#USA, #Oregon: Avoid #contact with #bats to reduce #rabies exposure risk (Dept. of Health, July 31 '26)

 

July 30, 2026

    PORTLAND, Ore.—Oregon Health Authority (OHA) and the Oregon Department of Fish and Wildlife (ODFW) are urging people to prevent exposure to rabies while highlighting the importance of bats and other wildlife to the state’s ecosystems.

    So far, 22 bats have tested positive for rabies in 2026, according to OHA data. That means the state has matched – and is poised to surpass – its record for the number of bats that test positive for rabies in a single year. Bats have carried the rabies virus in their populations for thousands of years and are well known to carry rabies today, but generally at a very low level. Nevertheless, they account for the most human exposures to the virus more than any other species in the U.S.

    The highest number of animals testing positive for rabies since 2000 was in 2006, when 22 bats and two foxes were found to be carrying the disease. In 2023, 20 bats tested positive for the virus.

    Emilio DeBess, DVM, public health veterinarian at OHA’s Public Health Division, said the more contact someone has with bats, the higher the risk of exposure to rabies.

    “Unfortunately, when people find a dead or dying bat, they may pick it up with their hands because they want to help it, or maybe they’re just curious,” DeBess said. “When a bat or other wild animal is sick or dying with rabies, there’s an increased chance they will bite or transmit the virus in other ways.”

    Colin Gillin, DVM, ODFW state wildlife veterinarian, agrees that bats and other wildlife rarely bite people but may do so if they are sick or feel threatened. Oregon bats, in particular, eat only insects—about 1,000 insects every hour—and avoid people.

    “Bats provide important ecosystem services in Oregon, but also globally with insect control, seed dispersal, and pollination of specific plants, supporting agriculture and forest systems,” Gillin said. “And like many animals that can carry disease, bats can also prevent or suppress disease by reducing mosquitoes and other vectors that carry human and animal pathogens.”

    ° What to do if you find a bat

        § Bats are protected wildlife, which makes it illegal to harm or keep them. If you see a bat that appears to be sick:

            * Stay calm, do not touch it, and keep people and pets away.

            * When the sick or dead bat is indoors, do not release the bat. It may have exposed someone or a pet to rabies. If it is safe to do so, place a container or box over the bat.

           * When the sick or dead bat is outdoors and may have exposed someone to rabies, cover it with a box or bucket to keep it in place, if safe to do so. Finding a dead bat does not require any action unless someone was bitten or scratched before the bat died.

            * Contact your local health authority or veterinarian for your area right away to discuss potential exposures to humans or pets.

            * If there are multiple sick or dead bats observed in an area, report it to ODFW.

        § When a person or pet has been bitten or scratched by an animal that may have rabies, report this exposure immediately to your local animal regulation services or local public health authority. Seek medical care immediately from a medical provider or veterinarian.

            * Teach children to avoid all contact with bats and other wildlife.

            * Avoid bats seen in the wild, such as while hiking.

            * Make sure your dog or cats' vaccinations are up to date, whether they are indoor or outdoor pets.

            * Unvaccinated pets that come into contact with a bat may be quarantined for up to four months, or euthanized.

            * Protect your home from bats by covering vents, chimneys, and other entry points with screens.

            * If you have roosting (nesting) bats living in your attic or other areas of your house, call a wildlife control operator (WCO). ODFW is unable to respond to homeowner requests for bat removal.

(...)

Source: 

Link: https://www.oregon.gov/oha/ERD/Pages/Avoid-contact-with-bats-to-reduce-rabies-exposure-risk.aspx

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Assessment of Quantitative #Genetic #Distances Supports the Separation of #H17N10 and #H18N11 Subtypes of #Influenza a Virus into a Distinct Species

 

Abstract

The taxonomic status of the H17N10 and H18N11 influenza A viruses isolated from bats remains unclear due to the absence of quantitative classification criteria at this taxonomic level. A total of 3328 representative IAV genomes, encompassing all eight protein-coding segments, were analysed. Various genetic distance-based metrics were assessed at the pairwise level, including intra- and intergroup nucleotide distances, dN/dS ratios, and transition/transversion ratios, to facilitate the differentiation of the Alphainfluenzavirus genus into distinct taxa. Pairwise distances for seven of the eight segments (PB2, PB1, PA, NP, M, NA, NS) consistently differentiated the H17–H18 group from H1–H16. Across segments, intergroup nucleotide divergence was consistently above a lower bound of ~25%, with segment-specific values extending to higher levels (up to ~40% in PB2 and PA), while intragroup divergence remained substantially lower. The HA segment did not conform to this pattern, which is consistent with the hypothesis of ancient reassortment. The distribution of pairwise dN/dS values for the PB2, PB1, PA, and NP segments is evidently bimodal. Intergroup comparisons were consistently higher across all segments, whereas intragroup values remained lower. A similar lower boundary of approximately 0.12 was observed across segments, while the upper range of intergroup values varied by gene. Overall, the results support a consistent gene-specific separation pattern. Previously demonstrated absence of reassortment compatibility between bat viruses (H17–H18) and canonical influenza A (H1–H16) viruses indicates that these lineages have evolved independently over an extended period. These consistent genomic patterns provide support for the hypothesis that H17N10 and H18N11 viruses may represent a separate species within the genus Alphainfluenzavirus.

Source: 

Link: https://www.mdpi.com/1999-4915/18/8/838

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Characterization and evolutionary history of novel #SARS-CoV-2-related viruses in #bats from #Cambodia

 

Abstract

Circulating bat coronaviruses present a significant pandemic threat, yet our understanding of their genetic diversity and evolutionary dynamics remains limited. Over 3 years, we sampled 1,462 bats in Cambodia’s Steung Treng province, identifying extensive and diverse coronaviruses co-circulation. Using metatranscriptomic and amplicon sequencing, we generated 33 complete sarbecovirus genomes sequences, revealing novel lineages that cluster into four distinct groups, each associated with different Rhinolophus bat species. Our analysis highlights rapid migration and recombination of sarbecovirus lineages over short distances and timescales. Of note, the receptor-binding domains of two novel viral groups exhibit high similarity to SARS-CoV-2, and pseudovirus assays confirmed the ability of this spike protein to mediate entry into cells expressing human ACE2, suggesting a potential zoonotic risk. The observed genetic diversity underscores the urgent need for continuous surveillance to identify high-risk animal-to-human interfaces and inform pandemic preparedness.

Source: 

Link: https://www.nature.com/articles/s41467-026-75954-1

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#MHC-II acts as a #fusion-triggering #receptor for #bat #influenza virus

 

Abstract

Influenza A virus hemagglutinin is a prototypical class I viral fusion protein that binds sialylated glycans and is activated by low pH in endosomes. In contrast, bat-derived IAV subtypes H17N10 and H18N11 use major histocompatibility complex class II (MHC-II) as an entry receptor, but how this receptor contributes to membrane fusion remains unknown. We find that MHC-II-dependent hemagglutinin subtypes H17, H18, and H19 possess an increased negative net charge relative to canonical HAs. Using cryo-electron tomography, we demonstrate that H18N11 morphology remains stable and H18 is in prefusion conformation at strongly acidic pH. Remarkably, H18 undergoes fusion-relevant conformational changes only when both MHC-II binding and low pH are present. By reconstitution of H18N11 fusion with liposomes and purified MHC-II, we show that receptor engagement is required to trigger the fusion activity of H18. These findings identify MHC-II as a receptor that directly triggers membrane fusion and reveal a previously unrecognized receptor-dependent mechanism of influenza virus entry.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

Deutsche Forschungsgemeinschaft, https://ror.org/018mejw64, 240245660 – P19, 537227910

European Research Council, 882631—Bat Flu

Excellence Initiative of the German Research Foundation, GSC-4, Spemann Graduate School

Hans A. Krebs Medical Scientist Programme

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.07.08.737388v1

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#Filovirus #Surveillance in Communities Bordering Equatorial Guinea, #Marburg #Outbreak, #Cameroon, 2023

 

Abstract

After the 2023 Equatorial Guinea Marburg virus (MARV) outbreak, surveillance of 181 persons in southern Cameroon detected MARV antibodies in 3 persons and Ebola virus antibodies in 7. Testing of 289 captured bats, including 158 Rousettus aegyptiacus bats, did not detect MARV RNA. Enhanced surveillance for regional filovirus spillover risks is warranted.

Source: 

Link: https://wwwnc.cdc.gov/eid/article/32/8/26-0117_article

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{#Canada} #Fatal #rabies in a #child (CMAJ)

 

{Summary}

Key points

    ° Rabies is a neurotropic infection that is rare in Canada and almost always fatal once symptoms develop.

    ° Rabies postexposure prophylaxis is highly effective in preventing infection in exposed humans if administered promptly and before onset of rabies symptoms.

    ° Any direct human contact with a bat is an indication for rabies postexposure prophylaxis and should be discussed with the regional public health authority.

    ° No established efficacious therapies are available for treatment of rabies once symptom onset has occurred.

An immunocompetent 11-year-old boy presented with odynophagia and emesis to an urban hospital emergency department in Ontario, Canada. Seven days before presentation, he had developed progressive right-sided facial paresthesia and numbness, followed by anorexia and right-sided facial swelling. Four days after symptom onset, he had been prescribed oral valacyclovir (1 g, 3 times daily) at a local urgent care clinic for presumed Bell palsy secondary to herpes simplex virus; however, he was unable to tolerate this because of odynophagia. He had no history of allergies, sick contacts, tick bites, or recent travel outside the country.

(...)

Source: Canadian Medical Association Journal, https://www.cmaj.ca/

Link: https://www.cmaj.ca/content/198/25/E969

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#Nipah Virus Shedding in #Urine from Fruit #Bats, #SriLanka, 2018–2019

 

Abstract

Nipah virus causes outbreaks in humans with high case-fatality rates. In this study, we confirmed the presence of Nipah virus in Sri Lanka in Pteropus medius fruit bats, one of the known natural reservoir species. Sequences we generated were genetically related to Nipah virus strains from outbreaks in southern India.

Source: 

Link: https://wwwnc.cdc.gov/eid/article/32/7/25-1567_article

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Egyptian rousette #bat humoral #immunity to #H9 #influenza hemagglutinin

 

Abstract

In mammals, antibodies are central to antiviral defense, but they can also impose selective pressure that drives viral evolution. The interplay between viral antigenic variation and host antibody diversification constitutes a molecular arms race that influences pathogenicity, transmission, and spillover risk. Bats are reservoirs for zoonotic viruses with pandemic potential yet they appear to tolerate infection without overt disease. Although distinctive features of bat innate immunity have been described, the role of adaptive immunity, particularly antibody-mediated responses, remains largely undefined. Moreover, how antibody evolutionary pressure operates in bats is unknown, in part because tools to interrogate bat B cell responses at the monoclonal level are limited. Here, we developed a yeast surface display library of bat antibodies derived from splenic RNA of wild-caught Egyptian rousette bats to interrogate humoral responses to the bat-derived H9 influenza hemagglutinin. We isolated monoclonal antibodies recognizing the hemagglutinin (HA) antigen and defined their gene usage, somatic hypermutation frequency, binding affinities, and breadth. We then used cryo-EM to structurally characterize three bat antibodies in complex with HA engaging distinct antigenic sites. Together, these data enable direct comparison with human anti-influenza antibodies highlighting similarities in humoral immunity across mammals and provides a tool to examine bat antibody responses to other potential zoonotic viruses.

Competing Interest Statement

The authors have declared no competing interest.

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.06.04.730146v1

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Detection of a #Merbecovirus with potential #ACE2 usage in #France

 

ABSTRACT

A novel Merbecovirus, designated Cam-2023, has been identified in Pipistrellus pipistrellus in France through non-invasive surveillance. Phylogenetic analysis demonstrates that Cam-2023 belongs to a Merbecovirus clade previously associated with ACE2 usage in closely related viruses detected in the Netherlands and Russia. While the receptor usage of Cam-2023 remains to be functionally validated, sequence similarities within the Spike protein, particularly the receptor-binding domain, suggest a putative association with a Merbecovirus clade previously associated with ACE2 usage. This discovery broadens the known host diversity of this lineage and extends its geographical range to Western Europe. Our findings highlight the importance of continuous surveillance in European bat populations to better characterize the distribution and zoonotic potential of such high-risk coronaviruses.

Source: 

Link: https://www.tandfonline.com/doi/full/10.1080/22221751.2026.2651469

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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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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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Paralytic #rabies #outbreak mimicking #GBS in French #Amazonia

 

Abstract

Background

In the Amazonian region, vampire bats are the primary reservoir of rabies virus, causing sporadic and lethal human rabies cases that often remain unnoticed. Managing human cases in this region is challenging and further complicated by atypical clinical forms and the potential exposure to various toxic compounds, particularly among gold miners.

Methods

We carried out clinical, electrical, biological and histological analysis of concurrent cases of progressive motor neuronopathy and fatal encephalitis in a context of regular exposure to bat bites of gold miners living in a small and remote gold mine camp in Amazonia, in French Guiana, South America.

Findings

We analyzed a spatio-temporal cluster of three suspected rabies cases in 2024 with a fatal outcome, with concomitant onset of acute bilateral lower-limb paralysis without demyelination, two of which occurred presumably two weeks after a bat-bite. Electroneuromyography suggested the involvement of the anterior horn of the spinal cord, as described in furious forms of rabies. None of the cases exhibited other cardinal signs of the furious form. Confirmation of rabies was obtained for them on sera and brain biopsies collected ante- and post-mortem respectively.

Interpretation

The concurrent occurrence of disease, the axonal motor neuropathy mimicking the motor form of Guillain Barré syndrome in the context of paralytic rabies, lead to diagnostic-wandering. This underscores the importance of thinking about vampire bat rabies virus in the presence of any atypical neurological picture in patients living in exposed areas in Latin America.

Source: 

Link: https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014149

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Three decades of #discovery: An overview of #Hendra virus, the original #Henipavirus

 

Abstract

Hendra virus (HeV) emerged in Australia in 1994, causing a devastating outbreak among horses in Brisbane with spread to humans, resulting in one death. This nonsegmented, negative-stranded RNA virus belongs to the family Paramyxoviridae and represents the first zoonotic paramyxovirus isolated from bats. Flying foxes (genus Pteropus) serve as the natural reservoir, with all four mainland Australian species carrying antibodies with no apparent disease. HeV initiates infection by binding ephrin-B2 receptors on vascular endothelial cells, driving characteristic pathology involving vasculitis, thrombosis, and neurological complications. Horses are amplifying hosts, shedding virus abundantly in respiratory secretions and posing transmission risks to humans during invasive procedures. To date, seven confirmed human infections have been documented, with a 57% fatality rate, presenting as severe respiratory disease or progressive encephalitis. Two genetic variants are now recognized: the original HeV genotype 1 and the emerging HeV genotype 2, identified in limited equine cases. Recent surveillance of bat roosts revealed substantial viral diversity, with peak shedding occurring during winter—coinciding with equine spillover peaks. Prevention integrates multiple strategies: the licensed equine vaccine Equivac which provides One Health protection for both horses and human contacts; biosecurity measures including proper PPE; and habitat restoration to reduce nutritional stress in bat populations. Emerging therapeutics include monoclonal antibodies, with m102.4 showing cross-protective activity against both HeV and the closely related Nipah virus. No licensed human vaccines currently exist, though candidates are in development. Future prevention strategies increasingly recognize the importance of Indigenous-led conservation approaches alongside biomedical interventions. This review will focus on the history of HeV, virus replication and diversity, epidemiology, clinical manifestations, diagnosis, treatment, prevention, as well as ecological and interdisciplinary countermeasures.

Author summary

Hendra virus (HeV) was first detected in 1994, with two outbreaks occurring within 2 months of that year. One was the index outbreak in the Brisbane suburb of Hendra, and the other was retrospectively diagnosed in the following year. This review examines the discoveries that have been made in the 30 years since its discovery.

Source: 

Link: https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014138

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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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Swine acute #diarrhea syndrome #coronavirus-related viruses from #bats show potential #interspecies infection

 

ABSTRACT

Swine acute diarrhea syndrome coronavirus (SADS-CoV) is a bat-originated virus causing severe diseases in piglets. Since the 2016 outbreak, diverse SADS-related CoVs (SADSr-CoVs) have been detected in Rhinolophus bats in China and Southeast Asia, but their potential interspecies infection and pathogenicity remain unknown. Herein, we sequenced the spike (S) genes of bat SADSr-CoVs and classified them into four genotypes. We constructed an infectious SADS-CoV cDNA clone (rSADS-CoV) and nine recombinant viruses by replacing the SADS-CoV S gene with that of bat SADSr-CoVs. Recombinant SADSr-CoVs could replicate efficiently in respiratory and intestinal cell lines and human- and swine-derived organoids and caused varying tissue damage and mortality in suckling mice. These viruses can be classified into at least five serotypes based on cross-neutralization assays. Our findings highlight the potential risk of interspecies infection and provide important information for future surveillance of these bat viruses.

Source: Journal of Virology, https://journals.asm.org/doi/full/10.1128/jvi.02240-24?af=R

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#Spillover of #H5 #influenza viruses to vampire #bats at the marine-terrestrial interface

 

Abstract

The highly pathogenic H5N1 avian influenza A virus (IAV) clade 2.3.4.4b has spread globally and spilled over into multiple mammalian species, raising concerns about its pandemic potential. In late 2022, clade 2.3.4.4b viruses devastated seabird and marine mammal populations along the Pacific coast of South America. Here, we report the first evidence of H5 IAV infections in wild bats globally, focusing on common vampire bats (Desmodus rotundus) in coastal areas of Peru. Longitudinal serological screening, stable isotope analysis and metabarcoding revealed repeated exposures to H5 IAVs in vampire bats which feed on coastal wildlife species heavily impacted by the 2.3.4.4b epizootic, but no evidence of infection in populations without access to marine prey. We further report bat gene flow between IAV-exposed and IAV-naive populations, and IAV infections in a vampire bat colony that fed on both marine and terrestrial livestock prey, providing insights into how future IAV epizootics might spread spatially within bats and between marine and terrestrial ecosystems if a bat reservoir were established. Immunohistochemistry demonstrated that the H5 haemagglutinin protein binds to the upper respiratory tract of vampire bats, suggesting bat tissue susceptibility to H5 IAVs. Finally, vampire bat-derived kidney, liver, and lung cells supported entry, replication, and egress of avian and mammalian 2.3.4.4b viruses, confirming cellular infectivity. These results illustrate how combining ecological inference and experimental virology can pinpoint the species origins and biological significance of viral spillover at species interfaces. Recurrent exposures from marine wildlife, tissue and cellular susceptibility to H5N1 IAVs, and connections to other IAV-susceptible terrestrial mammals establish the prerequisite conditions for vampire bats to spread IAVs between marine and terrestrial environments or to form a novel reservoir of highly pathogenic IAVs.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

Wellcome Trust, https://ror.org/029chgv08, 218518/Z/19/Z, 217221/Z/19/Z, CC1114

Medical Research Council, MC_UU_00034/3, CC1114

NSF/Biotechnology and Biological Sciences Research Council, DEB 2011069, BB/V003798/1, BB/V004697/1

Medical Research Council and Department for Environment Food and Rural Affairs (FluTrailMap-One Health), MR/Y03368X/1, BB/Y007298/1

NERC, NE/V014730/1

Biotechnology and Biological Sciences Research Council/Medical Research Council, BB/Y006879/1

Carlsberg Foundation, https://ror.org/01kpjmx04, CF21-0411

Villum Fonden, VIL41390

Francis Crick Institute, Cancer Research UK, CC1114

National Institute of Allergy and Infectious Diseases, https://ror.org/043z4tv69, 75N93021C00015

Source: BioRxIV, https://www.biorxiv.org/content/10.1101/2025.11.09.686930v1

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Detection and genetic characterization of #alphacoronaviruses in co-roosting #bat species, southeastern #Kenya

 

Abstract

Bats are associated with some of the most significant and virulent emerging zoonoses globally, yet research and surveillance of bat pathogens remains limited across parts of the world. We surveyed the prevalence and genetic diversity of coronaviruses from bats in Taita Hills, southeastern Kenya, as part of ongoing surveillance efforts in this remote part of eastern Africa. We collected fecal and intestinal samples in May 2018 and March 2019 from 16 bat species. We detected one genus of coronavirus (alphacoronavirus), with an overall RNA prevalence of 6.5% (30/463). The prevalence of coronavirus RNA was 3.8% (9/235) and 11.6% (21/181) for the two most captured free-tailed bat species, Mops condylurus and M. pumilus respectively, with no detections from other bat species (0/90). Phylogenetic analyses based on the partial RNA-dependent RNA polymerase gene and whole genome sequences revealed that the sequences clustered together and were closely related to alphacoronavirus detected in free tailed bats in Eswatini, Nigeria and Rhinolophus simulator bats in South Africa. The sequences were more distantly related to alphacoronavirus isolated from Chaerophon plicatus bat species in Yunnan province, China and Ozimops species from southwestern Australia. These findings highlight coronavirus transmission among bats that share habitats with humans and livestock, posing a potential risk of exposure. Future research should investigate whether coronaviruses detected in these bats have the potential to spillover to other hosts.

Author summary

Bats are known to carry several zoonotic pathogens with potential to cause serious illnesses and death in humans. Yet, surveillance on the pathogens they carry remains limited in much of the world. We studied the prevalence and diversity of coronaviruses from bats in Taita Hills, southeastern Kenya to better understand the circulation of these viruses and inform disease preparedness. We detected alphacoronaviruses in urban Mops condylurus and M. pumilus bat species. The bat alpha coronaviruses we detected were closely related to alphacoronaviruses that have been previously detected in bats elsewhere in Africa and distantly related to alphacoronavirus detected from Chaerophon plicatus bat species in Yunnan province, China and Ozimops species from southwestern Australia. This work demonstrates coronavirus circulation among bats that share habitats with people and livestock providing conditions that can lead to spillover. Identifying whether coronaviruses detected in these bats have the potential to infect other hosts is critical for developing countermeasures and mitigating potential outbreaks.

Source: PLoS Neglected Tropical Diseases, https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0012805

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HKU25 clade #MERS-related #coronaviruses use #ACE2 as a functional #receptor

 

Abstract

Dipeptidyl peptidase-4 (DPP4) is an established receptor for Middle East respiratory syndrome-related coronaviruses (MERSr-CoVs), while recent studies have identified angiotensin-converting enzyme 2 (ACE2) usage in multiple merbecovirus clades. Yet, receptor usage of many genetically diverse bat MERSr-CoVs remains unclear. Here we show that broadly distributed HKU25 clade merbecoviruses use ACE2, rather than DPP4, as their receptor. Cryo-electron microscopy revealed that HsItaly2011 and VsCoV-a7 strains engage ACE2 similarly to HKU5 but with remodelled interfaces and distinct orthologue selectivity, suggesting a shared evolutionary origin of ACE2 recognition. EjCoV-3, a close relative of the DPP4-using BtCoV422, showed broad multi-species ACE2 tropism and preadaptation to human ACE2. Several ACE2 glycans and residues within or near the binding interface were identified as determinants of orthologue selectivity. These viruses remain sensitive to several broadly neutralizing antibodies and entry inhibitors, indicating potential countermeasures for future outbreaks. These findings highlight the versatility of ACE2 as a functional receptor for diverse coronaviruses.

Source: Nature Microbiology, https://www.nature.com/articles/s41564-025-02152-y

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#Bat #sarbecovirus WIV1-CoV bears an adaptive #mutation that alters #spike dynamics and enhances #ACE2 binding

 

Abstract

SARS-like betacoronaviruses (sarbecoviruses) endemic in bats pose a significant zoonotic threat to humans. Genetic pathways associated with spillover of bat sarbecoviruses into humans are incompletely understood. We previously showed that the wild-type spike of the rhinolophid bat coronavirus SHC014-CoV has poor entry activity and uncovered two distinct genetic pathways outside the receptor-binding domain (RBD) that increased spike opening, ACE2 binding, and cell entry. Herein, we show that the widely studied bat sarbecovirus WIV1-CoV is likely a cell culture-adapted variant whose progenitor bears a spike resembling that of Rs3367-CoV, which was sequenced from the same population of rhinolophid bats as SHC014-CoV. Our findings suggest that the acquisition of a single amino-acid substitution in the ‘630-loop’ of the S1 subunit was the key spike adaptation event during the successful isolation of WIV1-CoV, and that it enhances spike opening, virus-receptor recognition, and cell entry in much the same manner as the substitutions we previously identified in SHC014-CoV using a pseudotype system. The conformational constraints on both the SHC014-CoV and Rs3367-CoV spikes could be alleviated by pre-cleaving them with trypsin, suggesting that the spike-opening substitutions arose to circumvent the lack of S1–S2 cleavage. We propose that the ‘locked-down’ nature of these spikes and their requirement for S1–S2 cleavage to engage ACE2 represent viral optimizations for a fecal-oral lifestyle and immune evasion in their natural hosts. These adaptations may be a broader property of bat sarbecoviruses than currently recognized. The acquisition of a polybasic furin cleavage site at the S1–S2 boundary is accepted as a key viral adaptation for SARS-CoV-2 emergence that overcame a host protease barrier to viral entry in the mammalian respiratory tract. Our results suggest alternative spillover scenarios in which spike-opening substitutions that promote virus-receptor binding and entry could precede, or even initially replace, substitutions that enhance spike cleavage in the zoonotic host.

Source: PLoS Pathogens, https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1013123

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First #Evidence of #Mammarenavirus in the Giant Fruit #Bat (Artibeus lituratus) in #Mexico

 

Abstract

Background: 

In Mexico, two Mammarenavirus genotypes have been identified: Real de Catorce virus and Ocozocoautla de Espinosa virus (OCEV), which are found in rodents (Neotoma leucodon and Peromyscus mexicanus). Mammarenaviruses from clade B cause mild to severe infectious diseases in humans, particularly in South America. A 1967 outbreak in Chiapas, Mexico, was potentially linked to the OCEV.

Materials and Methods: 

Between 2017 and 2020, we collected bats across southern/southeastern Mexico to identify Mammarenavirus reservoirs. We analyzed 81 liver samples from 14 bat species using nested PCR. For quality control, we synthesized and OCEV S-region fragment into an ampicillin-resistant pUC57 plasmid, cloned in One Shot Stbl3 chemically competent E. coli.

Results: 

Here, we report the first detection of a Mammarenavirus (OCEV) in an Artibeus lituratus bat from Sabancuy, Campeche, southeastern Mexico. This finding represents the third Mammarenavirus recorded in this bat species in the Americas, suggesting it may harbor multiple Mammarenavirus species (OCEV and Mammarenavirus tacaribeense).

Conclusions: 

While this represents the first documentation of OCEV in a bat, it remains unknown whether environmental stressors could facilitate potential transmission to humans, particularly given the close association between Artibeus bats and human populations.

Source: Vector-Borne and Zoonotic Diseases, https://www.liebertpub.com/doi/abs/10.1177/15303667251377563

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