scholarly journals Genetic and biological characteristics of the globally circulating H5N8 avian influenza viruses and the protective efficacy offered by the poultry vaccine currently used in China

2021 ◽  
Author(s):  
Pengfei Cui ◽  
Xianying Zeng ◽  
Xuyong Li ◽  
Yanbing Li ◽  
Jianzhong Shi ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Animal Studies ◽  
Protective Efficacy ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Virus Challenge ◽  
H5n8 Virus ◽  
Virus Genotypes ◽  
Poultry Vaccine

AbstractThe H5N8 avian influenza viruses have been widely circulating in wild birds and are responsible for the loss of over 33 million domestic poultry in Europe, Russia, Middle East, and Asia since January 2020. To monitor the invasion and spread of the H5N8 virus in China, we performed active surveillance by analyzing 317 wild bird samples and swab samples collected from 41,172 poultry all over the country. We isolated 22 H5N8 viruses from wild birds and 14 H5N8 viruses from waterfowls. Genetic analysis indicated that the 36 viruses formed two different genotypes: one genotype viruses were widely detected from different wild birds and domestic waterfowls; the other genotype was isolated from a whopper swan. We further revealed the origin and spatiotemporal spread of these two distinct H5N8 virus genotypes in 2020 and 2021. Animal studies indicated that the H5N8 isolates are highly pathogenic to chickens, mildly pathogenic in ducks, but have distinct pathotypes in mice. Moreover, we found that vaccinated poultry in China could be completely protected against H5N8 virus challenge. Given that the H5N8 viruses are likely to continue to spread in wild birds, vaccination of poultry is highly recommended in high-risk countries to prevent H5N8 avian influenza.

scholarly journals Antibody responses to avian influenza viruses in wild birds broaden with age

2016 ◽  
Vol 283 (1845) ◽  
pp. 20162159 ◽  
Author(s):  
Sarah C. Hill ◽  
Ruth J. Manvell ◽  
Bodo Schulenburg ◽  
Wendy Shell ◽  
Paul S. Wikramaratna ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Haemagglutination Inhibition ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Antibody Responses ◽  
Immune Recognition ◽  
Avian Influenza Viruses ◽  
Highly Pathogenic ◽  
Age Related ◽  
Pathogenic H5n1

For viruses such as avian influenza, immunity within a host population can drive the emergence of new strains by selecting for viruses with novel antigens that avoid immune recognition. The accumulation of acquired immunity with age is hypothesized to affect how influenza viruses emerge and spread in species of different lifespans. Despite its importance for understanding the behaviour of avian influenza viruses, little is known about age-related accumulation of immunity in the virus's primary reservoir, wild birds. To address this, we studied the age structure of immune responses to avian influenza virus in a wild swan population ( Cygnus olor ), before and after the population experienced an outbreak of highly pathogenic H5N1 avian influenza in 2008. We performed haemagglutination inhibition assays on sampled sera for five avian influenza strains and show that breadth of response accumulates with age. The observed age-related distribution of antibody responses to avian influenza strains may explain the age-dependent mortality observed during the highly pathogenic H5N1 outbreak. Age structures and species lifespan are probably important determinants of viral epidemiology and virulence in birds.

scholarly journals Serologic Testing for Avian Influenza Viruses in Wild Birds: Comparison of Two Commercial Competition Enzyme-Linked Immunosorbent Assays

2010 ◽  
Vol 5 (s1) ◽  
pp. e178-e179
Author(s):  
Elisa Pérez-ramírez ◽  
Vanessa Rodríguez ◽  
Dagmar Sommer ◽  
Juan Manuel Blanco ◽  
Pelayo Acevedo ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Serologic Testing ◽  
Immunosorbent Assays

scholarly journals Monitoring Emergent Avian Influenza Viruses Subtypes H5 and H7 in Wild Birds in Ukraine

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Borys Stegniy ◽  
Denys Muzyka ◽  
Mary Pantin-Jackwood ◽  
Oleksandr Rula ◽  
Anton Stegniy ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Black Sea ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Wild Waterfowl

The abstract is devoted to monitoring studies of circulation of the AIV subtypes H5 and H7 in wild waterfowl and shorebirds around the Azov-Black Sea in Ukraine

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 Surveillance for avian influenza viruses in wild birds at live bird markets, Egypt, 2014‐2016

2019 ◽  
Vol 13 (4) ◽  
pp. 407-414 ◽  
Author(s):  
Ahmed S. Kayed ◽  
Ahmed Kandeil ◽  
Mokhtar R. Gomaa ◽  
Rabeh El‐Shesheny ◽  
Sara Mahmoud ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Live Bird Markets ◽  
Live Bird
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