scholarly journals Pathogenicity and Transmissibility of North American H7 Low Pathogenic Avian Influenza Viruses in Chickens and Turkeys

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 163 ◽  
Author(s):  
Ishita Roy Chowdhury ◽  
Sai Yeddula ◽  
Shin-Hee Kim
Keyword(s):  
Avian Influenza ◽  
Respiratory Tract ◽  
Broiler Chickens ◽  
Influenza Viruses ◽  
Upper Respiratory Tract ◽  
Pathogenic Avian Influenza ◽  
Recent Emergence ◽  
Specific Pathogen ◽  
Upper Respiratory ◽  
Low Pathogenic Avian Influenza

Low pathogenic avian influenza (LPAI) viruses can silently circulate in poultry and wild aquatic birds and potentially mutate into highly pathogenic avian influenza (HPAI) viruses. In the U.S., recent emergence and spread of H7N8 and H7N9 HPAI viruses not only caused devastating losses to domestic poultry but also underscored the capability of LPAI viruses to mutate into HPAI viruses. Therefore, in this study, we evaluated pathogenicity and transmissibility of H7N8 and H7N9 LPAI viruses (the progenitors of HPAI viruses) in chickens and turkeys. We also included H7N2 isolated from an outbreak of LPAI in commercial chickens. H7 viruses replicated more efficiently in the respiratory tract than in the gastrointestinal tract, suggesting that their replication is restricted to the upper respiratory tract. Specifically, H7N2 replicated most efficiently in two-week-old chickens and turkeys. In contrast, H7N8 replicated least efficiently in those birds. Further, replication of H7N2 and H7N9 was restricted in the upper respiratory tract of four-week-old specific-pathogen-free (SPF) and broiler chickens. Despite their restricted replication, the two viruses efficiently transmitted from infected to naïve birds by direct contact, leading to seroconversion of contacted chickens. Our findings suggest the importance of continuous monitoring and surveillance of LPAI viruses in the fields.

scholarly journals Seasonal and Pandemic Human Influenza Viruses Attach Better to Human Upper Respiratory Tract Epithelium than Avian Influenza Viruses

2010 ◽  
Vol 176 (4) ◽  
pp. 1614-1618 ◽  
Author(s):  
Debby van Riel ◽  
Michael A. den Bakker ◽  
Lonneke M.E. Leijten ◽  
Salin Chutinimitkul ◽  
Vincent J. Munster ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Respiratory Tract ◽  
Influenza Viruses ◽  
Upper Respiratory Tract ◽  
Human Influenza ◽  
Avian Influenza Viruses ◽  
Upper Respiratory

scholarly journals Detection of Low Pathogenic Avian Influenza Viruses in Wild Ducks from Canada: Comparison of Two Sampling Methods

2011 ◽  
Vol 47 (2) ◽  
pp. 466-470 ◽  
Author(s):  
E. Jane Parmley ◽  
Catherine Soos ◽  
André Breault ◽  
Madeleine Fortin ◽  
Emily Jenkins ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Sampling Methods ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Pathogenic Avian Influenza ◽  
Low Pathogenic Avian Influenza

Opposite outcomes of the within-host competition between highly and low pathogenic H5N8 avian influenza viruses in chickens compared to ducks

2021 ◽  
Author(s):  
Pierre Bessière ◽  
Thomas Figueroa ◽  
Amelia Coggon ◽  
Charlotte Foret-Lucas ◽  
Alexandre Houffschmitt ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Reverse Genetics ◽  
Highly Pathogenic Avian Influenza ◽  
Viral Evolution ◽  
Influenza Viruses ◽  
Poultry Production ◽  
Avian Influenza Viruses ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Low Pathogenic Avian Influenza

Highly pathogenic avian influenza viruses (HPAIV) emerge from low pathogenic avian influenza viruses (LPAIV) through the introduction of basic amino acids at the hemagglutinin (HA) cleavage site. Following viral evolution, the newly formed HPAIV likely represents a minority variant within the index host, predominantly infected with the LPAIV precursor. Using reverse-genetics engineered H5N8 viruses differing solely at the HA cleavage, we tested the hypothesis that the interaction between the minority HPAIV and the majority LPAIV could modulate the risk of HPAIV emergence and that the nature of the interaction could depend on the host species. In chickens, we observed that the H5N8 LP increased H5N8 HP replication and pathogenesis. By contrast, the H5N8 LP antagonized H5N8 HP replication and pathogenesis in ducks. Ducks mounted a more potent antiviral innate immune response than chickens against the H5N8 LP , which correlated with H5N8 HP inhibition. These data provide experimental evidence that HPAIV may be more likely to emerge in chickens than in ducks and underscore the importance of within-host viral variants interactions in viral evolution. IMPORTANCE Highly pathogenic avian influenza viruses represent a threat to poultry production systems and to human health because of their impact on food security and because of their zoonotic potential. It is therefore crucial to better understand how these viruses emerge. Using a within-host competition model between highly and low pathogenic avian influenza viruses, we provide evidence that highly pathogenic avian influenza viruses could be more likely to emerge in chickens than in ducks. These results have important implications for highly pathogenic avian influenza virus emergence prevention and they underscore the importance of within-host viral variants interactions in virus evolution.

scholarly journals Insights into the Acquisition of Virulence of Avian Influenza Viruses during a Single Passage in Ferrets

Viruses ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 915
Author(s):  
Butler ◽  
Middleton ◽  
Haining ◽  
Layton ◽  
Rockman ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Respiratory Tract ◽  
Severe Disease ◽  
Influenza Viruses ◽  
Mammalian Host ◽  
Upper Respiratory Tract ◽  
Avian Influenza Viruses ◽  
Single Passage ◽  
H5n1 Isolate ◽  
High Pathogenicity

Circulating avian influenza viruses pose a significant threat, with human infections occurring infrequently but with potentially severe consequences. To examine the dynamics and locale of the adaptation process of avian influenza viruses when introduced to a mammalian host, we infected ferrets with H5N1 viruses. As expected, all ferrets infected with the human H5N1 isolate A/Vietnam/1203/2004 showed severe disease and virus replication outside the respiratory tract in multiple organs including the brain. In contrast infection of ferrets with the avian H5N1 virus A/Chicken/Laos/Xaythiani26/2006 showed a different collective pattern of infection; many ferrets developed and cleared a mild respiratory infection but a subset (25–50%), showed extended replication in the upper respiratory tract and developed infection in distal sites. Virus from these severely infected ferrets was commonly found in tissues that included liver and small intestine. In most instances the virus had acquired the common virulence substitution PB2 E627K but, in one case, a previously unidentified combination of two amino acid substitutions at PB2 S489P and NP V408I, which enhanced polymerase activity, was found. We noted that virus with high pathogenicity adaptations could be dominant in an extra-respiratory site without being equally represented in the nasal wash. Further ferret passage of these mutated viruses resulted in high pathogenicity in all ferrets. These findings illustrate the remarkable ability of avian influenza viruses that avoid clearance in the respiratory tract, to mutate towards a high pathogenicity phenotype during just a single passage in ferrets and also indicate a window of less than 5 days in which treatment may curtail systemic infection.

An experimental model to analyse the risk of introduction of a duck-originated H5 low-pathogenic avian influenza virus in poultry through close contact and contaminative transmission

2013 ◽  
Vol 142 (9) ◽  
pp. 1836-1847 ◽  
Author(s):  
G. CLAES ◽  
S. MARCHÉ ◽  
J. DEWULF ◽  
T. VAN DEN BERG ◽  
B. LAMBRECHT
Keyword(s):  
Avian Influenza ◽  
Close Contact ◽  
Animal Experiments ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Pathogenic Avian Influenza ◽  
Contaminated Drinking Water ◽  
Pathogenic Avian Influenza Virus ◽  
Efficient Route ◽  
Low Pathogenic Avian Influenza

SUMMARYAquatic wild birds are often carriers of low-pathogenic avian influenza viruses (LPAIVs). If H5 and H7 LPAIVs are transmitted to poultry and have the opportunity to circulate, a highly pathogenic AIV may arise. Contact with aquatic wild birds is one of the most important ways in which these LPAIVs can be introduced into poultry flocks. In this study, the transmissibility of a duck-originated H5 LPAIV between ducks and chickens was analysed in a series of animal experiments, using different transmission routes. Results indicate that the outcome of virus intake by chickens exposed to infectious ducks depends on the way the virus is presented. Faecally contaminated drinking water proved to be the most efficient route by which the virus can be transmitted to chickens. The results from this study also suggest that some duck-originated H5 LPAIVs may be introduced to poultry but do not have the potential to become established in poultry populations.

Characterization of two low pathogenic avian influenza viruses isolated in Hungary in 2007

2010 ◽  
Vol 145 (1-2) ◽  
pp. 142-147 ◽  
Author(s):  
Zsófia Szeleczky ◽  
Ádám Bálint ◽  
Péter Gyarmati ◽  
Giorgi Metreveli ◽  
Ádám Dán ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Pathogenic Avian Influenza ◽  
Low Pathogenic Avian Influenza
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