Estimating the #infection #fatality #ratio of zoonotic avian #influenza viruses with #pandemic potential using an evolutionary epidemiological model

 

Abstract

The risk of zoonotic avian influenza (AIV) infection to humans is challenging to estimate as many human avian influenza virus infections are undetected because infections may be asymptomatic, symptomatic but not tested, and difficult to identify through contact tracing, as human-to-human transmission is rare. We derive equations that consider the evolutionary mechanisms that give rise to pandemics and are parameterized to be consistent with records of past pandemics. We estimate that thousands of human infections with AIVs possessing pandemic potential occur worldwide in an average year. Combining these estimates with H5N1 fatality data, we estimate a historical average infection fatality ratio of 32 (95% uncertainty interval: 9.6-75) deaths per 10,000 infections. This estimate is comparable to SARS-CoV-2 during the recent pandemic and higher than seasonal human influenza. We estimate that preventing animal-to-human influenza spillovers would delay pandemic emergence by several years. Preventing human infections with AIVs is necessary given the high risk of severe outcomes to individuals and to reduce the risk of pandemics occurring in the future.

Competing Interest Statement

The authors have declared no competing interest.

Source: 

Link: https://www.medrxiv.org/content/10.64898/2026.01.21.26344526v3

____

#Germany - High pathogenicity avian #influenza #H5N1 viruses (Inf. with) (#poultry) - Immediate notification

 

A poultry farm in the Niedersachsen Region.

Source: 

Link: https://wahis.woah.org/#/in-review/7738

____

#Seroprevalence of #Influenza #H5N1 Virus in Domestic #Cats at Epicenter of Dairy #Cattle #Outbreaks, #California, #USA, 2024–2026

 

Abstract

We conducted a serologic study of domestic cats near the epicenter of the dairy cattle outbreaks of influenza A(H5N1) in California, USA. Three of the 12 cats sampled within 2 km of farms had neutralizing antibodies against H5N1 virus. Proximity to dairy farms was a statistically significant risk factor for seropositivity.

Source: 

Link: https://wwwnc.cdc.gov/eid/article/32/9/26-0785_article

____

#Mutations in severe #human #H5N1 cases facilitate #evasion from human mucus and #antivirals

 

Abstract

In late 2024, two individuals in Canada and the United States were treated in intensive care for acute respiratory distress caused by infection with the avian Influenza A Virus H5N1 2.3.4.4b genotype D1.1. Viral sequence data obtained from sampling these patients indicated mixed alleles at haemagglutinin (HA) positions 190 and 226. Mutations at these positions are key determinants of HA usage of α2,6-linked sialic acids (SA), the most abundant influenza receptors in human upper respiratory tracts. Thus, these mutations raised concerns about human adaptation and pandemic potential of the H5N1 virus. In this study, we investigated the impact of the mutations at residues 190 and 226 in H5 HA. We studied the receptor binding properties, cell entry phenotypes and fitness impacts of the mutations using recombinant proteins, pseudotyped lentiviruses, and in the context of influenza viruses using reverse genetics. The mutations did not confer any detectable α2,6-linked sialic acid receptor usage either alone or in combination. Rather, viruses carrying these mutations exhibit weakened binding towards α2,3-linked sialic acid receptors. This correlated with an enhanced capacity to evade human airway mucus, and a reduced susceptibility to oseltamivir and zanamivir. This research underscores that in addition to the way HA interacts with SA as entry receptors, other factors that impact the HA/NA balance might influence the evolutionary trajectory of a zoonotic virus in the human respiratory tract. This study presents a new paradigm for the evolutionary drivers of HA, where reduced sialic acid binding can serve as an advantage for escape from host barriers and antivirals.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

Medical Research Council, https://ror.org/03x94j517, MR/Y03368X/1, MR/Y015061/1, CC2127

Biotechnology and Biological Sciences Research Council, BB/Y007298/1, APP104179, BBS/E/PI/23NB000, BBS/E/PI/23NB0003

Wellcome Trust, https://ror.org/029chgv08, CC2127, 218304/Z/19/Z

Department for Environment Food and Rural Affairs, BB/Y007298/1

The Pirbright Institute, BBS/E/PI/230002A, BBS/E/PI/230001C, BBS/E/PI/230002B

Cancer Research UK, CC2127

UK Research and Innovation, https://ror.org/001aqnf71, UKRI3602

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.07.28.740943v1

____

HPAI #H5N1 #risk in #Australia: a model for the prediction of #poultry #outbreaks

 

Abstract

The panzootic highly pathogenic avian influenza (HPAI) H5N1 virus has now been detected on the Australian mainland, with incursions from the sub-Antarctic region posing an increasing threat to domestic wildlife and poultry populations. Our study aimed to predict the risk of HPAI H5N1 poultry outbreaks across Australia at the local government area (LGA) level using a range of influential risk factors. We first used a Maximum Entropy (MaxEnt) model to estimate the environmental suitability for HPAI H5N1 occurrence across Australia. The resulting suitability layer was then integrated with five additional predictor layers, including abundance data for two Southern Ocean wild birds, one of which has introduced HPAI H5N1 into Australia; abundance data for 28 native Australian wild birds; native bird flyways across Australia; Australian chicken density; and poultry farm density. The six layers were aggregated and averaged to generate an HPAI H5N1 risk map for poultry outbreaks across Australian LGAs. Although most incursions have occurred in Western Australia (WA) and South Australia (SA), we identified New South Wales (NSW) and Victoria (VIC) as having the highest predicted risk of HPAI H5N1 poultry outbreaks. Additional high-risk areas were identified in WA, SA, and Tasmania (TAS). In contrast, the Northern Territory (NT) and large parts of Queensland (QLD), WA, and SA were predicted to be at low risk. These findings provide a spatially explicit framework to support targeted surveillance, preparedness, and biosecurity measures aimed at mitigating the impact of future HPAI H5N1 outbreaks in Australian poultry.

Competing Interest Statement

CR MacIntyre is funded by NHMRC and Medical Research Futures Fund and is Founding Director of EPIWATCH Global Pty Ltd.

Funder Information Declared

NHMRC, CRM funded by NHMRC Investigator Grant 2016907

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.07.27.740638v1

____

#H5N1 #influenza binding and cell entry via #human class II #MHC, and blocking by cross-reactive #antibodies

 

Abstract

Highly pathogenic avian influenza H5N1 clade 2.3.4.4b viruses are currently responsible for a multi-species outbreak affecting wild birds, poultry, numerous mammalian species, and humans. Influenza A viruses typically initiate infection through binding to sialic acid, although select bat and human influenza viruses can also exploit class II major histocompatibility complex (MHC–II) molecules for cell entry. Here we show that emerging H5N1 clade 2.3.4.4b viruses, but not historical H5 lineages, bind human MHC–II HLA-DR and mediate sialic acid-independent cell entry. Hemagglutinin binding to primary human immune cells varies with MHC–II expression and is further shaped by HLA–DR allelic variation, identifying host genetic determinants that may influence susceptibility to infection. Mammalian-adaptive substitutions within the hemagglutinin sialic acid receptor-binding domain reduce MHC–II binding, suggesting this interaction is remodeled during clade 2.3.4.4b H5 adaptation to a human host. Lastly, cross-reactive monoclonal antibodies isolated from clade 2.3.4.4b H5–naive humans can block the hemagglutinin–MHC–II interaction. These findings identify a previously unrecognized receptor pathway in contemporary H5N1 viruses and reveal that both human genetic variation and pre-existing humoral immunity can modulate this interaction, with implications for host range, cellular tropism, spillover risk, and therapeutic intervention.

Competing Interest Statement

S.D.B. has consulted for Regeneron, Sanofi, Novartis, Genentech, Pfizer, Visterra, and Otsuka on topics unrelated to the research presented here; owns stock in AbCellera Biologics; and is a scientific cofounder of Immunera, Inc.; S.E.H reports receiving consulting fees from Sanofi, Pfizer, Lumen, Novavax, and Merck.

Funder Information Declared

NIH/NIAID CEIRR contract, 75N93021C00015

NIH, 1U54CA260517

HIPC, U19AI057266

P01 grant, 5P01AI153559

David Crown Foundation endowment

Early Postdoc Mobility Fellowship Stipend from the Swiss

National Institutes of Health NRSA T32, T32OD011121

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.07.22.739677v1

____

Mapping Reported Modes of #Transmission of Highly Pathogenic Avian #Influenza #H5N1 to #Humans: A Scoping Review

 

Abstract

Background

Highly Pathogenic Avian Influenza A (subtype H5N1) poses a threat to human health, and its pandemic potential emphasizes the need to better understand detailed reported transmission pathways to humans. Existing literature is outdated or lacks detailed, comprehensive analysis of the range of transmission routes and how the virus may enter the human body.

Objective

To comprehensively map all reported H5N1 transmission pathways to humans, as well as viral entry routes.

Methods

CINAHL, Embase, MEDLINE, Scopus, PubMed, grey literature, and reference lists (of included studies) were searched up to October 29th, 2025, with no language restrictions. Observational studies and grey literature reporting H5N1 transmission evidence to humans were included. Two reviewers conducted duplicate screening independently (two of three reviewers per record). One reviewer completed data extraction, which was cross-verified for accuracy by a second. Findings were summarized narratively.

Results

120 sources met inclusion criteria (70 studies, 50 grey literature). Reported H5N1 transmission pathways were classified into animal-to-human (109 of 120 sources, 90.8%; including poultry-to-human in 100 sources [83.3%] and cattle-to-human in nine sources [7.5%]), environment-to-human (32 of 120 sources, 26.7%), and human-to-human (14 of 120 sources, 11.7%). Reported transmission pathways were further classified as direct or indirect contact, synthesized, and linked to suspected routes of human entry, including mucosal entry (eyes, nose, mouth), inhalation of aerosols or droplets, ingestion, and percutaneous exposure. Entry routes are biologically plausible and do not imply relative likelihood or causal attribution.

Conclusions

There are multiple reported pathways of H5N1 exposure, and a single pathway may involve multiple ways to infect humans. Further research is needed to determine causal mechanisms, identify specific risk factors and measures of association, and strengthen evidence-based prevention strategies.

Source: 

Link: https://www.sciencedirect.com/science/article/pii/S235277142600176X?via%3Dihub

____

#Ecuador - #Influenza A #H5N1 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification [FINAL]

 

{Click on Image to Enlarge}

__

By Manuel González Olaechea y Franco - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=12026471

___

These occurrences were detected through passive surveillance conducted by the Ministry of Environment and Energy along the entire coast of mainland Ecuador.

{Peruvian Pelican} Wild bird population in situ in Guayas Province (bird morbidity history). Out of eight birds, one tested positive.

Source: 

Link: https://wahis.woah.org/#/in-review/7717

____

#Oseltamivir #Resistance in #Human #Influenza #H5N1 and #H7N9 Infections: A Mini Review

 

Abstract

Avian influenza viruses (AIVs) have been reported to cause infections in humans following avian-to-human transmission, resulting in a range of clinical outcomes. A(H5N1) and A(H7N9) infections, which constitute the majority of human AIV cases, are responsible for severe infections leading to high mortality. The neuraminidase inhibitor oseltamivir is expected to play a major role for the control of AIV infections in humans. However, the emergence of resistance may compromise the impact of antiviral therapy. The objective of this article is to review human cases of A(H5N1) and A(H7N9) infections for which mutations of oseltamivir resistance were detected. Neuraminidase mutations rapidly occurred in a subtype-specific manner, with H274Y and N294S substitutions predominating in A(H5N1) cases and the R292K substitution in A(H7N9) cases. Serious clinical outcomes and mortality were seen in most A(H5N1) and A(H7N9) cases despite oseltamivir therapy, thus highlighting the need for improving antiviral strategies against these AIVs.

Source: 

Link: https://academic.oup.com/ofid/article/13/7/ofag393/8722865

____

#Geographic Concentration of #Genomic #Surveillance for Highly Pathogenic Avian #Influenza #H5, South #Asia, 2015-2025

 

Abstract

Early detection of mammalian adaptation in highly pathogenic avian influenza A(H5) depends on genomic surveillance, yet its distribution across high-burden regions is poorly characterized. We quantified open-access (GenBank/INSDC) H5 genomic coverage relative to reported outbreak burden across nine South Asian countries during 2015-2025, linking isolates to FAO EMPRES-i/WOAH events. Of 919 H5 isolates, 814 (89%) came from one country (Bangladesh); the other eight contributed 105. India, with the largest burden (322 events), yielded only 42 isolates (13 per 100); Nepal, 2 of 78; Afghanistan, none of 5. Concentration was extreme (Gini 0.83) and unchanged by adding restricted GISAID records (1,297 combined isolates; Bangladesh 89%) or by normalizing to poultry or human population. Because reported outbreaks track reporting effort, these coverage ratios are directional, not rates. This single-country dependency, deepest where burden is highest, is a regional early-warning vulnerability.

Competing Interest Statement

The authors have declared no competing interest.

Source: 

Link: https://www.medrxiv.org/content/10.64898/2026.07.20.26358505v1

____

Within- and between-host #dynamics of highly pathogenic avian #influenza in domestic #birds from #Pennsylvania #farms and live bird #markets

 

Abstract

Since late 2021, highly pathogenic avian influenza viruses (HPAI) of the H5 subtype clade 2.3.4.4b have spread across the Americas, devastating wildlife, agricultural animals, and resulting in dozens of human spillovers. National surveillance strategies generally provide only a single representative sequence per poultry outbreak, precluding fine-scale geographic transmission inference or studies of within-outbreak evolution. We produced high-quality deep sequence data from 46 infected Galliformes and Anseriformes sampled from commercial farm and live bird market (LBM) outbreaks in Pennsylvania from 2023-2025. We found that H5N1 viruses were introduced into Pennsylvania at least 68 independent times. We recover independent origins of live bird market outbreaks within the same county 3 weeks apart, and transmission between Pennsylvania LBM and New York commercial birds, suggesting high transmission risk within the Northeast live bird market distribution system. Analyses of within-farm variant populations show frequent variant sharing between samples from the same outbreak, suggesting that variants are propagated among epidemiologically linked infections. We identified 9 known adaptive mutations in these samples, including one instance of PB2 D701N in a LBM chicken sample, suggesting that while rare, concerning mammalian adaptive mutations can be present within these domestic outbreaks. Our data suggest that domestic bird outbreaks support high circulating diversity and wide transmission bottlenecks, increasing the risk of minority variants arising and propagating between infections. These data can help inform targeted biosecurity measures and better quantify the risk of viral adaptation during agricultural outbreaks.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

NIAID, NIH 75N93021C00015

Pew Charitable Trusts

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.07.17.739193v1

____

Elicitation of #stem-directed #antibodies in rhesus #macaques by a conventional #hemagglutinin immunogen

 

Abstract

Because they can bind many strains of influenza, antibodies targeting the hemagglutinin (HA) stem have been attractive targets for vaccine development. Many monoclonal antibodies (mAbs) directed at the HA stem have been isolated from humans, and these mAbs have mediated broad protection in animal models. We describe here HA stem-directed mAbs isolated from rhesus macaques immunized with an "ordinary" H1 HA trimer. All immunized rhesus macaques developed high serum titers with broad reactivity to diverse H1N1 and H5N1 viruses, and 7 isolated mAbs strongly blocked canonical stem antibody CR6261 binding to H1. MAb DH726.1 robustly protected mice from lethal challenge with H1N1 and H5N1 viruses, and cryo-EM showed the binding footprint overlapped that of some human mAbs. These findings suggest that vaccination with the standard, trimeric HA immunogens may be sufficient to elicit stem antibodies at titers adequate to protect against zoonotic H5N1 influenza.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

NIH NIAID, Division of Microbiology and Infectious Diseases, P01-AI089618

NIH NIAID Division of AIDS, Center for HIV/AIDS Vaccine Immunology, U19-AI067854

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.07.16.738984v1

____

#Togo - High pathogenicity avian #influenza #H5N1 viruses (Inf. with) (#poultry) - Immediate notification

 

Poultry farms in the Maritime Region.

Source: 

Link: https://wahis.woah.org/#/in-review/7714

____

Detection of #H5N1 HPAIV Clade 2.3.4.4b Avian #Influenza Virus in Backyard #Chickens in #CostaRica

 

Abstract

Influenza A virus is a segmented, negative-sense RNA virus. Since the early 2020s, H5 clade 2.3.4.4b viruses have spread widely across Europe, Africa, and Asia, affecting wild birds and poultry. Costa Rica reported its first H5 clade 2.3.4.4b avian influenza virus (AIV) case on 19 January 2023. This study describes an outbreak in backyard chickens and ducks. Initial serum samples collected on 24 January showed three chickens negative for AIV, while one duck tested positive by ELISA and agar gel immunodiffusion (AGID). During a second visit on 27 January, three of four chicken sera collected tested positive by ELISA and AGID. Tissue samples were positive for influenza A by qRT-PCR. Next-generation sequencing recovered five of the eight viral genomic segments, and the hemagglutinin cleavage site sequence (REKRRKR↓G) confirmed a highly pathogenic avian influenza virus (HPAIV) H5 strain. The samples were submitted to the National Veterinary Services Laboratories for confirmation. Serological testing showed reactivity to North American low pathogenic H5 antigens, and qRT-PCR amplified influenza A and N1 genes. Virus isolation and next-generation sequencing (NGS) of all eight viral genome segments were successfully performed at the WHO Collaborating Centre at St. Jude Children’s Research Hospital (SJCRH).

Source: 

Link: https://www.mdpi.com/1999-4915/18/7/799

____

#Bovine-derived #H5N1 #influenza virus efficiently infects lactating #swine via the #mammary gland

 

Abstract

Since 2024, highly pathogenic influenza A(H5N1) viruses have spread extensively among U.S. dairy cattle, where they replicate efficiently in the mammary gland and are shed at high titers in milk. To directly assess susceptibility of commercial swine populations to bovine-derived H5N1 virus, lactating sows with prior influenza virus vaccination histories representative of U.S. commercial swine production systems were inoculated via the intramammary route and co-housed with their 1-week-old piglets to evaluate disease outcomes, viral replication, and potential for vertical transmission. Intramammary inoculation of lactating sows resulted in sustained viral RNA shedding in milk, while piglets exhibited sporadic oral viral RNA positivity that mirrored viral kinetics in milk. Lesions in mammary tissue and viral antigen staining, as well as development of neutralizing antibody responses and changes in milk color and consistency, further confirmed infection in the sows. Despite these molecular findings, none of the animals developed overt clinical disease, and respiratory involvement was not noted during the study period. Collectively, we demonstrate that intramammary exposure results in productive influenza A(H5N1) virus infection in lactating sows despite their vaccination histories, indicating the potential threat of viral spillover into commercial swine populations. The clinically inapparent nature of infection presents a risk of subclinical spread and underscores the importance of expanding viral surveillance to swine.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

Swine Health Information Center, 25-020

United States Department of Agriculture (USDA) National Institute of Food and Agriculture (NIFA), 2025-39601-44639

National Institutes of Health, P30 CA016058

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.07.18.739312v1

____

Characterization of #bovine-derived #H5N1 viruses expressing fluorescent and luminescent reporter #proteins

ABSTRACT

Highly pathogenic avian influenza H5N1 clade 2.3.4.4b viruses present a broad host range, with recent spillover and sustained transmission in dairy cattle reported in the USA. Replication-competent reporter viruses are critical tools that enable real-time monitoring of virus replication, facilitating high-throughput screens. In this study, we engineered three recombinant H5N1 clade 2.3.4.4b reporter viruses expressing nanoluciferase (NLuc) and two fluorescent reporter proteins, miniGFP2 and UnaG within the open reading frame of the nonstructural gene of the bovine A/Cattle/Texas/063224-24-1/2024 (TX2/24) virus. All reporter viruses replicated efficiently in vitro, presenting replication kinetics comparable to the parental rTX2/24 virus, but exhibited smaller plaque sizes, suggesting reduced cell-to-cell spread. In vivo infection studies in mice showed comparable pathogenicity among all four viruses, although rTX2/24-miniGFP2 and rTX2/24-UnaG exhibited decreased virus shedding relative to rTX2/24 and rTX2/24-NLuc. Virus titrations and in situ localization of virus replication sites demonstrated robust replication in respiratory tissues, with slightly attenuated systemic dissemination of all three reporter viruses. Fluorescent virus neutralization assays using miniGFP2 and UnaG reporter viruses accurately quantified neutralizing antibody titres in sera from naturally infected dairy cattle, consistent with wild-type virus assays. Additionally, the utility of the NLuc reporter virus for antiviral screening was validated against oseltamivir in vitro. Collectively, these results establish the H5N1 TX2/24-based reporter viruses as versatile and biologically relevant tools for investigating H5N1 pathogenesis and for use in serological and antiviral drug screens.

Source: 

Link: https://www.microbiologyresearch.org/content/journal/jgv/10.1099/jgv.0.002298

____

Pan-continental #spillover #risk: integrated spatiotemporal, transmissibility and #surveillance analysis of avian #influenza #H5N1 in #Africa

 

Abstract

Background: 

The HPAI H5N1 panzootic represents a critical threat to human health in Africa, where traditional poultry systems and dense human-animal interfaces facilitate frequent zoonotic spillover. While sporadic human cases raise pandemic concerns, continent-wide integration of spatial dynamics, transmissibility indicators, and surveillance performance has been lacking. This study quantifies avian influenza transmission over two decades across Africa, identifies geographical hotspots, and evaluates the responsiveness of current surveillance systems.

Methods: 

We analysed 8,037 avian influenza outbreak events and 369 laboratory-confirmed human cases, predominantly caused by HPAI H5N1 (2004–2025), using harmonised data from FAO (EMPRES-i+), WHO, and WOAH. A Bayesian Besag-York-Mollié (BYM) spatiotemporal model estimated residual transmission risks and Incidence Rate Ratios (IRR) by subtype. The basic reproduction number (R₀) was derived via an exponential growth model applied to human outbreak phases across infectious durations of 7–30 days. Surveillance responsiveness was assessed by quantifying notification delays between clinical observation and official reporting.

Results: 

Risk of infection in animals: HPAI H5N1 was the dominant strain, representing 87.8% of animal cases, with Egypt acting as the primary epidemiological epicentre (66% of total records). The spatiotemporal model revealed that H5N1 is associated with a significantly higher risk of animal infection (IRR = 8.37; 95% CI: 6.65–10.53). Although 71% of outbreaks were reported within 5 days of detection, significant delays (≥15 days) occurred in 12% of cases, with notable regional disparities. Risk of infection in human: H5N1 was associated with a 67-fold increase in the incidence of human cases compared to other subtypes (IRR = 66.78; 95% CI: 25.29–176.37). Sensitivity analyses yielded R0 estimates ranging from 1.05 (95% CI: 0.91–1.31) to 1.23 (95% CI: 0.60–2.33), indicating localised epidemic potential.

Conclusion: 

Our findings highlight a persistent and geographically heterogeneous H5N1 reservoir in Africa with high zoonotic affinity. Although sustained human-to-human transmission remains limited, the identification of dual poultry-human hotspots and localised R0 peaks underscores the urgent need for geographically targeted One Health interventions. Strengthening real-time reporting systems and improving biosecurity in high-risk poultry value chains are critical to mitigating future pandemic threats on the continent.

Source: 

Link: https://www.frontiersin.org/journals/epidemiology/articles/10.3389/fepid.2026.1813211/full

____

#NewZealand - #Influenza A #H5N1 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

 

Di Antoine Lamielle, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=128547540

___

    ° This is the first detection of highly pathogenic avian influenza H5N1 clade 2.3.4.4b virus in New Zealand. 

    ° The detection is in a single subantarctic skua (Stercorarius antarcticus) found on Petone Beach, Lower Hutt. 

    ° The bird was found weak and emaciated and no neurological or respiratory clinical signs were observed. 

    ° Subantarctic skua are an ocean-going species. 

    ° Genomic sequencing indicates that the virus is closely related to H5N1 HPAI clade 2.3.4.4b viruses recently detected in Western Australia. 

    ° An epidemiological investigation is underway, and general surveillance is continuing. At this time, there is no evidence of further spread. 

    ° Vaccination of specific populations of threatened avian species is being initiated.

    ° A single ocean-going subantarctic skua (Stercorarius antarcticus), also known as brown skua.

Source: 

Link: https://wahis.woah.org/#/in-review/7709

____

Detection of Highly Pathogenic Avian #Influenza #H5N1 Clade 2.3.4.4b Genotype #D1.2 Virus in #Swine after Experimental Inoculation

 

Abstract

Highly pathogenic avian influenza H5NX clade 2.3.4.4b viruses continue to circulate globally. Reintroduction of Eurasian lineage viruses into North America and reassortment with endemic low pathogenicity strains have resulted in new genotypes, including D1.2. To assess pathogenicity and cellular tropism, we intranasally inoculated genotype D1.2 virus into pigs. We isolated virus from nasal secretions from most inoculated animals for multiple days. At 5 days postinoculation, PCR and immunohistochemistry detected virus in musculoskeletal, respiratory, digestive, lymphatic, and nervous systems and isolates from meat juice. At 35 days postinoculation, we detected viral antigen and low levels of RNA in the brain of an animal with lesions consistent with a viral etiology and found viral antigen in the ethmoid of 2 animals. Consistent detection in nasal swab specimens, combined with subclinical respiratory infection, systemic distribution, and protracted detection of clade 2.3.4.4b virus in swine, suggest identifying infection in commercial swine without overt respiratory signs could be difficult.

Source: 

Link: https://wwwnc.cdc.gov/eid/article/32/8/25-1765_article

____

#Peru - High pathogenicity avian #influenza #H5N1 viruses (Inf. with) (#poultry) - Immediate notification

 

    ° The National Agricultural Health Service (SENASA) within its epidemiological surveillance responds to reports of suspected animal diseases. 

    ° It has identified an outbreak of highly pathogenic avian influenza in poultry (fighting birds) exhibiting respiratory and neurological signs. 

    ° Real-time PCR confirmed the presence of the H5N1 avian influenza virus, prompting the immediate implementation of quarantine measures and an epidemiological investigation. 

    ° All birds were culled, and the affected premises were cleaned and disinfected; in addition, surveillance around the outbreak was conducted to detect possible cases.

    ° A premises raising fighting cocks and backyard poultry of various ages

Source: 

Link: https://wahis.woah.org/#/in-review/7700

____