Infectious Disease Emergence and Economics of Altered Landscapes (IDEEAL)

The USAID funded Infectious Disease Emergence and Economics of Altered Landscapes (IDEEAL) project began in October 2013 and was implemented by Conservation Medicine, EcoHealth Alliance, Universiti Malaysia Sabah, our Malaysian government partners, and local NGOs. It also involved close engagement with industries involved with land-use change. IDEEAL investigated how land-use change contributes to disease outbreaks. This project developed knowledge about the benefits of conserving forests to regulate disease, estimated both the far-reaching pros and cons of converting land, and provided governments, industries, and communities with tools and data to make more informed land-use decisions.

In the second phase of the project, research expanded to Peninsular Malaysia, Thailand, and in a limited capacity, Indonesia, and Sarawak. Local communities, private entities, and local and international governments were involved throughout the project with developing the economic modelling and the toolkits, and were kept informed about project progress and outcomes through regular stakeholder meetings over the course of the project.

Infectious diseases caused by wildlife viruses and bacteria are increasing in frequency and economic impact. Recent viruses (SARS-CoV-1, Nipah, Zika, Ebola and SARS-CoV-2) all originated from wildlife and had huge impacts on the global economy. Nipah virus alone cost the Malaysian economy USD$550 million. The COVID-19 pandemic and measures to slow its spread have cost the global economy trillions of dollars and put hundreds of millions of people out of work. Deforestation, intensive agriculture practices, and the wildlife trade all increase contact between people and wild animals heightening the odds of virus and bacteria spillover and its corresponding negative impacts to local and global economies.

Over the past three centuries, land-use change has grown exponentially to keep pace with human population growth and the subsequent demand for natural resources. Intact forests provide invaluable benefits to people and our planet, including water filtration, carbon storage and sequestration, flood prevention, biodiversity conservation, and the maintenance of human health. Although changes in land-use practices have benefited people through economic and social development, they have also led to long-term negative impacts on human health and the provision of ecosystem services. There is increasing evidence that land-use change is a major driver of emerging infectious diseases. Over thirty percent of the emerging infectious diseases affecting people are causally linked to land-use change. This includes deadly diseases such as HIV/AIDS, Ebola, and Zika Virus – all of which originated in altered forest landscapes.

Any land-use decision should maximise both private and public well-being. A trade-off occurs each time a hectare of natural land is developed for human use. Decisions by private entities and governments to develop natural forests for human use creates job opportunities and economic growth, but land development can also reduce ecosystem services that benefit the public (disease regulation) and have negative effects like water pollution, wildfires, and loss of endangered species. By calculating the economic impact of public health risks introduced via land-use change, IDEEAL advocates for sustainable land management policies. The best way to do this is by choosing the optimal amount of land to develop each year in a particular area, considering all the benefits and costs. This benefit-cost balance is achieved by choosing to develop areas where those ecosystem services are already lowest (degraded land) and industry’s net benefits are highest and, conserving areas where ecosystem services are highest and industry’s net benefit yield is lowest.

IDEEAL used data from Malaysia with a focus on Sabah where the project began, to estimate the value of nature’s role in mitigating infectious disease threats. Our results can be used to inform future land-use planning, prioritising areas for conservation and reducing the likelihood of infectious disease emergence linked to deforestation. Preliminary simulations using data from Sabah suggest excessive deforestation in the past decade in Sabah. The cost burden of disease outbreaks ultimately falls to the Malaysian government and its citizens. Both private and public welfare benefit from a strategy to manage land conversion, which then prevents disease emergence and slows deforestation and forest degradation. Our tool also generates maps to help with decision-making by identifying optimal land areas for development, considering the value of ecosystem services on land left undeveloped.

One of the main objectives of IDEEAL was to quantify the economic costs of the impact of deforestation on malaria outcomes in Sabah, Malaysia, and determine the optimal amount of land to be converted to agriculture that minimised these costs. IDEEAL examined how different ecological and land-use change variables impacted the number of malaria cases in each location. The results showed that these variables differed across regions and timescales, ranging from precipitation to the amount of flooding, forest, or cropland. When considering the link between deforestation and malaria, the IDEEAL economic model indicates that Sabah, Malaysia has exceeded the optimal amount for forest to agricultural land conversion. In all sites in South East Asia, including health costs in land-use planning substantially lowered the optimal level of converted land.

Malaria has already cost Sabah more than USD$8.9 million per year. Reducing malaria transmission by just 10% comes to approximately USD$14 million in future savings. That is, for each dollar invested in reducing malaria through better land-use planning, Sabah’s government secures a return of USD$4 dollars on future savings that it could pass to its citizens. The return on this investment would be even higher when considering the potential for sustainable land management policies to reduce the risk of a spillover event like Nipah virus in 1999 that was also linked to land-use change, or the next Disease X. The IDEEAL economic model indicates that Sabah, Malaysia has exceeded the optimal amount for forest to agricultural land conversion. The economic loss from land-use change reducing forest cover below the socially optimal amount today exceeds USD$25 million annually.

The IDEEAL project also supported the founding of the Development and Health Research Unit at Universiti Malaysia Sabah. The Development and Health Research Unit functions as a centre of excellence for research and education on the intersection of health, land-use change, and economics. Furthermore, IDEEAL supported three Master’s students (including our Field Manager Jimmy Lee) and the training of 156 stakeholders.

Through the Development and Health Research Unit, Land-Use Change Toolkits were developed for communicating the health impacts of different land-use options. These toolkits highlight the links between land-use change and diseases such as malaria, dengue, and leptospirosis. They provide an interactive and clear way to communicate complex modelling results to communities in remote and low-resource areas and to foster discussions reducing the health impacts and economic costs of land change. These have been disseminated to industry, government and rural communities in Sabah and Peninsular Malaysia in collaboration with local NGOs that have partnered with Conservation Medicine, EcoHealth Alliance and Universiti Malaysia Sabah.