#Honduras - #Influenza A #H5 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

 

{Click on Image to Enlarge}

By Charles J. Sharp - Own work, from Sharp Photography, sharpphotography.co.uk, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=129540572

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    On June 3, 2026, the Regional Office of the National Agri-Food Health and Safety Services (SENASA) was notified of an unusual mortality event among wild birds in the community of El Higuito, Talgua, in the department of Lempira, an area bordering the department of Copán. 

    Following the official reception of the notification and the collection of samples, the Central Laboratory (IHIMV) confirmed on June 5, 2026, via RT-PCR, the presence of Avian Influenza Type A Subtype H5. 

    The event involved the mortality of black vultures (Coragyps atratus), which poses a potential risk to small-scale and commercial poultry farming in the area. 

    As an immediate response, the contingency team was activated, carrying out the collection, incineration, and sanitary burial of 136 wild birds found dead, with the aim of reducing the environmental viral load and limiting the spread of the pathogen. 

    Additionally, coordination with poultry sector authorities was strengthened to implement preventive and biosecurity measures. 

    Epidemiological surveillance has been intensified both in the outbreak zone of the event and around the outbreak. 

    Through door-to-door monitoring conducted in six surrounding communities, 14,282 backyard birds were inspected without identifying clinical signs compatible with avian influenza or mortality events. 

    These findings indicate that, to date, there is no evidence of transmission to domestic poultry. 

    Given the epidemiological risk associated with the circulation of the virus in wildlife, active surveillance will continue in neighbouring communities and municipalities, along with the strengthening of biosecurity measures and risk communication directed at producers and the general public. 

    Follow-up reports will be submitted to provide periodic updates.

Source: 

Link: https://wahis.woah.org/#/in-review/7612

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#USA, #Wastewater Data for Avian #Influenza #H5 (CDC, June 5 '26)

 

{Excerpt}

(...)

Time Period: May 24, 2026 - May 30, 2026

    -- A(H5) Detection: 6 site(s) (1.4%)

    -- No Detection: 421 site(s) (98.6%)

    -- No samples: 69 site(s)

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(...)

Source: 

Link: https://www.cdc.gov/wastewater/emerging-viruses/h5.html?

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Data #gaps of international #databases on HPAI #H5 in #wildlife in the #Americas: implications for #surveillance, research, and #conservation

 

Abstract

Global efforts to prevent and mitigate the impacts of high pathogenicity avian influenza (HPAI) H5 on domestic animals, humans, and wildlife rely on timely and transparent information that is both accurate and interpretable across countries and sectors. International epidemiological and genomic databases, such as the World Animal Health Information System (WAHIS), the Global Animal Disease Information System (EMPRES-i+), the Global Initiative on Sharing All Influenza Data (GISAID), and the National Center for Technological Bioinformation Virus Portal (NCBI) provide essential information for surveillance, research, and decision-making. To evaluate how well these resources capture recent wildlife impacts, we consolidated information from these databases and complementary public sources including government reports, scientific literature, and news articles, on wildlife mortality associated with HPAI H5 in the Americas from November 2021 to July 2024. The consolidated dataset comprised 615,883 wild birds (287 spp.) and 63,409 wild mammals (39 spp.). In comparison, WAHIS represented 16,902 wild birds (261 spp.) and 6,323 wild mammals (31 spp.) while EMPRES-i+ captured a substantially smaller portion of affected host diversity for both wild birds (105 spp.) and wild mammals (27 spp.). Genomic databases (GISAID and NCBI) represented 7,027 whole genome equivalents of H5 viruses from wild birds (175 spp.) and 371 from wild mammals (26 spp.). These discrepancies indicate that international databases, while essential, provide an incomplete picture of HPAI impacts on wildlife, with significant geographic and taxonomic asymmetries attributable to differences in surveillance capacity, reporting practices, sequencing effort, and data-sharing pathways. Studies and management strategies relying on these resources without complementary validation may therefore mistake data gaps for real-world epidemiological patterns. Strengthening data reporting standards, improving validation procedures, and integrating international databases with national reports, scientific publications, and other sources will enhance the reliability of epidemiological analyses and support more effective One Health surveillance, risk assessment, and conservation action.

Competing Interest Statement

The authors have declared no competing interest.

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.05.30.728949v1

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#USA, #Wastewater Data for Avian #Influenza #H5 (CDC, May 29 '26)

 

{Excerpt}

(...)

Time Period: May 17, 2026 - May 23, 2026

-- A(H5) Detection: 7 site(s) (1.6%)

-- No Detection: 438 site(s) (98.4%)

-- No samples: 49 site(s)

{Click on Image to Enlarge}

(...)

Source: 

Link: https://www.cdc.gov/wastewater/emerging-viruses/h5.html?

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Detection of Anti- #H5 #Antibodies in People with Exposure to Wild #Birds in Northern #Canada

 

Abstract

Using a commercially available H5 serology assay, we identified a 7.4% (n=5/68) anti-H5 seroreactivity rate among hunters in Northern Canada. All participants reported close contact with wild birds.

Competing Interest Statement

This study was performed outside of JK's duties and responsibilities with the Public Health Agency of Canada.

Source: 

Link: https://www.medrxiv.org/content/10.64898/2026.05.24.26353994v1

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The Q226H #Mutation in #Avian #H5N1 #Hemagglutinin Mediates a Path towards Structural #Adaptation in #Humans

 

Abstract

The global outbreak of highly pathogenic avian influenza (HPAI) A(H5N1) among birds and the spillover to mammals increases the risk for humans. A recent case in British Columbia with a clade 2.3.4.4b H5 virus infection revealed a mixture of 226Q/H in the receptor-binding site of hemagglutinin. While significant changes in pre-existing immunity by H1 or H3 polyclonal sera are not evident, we show that the Q226H mutation enables binding to human-type α2-6 sialic acid receptors. High-resolution cryo-EM structures provide a basis for the alteration in receptor preference and show that a possible path towards human adaptation also requires a conformational change of the bound α2-6-sialylated glycan. Continued surveillance for additional mutations that could enhance this phenotype is warranted.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

Ministry of Technology and Innovation through Striving for Pandemic Preparedness—The Alberta Research Consortium

Canada Excellence Research Chair Program

Alberta Innovates Graduate Student Scholarship

Canada Biomedical Research Fund grant

Biosciences Research Infrastructure Fund grant

Natural Sciences and Engineering Research Council of Canada Discovery Grant

Natural Sciences and Engineering Research Council of Canada

Canada Foundation for Innovation

Alberta Innovation and Advanced Education Research Capacity Program

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.05.21.726965v1

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Serologic #Surveillance of Highly Pathogenic Avian #Influenza Virus Subtype #H5 in #Wildlife, Northeast #Germany, 2023–2025

 

Abstract

We tested wild ruminants, boar, and carnivores in northeast Germany for highly pathogenic avian influenza subtype H5 antibodies. Wild ruminants were seronegative, but 3.5% of boar and 12.5%–21.9% of carnivores were seropositive, indicating frequent spillover. Because such events might accelerate mammalian (and ultimately human) adaptation, sustained monitoring remains essential.

Source: 

Link: https://wwwnc.cdc.gov/eid/article/32/5/25-1555_article

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Porcine #influenza #mAbs to #H3, #H5, and #H7 hemagglutinins recognize H3 egg adapted site and target the HA stem

 

Abstract

Introduction

Monoclonal antibodies (mAbs) are critical tools for elucidating viral evolution, informing vaccine design, and developing antiviral therapeutics. Large-animal models, such as the pig, that closely mirror human immune responses are essential for understanding influenza immunity.

Methods

Pigs were either infected or sequentially immunized with influenza viruses and monoclonal antibodies directed against H3, H5, and H7 influenza virus haemagglutinins were isolated. Antibody specificity, breadth, epitope targeting (head versus stem), neutralizing capacity, and Fc-mediated activity were assessed across influenza subtypes.

Results

Pigs generated both strain-specific and broadly reactive mAbs targeting haemagglutinin head and stem epitopes. An H3-specific mAb (H3–57) selectively recognized the egg-adapted L194P mutation associated with reduced human vaccine effectiveness. H5 and H7 immunization induced neutralizing antibodies, including cross-group stem mAbs reactive with H1, H3, and H5 haemagglutinins. Fc-mediated activity correlated with antibody binding strength rather than epitope location.

Conclusions

These findings demonstrate that pigs mount antibody responses closely resembling those observed in humans, including recognition of conserved stem epitopes and adaptive head mutations. Porcine mAbs represent powerful new tools for dissecting influenza immunity, guiding vaccine design, and enhancing pandemic preparedness using a physiologically relevant large-animal model.

Source: 

Link: https://academic.oup.com/discovimmunology/article/5/1/kyag006/8503709

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Host-specific functional #evolution of #seal #influenza A virus #NS1 protein following #avian-to-seal #transmission

 

ABSTRACT

Marine mammals, particularly seals, are susceptible to both avian and human influenza A viruses (IAVs), making them potential intermediates for zoonotic virus emergence. In recent decades, repeated transmissions of avian influenza viruses (AIVs) from wild aquatic birds, their natural reservoir, have caused significant mortality in seals. Defining the molecular determinants of viral adaptation in marine mammals, and their implications for replication in human cells, is therefore essential. The non-structural protein 1 (NS1) of AIV, a key antagonist of the interferon (IFN) response, plays a central role in host adaptation. Here, we analyzed NS1 proteins from seal influenza viruses (H3, H4, H5, H7, and H10 subtypes) and their closest avian relatives isolated between 1980 and 2023, and evaluated their function in seal, avian, and human cells. Phylogenetic analysis confirmed multiple bird-to-seal transmission events. Seal-derived NS1 proteins generally contained few strain-specific amino acid substitutions and showed comparable expression and IFN antagonism to their avian precursors. A notable exception was the seal H10N7 virus isolated in 2014 in Northeastern Europe, which harbored three previously uncharacterized substitutions at NS1 amino acid residues 94, 104, and 171. These amino acid substitutions markedly altered NS1 properties to enhance protein stability, suppress IFN induction, mediate host transcription shut-off, and increase polymerase activity in human cells, without affecting NS1 expression or reducing virus replication in avian cells. Overall, these results reveal how NS1 undergoes host-specific functional evolution following avian-to-seal transmission and provide mechanistic insight into the adaptation of influenza A viruses to mammalian hosts.

IMPORTANCE

Avian influenza viruses (AIVs) circulate naturally in wild aquatic birds but occasionally infect mammals, including seals, where they can cause severe outbreaks. Seals are of particular concern because they can harbor both avian and human influenza viruses, creating opportunities for reassortment and the emergence of novel zoonotic strains. Understanding how AIVs adapt to mammalian hosts is therefore critical for anticipating and mitigating future influenza threats. Here, we investigated the role of the NS1 protein, a key viral factor that suppresses host immune responses, in seal-derived AIVs. Overall, NS1 expression and function were conserved across different subtypes and host cells. However, we identified unique amino acid substitutions in the NS1 of a seal H10N7 virus that enhanced protein stability, interferon antagonism, and viral adaptation in human cells. These findings illustrate how minor changes in NS1 protein can drive host adaptation and underscore the need for continued surveillance of AIVs in seals.

Source: 

Link: https://journals.asm.org/doi/full/10.1128/jvi.01650-25?af=R

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#Argentina - #Influenza A #H5 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

 

{A Coscoroba Swan. By Charles J. Sharp - Own work, from Sharp Photography, sharpphotography.co.uk, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=179069673}

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{A Black-Necked Swan. By Charles J. Sharp - Own work, from Sharp Photography, sharpphotography.co.uk, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=178158764}

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{A Fulvous Whistling Duck. By JeffreyGammon - Own work, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=158156460}

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{A Brown-Hooded Gull. By Charles J. Sharp - Own work, from Sharp Photography, sharpphotography.co.uk, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=179073441}

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Contact with wild migratory birds present in the area is presumed to be the likely source of infection. Virological analysis has identified the presence of the H5 subtype of high pathogenicity avian influenza (HPAI). The determination of the neuraminidase subtype is pending in order to complete the characterisation of the pathogenic agent. Further information is provided in the epidemiological comments of the outbreak.

Source: 

Link: https://wahis.woah.org/#/in-review/7291

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#Argentina - High pathogenicity avian #influenza #H5 viruses (Inf. with) (#poultry) - Immediate notification

 

At a heavy breeding poultry farm located in the province of Buenos Aires, an increase in mortality and the presence of clinical signs consistent with high pathogenicity avian influenza (HPAI) were observed. Given the clinical suspicion, official intervention was carried out, including a health inspection and the collection of diagnostic samples for processing. Laboratory analyses confirmed a positive result for high pathogenicity avian influenza subtype H5 (HPAI H5).

The event occured on a farm raising heavy breeding stock. On 21/02/2026, the National Service of Agri-Food Health and Quality (SENASA) received a notification concerning mortality and clinical signs consistent with high pathogenicity avian influenza (HPAI) which began on 19/02/2026, as reported by the reporting person. On 22/02/2026, the suspicion was officially addressed with the restriction of the establishment and taking of samples for official diagnosis. On 23/02/2026, the samples tested positive for HPAI H5. All the birds on the establishment will be culled. We will update the population data in subsequent follow-up reports.

Source: 

Link: https://wahis.woah.org/#/in-review/7290

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#Philippines - High pathogenicity avian #influenza #H5 viruses (#poultry) (Inf. with) - Immediate notification

 

Affected avian species were grazing ducks in Davao del Sur Region.

Source: 

Link: https://wahis.woah.org/#/in-review/7105

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#Finland - #Influenza A #H5 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification [FINAL]

 

A Whooper Swan in Lounais-Suomen aluehallintovirasto Region.

Source: 

Link: https://wahis.woah.org/#/in-review/7156

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#Italy - #Influenza A #H5 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

 

{Eurasian Teal}

{Eurasian Wigeon}

{Mute Swan}

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This is a new event opened to report outbreaks for which the N subtype could not be determined due to insufficient diagnostic material; in these cases, only the presence of H5 can be confirmed.

Three Common Teals (Friuli Venezia Giulia, Lombardy) , two Eurasian Wigeons (Friuli Venezia Giulia), one Mute Swan (Lombardy). 

Source: 

Link: https://wahis.woah.org/#/in-review/7144

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Isolation and subtyping of avian #influenza A virus from wild #birds in #Khartoum, #Sudan

 

Abstract

Avian influenza (AI) is a significant disease affecting chickens and other avian species. Wild birds are thought to contribute to the virus transmission. The present study intends to explore the existence of AI type A virus in wild birds at the Six April Zoo, Khartoum State, Sudan. A total of 42 cloacal and tracheal swabs were collected from clinically healthy individuals belonging to five different wild bird species. The selected wild bird species were Common crane Grus grus, Sudan crowned crane Balearica pavonina, Helmeted guinea fowl Numida meleagris, Duck sp. Anatidae and Chestnut-billed sand grouse Pterocles exustus. Swabs were examined for AI virus antigen using the agar gel immunodiffusion (AGID) test, and all tested swabs produced positive results. The swab samples were inoculated into embryonated chicken eggs. The isolated virus was identified by AGID test and polymerase chain reaction. The virus was isolated from swabs collected from Grus grus, Balearica pavonina, Numida meleagris, Duck sp. Anatidae and Pterocles exustus. Subtyping of the isolated viruses was performed using reverse transcriptase-polymerase chain reaction, which identified the H5 subtype.

Source: 

Link: https://ojvr.org/index.php/ojvr/article/view/2228

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#Kazakhstan - #Influenza A #H5 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification [FINAL]

{Greylag Goose}

{Mallards}

A Greylag Goose, two Mallards  in Aqmola Region.

Source: 

Link: https://wahis.woah.org/#/in-review/7093

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#Spain - #Influenza A #H5 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

 

{By Pierre Dalous - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=29066936}

This event will collect the detections made by sampling carried out in 2025.

Report (LNR): 2025/005921 B. A vulture (Gyps fulvus) collected at Quintanas de Valdelucio.

Source: 

Link: https://wahis.woah.org/#/in-review/7077

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#USA, #Influenza A #H5: #Situation #summary of confirmed and probable #human cases since 2024 (as of Nov. 25 '25)

 

{Summary}

Confirmed Cases at National Level

[National - Total Cases: 71 {+1}{§}]

[Cases - Exposure Source]

-- 41 - Dairy Herds (Cattle){*}

-- 24 - Poultry Farms and Culling Operations{*}

-- 3 - Other Animal Exposure{†}

-- 3 - Exposure Source Unknown{‡}

Probable Cases at National Level

[National - Total Cases: 7 {no change}]

[Cases - Exposure Source]

-- 1 - Dairy Herds (Cattle){*}

-- 5 - Poultry Farms and Culling Operations{*}

-- 0 - Other Animal Exposure{†}

-- 1 - Exposure Source Unknown{‡}

NOTE: One additional case was previously detected in a poultry worker in Colorado in 2022. Louisiana reported the first H5 bird flu death in the U.S.

{*} Exposure Associated with Commercial Agriculture and Related Operations

{†} Exposure was related to other animals such as backyard flocks, wild birds, or other mammals

{‡} Exposure source was not able to be identified

(...)

{§} A case from Washington State, see more at: https://doh.wa.gov/newsroom/grays-harbor-county-resident-dies-complications-avian-influenza

Source: 

Link: https://www.cdc.gov/bird-flu/situation-summary/?CDC_AAref_Val=https%3A%2F%2Fwww.cdc.gov%2Fflu%2Favianflu%2Favian-flu-summary.htm&cove-tab=1

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#Portugal - High pathogenicity avian #influenza #H5 viruses (#poultry) (Inf. with) - Immediate notification

 

{Porto Region}

Small farm keeping 197 mixed species poultry and 187 captive birds of exotic species.

Source: WOAH, https://wahis.woah.org/#/in-review/7015

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#Cambodia notified two additional #human cases of infection with #influenza #H5N1, #Bangladesh one case of #H5, #China four cases of #H9N2 (HK CHP, Nov. 21 '25)

{Excerpt}

This Week:

[Date of report - Country - Province / Region District / City - Sex - Age - Condition at time of reporting  - Subtype of virus]

1) .../10/2025 - Cambodia - Takeo Province - F - 14 - Hospitalised - H5N1 

2) 16/10/2025 - Cambodia - Kampong Speu Province - F - 3 - Under intensive care - H5N1

(...)

[Place of occurrence - No. of cases  (No. of deaths) - Details]

-- Bangladesh - 1(0) 

- Avian influenza A(H5): 

1) Sylhet Division: A boy with onset on July 27, 2025. 

-- Chinese Mainland - 4(0) 

- Avian influenza A(H9N2): 

- Guangdong Province: 

1) An individual with onset in February 2025. The case was retrospectively reported. 

- Guangxi Zhuang Autonomous Region: 

2, 3) Two individuals with onset in February 2025. Both cases were retrospectively reported.  

- Tianjin Municipality: 

4) An individual with onset in February 2025. The case was retrospectively reported. 

-- Mexico - 1(0) 

- Avian influenza A(H5): 

1) Mexico City: A 23-year-old woman with onset on September 14, 2025. 

(...)

Source: Centre for Health Protection, Hong Kong PRC SAR, https://www.chp.gov.hk/files/pdf/2025_avian_influenza_report_vol21_wk42.pdf

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