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Emerging Infectious Diseases Apr 2024Highly pathogenic avian influenza (HPAI) viruses have potential to cross species barriers and cause pandemics. Since 2022, HPAI A(H5N1) belonging to the goose/Guangdong...
Highly pathogenic avian influenza (HPAI) viruses have potential to cross species barriers and cause pandemics. Since 2022, HPAI A(H5N1) belonging to the goose/Guangdong 2.3.4.4b hemagglutinin phylogenetic clade have infected poultry, wild birds, and mammals across North America. Continued circulation in birds and infection of multiple mammalian species with strains possessing adaptation mutations increase the risk for infection and subsequent reassortment with influenza A viruses endemic in swine. We assessed the susceptibility of swine to avian and mammalian HPAI H5N1 clade 2.3.4.4b strains using a pathogenesis and transmission model. All strains replicated in the lung of pigs and caused lesions consistent with influenza A infection. However, viral replication in the nasal cavity and transmission was only observed with mammalian isolates. Mammalian adaptation and reassortment may increase the risk for incursion and transmission of HPAI viruses in feral, backyard, or commercial swine.
Topics: Animals; Birds; Influenza A Virus, H5N1 Subtype; Influenza in Birds; Mammals; Phylogeny; Poultry; Swine; Orthomyxoviridae Infections
PubMed: 38478379
DOI: 10.3201/eid3004.231141 -
Virulence Dec 2024
Topics: Animals; Cattle; United States; Humans; Influenza in Birds; Influenza A Virus, H5N1 Subtype; Livestock; Influenza A virus; Influenza, Human; Poultry; Phylogeny; Poultry Diseases
PubMed: 38632687
DOI: 10.1080/21505594.2024.2343931 -
Emerging Infectious Diseases Feb 2024During October 2022-March 2023, highly pathogenic avian influenza (HPAI) A(H5N1) clade 2.3.4.4b virus caused outbreaks in South Korea, including 174 cases in wild birds....
During October 2022-March 2023, highly pathogenic avian influenza (HPAI) A(H5N1) clade 2.3.4.4b virus caused outbreaks in South Korea, including 174 cases in wild birds. To understand the origin and role of wild birds in the evolution and spread of HPAI viruses, we sequenced 113 HPAI isolates from wild birds and performed phylogenetic analysis. We identified 16 different genotypes, indicating extensive genetic reassortment with viruses in wild birds. Phylodynamic analysis showed that the viruses were most likely introduced to the southern Gyeonggi-do/northern Chungcheongnam-do area through whooper swans (Cygnus cygnus) and spread southward. Cross-species transmission occurred between various wild bird species, including waterfowl and raptors, resulting in the persistence of HPAI in wild bird populations and further geographic spread as these birds migrated throughout South Korea. Enhanced genomic surveillance was an integral part of the HPAI outbreak response, aiding in timely understanding of the origin, evolution, and spread of the virus.
Topics: Animals; Humans; Influenza in Birds; Influenza A Virus, H5N1 Subtype; Phylogeny; Animals, Wild; Birds; Influenza, Human; Ducks; Republic of Korea
PubMed: 38215495
DOI: 10.3201/eid3002.231274 -
Nature Microbiology Sep 2023
Topics: Animals; Influenza in Birds
PubMed: 37644326
DOI: 10.1038/s41564-023-01457-0 -
Insights from Avian Influenza: A Review of Its Multifaceted Nature and Future Pandemic Preparedness.Viruses Mar 2024Avian influenza viruses (AIVs) have posed a significant pandemic threat since their discovery. This review mainly focuses on the epidemiology, virology, pathogenesis,... (Review)
Review
Avian influenza viruses (AIVs) have posed a significant pandemic threat since their discovery. This review mainly focuses on the epidemiology, virology, pathogenesis, and treatments of avian influenza viruses. We delve into the global spread, past pandemics, clinical symptoms, severity, and immune response related to AIVs. The review also discusses various control measures, including antiviral drugs, vaccines, and potential future directions in influenza treatment and prevention. Lastly, by summarizing the insights from previous pandemic control, this review aims to direct effective strategies for managing future influenza pandemics.
Topics: Animals; Humans; Influenza in Birds; Influenza, Human; Pandemic Preparedness; Influenza Vaccines; Influenza A virus; Pandemics
PubMed: 38543823
DOI: 10.3390/v16030458 -
Emerging Microbes & Infections Dec 2023Avian influenza H5N1 is a highly pathogenic virus that primarily affects birds. However, it can also infect other animal species, including mammals. We report the...
Avian influenza H5N1 is a highly pathogenic virus that primarily affects birds. However, it can also infect other animal species, including mammals. We report the infection of nine juvenile red foxes () with Highly Pathogenic Avian Influenza A type H5N1 (Clade 2.3.4.4b) in the spring of 2022 in the central, western, and northern regions of New York, USA. The foxes displayed neurologic signs, and examination of brain and lung tissue revealed lesions, with brain lesions ranging from moderate to severe meningoencephalitis. Analysis of tissue tropism using RT-PCR methods showed a comparatively lower Ct value in the brain, which was confirmed by hybridization targeting Influenza A RNA. The viral RNA labelling was highly clustered and overlapped the brain lesions, observed in neurons, and grey matter. Whole viral genome sequences obtained from the affected foxes were subjected to phylogenetic and mutation analysis to determine influenza A clade, host specificity, and potential occurrence of viral reassortment. Infections in red foxes likely occurred due to preying on infected wild birds and are unlikely due to transmission between foxes or other mammals.
Topics: Animals; Humans; Influenza in Birds; Foxes; Influenza, Human; Influenza A Virus, H5N1 Subtype; Tissue Distribution; Phylogeny
PubMed: 37589241
DOI: 10.1080/22221751.2023.2249554 -
Influenza and Other Respiratory Viruses Dec 2023Highly pathogenic avian influenza A(H5) human infections are a global concern, with many A(H5) human cases detected in Vietnam, including a case in October 2022. Using...
BACKGROUND
Highly pathogenic avian influenza A(H5) human infections are a global concern, with many A(H5) human cases detected in Vietnam, including a case in October 2022. Using avian influenza virus surveillance from March 2017-September 2022, we described the percent of pooled samples that were positive for avian influenza A, A(H5), A(H5N1), A(H5N6), and A(H5N8) viruses in live bird markets (LBMs) in Vietnam.
METHODS
Monthly at each LBM, 30 poultry oropharyngeal swab specimens and five environmental samples were collected. Samples were pooled in groups of five and tested for influenza A, A(H5), A(H5N1), A(H5N6), and A(H5N8) viruses by real-time reverse-transcription polymerase chain reaction. Trends in the percent of pooled samples that were positive for avian influenza were summarized by LBM characteristics and time and compared with the number of passively detected avian influenza outbreaks using Spearman's rank correlation.
RESULTS
A total of 25,774 pooled samples were collected through active surveillance at 167 LBMs in 24 provinces; 36.9% of pooled samples were positive for influenza A, 3.6% A(H5), 1.9% A(H5N1), 1.1% A(H5N6), and 0.2% A(H5N8). Influenza A(H5) viruses were identified January-December and at least once in 91.7% of sampled provinces. In 246 A(H5) outbreaks in poultry; 20.3% were influenza A(H5N1), 60.2% A(H5N6), and 19.5% A(H5N8); outbreaks did not correlate with active surveillance.
CONCLUSIONS
In Vietnam, influenza A(H5) viruses were detected by active surveillance in LBMs year-round and in most provinces sampled. In addition to outbreak reporting, active surveillance for A(H5) viruses in settings with high potential for animal-to-human spillover can provide situational awareness.
Topics: Animals; Humans; Influenza, Human; Influenza in Birds; Vietnam; Influenza A Virus, H5N1 Subtype; Disease Outbreaks; Influenza A Virus, H5N8 Subtype; Influenza A virus
PubMed: 38149927
DOI: 10.1111/irv.13245 -
Avian Diseases Jan 2024The complexity of influenza A virus (IAV) infections in avian hosts leads to equally complex scenarios for the vaccination of poultry. Vaccination against avian...
The complexity of influenza A virus (IAV) infections in avian hosts leads to equally complex scenarios for the vaccination of poultry. Vaccination against avian influenza strains can be used to prevent infections from sources with a single strain of IAV. It has been used as a part of outbreak control strategies as well as a way to maintain production for both low and high pathogenicity outbreaks. Unlike other viral pathogens of birds, avian influenza vaccination when used against highly pathogenic avian influenza virus, is tied to international trade and thus is not freely available for use without specific permission.
Topics: Animals; Humans; Influenza, Human; Poultry; Influenza in Birds; Commerce; Internationality; Poultry Diseases; Influenza A virus; Vaccination
PubMed: 38300659
DOI: 10.1637/aviandiseases-D-23-99995 -
Emerging Microbes & Infections Dec 2023The continued evolution and emergence of novel influenza viruses in wild and domestic animals poses an increasing public health risk. Two human cases of H3N8 avian...
The continued evolution and emergence of novel influenza viruses in wild and domestic animals poses an increasing public health risk. Two human cases of H3N8 avian influenza virus infection in China in 2022 have caused public concern regarding the risk of transmission between birds and humans. However, the prevalence of H3N8 avian influenza viruses in their natural reservoirs and their biological characteristics are largely unknown. To elucidate the potential threat of H3N8 viruses, we analyzed five years of surveillance data obtained from an important wetland region in eastern China and evaluated the evolutionary and biological characteristics of 21 H3N8 viruses isolated from 15,899 migratory bird samples between 2017 and 2021. Genetic and phylogenetic analyses showed that the H3N8 viruses circulating in migratory birds and ducks have evolved into different branches and have undergone complicated reassortment with viruses in waterfowl. The 21 viruses belonged to 12 genotypes, and some strains induced body weight loss and pneumonia in mice. All the tested H3N8 viruses preferentially bind to avian-type receptors, although they have acquired the ability to bind human-type receptors. Infection studies in ducks, chickens and pigeons demonstrated that the currently circulating H3N8 viruses in migratory birds have a high possibility of infecting domestic waterfowl and a low possibility of infecting chickens and pigeons. Our findings imply that circulating H3N8 viruses in migratory birds continue to evolve and pose a high infection risk in domestic ducks. These results further emphasize the importance of avian influenza surveillance at the wild bird and poultry interface.
Topics: Animals; Humans; Mice; Influenza A Virus, H3N8 Subtype; Influenza in Birds; Phylogeny; Chickens; Prevalence; Influenza A virus; Ducks; China
PubMed: 36913241
DOI: 10.1080/22221751.2023.2184178 -
Emerging Infectious Diseases Apr 2024We report full-genome characterization of highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus from an outbreak among sea lions (August 2023) in Argentina and...
We report full-genome characterization of highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus from an outbreak among sea lions (August 2023) in Argentina and possible spillover to fur seals and terns. Mammalian adaptation mutations in virus isolated from marine mammals and a human in Chile were detected in mammalian and avian hosts.
Topics: Animals; Humans; Influenza A Virus, H5N1 Subtype; Influenza in Birds; Argentina; Influenza A virus; Birds; Disease Outbreaks; Phylogeny; Mammals
PubMed: 38413243
DOI: 10.3201/eid3004.231725