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.

scholarly journals Characterization of Subtype H6 Avian Influenza A Viruses Isolated From Wild Birds in Poyang Lake, China

2021 ◽  
Vol 8 ◽  
Author(s):  
Zhimin Wan ◽  
Qiuqi Kan ◽  
Zhehong Zhao ◽  
Hongxia Shao ◽  
Thomas J. Deliberto ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Avian Influenza ◽  
Mammalian Cells ◽  
Influenza A ◽  
Poyang Lake ◽  
Wild Birds ◽  
Mouse Lung ◽  
Influenza A Viruses ◽  
Domestic Poultry ◽  
History Of

Subtype H6 avian influenza A viruses (IAVs) are enzootic and genetically diverse in both domestic poultry and wild waterfowl and may cause spillovers in both pigs and humans. Thus, it is important to understand the genetic diversity of H6 IAVs in birds and their zoonotic potential. Compared with that in domestic poultry, the genetic diversity of H6 viruses in wild birds in China has not been well-understood. In this study, five H6 viruses were isolated from wild birds in Poyang Lake, China, and genetic analyses showed that these isolates are clustered into four genotypes associated with reassortments among avian IAVs from domestic poultry and wild birds in China and those from Eurasia and North America and that these viruses exhibited distinct phenotypes in growth kinetics analyses with avian and mammalian cells lines and in mouse challenge experiments. Of interest is that two H6 isolates from the Eurasian teal replicated effectively in the mouse lung without prior adaptation, whereas the other three did not. Our study suggested that there are variations in the mammalian viral replication efficiency phenotypic among genetically diverse H6 IAVs in wild birds and that both intra- and inter-continental movements of IAVs through wild bird migration may facilitate the emergence of novel H6 IAV reassortants with the potential for replicating in mammals, including humans. Continued surveillance to monitor the diversity of H6 IAVs in wild birds is necessary to increase our understanding of the natural history of IAVs.

scholarly journals Evaluation of potential risk of transmission of avian influenza A viruses at live bird markets in response to unusual crow die‐offs in Bangladesh

2020 ◽  
Vol 14 (3) ◽  
pp. 349-352
Author(s):  
Mahbubur Rahman ◽  
Punam Mangtani ◽  
Timothy M. Uyeki ◽  
Jacqueline M. Cardwell ◽  
Montserrat Torremorell ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Potential Risk ◽  
Influenza A ◽  
Influenza A Viruses ◽  
Live Bird Markets ◽  
Live Bird

scholarly journals Genetic Characterization of Highly Pathogenic Avian Influenza A(H5N8) Virus in Pakistani Live Bird Markets Reveals Rapid Diversification of Clade 2.3.4.4b Viruses

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1633
Author(s):  
Muzaffar Ali ◽  
Tahir Yaqub ◽  
Muhammad Furqan Shahid ◽  
Foong Ying Wong ◽  
Nadia Mukhtar ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Virus Detection ◽  
Human Infection ◽  
Economic Losses ◽  
Influenza Surveillance ◽  
Highly Pathogenic ◽  
Live Bird Markets ◽  
Domestic Poultry ◽  
Live Bird

The highly pathogenic (HPAI) avian influenza A(H5N1) viruses have undergone reassortment with multiple non-N1-subtype neuraminidase genes since 2008, leading to the emergence of H5Nx viruses. H5Nx viruses established themselves quickly in birds and disseminated from China to Africa, the Middle East, Europe and North America. Multiple genetic clades have successively evolved through frequent mutations and reassortment, posing a continuous threat to domestic poultry and causing substantial economic losses. Live bird markets are recognized as major sources of avian-to-human infection and for the emergence of zoonotic influenza. In Pakistan, the A(H5N1) virus was first reported in domestic birds in 2007; however, avian influenza surveillance is limited and there is a lack of knowledge on the evolution and transmission of the A(H5) virus in the country. We collected oropharyngeal swabs from domestic poultry and environmental samples from six different live bird markets during 2018–2019. We detected and sequenced HPAI A(H5N8) viruses from two chickens, one quail and one environmental sample in two markets. Temporal phylogenetics indicated that all novel HPAI A(H5N8) viruses belonged to clade 2.3.4.4b, with all eight genes of Pakistan A(H5N8) viruses most closely related to 2017 Saudi Arabia A(H5N8) viruses, which were likely introduced via cross-border transmission from neighboring regions approximately three months prior to virus detection into domestic poultry. Our data further revealed that clade 2.3.4.4b viruses underwent rapid lineage expansion in 2017 and acquired significant amino acid mutations, including mutations associated with increased haemagglutinin affinity to human α-2,6 receptors, prior to the first human A(H5N8) infection in Russian poultry workers in 2020. These results highlight the need for systematic avian influenza surveillance in live bird markets in Pakistan to monitor for potential A(H5Nx) variants that may arise from poultry populations.

scholarly journals Feral Swine in the United States Have Been Exposed to both Avian and Swine Influenza A Viruses

2017 ◽  
Vol 83 (19) ◽  
Author(s):  
Brigitte E. Martin ◽  
Hailiang Sun ◽  
Margaret Carrel ◽  
Fred L. Cunningham ◽  
John A. Baroch ◽  
...  
Keyword(s):  
United States ◽  
Influenza A ◽  
Swine Influenza ◽  
The United States ◽  
Wild Birds ◽  
Influenza A Viruses ◽  
Serum Samples ◽  
Feral Swine ◽  
Free Ranging ◽  
Domestic Swine

ABSTRACT Influenza A viruses (IAVs) in swine can cause sporadic infections and pandemic outbreaks among humans, but how avian IAV emerges in swine is still unclear. Unlike domestic swine, feral swine are free ranging and have many opportunities for IAV exposure through contacts with various habitats and animals, including migratory waterfowl, a natural reservoir for IAVs. During the period from 2010 to 2013, 8,239 serum samples were collected from feral swine across 35 U.S. states and tested against 45 contemporary antigenic variants of avian, swine, and human IAVs; of these, 406 (4.9%) samples were IAV antibody positive. Among 294 serum samples selected for antigenic characterization, 271 cross-reacted with ≥1 tested virus, whereas the other 23 did not cross-react with any tested virus. Of the 271 IAV-positive samples, 236 cross-reacted with swine IAVs, 1 with avian IAVs, and 16 with avian and swine IAVs, indicating that feral swine had been exposed to both swine and avian IAVs but predominantly to swine IAVs. Our findings suggest that feral swine could potentially be infected with both avian and swine IAVs, generating novel IAVs by hosting and reassorting IAVs from wild birds and domestic swine and facilitating adaptation of avian IAVs to other hosts, including humans, before their spillover. Continued surveillance to monitor the distribution and antigenic diversities of IAVs in feral swine is necessary to increase our understanding of the natural history of IAVs. IMPORTANCE There are more than 5 million feral swine distributed across at least 35 states in the United States. In contrast to domestic swine, feral swine are free ranging and have unique opportunities for contact with wildlife, livestock, and their habitats. Our serological results indicate that feral swine in the United States have been exposed to influenza A viruses (IAVs) consistent with those found in both domestic swine and wild birds, with the predominant infections consisting of swine-adapted IAVs. Our findings suggest that feral swine have been infected with IAVs at low levels and could serve as hosts for the generation of novel IAVs at the interface of feral swine, wild birds, domestic swine, and humans.

scholarly journals Outbreak Severity of Highly Pathogenic Avian Influenza A(H5N8) Viruses Is Inversely Correlated to Polymerase Complex Activity and Interferon Induction

2020 ◽  
Vol 94 (11) ◽  
Author(s):  
René M. Vigeveno ◽  
Marjolein J. Poen ◽  
Edyth Parker ◽  
Melle Holwerda ◽  
Karen de Haan ◽  
...  
Keyword(s):  
The Netherlands ◽  
Avian Influenza ◽  
Influenza A ◽  
Highly Pathogenic Avian Influenza ◽  
The United States ◽  
Wild Birds ◽  
Complex Activity ◽  
Highly Pathogenic ◽  
Polymerase Complex ◽  
Pathogenic Avian Influenza

ABSTRACT Highly pathogenic avian influenza A(H5N8) viruses first emerged in China in 2010 and in 2014 spread throughout Asia and to Europe and the United States via migrating birds. Influenza A(H5N8) viruses were first detected in the Netherlands in 2014 and caused five outbreaks in poultry farms but were infrequently detected in wild birds. In 2016, influenza A(H5N8) viruses were reintroduced into the Netherlands, resulting in eight poultry farm outbreaks. This outbreak resulted in numerous dead wild birds with severe pathology. Phylogenetic analysis showed that the polymerase genes of these viruses had undergone extensive reassortment between outbreaks. Here, we investigated the differences in virulence between the 2014-15 and the 2016-17 outbreaks by characterizing the polymerase complex of influenza A(H5N8) viruses from both outbreaks. We found that viruses from the 2014-15 outbreak had significantly higher polymerase complex activity in both human and avian cell lines than did those from the 2016-17 outbreak. No apparent differences in the balance between transcription and replication of the viral genome were observed. Interestingly, the 2014-15 polymerase complexes induced significantly higher levels of interferon beta (IFN-β) than the polymerase complexes of the 2016-17 outbreak viruses, mediated via retinoic acid-inducible gene I (RIG-I). Inoculation of primary duck cells with recombinant influenza A(H5N8) viruses, including viruses with reassorted polymerase complexes, showed that the polymerase complexes from the 2014-15 outbreak induced higher levels of IFN-β despite relatively minor differences in replication capacity. Together, these data suggest that despite the lower levels of polymerase activity, the higher 2016-17 influenza A(H5N8) virus virulence may be attributed to the lower level of activation of the innate immune system. IMPORTANCE Compared to the 2014-15 outbreak, the 2016-17 outbreak of influenza A(H5N8) viruses in the Netherlands and Europe was more virulent; the number of dead or diseased wild birds found and the severity of pathological changes were higher during the 2016-17 outbreak. The polymerase complex plays an important role in influenza virus virulence, and the gene segments of influenza A(H5N8) viruses reassorted extensively between the outbreaks. In this study, the 2014-15 polymerase complexes were found to be more active, which is counterintuitive with the observed higher virulence of the 2016-17 outbreak viruses. Interestingly, the 2014-15 polymerase complexes also induced higher levels of IFN-β. These findings suggest that the higher virulence of influenza A(H5N8) viruses from the 2016-17 outbreak may be related to the lower induction of IFN-β. An attenuated interferon response could lead to increased dissemination, pathology, and mortality, as observed in (wild) birds infected during the 2016-2017 outbreak.

scholarly journals Highly Pathogenic Avian Influenza A(H5N1) Virus Infection among Workers at Live Bird Markets, Bangladesh, 2009–2010

2015 ◽  
Vol 21 (4) ◽  
pp. 629-637 ◽  
Author(s):  
Sharifa Nasreen ◽  
Salah Uddin Khan ◽  
Stephen P. Luby ◽  
Emily S. Gurley ◽  
Jaynal Abedin ◽  
...  
Keyword(s):  
Virus Infection ◽  
Avian Influenza ◽  
Influenza A ◽  
H5n1 Virus ◽  
Highly Pathogenic Avian Influenza ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Live Bird Markets ◽  
Live Bird

scholarly journals Evaluating the role of wild songbirds or rodents in spreading avian influenza virus across an agricultural landscape

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4060 ◽  
Author(s):  
Derek D. Houston ◽  
Shahan Azeem ◽  
Coady W. Lundy ◽  
Yuko Sato ◽  
Baoqing Guo ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Influenza A Virus ◽  
Influenza A ◽  
Agricultural Landscape ◽  
Clinical Signs ◽  
The United States ◽  
Wild Birds ◽  
Influenza A Viruses

Background Avian influenza virus (AIV) infections occur naturally in wild bird populations and can cross the wildlife-domestic animal interface, often with devastating impacts on commercial poultry. Migratory waterfowl and shorebirds are natural AIV reservoirs and can carry the virus along migratory pathways, often without exhibiting clinical signs. However, these species rarely inhabit poultry farms, so transmission into domestic birds likely occurs through other means. In many cases, human activities are thought to spread the virus into domestic populations. Consequently, biosecurity measures have been implemented to limit human-facilitated outbreaks. The 2015 avian influenza outbreak in the United States, which occurred among poultry operations with strict biosecurity controls, suggests that alternative routes of virus infiltration may exist, including bridge hosts: wild animals that transfer virus from areas of high waterfowl and shorebird densities. Methods Here, we examined small, wild birds (songbirds, woodpeckers, etc.) and mammals in Iowa, one of the regions hit hardest by the 2015 avian influenza epizootic, to determine whether these animals carry AIV. To assess whether influenza A virus was present in other species in Iowa during our sampling period, we also present results from surveillance of waterfowl by the Iowa Department of Natural Resources and Unites Stated Department of Agriculture. Results Capturing animals at wetlands and near poultry facilities, we swabbed 449 individuals, internally and externally, for the presence of influenza A virus and no samples tested positive by qPCR. Similarly, serology from 402 animals showed no antibodies against influenza A. Although several species were captured at both wetland and poultry sites, the overall community structure of wild species differed significantly between these types of sites. In contrast, 83 out of 527 sampled waterfowl tested positive for influenza A via qPCR. Discussion These results suggest that even though influenza A viruses were present on the Iowa landscape at the time of our sampling, small, wild birds and rodents were unlikely to be frequent bridge hosts.

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