Strain-dependent variations in replication of European clade 2.3.4.4b influenza A(H5N1) viruses in bovine cells and thermal inactivation in semi-skimmed or whole milk
Diana I Palme, Juliane Lang, Dajana Helke, Maryna Kuryshko, Elsayed M Abdelwhab
Abstract
We investigated the thermostability of four European avian influenza A(H5N1) viruses in whole and semiskimmed milk and their replication in bovine kidney and lung cells amid the current influenza A(H5N1) dairy cattle outbreak in the United States. Results showed strain-dependent differences in thermal inactivation, particularly in whole milk, and variable replication efficacy in lung cells. These findings support assessing the inactivation of European H5N1 viruses in milk and their replication in bovine cells, aiding biosafety protocols and public health measures.
Outcome of H5N1 clade 2.3.4.4b virus infection in calves and lactating cows
Nico Joel Halwe, Konner Cool, Angele Breithaupt, Jacob Schön, Jessie D. Trujillo, Mohammed Nooruzzaman, Taeyong Kwon, Ann Kathrin Ahrens, Tobias Britzke, Chester D. McDowell, Ronja Piesche, Gagandeep Singh, Vinicius Pinho dos Reis, Sujan Kafle, Anne Pohlmann, Natasha N. Gaudreault, Björn Corleis, Franco Matias Ferreyra, Mariano Carossino, Udeni B.R. Balasuriya, Lisa Hensley, Igor Morozov, Lina M. Covaleda, Diego Diel, Lorenz Ulrich, Donata Hoffmann, Martin Beer, Juergen A. Richt
Abstract
In March 2024, highly pathogenic avian influenza virus (HPAIV) clade 2.3.4.4b H5N1 infections in dairy cows were first reported from Texas, USA. Rapid dissemination to more than 190 farms in 13 states followed. Here, we provide results of two independent clade 2.3.4.4b experimental infection studies evaluating (i) oronasal susceptibility and transmission in calves to a US H5N1 bovine isolate genotype B3.13 (H5N1 B3.13) and (ii) susceptibility of lactating cows following direct mammary gland inoculation of either H5N1 B3.13 or a current EU H5N1 wild bird isolate genotype euDG (H5N1 euDG). Inoculation of the calves resulted in moderate nasal replication and shedding with no severe clinical signs or transmission to sentinel calves. In dairy cows, infection resulted in no nasal shedding, but severe acute mammary gland infection with necrotizing mastitis and high fever was observed for both H5N1 genotypes/strains. Milk production was rapidly and drastically reduced and the physical condition of the cows was severely compromised. Virus titers in milk rapidly peaked at 108 TCID50/mL, but systemic infection did not ensue. Notably, adaptive mutation PB2 E627K emerged after intramammary replication of H5N1 euDG. Our data suggest that in addition to H5N1 B3.13, other HPAIV H5N1 strains have the potential to replicate in the udder of cows and that milk and milking procedures, rather than respiratory spread, are likely the primary routes of H5N1 transmission between cattle.
A vaccine antigen central in influenza A(H5) virus antigenic space confers subtype-wide immunity
Adinda Kok, Samuel H. Wilks, Sina Tureli, Sarah L. James, Theo M. Bestebroer, David F. Burke, Mathis Funk, Stefan van der Vliet, Monique I. Spronken, Willemijn F. Rijnink, David Pattinson, Dennis de Meulder, Miruna E. Rosu, Pascal Lexmond, Judith M.A. van den Brand, Sander Herfst, Derek J. Smith, Ron A.M. Fouchier, Mathilde Richard
Abstract
Highly pathogenic avian influenza A(H5) viruses globally impact wild and domestic birds, and mammals, including humans, underscoring their pandemic potential. The antigenic evolution of the A(H5) hemagglutinin (HA) poses challenges for pandemic preparedness and vaccine design. Here, the global antigenic evolution of the A(H5) HA was captured in a high-resolution antigenic map. The map was used to engineer immunogenic and antigenically central vaccine HA antigens, eliciting antibody responses that broadly cover the A(H5) antigenic space. In ferrets, a central antigen protected as well as homologous vaccines against heterologous infection with two antigenically distinct viruses. This work showcases the rational design of subtype-wide influenza A(H5) pre-pandemic vaccines and demonstrates the value of antigenic maps for the evaluation of vaccine-induced immune responses through antibody profiles.
The neuropathogenesis of highly pathogenic avian influenza H5Nx viruses in mammalian species including humans
Lisa Bauer, Feline F.W. Benavides, Edwin J.B. Veldhuis Kroeze, Emmie de Wit, Debby van Riel
Highlights
High-resolution animal movement data are becoming increasingly available, yet having a multitude of empirical trajectories alone does not allow us to easily predict animal movement. To answer ecological and
Highly pathogenic avian influenza (HPAI) H5Nx viruses can cause neurological complications in many mammalian species, including humans.
Neurological disease induced by HPAI H5Nx viruses in mammals can manifest without clinical respiratory disease.
HPAI H5Nx viruses are more neuropathogenic than other influenza A viruses in mammals.
Severe neurological disease in mammals is related to the neuroinvasive and neurotropic potential of HPAI H5Nx viruses.
Cranial nerves, especially the olfactory nerve, are important routes of neuroinvasion for HPAI H5Nx viruses.
HPAI H5Nx viruses have a broad neurotropic potential and can efficiently infect and replicate in various CNS cell types.
Vaccination and/or antiviral therapy might in part prevent neuroinvasion and neurological disease following HPAI H5Nx virus infection, although comprehensive studies in this area are lacking.
Detection of clade 2.3.4.4 highly pathogenic avian influenza H5 viruses in healthy wild birds in the Hadeji-Nguru wetland, Nigeria 2022
Kayode Olawuyi, Olukayode Orole, Clement Meseko, Isabella Monne, Ismaila Shittu, Zecchin Bianca, Alice Fusaro, Bitrus Inuwa, Ruth Akintola, Josiah Ibrahim and Maryam Muhammad
Abstract
Background: The introduction of multiple avian influenza virus (AIV) subtypes into Nigeria has resulted in several poultry outbreaks purportedly linked to trade and wild birds. The role of wild birds in perpetuating AIV in Nigeria was, therefore, elucidated.
Methods: A cross-sectional study was conducted among wild aquatic bird species at the Hadejia-Nguru wetlands in Northeastern Nigeria between March and April 2022. A total of 452 swabs (226 cloacae and 226 oropharyngeal) were collected using a mist net to capture the birds. These samples were tested by RT-qPCR, followed by sequencing.
Results: Highly pathogenic AIV of the H5N1 subtype was identified in clinically healthy wild bird species, namely, African jacana, ruff, spur-winged goose, squared-tailed nightjar, white-faced whistling ducks, and white stork. A prevalence of 11.1% (25/226) was recorded. Phylogenetic analysis of the complete HA gene segment indicated the presence of clade 2.3.4.4b. However, these H5N1 viruses characterized from these wild birds cluster separately from the H5N1 viruses characterized in Nigerian poultry since early 2021. Specifically, the viruses form two distinct genetic groups both linked with the Eurasian H5N1 gene pool but likely resulting from two distinct introductions of the virus in the region. Whole-genome characterization of the viruses reveals the presence of mammalian adaptive marker E627K in two Afrotropical resident aquatic ducks. This has zoonotic potential.
Conclusion: Our findings highlight the key role of surveillance in wild birds to monitor the diversity of viruses in this area, provide the foundations of epidemiological understanding, and facilitate risk assessment.
Utilising citizen science data to rapidly assess potential wild bridging hosts and reservoirs of infection: avian influenza outbreaks in Great Britain
Stephen H. Vickers, Jayna Raghwani, Ashley C Banyard, Ian H Brown, Guillaume Fournie & Sarah C. Hill
Abstract
High pathogenicity avian influenza virus (HPAIV) is a rapidly evolving orthomyxovirus causing significant economic and environmental harm. Wild birds are a key reservoir of infection and an important source of viral incursions into poultry populations. However, we lack thorough understanding of which wild species drive incursions and whether this changes over time. We explored associations between abundances of 152 avian species and cases of HPAI in poultry premises across Great Britain between October-2021 and January-2023. Spatial generalised additive models were used, with species abundance distributions sourced from eBird modelled predictions. Associations were investigated at the species-specific level and across aggregations of species. During autumn/winter, associations were generally strongest with waterbirds such as ducks and geese; however, we also found significant associations in other groups such as non-native gamebirds, and rapid change in species-specific associations over time. Our results demonstrate the value of citizen science in rapid exploration of wild reservoirs of infection as facilitators of disease incursion into domestic hosts, especially in regions where surveillance programmes in wild birds are absent. This can be a critical step towards improving species-specific biosecurity measures and targeted surveillance; particularly for HPAIV, which has undergone sudden shifts in host-range and continues to rapidly evolve.
https://www.biorxiv.org/content/10.1101/2024.03.28.587127v1.full
Iceland: an underestimated hub for the spread of highpathogenicity avian influenza viruses in the North Atlantic
Ann Kathrin Ahrens, Stefán Ragnar Jónsson, Vilhjálmur Svansson, Brigitte Brugger, Martin Beer, Timm C. Harder, and Anne Pohlmann
Abstract
High-pathogenicity avian influenza viruses (HPAIVs) of the goose/Guangdong lineage are enzootically circulating in wild bird populations worldwide. This increases the risk of entry into poultry production and spill-over to mammalian species, including humans. Better understanding of the ecological and epizootiological networks of these viruses is essential to optimize mitigation measures. Based on full genome sequences of 26 HPAIV samples from Iceland, which were collected between spring and autumn 2022, as well as 1 sample from the 2023 summer period, we show that 3 different genotypes of HPAIV H5N1 clade 2.3.4.4b were circulating within the wild bird population in Iceland in 2022. Furthermore, in 2023 we observed a novel introduction of HPAIV H5N5 of the same clade to Iceland. The data support the role of Iceland as an utmost northwestern distribution area in Europe that might act also as a potential bridging point for intercontinental spread of HPAIV across the North Atlantic.
Panzootic HPAIV H5 and risks to novel mammalian hosts
E. M. Abdelwhab & Martin Beer
Abstract
The H5 subtype of highly pathogenic avian influenza viruses represents a significant challenge to animal and human health. H5 clade 2.3.4.4b viruses have experienced an unprecedented global spread, coupled with remarkable genetic plasticity for adaptation in birds and mammals. Although human infections remain very limited, the establishment in wild, marine, and farmed animals, including recently dairy cattle, is of concern. The role of mammalian hosts as intermediaries for zoonotic or even pandemic influenza A viruses should not be underestimated. In order to mitigate the zoonotic risk and be adequately prepared, it is essential to understand and monitor the dynamics of HPAIV H5 at the avian-mammal interface.
Unexpected delayed incursion of highly pathogenic avian influenza H5N1 (clade 2.3.4.4b) in the Antarctic region
Simeon Lisovski, Anne Günther, Meagan Dewar, David Ainley, Fabián Aldunate, Rodrigo Arce, Grant Ballard, Silke Bauer, Josabel Belliure, Ashley C. Banyard, Thierry Boulinier, Ashley Bennison, Christina Braun, Craig Cary, Paulo Catry, Augustin Clessin, Maelle Connan, Edna Correia, Aidan Cox, Juan Cristina, Megan Elrod, Julia Emerit, Irene Ferreiro, Zoe Fowler, Amandine Gamble, José P. Granadeiro, Joaquin Hurtado, Dennis Jongsomjit, Célia Lesage, Mathilde Lejeune, Amanda Kuepfer, Amélie Lescroël, Amy Li, Ian R. McDonald, Javier Menéndez-Blázquez, Virginia Morandini, Gonzalo Moratorio, Teresa Militão, Pilar Moreno, Paula Perbolianachis, Jean Pennycook, Maryam Raslan, Scott M. Reid, Roanna Richards-Babbage, Annie E. Schmidt, Martha Maria Sander, Lucy Smyth, Alvaro Soutullo, Andrew Stanworth, Léo Streith, Jérémy Tornos, Arvind Varsani, Ulrike Herzschuh, Martin Beer, Michelle Wille
Abstract
The current highly pathogenic avian influenza H5N1 panzootic has substantial impacts on wild birds and marine mammals. Although major outbreaks occurred in South America, incursion to Antarctica emerged late in the breeding season of 2023/2024 and was confined the wider region of the Antarctic Peninsula. To infer potential underlying processes, we compiled H5N1 surveillance from Antarctica and Sub-Antarctic Islands prior to the first confirmed cases.
Pathogen-prey-predator relations of avian raptors during epizootics of highly pathogenic avian influenza virus HPAIV H5N1 (clade 2.3.4.4b) in Germany
Anne Günther, Oliver Krone, Anja Globig, Anne Pohlmann, Jacqueline King, Christine Fast, Christian Grund, Christin Hennig, Christof Herrmann, Simon Piro, Dennis Rubbenstroth, Jana Schulz, Christoph Staubach, Lina Stacker, Lorenz Ulrich, Ute Ziegler, Timm Harder, Martin Beer
Abstract
Transition of highly pathogenic clade 2.3.4.4b H5 avian influenza virus (HPAIV) from epizootic to enzootic status in Northern European countries was associated with severe losses and even mass mortalities among various wild bird species. Both avian and mammalian raptors hunting infected debilitated birds or scavenging on virus-contaminated avian carcasses contracted HPAIV infection. This precarious pathogen-prey-predator relation further worsened when in 2021 and 2022 outbreaks in Germany overlapped with the hatching season of avian raptor species. Retro- and prospective surveillance revealed avian raptors as important indicators of HPAIV and its genetic diversity on the one hand. On the other hand, their role as victims of HPAIV is stipulated. The first case of an HPAIV H5N1-related death of a white-tailed sea eagle (Haliaeetus albicilla; WTSE) hatch in Germany, 2021, followed by several such cases in 2022, and a low overall seropositivity rate of 5.0-7.9% among WTSE nestlings, raised fears of a serious negative impact on reproduction rates of WTSEs and other birds of prey when HPAIV becomes enzootic in an ecosystem. However, comparably stable breeding success of WTSE in the study area in 2022 and a potentially evolving natural immunity raises hope for a less severe long-term impact.
Asymptomatic infection with clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) in carnivore pets, Italy, April 2023
Ana Moreno, Francesco Bonfante, Alessio Bortolami, Irene Cassaniti, Anna Caruana, Vincenzo Cottini, Danilo Cereda, Marco Farioli, Alice Fusaro, Antonio Lavazza, Pierdavide Lecchini, Davide Lelli, Andrea Maroni Ponti, Claudia Nassuato, Ambra Pastori, Francesca Rovida, Luigi Ruocco, Marco Sordilli, Fausto Baldanti, Calogero Terregino
Abstract
In April 2023, an outbreak of clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) viruses carrying the T271A mammalian adaptive mutation in the PB2 protein was detected in a backyard poultry farm in Italy. Five domestic dogs and one cat living on the premises had seroconverted in the absence of clinical signs. Virological and serological monitoring of individuals exposed to the virus proved the absence of human transmission, however, asymptomatic influenza A(H5N1) infections in mammalian pets may have important public health implications.
Highly pathogenic avian influenza A(H5N1) virus infections on fur farms connected to mass mortalities of black-headed gulls, Finland, July to October 2023
Lauri Kareinen, Niina Tammiranta, Ari Kauppinen, Bianca Zecchin, Ambra Pastori, Isabella Monne, Calogero Terregino, Edoardo Giussani, Riikka Kaarto, Veera Karkamo, Tanja Lähteinen, Hanna Lounela, Tuija Kantala, Ilona Laamanen, Tiina Nokireki, Laura London, Otto Helve, Sohvi Kääriäinen, Niina Ikonen, Jari Jalava, Laura Kalin-Mänttäri, Anna Katz, Carita Savolainen-Kopra, Erika Lindh, Tarja Sironen, Essi M Korhonen, Kirsi Aaltonen, Monica Galiano, Alice Fusaro, Tuija Gadd
Abstract
Highly pathogenic avian influenza (HPAI) has caused widespread mortality in both wild and domestic birds in Europe 2020–2023. In July 2023, HPAI A(H5N1) was detected on 27 fur farms in Finland. In total, infections in silver and blue foxes, American minks and raccoon dogs were confirmed by RT-PCR. The pathological findings in the animals include widespread inflammatory lesions in the lungs, brain and liver, indicating efficient systemic dissemination of the virus. Phylogenetic analysis of Finnish A(H5N1) strains from fur animals and wild birds has identified three clusters (Finland I-III), and molecular analyses revealed emergence of mutations known to facilitate viral adaptation to mammals in the PB2 and NA proteins. Findings of avian influenza in fur animals were spatially and temporally connected with mass mortalities in wild birds. The mechanisms of virus transmission within and between farms have not been conclusively identified, but several different routes relating to limited biosecurity on the farms are implicated. The outbreak was managed in close collaboration between animal and human health authorities to mitigate and monitor the impact for both animal and human health.
Predicting resilience of migratory birds to environmental change
Simeon Lisovski, Bethany J. Hoye, Jesse R. Conklin, Phil F. Battley, Richard A. Fuller, Ken B. Gosbell, Marcel Klaassen, Chengfa Benjamin Lee, Nicholas J. Murray, and Silke Bauer
Abstract
The pace and scale of environmental change represent major challenges to many organisms. Animals that move long distances, such as migratory birds, are especially vulnerable to change since they need chains of intact habitat along their migratory routes. Estimating the resilience of such species to environmental changes assists in targeting conservation efforts. We developed a migration modeling framework to predict past (1960s), present (2010s), and future (2060s) optimal migration strategies across five shorebird species (Scolopacidae) within the East Asian-Australasian Flyway, which has seen major habitat deterioration and loss over the last century, and compared these predictions to empirical tracks from the present. Our model captured the migration strategies of the five species and identified the changes in migrations needed to respond to habitat deterioration and climate change. Notably, the larger species, with single or few major stopover sites, need to establish new migration routes and strategies, while smaller species can buffer habitat loss by redistributing their stopover areas to novel or less-used sites. Comparing model predictions with empirical tracks also indicates that larger species with the stronger need for adaptations continue to migrate closer to the optimal routes of the past, before habitat deterioration accelerated. Our study not only quantifies the vulnerability of species in the face of global change but also explicitly reveals the extent of adaptations required to sustain their migrations. This modeling framework provides a tool for conservation planning that can accommodate the future needs of migratory species.
Epidemiology-driven approaches to surveillance in HPAI-vaccinated poultry flocks aiming to demonstrate freedom from circulating HPAIV
Timm Harder, Sjaak de Wit, Jose L. Gonzales, Jeremy H.P. Ho, Paolo Mulatti, Teguh Y. Prajitno, Arjan Stegeman
Abstract
Incursion pressure of high pathogenicity avian influenza viruses (HPAIV) by secondary spread among poultry holdings and/or from infected migratory wild bird populations increases worldwide. Vaccination as an additional layer of protection of poultry holdings using appropriately matched vaccines aims at reducing clinical sequelae of HPAIV infection, disrupting HPAIV transmission, curtailing economic losses and animal welfare problems and cutting exposure risks of zoonotic HPAIV at the avian-human interface. Products derived from HPAIV-vaccinated poultry should not impose any risk of virus spread or exposure. Vaccination can be carried out with zero-tolerance for infection in vaccinated herds and must then be flanked by appropriate surveillance which requires tailoring at several levels: (i) Controlling appropriate vaccination coverage and adequate population immunity in individual flocks and across vaccinated populations; (ii) assessing HPAI-infection trends in unvaccinated and vaccinated parts of the poultry population to provide early detection of new/re-emerged HPAIV outbreaks; and (iii) proving absence of HPAIV circulation in vaccinated flocks ideally by real time-monitoring. Surveillance strategies, i.e. selecting targets, tools and random sample sizes, must be accommodated to the specific epidemiologic and socio-economic background. Methodological approaches and practical examples from three countries or territories applying AI vaccination under different circumstances are reviewed here.
High pathogenic avian influenza A(H5) viruses of clade 2.3.4.4b in Europe—Why trends of virus evolution are more difficult to predict
Alice Fusaro, Bianca Zecchin, Edoardo Giussani, Elisa Palumbo, Montserrat Agüero-García,Claudia Bachofen, Ádám Bálint, Fereshteh Banihashem, Ashley C Banyard, Nancy Beerens, Manon Bourg, Francois-Xavier Briand, Caroline Bröjer, Ian H. Brown, Brigitte Brugger, Alexander M.P. Byrne, Armend Cana, Vasiliki Christodoulou, Zuzana Dirbakova, Teresa Fagulha, Ron A M Fouchier, Laura Garza-Cuartero, George Georgiades, Britt Gjerset, Beatrice Grasland, Oxana Groza, Timm Harder, Ana Margarida Henriques, Charlotte Kristiane Hjulsager, Emiliya Ivanova, Zygimantas Janeliunas, Laura Krivko, Ken Lemon, Yuan Liang, Aldin Lika, Péter Malik, Michael J. McMenamy, Alexander Nagy, Imbi Nurmoja, Iuliana Onita, Anne Pohlmann, Sandra Revilla-Fernández, Azucena Sánchez-Sánchez, Vladimir Savic, Brigita Slavec, Krzysztof Smietanka, Chantal J. Snoeck, Mieke Steensels, Vilhjálmur Svansson, Edyta Swieton, Niina Tammiranta, Martin Tinak, Steven Van Borm, Siamak Zohari, Cornelia Adlhoch, Francesca Baldinelli, Calogero Terregino, and Isabella Monne
Abstract
Since 2016, A(H5Nx) high pathogenic avian influenza (HPAI) virus of clade 2.3.4.4b has become one of the most serious global threats not only to wild and domestic birds, but also to public health. In recent years, important changes in the ecology, epidemiology, and evolution of this virus have been reported, with an unprecedented global diffusion and variety of affected birds and mammalian species. After the two consecutive and devastating epidemic waves in Europe in 2020–2021 and 2021–2022, with the second one recognized as one of the largest epidemics recorded so far, this clade has begun to circulate endemically in European wild bird populations. This study used the complete genomes of 1,956 European HPAI A(H5Nx) viruses to investigate the virus evolution during this varying epidemiological outline. We investigated the spatiotemporal patterns of A(H5Nx) virus diffusion to/from and within Europe during the 2020–2021 and 2021–2022 epidemic waves, providing evidence of ongoing changes in transmission dynamics and disease epidemiology. We demon-strated the high genetic diversity of the circulating viruses, which have undergone frequent reassortment events, providing for the first time a complete overview and a proposed nomenclature of the multiple genotypes circulating in Europe in 2020–2022. We described the emergence of a new genotype with gull adapted genes, which offered the virus the opportunity to occupy new ecological niches, driving the disease endemicity in the European wild bird population. The high propensity of the virus for reassortment, its jumps to a progressively wider number of host species, including mammals, and the rapid acquisition of adaptive mutations make the trend of virus evolution and spread difficult to predict in this unfailing evolving scenario.
Detection and spread of high 1 pathogenicity avian influenza virus 2 H5N1 in the Antarctic Region
Ashley Bennison, Alexander M. P. Byrne, Scott M. Reid, Joshua G. Lynton-Jenkins, Benjamin Mollett, Dilhani De Silva, Jacob Peers-Dent, Kim Finlayson, Rosamund Hall, Freya Blockley, Marcia Blyth, Marco Falchieri, Zoe Fowler, Elaine M. Fitzcharles, Ian H. Brown, Joe James and Ashley C. Banyard
Abstract
Until recent events, the Antarctic was the only major geographical region in which high pathogenicity avian influenza virus (HPAIV) had never previously been detected. The current panzootic of H5N1 HPAIV has decimated wild bird populations across Europe, North America, and South America. Here we report on the detection of clade 2.3.4.4b H5N1 HPAIV in the Antarctic and sub-Antarctic regions of South Georgia and the Falkland Islands, respectively. We initially detected H5N1 HPAIV in samples collected from brown skuas at Bird Island, South Georgia on 8th October 2023. Since this detection, mortalities were observed in brown skuas, kelp gulls, South Georgia shag, Antarctic tern, elephant seals and fur seals at multiple sites across South Georgia. Subsequent testing confirmed H5N1 HPAIV across several sampling locations in multiple avian species and two seal species. Simultaneously, we also confirmed H5N1 HPAIV in southern fulmar and black-browed albatross in the Falkland Islands. Genetic assessment of the virus indicates spread from South America, likely through movement of migratory birds. Critically, genetic assessment of sequences from mammalian species demonstrates no increased risk to human populations. Here we describe the detection, species impact and genetic composition of the virus and propose both introductory routes and potential long-term impact on avian and mammalian species across the Antarctic region. We also speculate on the threat to specific populations following recent reports in the area.