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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Clade 2.3.4.4b #H5N1 #HPAIV from Migratory #Birds in Beidaihe #Wetland, North #China

 

Abstract

During 2022–2024, a highly pathogenic avian influenza virus (HPAIV) H5N1 strain, designated A/Seagull/Hebei/qhd6/2024 (H5N1), was isolated from migratory birds in Beidaihe National Wetland Park, North China. Phylogenetic analyses revealed that its hemagglutinin (HA) gene belongs to the 2.3.4.4b clade, while the neuraminidase (NA) gene and internal genes clustered with strains originating from multiple continents, consistent with a transcontinental reassortment event. The virus also exhibited 90.1–98.1% nucleotide homology with human-derived H5N1 isolates. Molecular characterization identified key virulence-associated mutations, including the classic HPAIV HA cleavage site, HA-T160A (associated with enhanced human receptor-binding capacity), and NA-I117T (potentially linked to drug resistance). BALB/c mouse infection experiments confirmed systemic replication and high pathogenicity of strain qhd6, with a 50% lethal dose (LD50) of 0.95 log10EID50/mL. Antigenic analysis revealed good cross-reactivity with the widely used H5-Re14 vaccine strain. This study reports the identification, in Beidaihe National Wetland Park, of an HPAIV H5N1 strain whose genetic characteristics suggest intercontinental reassortment and indicate cross-species transmission risk. It clarifies the genetic characteristics and pathogenicity of this strain, providing an important theoretical and practical basis for precise surveillance, risk early warning, and comprehensive prevention and control of AIV at migratory bird stopover sites in North China.

Source: 

Link: https://www.mdpi.com/1999-4915/18/6/595

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Epidemiological #surveillance against the #Andes virus: have we learned anything after #COVID19?

 

Summary

Recent outbreaks associated with Andes hantavirus have reignited the international debate on healthcare preparedness for hantaviruses with documented human-to-human transmission. Unlike other orthohantaviruses, Andes hantavirus has demonstrated human-to-human transmission in certain epidemiological contexts, including household and hospital settings. The recent emergence of cases linked to multinational outbreaks has prompted new assessments and recommendations from international public health organizations.

This manuscript presents an epidemiological reflection on the current challenges of surveillance against emerging hantaviruses, drawing on the experience gained during the COVID-19 pandemic. It also reviews aspects related to zoonotic surveillance, molecular monitoring, early detection, and integrated One Health approaches applied to preparedness for future emerging threats.

The available evidence suggests the need to strengthen surveillance systems capable of integrating human, environmental, and animal information to improve the response to complex epidemiological scenarios associated with emerging hantaviruses.

Source: 

Link: https://ojs.sanidad.gob.es/index.php/resp/article/view/1824

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#USA, #Wastewater Data for Avian #Influenza #H5 (CDC, May 22 '26)

 

{Excerpt}

(...)

Time Period: May 10, 2026 - May 16, 2026

    -- A(H5) Detection: 4 site(s) (1.0%)

    -- No Detection: 413 site(s) (99.0%)

    -- No samples: 81 site(s)

{Click on Image to Enlarge}

(...)

Source: 

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

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#Coronavirus #diversity and #SARS-CoV-2 #exposure at the #wildlife – #human interface in Northern #Italy

 

Abstract

Background

Members of the Coronaviridae family infect humans as well as domestic and wild animals. Over the past three decades, three members of this family, all with zoonotic origins, have caused significant epidemics or pandemics (SARS, MERS, and COVID-19). Despite the spread of SARS-CoV-2 being primarily driven by human-to-human transmission, various animal species are susceptible to infection and may contribute to viral circulation. Aim of this work was to monitor coronavirus (CoV) infections in wild mammals in the Emilia-Romagna region (RER), Italy, using a combined approach of molecular screening for viral RNA detection and serological testing for anti-SARS-CoV-2 antibodies.

Methods

Respiratory and gastrointestinal tissue samples were collected from wild animal carcasses between 2022 and 2024. Samples were tested for SARS-CoV-2 using two RT-qPCR assays targeting the E and N genes, and for other CoVs using a nested pan-coronavirus RT-PCR followed by Sanger sequencing of positive samples. Additionally, serum samples obtained from blood, cardiac clot, or thoracic exudate were screened for antibodies against the SARS-CoV-2 nucleocapsid (N) protein, with positive samples subsequently confirmed by an ELISA targeting antibodies to the receptor-binding domain (RBD) of the Spike (S) protein, focused on variants circulating during the study period.

Results

Molecular analyses were performed on 2,238 animals, all of which tested negative for SARS-CoV-2, while 90 (79% hedgehogs) tested positive for CoVs. Among these, most sequences were consistent with coronaviruses typically reported in the respective host species. However, some exceptions – such as Betacoronavirus erinacei in fox, porcupine, hare, and roe deer, and EmbeCoV-related sequences in a porcupine – warrant further attention. Suitable serum samples were available from 1,751 animals. Overall, 65 animals tested positive for anti-N antibodies, 31 of which (22 foxes, 4 badgers, 2 hedgehogs, 1 roe deer, 1 wolf, 1 rat) were subsequently confirmed by an anti-RBD ELISA.

Conclusions

This study provides an overview of CoVs circulation among wild mammals in RER, supporting the role of hedgehogs as reservoirs and identifying some species with evidence of exposure to SARS-CoV-2. Certain unexpected findings highlight the need for further investigations to clarify the potential for cross-species transmission.

Source: 

Link: https://link.springer.com/article/10.1186/s12985-026-03193-3

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#USA, #Wastewater Data for Avian #Influenza #H5 (CDC, May 15 '26)

 

{Excerpt}

(...)

Time Period: May 03, 2026 - May 09, 2026

-- A(H5) Detection: 6 site(s) (1.4%)

-- No Detection: 416 site(s) (98.6%)

-- No samples: 118 site(s)

{Click on Image to Enlarge}

(...)

Source: 

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

____

#Andes #hantavirus #outbreak - multi-country, 15 May 2026 (#ECDC, edited): No New Cases since last update

 

    ECDC was notified on 2 May 2026 of a cluster of severe respiratory illness on MV Hondius, a Dutch-flagged cruise ship with passengers and crew from 23 countries, including nine EU/EEA countries. 

    The virus has been identified as Andes hantavirus.

    As of 15 May, a total of eleven cases have been reported, including eight confirmed, two probable, and one inconclusive. 

    No new cases or deaths have been reported since the previous update. 

    The risk to the EU/EEA general population remains very low.

___

    -- Confirmed cases***: 8

    -- Probable cases**: 2

    -- Suspected cases*: 0

    -- Inconclusive cases****: 1

    -- Number of deaths: 3

Notes

{*} A suspected case is a person who has been on or visited the same transport (e.g. ship or plane) where a confirmed or probable Andes hantavirus (ANDV) case was present, 

    - OR - 

has been in contact with a passenger or crew member of the MV Hondius since 5 April, 

    - AND - 

has a fever (currently or recently), plus at least one of the following symptoms: 

        ° muscle aches

        ° chills

        ° headache

        ° stomach problems (such as nausea, vomiting, diarrhoea, or abdominal pain)

        ° breathing problems (such as cough, shortness of breath, chest pain, or difficulty breathing)

{**} A probable case is a person who has the symptoms listed above, and is known to have been in contact with a confirmed or probable ANDV case

{***} A confirmed case is a person who meets the suspected or probable case definition, and has a laboratory test that confirms ANDV infection (PCR or antibody test)

{****} An inconclusive case means awaiting further laboratory investigations.

Non-case: A non-case is a person who was initially considered a suspected or probable case, but tests negative for ANDV using laboratory tests (PCR or antibody test).

Source: 

Link: https://www.ecdc.europa.eu/en/infectious-disease-topics/hantavirus-infection/surveillance-and-updates/andes-hantavirus-outbreak

____

#Reassortant High Pathogenicity Avian #Influenza #H5N1 Viruses During the Reemergence in #Uruguay Suggest Increasing #Genetic Diversity in South #America

 

Abstract

Highly pathogenic avian influenza (HPAI) H5N1 viruses of the goose/Guangdong (Gs/GD) lineage have driven a global panzootic since 2020, with clade 2.3.4.4b establishing sustained transmission in wild birds. In South America, early outbreaks were largely associated with the North American-derived B3.2 genotype, which showed limited diversification after its introduction. Here, we report the genomic characterization of eight H5N1 viruses detected in Uruguay during the reemergence of avian influenza in February–March 2026. Complete genomes were obtained from wild birds exhibiting neurological signs, predominantly Coscoroba coscoroba. All viruses belong to clade 2.3.4.4b but exhibit a reassortant genomic constellation distinct from B3.2. The HA, NA, and MP segments retain the Eurasian backbone, whereas internal genes derive from both South American and North American low-pathogenicity avian influenza lineages. PB2 variation distinguishes two closely related viral groups differing in PB2 origin, whereas the remaining genomic segments retain a shared background. Sequence variation in the neuraminidase gene reduced the sensitivity of a widely used N1-specific RT-qPCR assay, highlighting limitations of existing diagnostic tools during viral evolution. These findings confirm the presence of reassortant H5N1 viruses in Uruguay and, together with recent reports from Argentina and Brazil, support an emerging pattern of genomic diversification in southern South America.

Source: 

Link: https://www.mdpi.com/1999-4915/18/5/558

____

The #Coinfection of #Bartonella spp. and #Hantavirus in Wild #Rodent and #Shrew Species in Eastern #China

 

Abstract

Background:

Bartonella spp. are Gram-negative bacteria that cause diseases including endocarditis, lymphadenopathy, and neuroretinitis. Hantavirus (HV), belonging to the family Hantaviridae, induces illnesses such as hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome. Both pathogens exhibit host specificity—defined as a preference or restriction to specific host species or ranges. Rodents and shrews are primary hosts for these pathogens, and their high coinfection rates often indicate elevated risk of human exposure. To our knowledge, however, data on Bartonella spp.–HV coinfection in rodents and shrews from Eastern China remain limited.

Materials and Methods:

Between 2020 and 2023, rodents (n = 311) and shrews (n = 16) were investigated for coinfection with Bartonella spp. and HV in Qingdao, eastern China. Nested Polymerase Chain Reaction (PCR) was used for the detection of RNA-dependent RNA polymerase (RdRp) gene of HV and the Internal Transcribed Spacer, citrate synthase (gltA) and RNA polymerase beta subunit (rpoB) genes of Bartonella spp.

Results:

The overall infection rates of Bartonella spp., HV, and coinfection were 21.4%, 6.7%, and 4.0%, respectively. The highest rates were observed in Apodemus agrarius (53.8%, 21.3%, and 15.0%). Coinfection rates differed significantly by species (p < 0.05), with A. agrarius exhibiting the highest rate (15.0%). Notably, the coinfection rate was significantly higher in male (28.9%) than female A. agrarius (7.1%) (p < 0.05).

Conclusions:

This study confirms the coinfection of Bartonella spp. and HV in rodents in the eastern region of China. Enhanced monitoring of rodent and shrew densities, as well as their carried pathogens, is essential. Additionally, timely screening, diagnosis, and treatment should be conducted for high-risk populations in the region to reduce the incidence of related zoonoses.

Source: 

Link: https://journals.sagepub.com/doi/10.1177/15303667261448824

____

#Genomic Analysis of #SinNombre Virus #Sequences, Northwestern #USA, 2023

 

Abstract

We report Sin Nombre virus (SNV) genome sequences in the northwestern United States, including SNV sequences recovered from montane voles. Analysis of samples collected from 189 individual rodents revealed high SNV prevalence in the region and evidence of virus reassortment or coinfection, highlighting ongoing virus diversification in rodents.

Source: 

Link: https://pubmed.ncbi.nlm.nih.gov/42116630/

____

Sequencing of #Betacoronavirus erinacei from faeces of pet #hedgehogs demonstrates a continuity of #MERS-CoV like viruses in #European and Eurasian hedgehog species

 

Abstract

Hedgehogs have been recently identified as carriers of Betacoronavirus erinacei (also known as Erinaceus coronavirus, EriCoV) a virus closely related to B. cameli responsible for human Middle East Respiratory Syndrome (MERS), raising questions about the risk of hedgehog-to-human transmission and suggesting the need for coronavirus (CoV) surveillance in hedgehogs. This study investigated the presence of CoVs in fecal samples of hedgehogs kept as pets in Italy in 2021–2022. A pan-CoV nested RT-PCR targeting the RdRp gene was used for screening and positive samples were sequenced and phylogenetically analyzed. Two (6.2%) out of 30 hedgehogs analyzed were positive for B. erinacei represented by 2/3 (66.7%) long eared hedgehog (Hemiechinus auritus) while all the 27 tested African pygmy hedgehog (Atelerix albiventris) were negative. Whole genome sequence obtained from one B. erinacei-positive sample showed closest homology (85.7%) with B. erinacei previously detected in Erinaceus sp. from Eastern Russia. Phylogeny showed that the virus of this study formed a separate clade in the cluster with other B. erinacei identified in Europe and European Russia and did not cluster with other B. erinacei identified in China in Amur hedgehog (E. amurensis). No recombination events were observed. Analysis of the Spike protein revealed the presence of six out of the 11 key receptor binding residues, including two out of the three critical residues recently identified for the binding of Erinaceus europaeus receptor APN and B. erinacei. Results of this study suggest the presence of a long-eared hedgehog-specific strain of B. erinacei. Overall results support the circulation of coronaviruses along a phylogenetic continuum among different species of hedgehogs and geographic locations, suggesting the need for further CoV surveillance in both domestic and wild animals. There is also a need for studies on the affinity of EriCoV with the H. auritus APN specific receptor to confirm its involvement in the viral entry process.

Source: 

Link: https://www.sciencedirect.com/science/article/pii/S2352771426000960?via%3Dihub

____

#USA, California DPH Confirms Four Californians Being Monitored for #Andes #Hantavirus Exposure Related to Cruise Ship ​​(May 12 '26)

 

May 11, 2026 | NR26-019

Three exposed on cruise ship, one     other exposed on international flight. Risk to the public is extremely low. 

-- What You Need to Know: 

CDPH continues to closely coordinate with federal and local public health officials following notification that three California residents were aboard the MV Hondius, a Dutch cruise ship that experienced an outbreak of Andes hantavirus. 

An additional California resident was identified who was on an international flight sitting near an ill returning cruise passenger who later was confirmed to have Andes hantavirus.  

SACRAMENTO – The California Department of Public Health (CDPH) continues to coordinate with the U.S. Centers for Disease Control and Prevention (CDC) and local health officials to monitor four Californians exposed to the outbreak of Andes hantavirus that occurred aboard the cruise ship MV Hondius.  

Two of these individuals have returned to their respective homes and are being monitored by their local public health officials. 

Two additional California residents have been transported to the United States by federal authorities. 

They will return to California once health assessments have been done and arrangements have been made to protect their and the public’s health. 

The risk to the public remains extremely low. 

On May 8, CDPH announced that one individual from California had returned to the state and is being monitored by local public health officials. 

This weekend, CDC notified CDPH of an additional contact now under active monitoring in California due to potential exposure with a confirmed case on a shared flight. 

Two other California residents who were on the MV Hondius have been evacuated to a secure medical facility in Nebraska. 

"We understand public concern about this unusual outbreak," said Dr. Erica Pan, State Public Health Officer and CDPH Director. 

"Decades of experience in South America have shown that this Andes hantavirus rarely spreads between people. We continue to work with federal and local officials to monitor the health of potentially exposed individuals and prepare for our Californians to come home.” 

The Californians currently in Nebraska will be transported home after further health assessment and appropriate arrangements have been made to protect their and public health. 

After their return, local health officials will monitor the returned passengers as necessary. 

Currently, public health monitoring protocol includes daily temperature checks, assessment for any symptoms consistent with hantavirus, and direction to modify activities. 

Prior to response efforts related to this outbreak, the CDPH Viral and Rickettsial Disease Laboratory (VRDL) was the only public health laboratory in the U.S. with a validated diagnostic hantavirus PCR assay to conduct testing for hantavirus. 

If any exposed individual develops symptoms consistent with infection, California has the capability to test in the state.  

CDPH VRDL is also providing technical assistance to other laboratories across the country to support testing capacity. 

CDPH is coordinating closely with hospitals who can care for potential hantavirus cases and has issued clinical health advisories to clinicians to provide guidance for appropriate care.  

The risk to the public remains extremely low. 

About Hantavirus & Transmission Ris​​k

Hantavirus is a group of viruses that spread through the urine, droppings (feces), and saliva of wild rodents. 

Hantaviruses include both the Sin Nombre and Andes virus strains. 

The Andes hantavirus identified in this cruise ship outbreak is found in the southern Andes region of Argentina and Chile. 

Andes hantavirus has also been associated with rare human‑to‑human transmission after close, prolonged contact with an ill infected person. 

Andes hantavirus is different than the Sin Nombre hantavirus, which is native to California and North America. Sin Nombre hantavirus has not been associated with person-to-person transmission. 

From 1980 to 2025, 99 California residents have been diagnosed with Sin Nombre hantavirus infection. 

Hantavirus Pulmonary Syndrome (HPS) is a rare but severe respiratory illness that can develop following exposure. 

Early symptoms resemble influenza, can include gastrointestinal symptoms, and can progress rapidly to life‑threatening respiratory distress. 

The fatality rate is approximately 30 - 40 percent. 

There is no antiviral treatment for hantavirus and HPS typically needs aggressive critical medical supportive care. 

Further Reading and Upd​ates

More information on hantavirus is available on CDPH’s hantavirus website and from the CDC’s hantavirus web page. An update on the federal government evacuation and repatriation efforts was issued in a CDC health alert on Friday, May 8. 

This is a dynamic and evolving investigation and response. CDPH will continue to update the public as new information becomes available. ​

Source: 

Link: https://www.cdph.ca.gov/Programs/OPA/Pages/NR26-019.aspx

____

#Taiwan, potential for cross-species #human #infection by "Cryptopathic #Noda Virus (CMNV)," CDC convened an expert meeting and established a testing mechanism (May 12 '26)

 

The Centers for Disease Control (CDC) announced today (May 12) that, in response to a recent study published in the international journal *Nature Microbiology*, which suggests that the "Cryptant Morbid Noda Virus (CMNV)," found in aquatic animals, may have cross-species transmission capabilities and could potentially cause "Persistent High-Pressure Viral Anterior Uveitis (POH-VAU)" in humans, the CDC proactively convened a meeting on May 4 with relevant medical associations and experts to discuss and establish a testing mechanism to protect the health and safety of the public.

The CDC explained that CMNV has been listed as an emerging infectious disease by the World Organisation for Animal Health (OIE), and infection cases have been reported in shrimp farms in China and Thailand; currently, only China has reported suspected human cases of CMNV infection globally. 

The research report inferred that human infection with CMNV may be related to handling or consuming raw aquatic products; however, further evidence is needed to confirm whether this virus has the ability to effectively infect human eye tissues. 

Major international public health organizations, including the World Health Organization (WHO), the US CDC, and the European Centre for Disease Prevention and Control (ECDC), have not received any reports of related human cases, nor have they listed it as an urgent public health threat. 

Furthermore, regarding domestic surveillance, the Taiwan Agricultural Bureau's (Agricultural Science Institute) has not detected CMNV in any of the past five years (2021-2026) of surveillance of white shrimp cases and the domestic animal disease prevention and control network. 

Based on a comprehensive assessment, the risk of domestic transmission is extremely low. 

However, to prevent any potential outbreaks, the Taiwan Centers for Disease Control (CDC) has established a relevant specimen submission mechanism and issued a circular to the medical community today, reminding clinicians to be vigilant and, in the event of suspected cases, to thoroughly investigate the patient's exposure history to aquatic animals and seafood, and to collect clinical specimens for testing if necessary.

The CDC emphasizes that agriculture and health authorities will continue to maintain close communication, strengthen monitoring of domestic and international epidemic dynamics and transmission risks, and implement the spirit of integrated epidemic prevention. 

The Centers for Disease Control (CDC) also reiterated its reminder to tourists traveling to China and Thailand to take special precautions against CMNV (Contagious Disease Infection). 

Tourists should ensure seafood is thoroughly cooked, and high-risk groups (such as those with weakened immune systems and chronic diseases) should avoid eating raw seafood. 

When handling raw seafood, it is recommended to wear gloves, avoid direct contact with raw food if you have any open wounds, and wash your hands thoroughly with soap and water after handling to reduce the risk of infection.

Source: 

Link: https://www.cdc.gov.tw/Bulletin/Detail/y-8WwSZtKW-JANyrfc6B4A?typeid=9

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Identification and #genetic characterization of a distinct #genotype of #Puumala #orthohantavirus in #Hebei Province, #China

 

Abstract

Orthohantavirus infections pose a significant threat to human health, while numerous orthohantaviruses have been identified, suspected viral infections remain undiagnosed in the world, which highlights the need for further identification and characterization of viruses circulating in humans and host animals. In this study, viral metagenomics was utilized to investigate orthohantaviruses present in tissue samples collected from rodents trapped at the Bashang Grassland of Hebei Province, China. A total of 145 wild rodents belonging to six species were captured in the study area, and 725 tissue samples (lung, liver, kidney, spleen, gut) were collected in 2024. A Puumala orthohantavirus (PUUV), named Guyuan strain, was identified in Myodes rufocanus, with a positive rate of 0.69%. The complete genomic sequences of the L, M, and S segments were obtained and confirmed by Sanger sequencing. Phylogenetic analysis of these genomic sequences with those of other orthohantavirus species showed that the L, M, and S segments clustered with PUUV genomic sequences, while sharing a nucleotide sequence similarity of 81.2%, 80.2%, and 84.3% with previously characterized reference viral strains Kitahiyama128L, Tobetsu_04, and Baltic/205 Cg, respectively. Amino acid homology analysis demonstrated that the sequences exhibited the highest identity to PUUV Hokkaido strain at a level of 95.4%, 94.6%, and 97.0% respectively. Viral particles were observed in lung and kidney tissues using transmission electron microscopy, and viral protein antigen was detected in viral RNA-positive lung, liver, and kidney tissues through immunofluorescence assay with antibodies against the PUUV nucleocapsid protein, thereby confirming the virus’s multiorgan tropism. The results demonstrated that a distinct genotype of PUUV was circulating in rodents in the study areas, which may have implications for zoonotic transmission surveillance and public health management in Hebei Province.

Source: 

Link: https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014250

____

#Detection and #isolation of #H5N1 clade 2.3.4.4b #influenza virus from #ticks recovered from a naturally infected slender-billed #gull

 

Abstract

Laridae birds, such as gulls, are known reservoirs of H13 and H16 low pathogenicity avian influenza virus (LPAIV) subtypes. However, during the recent outbreaks linked to the reemergence of high pathogenicity avian influenza virus (HPAIV) H5N1 clade 2.3.4.4b of the Goose/Guangdong lineage, European populations of Laridae birds suffered significant losses. HPAI cases were reported not only along the coastlines but also inland areas, particularly in France and Central Europe. During a diagnostic investigation of a group of Laridae birds, part of a HPAIV outbreak reported in the South of France in 2023, larval stages of Ornithodoros maritimus, a nidicolous soft tick parasitizing seabirds, were recovered from a slender-billed gull (Chroicocephalus genei). Affected birds exhibited gross and histopathological lesions consistent with systemic HPAIV infection. Immunohistochemistry revealed marked neurotropism, oculotropism and multicentric epitheliotropism. Viral isolation and sequencing analysis confirmed the presence of HPAIV H5N1 clade 2.3.4.4b in both the gull and ectoparasites, showing from 99.64% to 100% nucleotide identity across five of eight RNA segments. While additional research is needed to properly assess the vector competence of O. maritimus for HPAIV, ticks may represent an interesting non-invasive surveillance tool for these viruses. This is the first time a HPAIV has been successfully isolated from tick larvae. These findings represent a first step toward understanding the potential role played by ticks in the spread of avian influenza viruses within marine bird colonies and among other ecosystems, considering the occurrence of specific behavioral traits, such as kleptoparasitim and the position of gulls at the interface between wild and domestic species.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

Agence Nationale de la Recherche, https://ror.org/00rbzpz17

INRAe Animal Health Department

Source: 

Link: https://www.biorxiv.org/content/10.1101/2025.11.28.689408v2

____

Migratory #bird and marine #mammal #surveillance fails to find #evidence for an HPAI #H5N1 2.3.4.4b incursion into #Australia in 2025

 

Abstract

The panzootic caused by high pathogenicity avian influenza (HPAI) H5N1 clade 2.3.4.4b has been devastating for animals, globally. Despite global spread, the virus remains absent in Oceania. Herein we report the results of our fourth year of enhanced migratory bird surveillance, coinciding with the spring migration of wild birds in 2025; none of the 847 migratory wild birds or 38 marine mammals were positive for HPAI H5N1, although we did detect LPAI. Surveillance remains a critical tool for HPAI H5N1 response, with early detection and rapid response being critical to mitigate the impacts of this virus on animal, environment and human health.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

Australian Government Department of Agriculture, Fisheries and Forestry

Wildlife Health Australia

Australian Department of Health, Disability and Ageing

Western Australian Marine Science Institution

Department for Environment and Water, https://ror.org/053gv9453

Department of Climate Change, Energy, the Environment and Water of Australia

Department of Climate Change, Energy, the Environment and Water

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.05.07.722556v1

____

#USA, #Wastewater Data for Avian #Influenza #H5 (US CDC, May 8 '26)

 

{Excerpt}

(...)

Time Period: April 26, 2026 - May 02, 2026

-- A(H5) Detection: 8 site(s) (1.7%)

-- No Detection: 457 site(s) (98.3%)

-- No samples: 82 site(s)

{Click on Image to Enlarge}

(...)

Source: 

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

____

Evidence of #Juquitiba and #Jaborá #Orthohantavirus Co-Circulation in #Rodent Communities of #Argentina

 

Abstract

Hantaviruses infect a wide range of vertebrate hosts. In the Americas, Orthohantavirus species pose a major public health concern due to their ability to cause Hantavirus Cardiopulmonary Syndrome (HCPS). Given the lack of approved vaccines and specific treatments for HCPS, identifying circulating orthohantavirus genotypes and their hosts, along with estimating prevalence, is essential for designing effective preventive strategies. The objectives of this study were: (1) to identify the orthohantavirus hosts, (2) to determine the circulating orthohantavirus genotypes, (3) to assess the population structure and dynamics of Akodon montensis, (4) to characterize the rodent communities, and (5) to evaluate associations between A. montensis abundance and environmental variables in two protected natural areas of Misiones Province, Argentina. A total of 12 rodent trapping sessions were conducted from April 2021 to February 2023 in Urugua-í and Cruce Caballero Provincial Parks. Orthohantavirus antibodies were detected in four A. montensis and three Oligoryzomys nigripes from both Provincial Parks. Molecular analyses provided evidence of the co-circulation of Jaborá and Juquitiba orthohantavirus genotypes. Both areas exhibited similar rodent community compositions, with A. montensis as the numerically dominant species and O. nigripes occurring at low abundance. In Urugua-í, A. montensis abundance varied in relation to precipitation and vegetation productivity, whereas no such associations were observed in Cruce Caballero. Further studies are needed to effectively monitor these communities and to gain a better understanding of potential fluctuations in seroprevalence, changes in genotype pathogenicity, and the possible detection of unknown genotypes.

Source: 

Link: https://link.springer.com/article/10.1007/s10393-026-01803-8

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Serologic #Evidence of #Influenza #H5N1 Virus #Infection in a #Veterinary Professional Exposed to an Infected #Cat — Los Angeles County, #California, Dec. '24–Jan. '25

 

Summary

-- What is already known about this topic?

- Transmission of influenza A(H5N1) viruses from domestic cats to humans has not been documented.

-- What is added by this report?

- During November 2024–January 2025, a total of 139 persons exposed to 19 A(H5N1)-infected domestic cats that consumed raw animal products were identified in Los Angeles County, California. Among 25 exposed persons who received serologic testing, one asymptomatic veterinary professional had serologic evidence of A(H5N1) infection after occupational exposure to an A(H5N1)-infected cat.

-- What are the implications for public health practice?

- These findings provide evidence of zoonotic transmission of influenza A(H5N1) virus from domestic cats to humans. Pet owners are advised not to feed raw animal products to cats. Veterinary professionals should be aware of infection risks, use appropriate personal protective equipment, and adhere to recommended infection control practices to reduce the risk for zoonotic transmission of influenza A(H5N1).

Abstract

Since 2021, avian influenza A(H5N1) clade 2.3.4.4b viruses have spread widely among wild birds and domesticated poultry in the United States, with sporadic spillover into mammals. During November 2024–January 2025, 19 domestic cats in Los Angeles County, California, became ill after consumption of commercially purchased raw milk, raw meat, or raw pet food; nine cats tested positive for influenza A(H5N1) virus (clade 2.3.4.4b genotype B3.13). Overall, 139 persons were exposed to the 19 infected cats, and all were monitored for symptoms. Although 30 persons reported influenza-like illness symptoms, none received a positive influenza A(H5) reverse transcription–polymerase chain reaction (RT-PCR) test result. In April 2025, the Los Angeles County Department of Public Health and CDC invited all exposed persons to participate in an influenza A(H5N1) serosurvey to determine whether transmission of influenza A(H5N1) virus occurred, including in those without symptoms. Sera from 25 (18%) of the 139 exposed persons were tested. Among these, antibodies specific to A(H5N1) clade 2.3.4.4.b (antigenically similar to the clade 2.3.4.4.b influenza A[H5N1] virus isolated from the infected cats) were detected in serum from one veterinary professional, who was asymptomatic. This person did not use respiratory or eye protection during the exposure, did not report influenza-like illness after the exposure, and reported no other known risk factors for A(H5N1) infection. These findings represent serologic evidence of possible transmission of influenza A(H5N1) clade 2.3.4.4.b virus from a domestic cat to a human, highlighting concerns about potential cat-to-human transmission of influenza A(H5N1) virus and the importance of infection control practices in veterinary settings.

Source: 

Link: https://www.cdc.gov/mmwr/volumes/75/wr/mm7517a1.htm?s_cid=OS_mm7517a1_e&ACSTrackingID=USCDC_921-DM155047&ACSTrackingLabel=Week%20in%20MMWR%3A%20Vol.%2075%2C%20May%207%2C%202026&deliveryName=USCDC_921-DM155047

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