In northern Italy, at least eight bat species are using areas in and around pig farms. New field evidence from the national institute for animal health, food safety and zoonoses, IZSVe, highlights a dual reality: these sites can function as conservation oases in intensively farmed landscapes, while gaps in farm biosecurity leave a residual pathway for interspecies viral exchange.
Field signals from a porous wildlife-livestock interface
Investigators assessed bat activity, farm layout and the presence of coronaviruses as a case study for potential spillover at the wildlife-livestock-human boundary. Drawing on a One Health framework that treats ecosystems, animals and people as part of the same risk system, the team documented how routine farming practices can unintentionally create shared space between bats and pigs.
“Reinforcing these measures could mitigate the risk of exposure to various coronaviruses (CoVs) and, more generally, to viruses associated with wildlife, ultimately contributing to improved coexistence between humans, livestock and wildlife,” the institute concludes.
- Setting: Commercial pig units in northern Italy situated within mixed agricultural landscapes.
- Wildlife use: Multiple bat species foraging over open yards, feed areas and water bodies, with some roosting in nearby structures.
- Virology focus: Coronaviruses identified on selected farms used as a lens to study cross-species transmission risk rather than to signal an imminent threat.
Identified risk factors and on-farm exposure pathways
While the absolute probability of spillover in any one location is uncertain and likely low, the study and broader veterinary experience point to recurring interface conditions that can be managed within standard biosecurity frameworks. For policymakers and farm operators, the question is less whether bats and pigs should share a landscape, and more how that coexistence is structured on the ground.
- Open-sided or naturally ventilated housing without wildlife-exclusion features.
- Unsealed feed or water points that are accessible to wildlife.
- Structural gaps in roofs, lofts or service areas that allow bat entry.
- Organic waste, slurry and standing water that elevate insect densities and bat foraging activity.
- Lighting and vegetation patterns that concentrate insects near pig areas.
- High local pig density and frequent vehicle movements that increase network connectivity between farms.
Individually, these factors are familiar to farm managers. In combination, they can create a permeable interface where bat guano or contaminated environmental material has a clearer pathway into pig housing, equipment or personnel workflows.
Conservation value with measurable public‑health trade‑offs
In simplified agricultural zones, pig facilities can provide habitat heterogeneity, supporting bat biodiversity and natural pest control. That ecological service can reduce pressure to use chemical pesticides, but it coexists with the virological reality that bats are reservoirs for diverse coronaviruses, some with known relevance for livestock and humans.
- Potential benefits observed: Suppression of insect pests; local biodiversity gains where surrounding land is uniform; additional roosting and commuting habitat for bat populations of conservation concern.
- Residual exposure considerations: Bats foraging or roosting near pigs increases the chance that contaminated materials contact farm environments, especially where roofs, feed storage and waste areas are not sealed against wildlife.
For environment and agriculture ministries, the findings underline that bat protection and disease prevention need not be in conflict, but they do require coordinated guidance on where to encourage roosts and where to rely on non-lethal deterrence.
Why swine systems matter in coronavirus evolution
“The interface between wildlife, livestock and humans constitutes a highly permeable boundary where infectious diseases with epidemic potential can emerge,” explains Stefania Leopardi, senior veterinarian and research coordinator. “We know that pig farms can serve as potential ‘hot spots’ for the spread and emergence of dangerous recombinant variants that may threaten both animal and human health. Accordingly, identifying new coronaviruses is key to assessing their capacity to adapt to pigs and humans, but it is equally important to understand the risk factors that could facilitate spillover events across animal species.”
Coronaviruses circulate widely in wildlife and livestock, including swine pathogens such as porcine epidemic diarrhoea virus. Recombination is a documented feature of coronavirus evolution, which is why veterinary public health programmes emphasize early detection, genetic characterization and risk assessment rather than assumptions about species barriers. Swine systems, with large populations and frequent animal movements, can act as amplifiers or mixing vessels if new viruses establish themselves.
Policy levers and institutional responsibilities in Europe
European animal‑health governance already embeds many of the tools required to manage wildlife-livestock interfaces without compromising conservation goals. The core framework, the EU Animal Health Law, sets out cross‑cutting duties on prevention, surveillance and early detection that member states can apply to emerging risks at bat-pig interfaces.
| Level | Measure or mandate | Purpose | Primary owner |
|---|---|---|---|
| EU | EU Animal Health Law | Sets general biosecurity duties, notification, and surveillance requirements for transmissible animal diseases, including emerging and wildlife‑linked infections. | European Commission; Member States |
| National/Regional | Veterinary public health institutes and reference laboratories | Wildlife disease monitoring, coronavirus detection and sequencing, risk assessment, and guidance to authorities, with scope to issue targeted advice for high‑density pig regions. | Public laboratories; competent authorities |
| Farm networks | Company and producer biosecurity standards | Structural barriers to wildlife entry; hygienic design for feed, water and waste handling; vector management policies that translate regulatory expectations into day‑to‑day practice. | Producers; integrators |
| Conservation | Protected status for bats; permitted roost management | Safeguards bat populations while enabling non‑lethal mitigation at sensitive sites, for example by relocating roosts away from the most exposed pig housing. | Environment ministries; wildlife agencies |
For regulators, the Italian fieldwork offers a concrete use case: how to operationalise existing rules on biosecurity and wildlife contact, turning high‑level obligations into specific design choices on farms.
System capacity and surveillance priorities
The study points to a set of practical priorities that can be adopted or scaled within existing surveillance and farm‑assurance systems.
- Targeted environmental sampling: Guano, surfaces and water near animal areas to screen for coronavirus signals, feeding into regional and national early‑warning systems.
- Genomic surveillance: Routine sequencing to detect emergence or recombination events with potential relevance to swine health, enabling risk‑based responses before disease spreads widely.
- Interface mapping: Geospatial profiling of bat activity, farm features and landscape attractants to identify higher‑risk configurations for regulatory attention or technical support.
- Information flow: Rapid reporting channels between farms, laboratories and veterinary authorities to support proportionate, time‑bound responses and avoid ad‑hoc, reactive measures.
- Cross‑sector coordination: One Health collaboration that aligns animal‑health, environmental and public‑health objectives, particularly when drafting guidance for farmers in bat‑rich regions.
Balancing co‑benefits with practical risk reduction
The northern Italy findings reinforce a pragmatic lens for policy and industry: coexistence is feasible when wildlife‑exclusion features, hygienic design and monitoring are treated as standard infrastructure rather than emergency add‑ons. That approach preserves the ecological upside of bats while narrowing pathways for viral exchange in dense livestock settings.
For decision‑makers, the signal from this work is less a call for new law than for disciplined implementation of what is already on the books. For producers, it is an argument for viewing bat‑proofing, waste management and environmental surveillance not as niche add‑ons, but as part of a modern, resilient swine‑health strategy.
