Pathobiology of H5N2 Mexican Avian Influenza Virus Infections of Chickens

1997 ◽  
Vol 34 (6) ◽  
pp. 557-567 ◽  
Author(s):  
D. E. Swayne
Keyword(s):  
Avian Influenza ◽  
Virus Replication ◽  
Structural Changes ◽  
Distribution Patterns ◽  
Mortality Rates ◽  
Influenza Viruses ◽  
Peptide Sequence ◽  
Virus Infections ◽  
Highly Pathogenic ◽  
Genomic Changes

To determine the association between specific structural changes in the hemagglutinin gene and pathogenicity of avian influenza viruses (AIVs), groups of 4-week-old White Plymouth Rock chickens were inoculated intravenously or intranasally with AIVs of varying pathogenicities isolated from chickens in central Mexico during 1994-1995. Mildly pathogenic (MP) viruses had a common hemagglutinin-connecting peptide sequence of Pro-Gln-Arg-Glu-Thr-Arg↓Gly and had restricted capability for replication and production of lesions in tissues. The principle targets for virus replication or lesion production were the lungs, lymphoid organs, and visceral organs containing epithelial cells, such as kidney and pancreas. Death was associated with respiratory and/or renal failure. By contrast, highly pathogenic (HP) AIVs had one substitution and the addition of two basic amino acids in the hemagglutinin connecting peptide, for a sequence of Pro-Gln-Arg-Lys-Arg-Lys-Thr-Arg↓Gly. The HP AIVs were pantropic in virus replication and lesion production ability. However, the most severe histologic lesions were produced in the brain, heart, adrenal glands, and pancreas, and failure of multiple critical organs was responsible for disease pathogenesis and death. No differences in lesion distribution patterns or in sites of AIV replication were evident to explain the variation in mortality rates for different HP AIVs, but HP AIVs that produced the highest mortality rates had more severe necrosis in heart and pancreas. The ability of individual HP AIVs to produce low or high mortality rates could not be explained by changes in sequence of the hemagglutinin-connecting peptide alone, but probably required the addition of other undetermined genomic changes.

scholarly journals The Microbiota Contributes to the Control of Highly Pathogenic H5N9 Influenza Virus Replication in Ducks

2020 ◽  
Vol 94 (10) ◽  
Author(s):  
Thomas Figueroa ◽  
Pierre Bessière ◽  
Amelia Coggon ◽  
Kim M. Bouwman ◽  
Roosmarijn van der Woude ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Virus Replication ◽  
Clinical Signs ◽  
Influenza Viruses ◽  
Highly Pathogenic ◽  
Antiviral Immune Response ◽  
Influenza Virus Replication

ABSTRACT Ducks usually show little or no clinical signs following highly pathogenic avian influenza virus infection. In order to analyze whether the microbiota could contribute to the control of influenza virus replication in ducks, we used a broad-spectrum oral antibiotic treatment to deplete the microbiota before infection with a highly pathogenic H5N9 avian influenza virus. Antibiotic-treated ducks and nontreated control ducks did not show any clinical signs following H5N9 virus infection. We did not detect any significant difference in virus titers neither in the respiratory tract nor in the brain nor spleen. However, we found that antibiotic-treated H5N9 virus-infected ducks had significantly increased intestinal virus excretion at days 3 and 5 postinfection. This was associated with a significantly decreased antiviral immune response in the intestine of antibiotic-treated ducks. Our findings highlight the importance of an intact microbiota for an efficient control of avian influenza virus replication in ducks. IMPORTANCE Ducks are frequently infected with avian influenza viruses belonging to multiple subtypes. They represent an important reservoir species of avian influenza viruses, which can occasionally be transmitted to other bird species or mammals, including humans. Ducks thus have a central role in the epidemiology of influenza virus infection. Importantly, ducks usually show little or no clinical signs even following infection with a highly pathogenic avian influenza virus. We provide evidence that the microbiota contributes to the control of influenza virus replication in ducks by modulating the antiviral immune response. Ducks are able to control influenza virus replication more efficiently when they have an intact intestinal microbiota. Therefore, maintaining a healthy microbiota by limiting perturbations to its composition should contribute to the prevention of avian influenza virus spread from the duck reservoir.

scholarly journals The Intestinal Microbiota Contributes to the Control of Highly Pathogenic H5N9 Influenza Virus Replication in Ducks

2019 ◽  
Author(s):  
Thomas Figueroa ◽  
Pierre Bessière ◽  
Amelia Coggon ◽  
Roosmarijn van der Woude ◽  
Maxence Delverdier ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Virus Replication ◽  
Intestinal Microbiota ◽  
Clinical Signs ◽  
Influenza Viruses ◽  
Highly Pathogenic ◽  
Influenza Virus Replication

ABSTRACTDucks usually show little or no clinical signs following highly pathogenic avian influenza virus infection. In order to analyze if the gut microbiota could contribute to the control of influenza virus replication in ducks, we used a broad-spectrum oral antibiotic treatment to deplete the gut microbiota before infection with a highly pathogenic H5N9 avian influenza virus. Antibiotic-treated ducks and non-treated control ducks did not show any clinical signs following H5N9 virus infection. We did not detect any difference in virus titers neither in the respiratory tract, nor in the brain and spleen. However, we found that antibiotic-treated H5N9 virus infected ducks had significantly increased intestinal virus excretion at day 3 and 5 post-infection. This was associated with a significantly decreased antiviral immune response in the intestine of antibiotic-treated ducks. Our findings highlight the importance of an intact microbiota for an efficient control of avian influenza virus replication in ducks.IMPORTANCEDucks are frequently infected with avian influenza viruses belonging to multiple subtypes. They represent an important reservoir species of avian influenza viruses, which can occasionally be transmitted to other bird species or mammals, including humans. Ducks thus have a central role in the epidemiology of influenza virus infection. Importantly, ducks usually show little or no clinical signs even following infection with a highly pathogenic avian influenza virus. We provide evidence that the intestinal microbiota contributes to the control of influenza virus replication in ducks by modulating the antiviral immune response. Ducks are able to control influenza virus replication more efficiently when they have an intact intestinal microbiota. Therefore, maintaining a healthy microbiota by limiting perturbations to its composition should contribute to prevention of avian influenza virus spread from the duck reservoir.

The East Jakarta Project: surveillance for highly pathogenic avian influenza A(H5N1) and seasonal influenza viruses in patients seeking care for respiratory disease, Jakarta, Indonesia, October 2011–September 2012

2015 ◽  
Vol 143 (16) ◽  
pp. 3394-3404 ◽  
Author(s):  
A. D. STORMS ◽  
R. KUSRIASTUTI ◽  
S. MISRIYAH ◽  
C. Y. PRAPTININGSIH ◽  
M. AMALYA ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Respiratory Disease ◽  
H5n1 Virus ◽  
Seasonal Influenza ◽  
Highly Pathogenic Avian Influenza ◽  
Influenza Viruses ◽  
Virus Infections ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Hpai H5n1

SUMMARYIndonesia has reported the most human infections with highly pathogenic avian influenza (HPAI) A(H5N1) virus worldwide. We implemented enhanced surveillance in four outpatient clinics and six hospitals for HPAI H5N1 and seasonal influenza viruses in East Jakarta district to assess the public health impact of influenza in Indonesia. Epidemiological and clinical data were collected from outpatients with influenza-like illness (ILI) and hospitalized patients with severe acute respiratory infection (SARI); respiratory specimens were obtained for influenza testing by real-time reverse transcription–polymerase chain reaction. During October 2011–September 2012, 1131/3278 specimens from ILI cases (34·5%) and 276/1787 specimens from SARI cases (15·4%) tested positive for seasonal influenza viruses. The prevalence of influenza virus infections was highest during December–May and the proportion testing positive was 76% for ILI and 36% for SARI during their respective weeks of peak activity. No HPAI H5N1 virus infections were identified, including hundreds of ILI and SARI patients with recent poultry exposures, whereas seasonal influenza was an important contributor to acute respiratory disease in East Jakarta. Overall, 668 (47%) of influenza viruses were influenza B, 384 (27%) were A(H1N1)pdm09, and 359 (25%) were H3. While additional data over multiple years are needed, our findings suggest that seasonal influenza prevention efforts, including influenza vaccination, should target the months preceding the rainy season.

scholarly journals Reverse genetics of influenza viruses

2006 ◽  
Vol 27 (4) ◽  
pp. 153
Author(s):  
Glenn A Marsh
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Virus Replication ◽  
Reverse Genetics ◽  
Highly Pathogenic Avian Influenza ◽  
Influenza Viruses ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Pathogenic Avian Influenza Virus ◽  
Virus Replication Cycle

Reverse genetics for generation of influenza viruses is a powerful tool allowing for the direct manipulation of the genome of viruses. It has the potential to allow for the generation of safer and more immunogenic vaccines and for a better understanding of the virus replication cycle. Reverse genetics is essential tool for producing a vaccine against the highly pathogenic avian influenza virus.

scholarly journals Highly Pathogenic Avian Influenza Viruses at the Wild–Domestic Bird Interface in Europe: Future Directions for Research and Surveillance

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 212
Author(s):  
Josanne H. Verhagen ◽  
Ron A. M. Fouchier ◽  
Nicola Lewis
Keyword(s):  
Avian Influenza ◽  
Highly Pathogenic Avian Influenza ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Highly Pathogenic ◽  
Future Directions ◽  
Pathogenic Avian Influenza ◽  
Domestic Bird ◽  
Hpai H5n1 ◽  
Host Identification

Highly pathogenic avian influenza (HPAI) outbreaks in wild birds and poultry are no longer a rare phenomenon in Europe. In the past 15 years, HPAI outbreaks—in particular those caused by H5 viruses derived from the A/Goose/Guangdong/1/1996 lineage that emerged in southeast Asia in 1996—have been occuring with increasing frequency in Europe. Between 2005 and 2020, at least ten HPAI H5 incursions were identified in Europe resulting in mass mortalities among poultry and wild birds. Until 2009, the HPAI H5 virus outbreaks in Europe were caused by HPAI H5N1 clade 2.2 viruses, while from 2014 onwards HPAI H5 clade 2.3.4.4 viruses dominated outbreaks, with abundant genetic reassortments yielding subtypes H5N1, H5N2, H5N3, H5N4, H5N5, H5N6 and H5N8. The majority of HPAI H5 virus detections in wild and domestic birds within Europe coincide with southwest/westward fall migration and large local waterbird aggregations during wintering. In this review we provide an overview of HPAI H5 virus epidemiology, ecology and evolution at the interface between poultry and wild birds based on 15 years of avian influenza virus surveillance in Europe, and assess future directions for HPAI virus research and surveillance, including the integration of whole genome sequencing, host identification and avian ecology into risk-based surveillance and analyses.

scholarly journals Antibodies to Highly Pathogenic A/H5Nx (Clade 2.3.4.4) Influenza Viruses in the Sera of Vietnamese Residents

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 394
Author(s):  
Tatyana Ilyicheva ◽  
Vasily Marchenko ◽  
Olga Pyankova ◽  
Anastasia Moiseeva ◽  
Tran Thi Nhai ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Wide Spectrum ◽  
Influenza Viruses ◽  
Serum Samples ◽  
Socialist Republic ◽  
Highly Pathogenic ◽  
Virus Variant ◽  
Human Sera ◽  
Hemagglutinin Inhibition

To cause a pandemic, an influenza virus has to overcome two main barriers. First, the virus has to be antigenically new to humans. Second, the virus has to be directly transmitted from humans to humans. Thus, if the avian influenza virus is able to pass the second barrier, it could cause a pandemic, since there is no immunity to avian influenza in the human population. To determine whether the adaptation process is ongoing, analyses of human sera could be conducted in populations inhabiting regions where pandemic virus variant emergence is highly possible. This study aimed to analyze the sera of Vietnamese residents using hemagglutinin inhibition reaction (HI) and microneutralization (MN) with A/H5Nx (clade 2.3.4.4) influenza viruses isolated in Vietnam and the Russian Federation in 2017–2018. In this study, we used sera from 295 residents of the Socialist Republic of Vietnam collected from three groups: 52 samples were collected from households in Nam Dinh province, where poultry deaths have been reported (2017); 96 (2017) and 147 (2018) samples were collected from patients with somatic but not infectious diseases in Hanoi. In all, 65 serum samples were positive for HI, at least to one H5 virus used in the study. In MN, 47 serum samples neutralizing one or two viruses at dilutions of 1/40 or higher were identified. We postulate that the rapidly evolving A/H5Nx (clade 2.3.4.4) influenza virus is possibly gradually adapting to the human host, insofar as healthy individuals have antibodies to a wide spectrum of variants of that subtype.

scholarly journals H5N2 Avian Influenza Outbreak in Texas in 2004: the First Highly Pathogenic Strain in the United States in 20 Years?

2005 ◽  
Vol 79 (17) ◽  
pp. 11412-11421 ◽  
Author(s):  
Chang-Won Lee ◽  
David E. Swayne ◽  
Jose A. Linares ◽  
Dennis A. Senne ◽  
David L. Suarez
Keyword(s):  
United States ◽  
Amino Acid ◽  
Avian Influenza ◽  
Cleavage Site ◽  
Basic Amino Acid ◽  
The United States ◽  
Influenza Viruses ◽  
Single Point Mutation ◽  
Highly Pathogenic

ABSTRACT In early 2004, an H5N2 avian influenza virus (AIV) that met the molecular criteria for classification as a highly pathogenic AIV was isolated from chickens in the state of Texas in the United States. However, clinical manifestations in the affected flock were consistent with avian influenza caused by a low-pathogenicity AIV and the representative virus (A/chicken/Texas/298313/04 [TX/04]) was not virulent for experimentally inoculated chickens. The hemagglutinin (HA) gene of the TX/04 isolate was similar in sequence to A/chicken/Texas/167280-4/02 (TX/02), a low-pathogenicity AIV isolate recovered from chickens in Texas in 2002. However, the TX/04 isolate had one additional basic amino acid at the HA cleavage site, which could be attributed to a single point mutation. The TX/04 isolate was similar in sequence to TX/02 isolate in several internal genes (NP, M, and NS), but some genes (PA, PB1, and PB2) had sequence of a clearly different origin. The TX/04 isolate also had a stalk deletion in the NA gene, characteristic of a chicken-adapted AIV. By analyzing viruses constructed by in vitro mutagenesis followed by reverse genetics, we found that the pathogenicity of the TX/04 virus could be increased in vitro and in vivo by the insertion of an additional basic amino acid at the HA cleavage site and not by the loss of a glycosylation site near the cleavage site. Our study provides the genetic and biologic characteristics of the TX/04 isolate, which highlight the complexity of the polygenic nature of the virulence of influenza viruses.

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.

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.

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