#Orthopoxvirus #Antibodies in Feral #Mammals in #Mpox #Outbreak Areas, #Nigeria, 2021–2022

 

Abstract

We analyzed tissue and serum samples from 124 wild animals from communities with confirmed mpox cases in Nigeria. Tissue samples were PCR-negative, but serum samples from 8 animals (6.45%)—3 feral cats, 4 giant pouched rats, and 1 shrew—revealed Orthopoxvirus antibodies, suggesting these species as probable reservoirs.

Source: 

Link: https://wwwnc.cdc.gov/eid/article/32/5/25-1565_article

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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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#Prion shedding is reduced by chronic wasting disease {#CWD} #vaccination

 

Abstract

Chronic wasting disease (CWD) is a strictly fatal and highly contagious prion disease of wild and farmed cervids currently expanding in North America. Prion diseases are caused by conversion of the cellular prion protein to its pathological isoform PrPSc. Vaccination is considered a promising strategy to contain CWD, even though prion diseases do not show classical immune responses. For CWD containment, it is important that vaccines reduce shedding of prions in excreta, a major contributor to transmission. Here, we tested the effect of vaccines on prion shedding in feces and urine by vaccinating and prion infecting knock-in mice that recapitulate CWD pathogenesis as found in cervids. Vaccination reduced or even prevented CWD shedding in feces and urine collected between 30–90% of incubation time to disease. This is the first report showing that prion shedding can be blocked in a prion disease. For CWD specifically it may reduce the environmental prion burden and break the disease transmission cycle.

Source: 

Link: https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1014166

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Heart-nosed #bat #alphacoronaviruses use #human CEACAM6 to enter #cells

 

Abstract

Identifying viruses with zoonotic potential on the basis of their ability to enter human cells is a critical component of pandemic prediction, prevention and preparedness. Here using a computational approach that retains maximum phylogenetic diversity, we selected an optimal subset of alphacoronavirus spike proteins to screen against broad coronavirus receptor libraries. Most of the selected spike proteins did not use any of the established coronavirus receptors. However, the pseudotyped spike protein of Cardioderma cor (heart-nosed bat) coronavirus KY43 (CcCoV-KY43) could enter human cells. Using a recombinant CcCoV receptor-binding domain (RBD) and a human receptor screening platform, we identified direct interactions with the human CEACAM proteins CEACAM3, CEACAM5 and CEACAM6. Overexpression of human CEACAM6—a protein widely expressed in the human lung—conferred permissivity to otherwise refractory human cells. A crystal structure showed that the RBD binds the amino-terminal IgV-like domain of human CEACAM6. Immune surveillance studies using sera of individuals from the Taveta region of Kenya, where CcCoV-KY43 was identified, did not show significant evidence of recent spillover. Wider characterization of alphacoronaviruses related to CcCoV-KY43 showed that human CEACAM6 is used by two other CcCoVs collected in Kenya. Moreover, there was more restricted nonhuman CEACAM6 tropism for viruses isolated from Rhinolophus bats from Russia and China. Thus, alphacoronaviruses that use CEACAM6 are probably geographically widespread, and viruses from East Africa show potential for transmission to humans.

Source: 

Link: https://www.nature.com/articles/s41586-026-10394-x

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ONWARD: a #OneHealth, pan - #European multidisciplinary #network advancing #surveillance, #research, clinical management and control of zoonotic #hepeviruses

 

Highlight

• HEV remains the leading cause of acute viral hepatitis in Europe

• Surveillance and diagnostics for HEV are heterogeneous across EU/EEA

• Zoonotic HEV circulates widely in pigs, wildlife and food chains

• Rat HEV expands the zoonotic spectrum and clinical burden in Europe

• ONWARD integrates One Health surveillance, research and capacity building

Abstract

Zoonotic hepeviruses, particularly hepatitis E virus (HEV, species Paslahepevirus balayani) represent a major yet underestimated public health challenge in Europe. Despite being the leading cause of acute viral hepatitis, surveillance, diagnostic practices and prevention strategies remain heterogeneous across EU/EEA countries, limiting comparability and hindering accurate burden estimates. Underdiagnosis is further compounded by extrahepatic manifestations and the growing impact of chronic HEV infection in immunocompromised patients. At the human–animal–environment interface, zoonotic HEV circulates widely in domestic pigs, wildlife and food products, while coordinated surveillance and control measures remain inconsistently implemented. The recent recognition of ratHEV (species Rocahepevirus ratti) as a cause of acute and chronic hepatitis in Europe further expands the spectrum of zoonotic hepevirus infections and underscores the need for integrated One Health approaches. To address these challenges, the One Health Zoonotic Hepevirus Network (ONWARD; COST Action CA24140) was launched in 2025 as a pan-European, multidisciplinary collaboration uniting experts across human, veterinary, food safety and environmental health sectors. ONWARD aims to harmonise diagnostic tools, strengthen clinical research, integrate multisectoral surveillance, promote capacity building and support evidence-based policy development. By fostering coordination with European stakeholders ONWARD provides a structured framework to strengthen preparedness, surveillance and response to zoonotic hepevirus threats across Europe.

Source: 

Link: https://www.sciencedirect.com/science/article/pii/S1386653226000338?dgcid=rss_sd_all

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#Species - and #variant - specific #ACE2 compatibility shapes #SARS-CoV-2 #spillover potential in North American #cervids

 

Abstract

Free-ranging white-tailed deer (WTD) are established SARS-CoV-2 reservoirs, but the susceptibility of other cervid species remains unclear. Here we integrate receptor analysis, structural modeling, and field surveillance to assess SARS-CoV-2 susceptibility across North American cervids. We identify species- and variant-specific differences in ACE2–spike compatibility. Elk ACE2 exhibits weak binding to the ancestral strain (Wuhan-Hu-1) and Delta spike receptor-binding domains (RBDs), likely due to a unique K31N substitution. In contrast, it shows stronger binding to Alpha, Beta, Gamma, and Omicron RBDs containing N501Y. Biophysical assays, gel filtration chromatography, and cryo-EM confirm stable complex formation between elk ACE2 and Alpha RBD, but not RBD from the ancestral strain. Despite weak binding, elk ACE2 supports viral entry and replication in vitro. However, surveillance revealed limited evidence of infection in the United States, contrasting with widespread WTD transmissions. These findings demonstrate that ACE2 compatibility alone is insufficient to predict reservoir potential and provide a framework for assessing species susceptibility to emerging coronaviruses.

Source: 

Link: https://www.nature.com/articles/s41467-026-71623-5

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#Genomic analysis of high pathogenicity avian #influenza viruses from #Antarctica reveals multiple introductions from South #America

 

Abstract

The spread of high pathogenic avian influenza virus (HPAIV) H5N1 clade 2.3.4.4b into Antarctica poses a major threat to polar wildlife. We report the detection of H5N1 in carcasses of eight species during the 2023-2024 and 2024-2025 austral summers in the South Shetland Islands: Antarctic shag, Antarctic tern, kelp gull, pintado petrel, Antarctic petrel, skuas, Antarctic fur seal, and southern elephant seal. Whole-genome sequencing, mutational profiling, and phylogenetic reconstruction revealed that the viruses detected in these hosts descended from distinct introduction events. One group of strains including complete and partial viral genomes from a gull, skuas, fur seals, an Antarctic tern, and a southern elephant seal clustered with H5N1 strains previously detected in marine mammals in South America and formed a polyphyletic lineage consistent with at least two independent introductions into Antarctica. A second group of strains including complete and partial viral genomes from petrels, shags, and skuas clustered with H5N1 strains previously detected in seabirds and marine mammals in South Georgia and with a previously reported HPAIV detection from Torgersen Island, Antarctic Peninsula. These findings reveal extensive epidemiological connectivity between South America and Antarctica, with South Georgia serving as a “stepping stone” for virus spread in the region.

Source: 

Link: https://www.nature.com/articles/s41467-026-71544-3

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The #Mengla virus (Filoviridae: #Dianlovirus)

 

Abstract

Introduction. 

Filoviruses associated with various species of pteropodid bats (Chiroptera: Pteropodidae) are traditionally regarded as potential causative agents of hemorrhagic fevers with epidemic potential. The known agents of Ebola and Marburg fevers periodically cause sporadic cases and epidemic outbreaks in African countries. Recent discoveries of novel filoviruses associated with pteropodid bats in South and Southeast Asia highlight the necessity to investigate their genetic diversity and pathogenic potential.

The aim of this study was to investigate the genetic diversity and pathogenic potential of new filoviruses associated with bats, based on literature data.

Materials and methods. 

This review is based on an analysis of published literature describing the detection and molecular characterization of novel filoviruses identified in different geographic regions, with a particular focus on filoviruses associated with pteropodid bats in South and Southeast Asia. The analyzed studies include data on virus discovery, genome organization, taxonomic classification, and experimental assessment of biological properties. 

Results. 

Several novel filoviruses have been identified by metagenomic RNA sequencing of tissues from pteropodid bats captured in South and Southeast Asia. Among them, Mengla virus was detected in tissues of pteropodid bats (Rousettus spp.) captured in Mengla County, Yunnan Province, People’s Republic of China. Owing to a high level of genetic divergence, Mengla virus was classified as a representative of a new genus, Dianlovirus, within the family Filoviridae. Although a live isolate of Mengla virus has not yet been obtained, experimental studies using chimeric minigenome systems and virus-like particles suggest that the virus may exhibit tropism for tissues of various vertebrate hosts, including humans.

Conclusion. 

Members of the family Filoviridae are widely distributed within the geographic range of their natural reservoir–pteropodid bats–across South and Southeast Asia, including viruses evolutionarily related to Ebola and Marburg viruses. Although human disease caused by Mengla virus and other recently discovered filoviruses has not been documented, the potential for cross-species transmission and the emergence of novel filovirus infections in endemic regions remains.

Source: 

Link: https://virusjour.crie.ru/jour/article/view/16805

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#Evidence of #SARS-CoV-2 #Exposure in #Rodents from Rural Localities in the #Yucatan Peninsula, #Mexico

 

Abstract

Zoonotic diseases involve pathogen transmission between humans and animals, with most research focused on animal-to-human spillover. However, reverse zoonosis—the transmission of pathogens from humans to animals—remains understudied despite its potential ecological and epidemiological consequences. The SARS-CoV-2 pandemic highlights this risk, as human-associated viruses may sporadically infect wildlife species and generate novel exposure pathways. To assess evidence of SARS-CoV-2 exposure in wildlife, we analyzed serum and rectal swab samples from rodents collected in rural localities of the Yucatan Peninsula, Mexico, between 2021 and 2022. An indirect ELISA detected antibodies against SARS-CoV-2 in 23.1% of sampled rodents. Molecular analysis detected one positive sample with a pan-coronavirus RT-PCR, though all were negative for SARS-CoV-2–specific assays. This study provides serological evidence of SARS-CoV-2 exposure in rodent communities from rural areas of Mexico and is consistent with sporadic wildlife spillback events rather than sustained transmission. The observed exposure patterns may be influenced by human activities and frequent human–wildlife interactions in heterogeneous rural landscapes. Our results underscore the need for integrated serological and genomic surveillance to better understand the ecological context of reverse zoonosis and its implications for public health.

Source: 

Link: https://www.mdpi.com/1999-4915/18/4/435

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Deciphering #HPAI #Influenza A Virus #H5N1: Molecular Basis of #Pathogenicity, Zoonotic Potential, and Advances in #Vaccination Strategies

 

Abstract

The ongoing panzootic of the highly pathogenic avian influenza (HPAI) H5N1 virus, dominated by clade 2.3.4.4b, constitutes a significant global threat to wildlife, animal health, and public health. Once characterized by sporadic outbreaks, H5N1 has evolved into a sustained, year-round infection with an expanded host range that now includes numerous mammalian species. Its high pathogenicity is primarily driven by the acquisition of a polybasic haemagglutinin cleavage site, enabling systemic viral spread, alongside emerging endothelial and neurotropic properties that contribute to severe disease and high mortality in mammals. Although zoonotic transmission remains limited, H5N1 continues to accumulate mutations associated with mammalian adaptation, particularly within the haemagglutinin and polymerase complex. Notably, recent outbreaks in U.S. dairy cattle highlight the emergence of novel mammalian reservoirs with increased human exposure risk. Concurrently, vaccination strategies are advancing beyond traditional adjuvanted inactivated vaccines toward next-generation platforms, including mRNA and virus-like particle vaccines, designed for rapid deployment and broader immune protection. However, ongoing viral evolution, constrained vaccine availability, and gaps in coordinated surveillance underscore the urgent need for an integrated One Health approach to reduce panzootic risk.

Source: 

Link: https://www.mdpi.com/1999-4915/18/4/410

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Rapid GeneXpert #surveillance of #influenza A virus in #seabirds and the #environment provides early warning for #wildlife health in #Aotearoa New Zealand

 

Abstract

The global expansion of highly pathogenic avian influenza (HPAI) virus A(H5N1) underscores the need for rapid surveillance at high-risk wildlife interfaces. Taiaroa Head (45.7828 S, 170.7333 E) in the South Island of Aotearoa New Zealand hosts a plethora of aquatic wildlife including a large red-billed gull (Chroicocephalus novaehollandiae scopulinus) colony as well as the only mainland breeding colony of northern royal albatross (Diomedea sanfordi). The Royal Albatross Centre is also a major nature tourism destination, attracting tens of thousands of visitors annually, thereby creating a dense ecological and human-wildlife interface vulnerable to viral incursion. We evaluated the GeneXpert II platform using the Xpert Xpress Flu/RSV cartridge as a field-deployable tool for avian influenza virus detection in environmental and wildlife-associated samples. The assay detected synthetic influenza A viral RNA and multiple endemic low pathogenic avian influenza virus subtypes (A(H3N8), A(H1N9), A(H5N2) and A(H7N7)) circulating in New Zealand birds. Influenza A virus was reliably identified in spiked environmental water samples with no consistent PCR inhibition as well as naturally occurring avian influenza virus in duck pond water. Field deployment demonstrated that the system could be operated by non-laboratory personnel with minimal training in a non-clinical setting. This study establishes the feasibility of near-real-time environmental monitoring. Repurposing clinical cartridge-based point-of-care diagnostics offers a practical early warning approach for avian influenza virus surveillance at ecologically and economically significant locations.

Competing Interest Statement

Steven G Badman is employed by Cepheid who supplied the Xpert Flu/RSV kits for free. Jo-Ann Stanton is the owner of JStanton Consulting Ltd who contributed in kind resources to the project. JLS has received support from Cepheid and Roche to attend scientific meetings.

Funder Information Declared

Te Niwha, TN/SWC/24/UoOJG

Rutherford Discovery Fellowship, RDF-20-UOO-007

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.03.23.713605v1

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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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#Dispersal, #adaptation and #persistence of #H5N1 in the sub-Antarctic and #Antarctica

 

Abstract

High pathogenicity avian influenza virus (HPAIV) H5N1 reached the sub-Antarctic and Antarctica in 2023, subsequently spreading to remote locations within this region where it had devastating impacts on seal, penguin and albatross populations. The threat to marine wildlife over this broad area exemplifies the need to understand H5N1 long-distance dispersal and evolution. We obtained 104 novel viral genomic sequences from samples that we collected at South Georgia, Kerguelen, Crozet, Prince Edward, Falklands/Malvinas Islands and the Antarctic Peninsula in a region spanning 8,000 kilometers. Using recent phylogeographic modeling advances we show that H5N1 spread encompassed numerous transmission events between distant locations, accumulating mammalian-adaptive mutations in the process. Seals are the most affected species, but we reveal that the long-distance eastward virus dispersal better aligns with the long-distance movements of large petrels and albatrosses. The risk of H5N1 endemisation, dispersal to other locations and ongoing evolution are highly concerning.

Competing Interest Statement

The authors have declared no competing interest.

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.03.20.713283v1

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High pathogenicity avian #influenza in #pinniped #conservation

 

Abstract

Since 2020, H5Nx high pathogenicity avian influenza viruses (HPAIVs) have caused widespread disruptions not only to global agriculture and trade but also to the health of free-ranging wildlife. Pinnipeds have experienced greater mortality from H5Nx HPAIV than any other mammalian taxa. Emergent virus strains, persisting over long time periods and vast geographic distances, have repeatedly triggered large-scale mortality events in pinniped populations. Of particular concern is the spread of H5Nx HPAIV to the Southern Hemisphere—including the emergence of a marine mammal-adapted clade in South America and detections in the sub-Antarctic and Antarctic—and to other remote locations such as the Hawaiian Islands. These developments elevate concern for the world’s endangered, isolated and endemic pinnipeds. While managing HPAIV in any animal population is a formidable task, working with free-ranging marine mammals poses unique challenges. In this review and perspective piece, we attempt to synthesize complexities at this intersection. We describe lessons learned from HPAIV investigations in marine wildlife, highlight gaps in knowledge and capacity, and discuss the incorporation of outbreak risk assessment and countermeasures into pinniped conservation. Finally, we propose ways in which pinnipeds—and marine wildlife broadly—could be better integrated into existing systems for HPAIV intelligence, control and prevention.

This article is part of the theme issue ‘Managing infectious marine diseases in wild populations’.

Source: 

Link: https://royalsocietypublishing.org/rstb/article/381/1945/20240320/480666/High-pathogenicity-avian-influenza-in-pinniped

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Multiple Introductions of Highly Pathogenic Avian #Influenza Viruses into the High #Arctic: #Svalbard and Jan Mayen, 2022 - 2025

 

Abstract

Between 2022 and 2025, highly pathogenic avian influenza viruses (HPAIVs) of clade 2.3.4.4b, including four distinct H5 Eurasian (EA) genotypes, were detected in wild birds and mammals in the Svalbard Archipelago and on the island of Jan Mayen. We describe their epidemiology and genomic characteristics to improve understanding of HPAIV occurrence and transmission in the High Arctic. The initial cases in 2022 occurred during summer and involved a glaucous gull (Larus hyperboreus) and great skuas (Stercorarius skua) on Svalbard and Jan Mayen, representing the first detections of HPAIVs in the High Arctic. Three HPAIV genotypes were identified: EA-2020-C (H5N1), EA-2021-AB (H5N1), and EA-2021-I (H5N5). In 2023, HPAIVs were detected in a broader range of bird species, and retrospectively in an Atlantic walrus reported by another research group (Odobenus rosmarus rosmarus). Genotypes identified in 2023 were EA-2020-C (H5N1), EA-2021-I (H5N5), and EA-2022-BB (H5N1). No cases were reported in 2024. In 2025, EA-2021-I (H5N5) was detected in Arctic foxes (Vulpes lagopus) on Svalbard, without preceding detections in wild birds. The foxes exhibited neurological symptoms, and necropsy of one individual revealed the presence of feathers in its stomach. All sequenced viruses from the Arctic foxes uniquely carried the combination of PB2-E627K and PB1-H115Q, which is associated with mammalian adaptation. The detection of multiple genotypes indicates repeated and independent introductions of HPAIVs into these regions. The co-circulation of genetically distinct virus strains in areas of high bird density further suggests that Arctic breeding grounds may facilitate local viral amplification, reassortment, and subsequent dissemination along migratory flyways, including transcontinental spread.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

EU4Health, 101132473

The Research Council of Norway, https://ror.org/00epmv149, 352880

The SEAPOP program, 192141

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.02.17.706283v1

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#Transmission of #Mpox Virus from fire-footed rope #squirrels to sooty #mangabeys

 

Abstract

Mpox, caused by the monkeypox virus (MPXV; Orthopoxvirus monkeypox), is on the rise in West and Central Africa. African rodents, especially squirrels, are suspected to be involved in MPXV emergence, but no evidence of a direct transmission to humans or non-human primates has been established. Here we describe an outbreak of MPXV in a group of wild sooty mangabeys (Cercocebus atys) in Taï National Park (Côte d’Ivoire). The outbreak affected one-third of the group, killing four infants. To track its origin, we analysed rodents and wildlife carcasses from the region. We identified a MPXV-infected fire-footed rope squirrel (Funisciurus pyrropus), found dead 3 km from the mangabey territory 12 weeks before the outbreak. MPXV genomes from the squirrel and the mangabey were nearly identical. A video record from 2014 showed a mangabey from this group eating the same squirrel species and diet metabarcoding of faecal samples collected from mangabeys before the outbreak identified two samples containing fire-footed rope squirrel DNA. One of these samples was also the first positive for MPXV. This represents a rare case of direct detection of interspecies transmission. Our findings indicate that rope squirrels were the source of the MPXV outbreak in mangabeys. Because squirrels and non-human primates are hunted, traded and consumed by humans in West and Central Africa10,11, exposure to these animals probably represents risk for zoonotic transmission of MPXV.

Source: 

Link: https://www.nature.com/articles/s41586-025-10086-y

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Genetic diversity of alpha and #betacoronaviruses in cave and temple-roosting #bats in #Vientiane Province, #Lao PDR

 

Abstract

The emergence of MERS-CoV, SARS-CoV-1, and SARS-CoV-2 highlights the significant public health and economic threats posed by coronaviruses. In Lao PDR, SARS-CoV-2-related bat coronaviruses capable of binding to human ACE2 receptors have been found in northern regions, but little is known about coronavirus diversity in anthropized environments like temples. This study investigated coronavirus circulation, diversity, and prevalence in bats from caves and temples in Vientiane Province, Lao PDR. A total of 648 guano samples (505 Chaerephon plicatus, 100 Hipposideros spp., 43 Taphozous spp.) were collected between December 2022 and June 2023 and screened using pan-coronavirus RT-PCR approach. The overall positivity rate was 17.28%, significantly higher in caves (18.8%) than temples (4.41%) (p = 0.003). C. plicatus showed the highest positivity rate (21.38%), followed by Hipposideros spp. 4%, while Taphozous spp. were negative. Phylogenetic analysis revealed diverse coronavirus lineages within Alphacoronavirus (80.4%) and Betacoronavirus (19.6%) genera. Although none were closely related to known human pathogens, coronaviruses of Decacovirus genus related to Chinese bat viruses and Pedacovirus genus similar to porcine epidemic diarrhea virus (PEDV) were detected. Unclassified betacoronaviruses identified were also related to viruses from C. plicatus in Thailand. This study provides valuable insights into coronavirus circulation in both natural and anthropized environments. The detection of PEDV-like viruses underlines the need for continued surveillance at the human-bat interface, where activities like guano harvesting and temple visits increase contacts. Further genomic and functional studies would enhance our understanding of their evolutionary relationships and potential for further cross-species transmission.

Source: 

Link: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0341737

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#Genomic #features associated with sustained #mammalian #transmission of avian #influenza A viruses

 

Abstract

Comparably few lineages of influenza A virus (IAV) have evolved long-term sustained transmission in mammals. The reasons remain largely unknown, and the possibility of avian IAVs evolving sustained mammalian transmission is an ongoing concern. Here we measured the GC content and frequency of GC dinucleotides in 115,520 whole genomes of IAVs using bioinformatic analyses. We found that persistent mammalian lineages showed declining trends in GC-related content and could be reliably separated from IAVs circulating only in birds and those sporadically infecting mammals. Similarly, the earliest viruses of persistent mammalian lineages showed reduced GC-related content, suggesting that this trait might in part contribute to their eventual persistence. Recent highly pathogenic 2.3.4.4b H5 viruses that spread in mink, foxes and humans were also characterized by reduced GC-related content. While not sufficient, reduced GC-related content may be a necessary condition for sustained mammalian transmission and should be included in risk assessment tools for pandemic influenza.

Source: 

Link: https://www.nature.com/articles/s41564-025-02257-4

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High pathogenicity avian #influenza virus #H5N1 clade 2.3.4.4b in #Antarctica: Multiple Introductions and the First Confirmed Infection of Ice-Dependent #Seals

 

Abstract

Highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b has expanded rapidly across the Southern Ocean since 2023, causing extensive mortality in sub-Antarctic wildlife. Yet its penetration into Antarctica and impacts on ice-dependent species remain poorly resolved primarily due to surveillance constraints. We report the first confirmed H5N1 infection in an Antarctic ice-dependent seal (crabeater seal; Lobodon carcinophaga) and document mortality of crabeater seals across the northern Weddell Sea during November-December 2024. Combining genomic, serological and observational data across nine species, we detected H5N1 RNA in a crabeater seal and a kelp gull (Larus dominicanus), and recovered complete HA, NA and M2 gene sequences from both. Phylogenetic analyses allowed us to identify at least two independent introductions of HPAI H5N1 clade 2.3.4.4b into the northern Antarctic Peninsula region. Serology provided strong evidence of prior exposure in scavenging birds, but no detectable H5 immunity in penguins or pinnipeds. Together, the results demonstrate ongoing novel viral incursions into Antarctica, likely facilitated by at-sea processes e.g. animal interactions on ice floes, that remain invisible to land-based surveillance. These findings highlight the vulnerability of ice-dependent pinnipeds to HPAI H5N1 clade 2.3.4.4b and the urgent need for expanded integrated Antarctic monitoring frameworks that pair serology, opportunistic carcass sampling and genomic sequencing.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

Rolex-National Geographic Perpetual Planet Expeditions

Schmidt Oceans Institute

Geoffrey Evans Trust

Kenneth C. Griffin

Griffin Catalyst

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.01.04.697571v1

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Expanding Horizons: #Host Range #Evolution and #Treatment Strategies for Highly Pathogenic Avian #Influenza #H5N1 and #H7N9

 

Abstract

Avian influenza viruses (AIVs), including H5N1 and H7N9, from the Orthomyxoviridae family present substantial public health concerns. The predominant circulating clade 2.3.4.4b has demonstrated enhanced capacity for mammalian adaptation, raising concerns about potential reassortment with human seasonal influenza viruses. Unlike H7N9’s limited host range, H5N1 infects birds, various mammals, and humans. Recent concerns include widespread H5N1 infection of U.S. dairy cattle across 18 states, affecting over 1000 herds with 71 human infections (70 H5N1 and 1 H5N5). Key observations include cow-to-cow transmission, viral presence in milk, and transmission to humans, mainly through occupational exposure. Evidence of mammal-to-mammal transmission has been documented in European and Canadian foxes and South American marine mammals. Standard pasteurization effectively inactivates the virus in milk. The continuing mammalian adaptations, particularly mutations like PB2-E627K, PB2-D701N, and PB2-M535I, suggest potential for further evolution in new hosts, emphasizing the need for enhanced surveillance to mitigate pandemic risks.

Source: 

Link: https://www.mdpi.com/1999-4915/18/1/54

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