Tracking disease in one of the most biodiverse ecosystems on Earth

Brazil’s Pantanal, one of the world’s largest and most biodiverse ecosystems, is an environmental treasure teeming with the world’s highest density of jaguars, more than 650 types of birds, and unique species found nowhere else on Earth. However, the Pantanal is increasingly threatened by wildfires, deforestation, and controversial hydroelectric projects. 

These challenges are compounded by the rise of zoonotic diseases—those that transfer from animals to humans—sparking new international efforts to understand how such diseases spread in this fragile environment.

Researchers from the University of Minnesota's College of Veterinary Medicine and College of Food, Agricultural and Natural Resource Sciences have teamed up with Brazil’s Universidade Católica Dom Bosco to explore the ecology of zoonotic diseases in the Pantanal. Their research is part of a broader initiative to track how diseases such as brucellosis, which affect both wildlife and livestock, are moving through the ecosystem.

Co-led by Brazilian veterinarian Heitor Miraglia Herrera, along with University of Minnesota wildlife epidemiologist Tiffany Wolf and wildlife movement ecologist James Forester, this collaboration uses innovative techniques to investigate how brucellosis is transmitted between domestic cattle, feral swine, and wildlife in the Pantanal. Herrera’s family has long been involved in cattle ranching in the region, where such activities are key to the local economy but increasingly threatened by environmental shifts.

While the U.S. successfully eradicated brucellosis in domestic cattle decades ago, it persists in wildlife populations such as bison and elk. This research aims to understand similar dynamics in Brazil, where brucellosis may be more widespread due to the overlap of wild and domestic animals in the same habitats.

Cutting-edge gene sequencing

To study the transmission of brucellosis in the Pantanal, the team uses cutting-edge technology known as nanopore adaptive sequencing. This portable device can analyze DNA samples from wildlife and livestock in real-time, identifying not just known pathogens like Brucella but also unexpected microbes. This is a significant improvement over previous methods, which could only detect known infections and often failed to capture the full complexity of pathogen transmission.

"We knew from what has been learned in the Greater Yellowstone system that we would need to generate a substantial amount of genetic data on any Brucella detected in this system to have any hope of understanding transmission patterns," Wolf says. 

The sequencing data is helping researchers uncover the full genetic landscape of Brucella, crucial for understanding how the disease spreads between species.

The team is also tracking the movement of pampas deer using GPS collars to better understand the role of habitat loss, disease, and other threats to their declining population. These insights could clarify the impact of brucellosis on wildlife in the region, especially as the Pantanal faces mounting environmental pressures.

The field station, a hub for both research and community collaboration, is an essential resource for this ongoing project. The University of Minnesota team’s expertise complements the decades of local knowledge. 

If successful, the collaboration could serve as a model for transboundary global health research, with implications far beyond Brazil. By understanding how zoonotic diseases like brucellosis behave in the Pantanal, the team aims to develop better strategies for managing such diseases worldwide, offering critical insights into disease transmission in a rapidly changing world.