"The Next Pandemic? Why 9% of Global Land Faces High Zoonotic Outbreak Risk"

 

A groundbreaking study published in Science Advances has revealed that over 9.3% of the world’s land surface is at high or very high risk of zoonotic outbreaks—diseases that jump from animals to humans, such as COVID-19, Ebola, and avian influenza. This alarming finding underscores the urgent need for enhanced global health surveillance, proactive public health strategies, and interdisciplinary collaboration to mitigate the growing threat of zoonotic diseases. With climate change, deforestation, and human encroachment into wildlife habitats identified as key drivers, the study paints a sobering picture of a world increasingly vulnerable to pandemics. In this article, we’ll explore the study’s findings, the factors fueling zoonotic risks, and what can be done to prevent the next global health crisis.

Understanding Zoonotic Diseases

Zoonotic diseases, or zoonoses, are infections transmitted from animals to humans, either directly or through vectors like mosquitoes or ticks. According to the World Health Organization (WHO), approximately 60% of emerging infectious diseases are zoonotic, with 75% of these originating in wildlife. Examples include:

• COVID-19, believed to have originated from bats, possibly via an intermediate host in a wildlife market.
• Ebola, linked to fruit bats and primates.
• Rabies, transmitted through bites from infected mammals like dogs.
• Swine flu (H1N1), which jumped from pigs to humans.

These diseases pose significant public health challenges, causing an estimated 2.5 billion cases of illness and 2.7 million deaths annually. The study’s findings highlight that zoonotic risks are not confined to remote jungles but are increasingly encroaching into human-populated areas due to environmental and socio-economic changes.

Key Findings of the Study

Published on July 25, 2025, the study estimates that 9.3% of global land—split into 6.3% at high risk and 3% at very high risk—is vulnerable to zoonotic outbreaks. Approximately 3% of the world’s population lives in these extremely risky areas, while a fifth resides in medium-risk zones. The research, featured in The Economic Times and other outlets, provides a detailed breakdown of regional vulnerabilities:

• Latin America: 27% of land is at high or very high risk, the highest globally.
• Oceania: 18.6% of land faces similar risks.
• Asia: 7% of land is at risk, with densely populated areas amplifying the threat.
• Africa: 5% of land is vulnerable, particularly in regions with wildlife-human overlap.

The study introduces an epidemic risk index, a tool to identify high-risk areas and guide policymakers in resource allocation, response capacity building, and international collaboration. This index is critical for prioritizing surveillance in regions where spillover events—when pathogens jump from animals to humans—are most likely.

Drivers of Zoonotic Risk

The study identifies several interconnected factors driving the heightened risk of zoonotic outbreaks, with climate change and human activities at the forefront.

1. Climate Change

Rising temperatures and altered rainfall patterns are reshaping ecosystems, forcing wildlife into closer contact with humans. For instance, warming climates push disease-carrying vectors like mosquitoes into new regions, increasing the spread of diseases such as dengue and Zika. The study notes that climate-related environmental changes significantly elevate a region’s vulnerability to spillover events.

2. Deforestation and Land-Use Change

Deforestation for agriculture, logging, and urban expansion destroys wildlife habitats, pushing animals into human settlements. The United Nations Environment Programme estimates that 75% of emerging infectious diseases are zoonotic, largely due to such human-induced changes. The study aligns with earlier research in Nature Communications, which found that zoonotic risk is elevated in forested tropical regions undergoing land-use changes.

3. Wildlife Trade and Markets

The global wildlife trade, valued at $2.9–4.4 trillion between 1997 and 2016, is a major conduit for zoonotic pathogens. Illegal and unregulated trade, worth up to $23 billion annually, exacerbates risks by moving infected animals across borders. Live animal markets, where diverse species are caged in close proximity, create ideal conditions for viral spillover, as seen with SARS and potentially COVID-19.

4. Agricultural Intensification

Intensive farming practices, including the heavy use of antibiotics, increase zoonotic risks. Agricultural workers face a 30 times higher risk of zoonotic influenza compared to the general public. The study references a 2022 World Bank report stating that 60% of major outbreaks since 1974 are linked to land-use changes, particularly in livestock operations.

5. Globalization and Urbanization

The movement of people, animals, and goods through global trade and travel accelerates disease spread. Since 2000, airline flights have doubled, enabling pathogens to cross continents in hours. Urbanization, with more people living in dense areas near wildlife, further amplifies transmission risks.

Regional Insights: A Global Problem with Local Nuances

The study’s regional data reveals stark disparities in zoonotic risk:

• Latin America’s high risk is driven by deforestation in the Amazon, coupled with biodiversity-rich ecosystems that harbor diverse pathogens.
• Oceania faces risks due to its unique wildlife and expanding agricultural frontiers.
• Asia, particularly Southeast Asia, is a hotspot due to dense populations, wet markets, and wildlife trade. A 2016 study predicted high zoonotic risk in this region due to rodent-borne diseases.
• Africa’s risk is tied to human-wildlife interactions in rural areas, exacerbated by climate-driven migration of animals.

A complementary study by the Indian Council of Medical Research (ICMR) found that 8.3% of outbreaks in India between 2018 and 2023 were zoonotic, peaking during monsoon months (June–August). These findings emphasize the need for region-specific strategies.

The Human Cost

Zoonotic diseases have profound social, economic, and health impacts. Since 2003, pandemics and related health threats have caused over 15 million deaths and $4 trillion in economic losses globally. Vulnerable populations, such as agricultural workers and indigenous communities, face disproportionate risks due to frequent animal contact and limited healthcare access. The study’s estimate that 3% of the global population lives in extremely risky areas highlights the scale of the challenge.

The One Health Approach: A Path Forward

The WHO and CDC advocate for a One Health approach, which integrates human, animal, and environmental health to combat zoonotic threats. This interdisciplinary strategy emphasizes:

1.     Enhanced Surveillance: Scaling up pathogen monitoring at the human-animal interface, especially in high-risk areas like markets and farms.

2.     Cross-Sectoral Collaboration: Bridging gaps between human health, veterinary, and environmental sectors to improve early detection and response.

3.     Risk Reduction: Regulating wildlife trade, improving biosecurity in agriculture, and protecting ecosystems to minimize spillover opportunities.

4.     Public Education: Raising awareness about zoonotic risks and promoting behaviors like safe handling of animals.

The World Bank estimates that investing in One Health could yield $37 billion annually in benefits, far outweighing the $4 billion in yearly prevention costs.

Policy Recommendations

The study calls for translating risk estimates into actionable policies. Key recommendations include:

• Global Risk Mapping: Using the epidemic risk index to prioritize surveillance and resources in high-risk regions.
• Stricter Regulations: Banning high-risk wildlife markets and tightening controls on legal animal trade. Over 200 wildlife groups have urged the WHO to support a global ban on such markets.
• Climate Action: Mitigating climate change to stabilize ecosystems and reduce animal migration into human areas.
• Capacity Building: Strengthening health systems in low- and middle-income countries, which face higher spillover risks.
• Research Investment: Studying pathogen diversity in wildlife, particularly in bats and primates, which are frequent zoonotic reservoirs.

Challenges and Ethical Considerations

Implementing these measures is not without challenges. Low-income countries, often at higher risk, lack resources for robust surveillance. Ethical dilemmas arise when balancing conservation with disease control—culling bat populations, for example, can increase viral transmission. Cultural practices, such as wildlife consumption, also complicate bans. A nuanced approach, respecting local contexts while prioritizing global health, is essential.

Lessons from Past Pandemics

History offers critical lessons. The 2003 SARS outbreak, linked to civet cats in markets, prompted temporary bans in China, but lax enforcement allowed risks to persist. The 2009 swine flu pandemic, which hospitalized over 900,000 Americans, highlighted vulnerabilities in livestock systems. COVID-19, with over 100 million U.S. cases, exposed regulatory gaps in animal markets globally. These events underscore the need for sustained, not reactive, action.

The Role of Individuals

While systemic change is crucial, individuals can contribute by:

• Supporting sustainable agriculture to reduce deforestation.
• Avoiding exotic pets, which fuel risky trade.
• Advocating for policies that protect ecosystems and regulate animal industries.
• Staying informed about zoonotic risks in their regions.

Conclusion: A Call to Action

The study’s revelation that over 9% of the world’s land is at high risk of zoonotic outbreaks is a stark reminder of our interconnectedness with nature. As human activities continue to disrupt ecosystems, the threat of pandemics grows. By embracing a One Health approach, investing in surveillance, and addressing root causes like climate change and wildlife trade, we can reduce these risks. The cost of inaction is too high—billions of lives and trillions of dollars are at stake. Let this study be a catalyst for global cooperation to prevent the next pandemic before it begins.