Biology subjects

Griffiths, M. E.

Publications and source records attributed to Griffiths, M. E..

4 recordsLinked to original sources

bioRxiv2026

Cross-Continental Analysis of Vampire Bat Betaherpesvirus Reveals Limited Interference Among Strains and Local Geographic Spread

Desmodus rotundus Betaherpesvirus (DrBHV) is a candidate vector for a transmissible vaccine targeting the circulation of rabies virus within its vampire bat reservoir. Studies assessing the potential for DrBHV as a vector have not considered its geographic range, potential for transboundary spread or how the diversity of wildtype DrBHV in natural bat populations might impede the spread of a modified vaccine strain. Here, by sequencing DrBHVs from vampire bats spanning 15 regions across 7 rabies-affected countries in Latin America and the Caribbean, we characterise the continent-scale distribution of DrBHV diversity and demonstrate widespread and apparently unconstrained co-infection. DrBHV occurred in all regions, forming a monophyletic clade consistent with a single introduction to vampire bats or host-virus co-speciation rather than frequent host switching. Phylogeographic analyses revealed cross-boundary spread that was predicted by geographic proximity. We identified 50 putative DrBHV strains and 79% of DrBHV-infected bats harboured multiple strains. No strains were over- or under-represented in co-infection and co-infections occurred proportionately to local strain prevalence. Whether strains circulated in given populations was predominantly driven by the geographic proximity of other populations containing that strain. The evolutionary relatedness of strains constrained neither rates of co-infection within individuals nor whether strains co-circulated within regions, suggesting vaccine vectors might be locally sourced rather than requiring imported, divergent strains to ameliorate interference. These results support the viability of DrBHV-vectored vaccines for mitigating rabies virus across Latin America and the Caribbean, despite widespread circulation of wildtype viruses.

genomics↗

bioRxiv2025

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

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.

ecology↗

bioRxiv2025

Mating behaviour and connectivity drive sporadic European bat lyssavirus 2 infections in Myotis myotis

Gaining insight into the transmission and persistence of zoonoses in wild reservoirs is essential for preventing outbreaks, assessing demographic impacts, and informing conservation strategies. Achieving this requires reliable estimates of key epidemiological parameters, which are governed by aspects of host ecology and behaviour that are notoriously difficult to quantify in many wild species. Taking advantage of a long term study of the ecology of five Greater mouse-eared bats (Myotis myotis) maternity colonies in France ([~]2700 marked individuals), we sought to characterise lyssavirus infection dynamics in a wild bat reservoir. Although no lyssavirus was isolated from any of the 422 saliva samples tested, we report the first indirect evidence of European bat lyssavirus 2 circulation in this species. Interestingly, seropositivity appeared sporadic within colonies (0-100% annually) and synchronized across them, with highest seroprevalence in 2015-2017, but remaining low otherwise. Fitting Bayesian compartmental epidemiological models, we found that shifts in EBLV-2 prevalence were primarily driven by mating season introduction, age-dependant variation in transmission, and frequency-dependent transmission dynamics. Lyssavirus outbreaks involve few deaths overall but can still yield high annual mortality rates. These findings underscore the value of integrating ecological and individual-level data with mechanistic modelling to enhance our understanding and management of zoonotic pathogens in wildlife.

ecology↗

bioRxiv2024

Dynamics of influenza transmission in vampire bats revealed by longitudinal monitoring and a large-scale anthropogenic perturbation

Interrupting pathogen transmission between species is a priority strategy to mitigate zoonotic threats. However, avoiding counterproductive interventions requires knowing animal reservoirs of infection and the dynamics of transmission within them, neither of which are easily ascertained from the cross-sectional surveys which currently dominate investigations into newly discovered viruses. We used biobanked sera and metagenomic data to reconstruct the transmission of recently discovered bat-associated influenza virus (BIV) over 12 years in three zones of Peru. Mechanistic models fit under a Bayesian framework, which enabled joint inference from serological and molecular data, showed that common vampire bats maintain BIV independently of the currently assumed fruit bat reservoir through immune waning and seasonal transmission pulses. A large-scale vampire bat cull targeting rabies incidentally halved BIV transmission, confirming vampire bats as maintenance hosts. Our results show how combining field studies, perturbation responses and multi-data type models can elucidate pathogen dynamics in nature and reveal pathogen-dependent effects of interventions.

ecology↗