, typically composed of 230 amino acids (aa), is a multifunctional protein which is also a pathogenicity factor. Here, we studied the evolutionary trajectory of H5N8 NS1 proteins from 2013 to 2019 and their role in the fitness of H5N8 viruses in chickens and ducks. Sequence analysis and in-vitro experiments indicated that clade-2.3.4.4A and clade-2.3.4.4B viruses have a preference for NS1 of 237-aa and 217-aa, respectively over NS1 of 230-aa. NS217 was exclusively seen in domestic and wild birds in Europe. The extension of the NS1 C-terminus of clade-B virus reduced virus transmission and replication in chickens and ducks and partially impaired the systemic tropism to the endothelium in ducks. Conversely, lower impact on fitness of clade-A virus was observed. Remarkably, the NS1 of clade-A and clade-B, regardless of length, was efficient to block interferon induction in infected chickens and changes in the NS1 C-terminus reduced the efficiency for interferon antagonism. Together, the NS1 C-terminus contributes to the efficient transmission and high fitness of H5N8 viruses in chickens and ducks.

scholarly journals Genetic analyses of avian influenza viruses in Mongolia, 2007 to 2009, and their relationships with Korean isolates from domestic poultry and wild birds

2011 ◽  
Vol 90 (10) ◽  
pp. 2229-2242 ◽  
Author(s):  
H.-M. Kang ◽  
M.-C. Kim ◽  
J.-G. Choi ◽  
D. Batchuluun ◽  
T.-O. Erdene-Ochir ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Genetic Analyses ◽  
Domestic Poultry

Isolation and Genetic Characterization of Avian Influenza Viruses Isolated from Wild Birds in the Azov-Black Sea Region of Ukraine (2001–2012)

2016 ◽  
Vol 60 (1s) ◽  
pp. 365-377 ◽  
Author(s):  
Denys Muzyka ◽  
Mary Pantin-Jackwood ◽  
Erica Spackman ◽  
Diane Smith ◽  
Oleksandr Rula ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Black Sea ◽  
Genetic Characterization ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Black Sea Region
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