

Policy brief: “Biodiversity mitigates health risks”
Biodiversity can mitigate the spread of infectious diseases. Human disruptions alter ecosystems’ ability to protect our health.
Recent decades have seen a dramatic increase in the emergence of new infectious diseases, most of which originate from wildlife. This increase has been attributed to human-driven degradation of natural ecosystems and the resulting dramatic decline in biodiversity. Biodiversity is the source of most infectious diseases, with more than 60% of human pathogens originating in animals (zoonoses). At the same time, biodiversity is essential for protecting human health, as intact ecosystems control the spread of pathogens. Biodiversity can also reduce the prevalence and transmission of some pathogens.
In 2018, Biodiversa+ launched the BiodivHealth call to support research at the intersection of biodiversity and health. This brief presents findings from BIODIV-AFREID, BioRodDis, Dr.FOREST, DiMoC, ANTIVERSA and SuppressSoil on how biodiversity can mitigate the propagation and spread of infectious diseases, including zoonotic diseases, vector-borne diseases, and antimicrobial diseases. It also examines how human disturbance of nature alters ecosystems and the ability of biodiversity to protect human health.
Emerging infectious diseases
Wildlife hosts a variety of pathogens. Many rodents and bats carry zoonotic viruses that can infect humans. Diverse ecosystems help reduce pathogen prevalence. However, human activities like habitat destruction, land-use change, and wildlife trade increase contact between humans and wildlife, facilitating pathogen spillover. Chemical pollution, climate change, invasive species, and global trade exacerbate these risks.
- Protect and restore biodiversity to benefit human health and reduce pathogen prevalence. The Convention on Biological Diversity (CBD) Kunming-Montreal Global Biodiversity Framework and the EU Biodiversity Strategy for 2030 acknowledge the interlinkages between biodiversity and human health. Findings on the effects of human disturbance on ecosystems and zoonotic spread emphasize the urgency of implementing these conservation plans to reduce spillover risks linked to ecosystem degradation.
- Strengthen the implementation of the One Health approach that recognises the link between the health of people, animals, and the environment by implementing the UN One Health Joint Plan of Action. Results presented in this brief indicate the need for cross-disciplinary collaborations, specifically between ecologists, veterinarians, and public health professionals, to address the interconnected risks to human health and biodiversity.
- Implement surveillance of pathogens in wildlife and the environment (soil, water) to identify emerging risks to humans. Support global reporting of zoonotic outbreaks in humans and wildlife as part of a pandemic preparedness plan under Regulation (EU) 2022/2371 on serious cross-border threats to health.
- Limit wild meat trade and strictly enforce bans on illegal wildlife trade, such as Regulation (EC) 338/97 on trade in wild species and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Illegal wildlife trade drives biodiversity loss and increases the risk of pathogen transmission to humans.
Complex interactions
While biodiversity can sometimes reduce pathogen spread (dilution effect), the relationship is complex and depends on specific interactions between hosts, pathogens, and species diversity within each ecological community. Reducing small mammal diversity can increase the prevalence of zoonotic pathogens. Higher vertebrate diversity can increase the prevalence of some mosquito-borne diseases. Habitat diversity, in addition to species diversity, is essential for managing pathogen prevalence. For example, forest diversity can reduce the spread of tick-borne diseases. Understanding these complex interactions is crucial for effective disease prevention and control strategies.
- Investigate the specific interaction between pathogens of zoonotic risk, host species, and biodiversity within local ecosystems. Locally tailored studies are needed to guide effective conservation practices and reduce zoonotic risks.
- Identify and restore habitat properties that reduce the prevalence of pathogens near human populations. Human health risks could be considered within the newly adopted EU Nature Restoration Law. For example, conserve urban ecosystems (Article 8) to support small mammal diversity and to reduce relative abundance of pathogen hosts, and restore forest structural and species diversity (Article 12) to reduce tick-borne pathogens.
- Apply animal control with caution. Non-specific eradication programmes can disrupt ecological balance and increase pathogen spread; targeted control is recommended. Amending Article 31 of Regulation (EU) 2016/429 (‘Animal Health Law’) to ensure high specificity to target species, might promote this goal. Similarly, target mosquito and tick control to relevant vector species to protect globally declining insect populations.
Microbial diversity
Microbial diversity plays a key role in limiting pathogen infection and antimicrobial resistance. Land-use change can reduce the diversity of gut microbiomes in small mammals, potentially impairing their immune response. In plants, diverse soil microbial communities can suppress pathogens and pests. Higher microbial diversity in natural environments (soils and water) is linked to lower abundance of antibiotic resistance genes.
- Support microbial diversity in a sustainable way to promote resistance to pathogenic infections. Restore ecosystem health and diversity and reduce the use of chemicals and broad-spectrum antimicrobials. Enforce Regulation (EU) 2019/6 to prohibit routine antibiotic use in farming (Article 107). Soil microbial diversity can be protected with the newly adopted EU Soil Strategy for 2030. Monitoring microbial diversity could also serve as an indicator of ecosystem health.
- Monitor the spread and propagation of antimicrobial resistance (AMR) in the environment, focusing on the role of local biodiversity in attenuating AMR propagation.