The recent study published in Nature Microbiology presents a comprehensive global assessment of zoonotic virus diversity within urban-adapted mammal species, unveiling critical insights into the potential origins and spillover mechanisms of future pandemics. Researchers compiled data spanning over four centuries, from 1574 to 2023, encompassing eight urban-adapted mammals—red foxes, raccoons, raccoon dogs, masked palm civets, European hedgehogs, European shrews, and wild boars—across 116 countries. This extensive dataset sheds light on viral diversity, urban ecological dynamics, and zoonotic threats that loom at the interface of wildlife and human habitats.
Urbanization is an accelerating global phenomenon that profoundly alters habitats and ecological interactions. As cities encroach upon natural landscapes, many wildlife species adapt to human-dominated environments. Such urban-adapted species often live in close proximity to dense human populations, creating unique opportunities for pathogen transmission. Despite their evident role in pathogen ecology, prior investigations have largely overlooked their virome diversity and zoonotic potential at global scales. This investigation bridges that gap by systematically cataloging viruses harbored by urban-adapted mammals and examining their evolutionary relatedness to known human viruses.
The compiled dataset identified 286 viral species spanning 24 viral orders and 38 families, revealing a viral diversity far broader than previously appreciated in these urban-adapted species. Of particular concern, 14 of these viruses were classified as carrying high-risk zoonotic potential, based on phylogenetic analyses and known infection histories. These high-risk viruses underline the tangible threat posed by wildlife reservoirs that thrive in city environments, accentuating the need for vigilant viral monitoring and surveillance initiatives.
Among species analyzed, raccoon dogs demonstrated a significantly elevated viral positivity in urban habitats compared to raccoons, wild boars, and red foxes. This finding is revealing given the raccoon dog’s adaptability and contact frequencies in urban spaces. The higher viral positivity suggests that certain urban-adapted mammals could serve as critical viral mixing vessels or reservoirs, facilitating the maintenance and spillover of zoonotic pathogens. Understanding species-specific viral carriage and urban ecology is paramount to predicting and curbing zoonotic events.
Phylogenetic analyses conducted in the study also underscored close evolutionary relationships between a notable proportion of viruses found in urban-adapted mammals and viruses infecting humans. Such proximity in viral lineage suggests historical and ongoing viral exchanges, potentially including bidirectional spillover events. The concept of viral spillback—where viruses circulate from humans back into wildlife reservoirs—emerges as a significant dynamic influencing viral diversity and evolution in urban ecosystems.
The multifaceted relationship between urban-adapted wildlife and human populations presents a complex landscape for infectious disease emergence. Urban wildlife often occupy niches in man-made structures, sewer systems, and green spaces in close contact with humans, pets, and livestock. These interactions can create ecological hotspots for viral transmission chains, complicating efforts to disentangle reservoirs and intermediate hosts. Enhanced surveillance, therefore, must integrate wildlife ecology, virology, and urban planning to preempt outbreak risks effectively.
Temporal coverage spanning nearly 450 years affords unprecedented perspective on the historical dynamics of viral presence among these mammals. Documented viral infections were compiled from diverse sources such as scientific literature, surveillance records, and museum specimens. This temporal breadth enables researchers to discern both recent and longstanding viral–host associations, accounting for historical patterns of zoonotic emergence and viral evolution.
The study reinforces the relevance of One Health approaches, emphasizing the intertwined health of humans, animals, and ecosystems within urbanized landscapes. Urban-adapted mammals represent sentinel populations whose virome diversity offers early warning signals for zoonotic pathogens. Incorporating wildlife viral surveillance into routine public health frameworks can augment preparedness for pandemics initiated by zoonotic spillover.
Moreover, the study accentuates the role of land-use change and anthropogenic pressures in reshaping pathogen distributions. Urbanization often fragments habitats while simultaneously increasing interfaces between humans and wildlife. These disruptions have cascading effects on immune pressures, population densities, and behavioral ecology of urban-adapted species, all contributing to altered viral ecology and host competence.
Viral families identified exhibited a range of genomic architectures and replication strategies, from RNA viruses with rapid mutation rates to DNA viruses with more stable genomes. This viral heterogeneity increases the challenge of tracking and predicting zoonotic potential, as some viruses may adapt quicker to new hosts or escape immune detection. Future research should incorporate metagenomics and viral ecology to decipher the functional impacts of this diversity.
In addition to species-level differences, geographic variability emerged in the distribution of detected viruses, reflecting region-specific ecological and social factors. Human population density, sanitation infrastructure, climate, and biodiversity gradients all influence viral transmission cycles. Understanding these spatial patterns can inform targeted interventions in urban hotspots where zoonotic spillover risk is highest.
This comprehensive dataset fundamentally alters our understanding of urban wildlife as reservoirs in zoonotic disease ecology. While traditional focus has often rested on rural or forested ecosystems, urban environments are establishing themselves as dynamic epicenters of viral evolution and transmission. Policymakers and health authorities must recognize the shifting epidemiological terrain shaped by urban-adapted mammals.
In summary, this landmark study reveals the extensive diversity and spillover potential of viruses harbored by urban-adapted mammal species at a global scale. It highlights species like raccoon dogs as high-priority viral hosts within urban ecosystems. Phylogenetic evidence of viral sharing between urban wildlife and humans calls for integrated surveillance and urban planning measures to prevent future zoonotic outbreaks. Fostering research collaborations that span wildlife biology, virology, and public health will be crucial in mitigating emerging infectious disease threats in our rapidly urbanizing world.
The insights provided pave the way for developing predictive models of zoonotic risk that incorporate ecological, evolutionary, and anthropogenic variables. Future surveillance platforms will benefit from incorporating novel molecular technologies and big data analytics to dynamically track viral emergence in urban wildlife. This knowledge empowers us to move from reactive responses towards proactive prevention strategies, securing health resilience at the human–animal interface.
As urban centers continue expanding, understanding the intricacies of zoonotic virus diversity in urban-adapted mammals becomes an urgent imperative. This study stands as a critical foundation for bolstering global health security by illuminating viral reservoirs in urban settings that could seed the next pandemic. Enhanced surveillance, cross-sectoral collaboration, and integrative research will be our strongest arsenal against the persistent threat posed by zoonotic diseases emerging from our shared urban ecosystems.
Subject of Research:
Zoonotic virus diversity and spillover potential in urban-adapted mammal species.
Article Title:
A global-scale assessment of zoonotic virus diversity and spillover potential in urban-adapted mammal species.
Article References:
Wei, X., Li, H., Huang, Z.Y.X. et al. A global-scale assessment of zoonotic virus diversity and spillover potential in urban-adapted mammal species. Nat Microbiol (2026). https://doi.org/10.1038/s41564-026-02311-9
