Movement networks in swine farms

How networks shape disease spread in farming systems

The swine farming sector faces a pressing challenge in controlling disease outbreaks, often influenced by movements of animals and humans between farms.  

While traditional models primarily focus on animal movement, recent studies have revealed the critical role of human activity in shaping these networks. 

A year-long analysis of swine farm systems studied 455 properties, identifying over 320,000 movements involving vehicles, humans, and animals. The findings revealed that human movements create a more interconnected network than animal movements alone.  

Metrics such as path lengths and connectivity were significantly altered when human activity was considered, reducing the longest path from 10 (animal-only) to 5 and increasing edge density in the combined network. 

The network analysis highlighted a "hub structure," where specific properties played a central role in movement. These hubs pose a higher risk as they can act as "super-spreaders" for disease, amplifying vulnerabilities within the system.  

The results emphasize that farms are more susceptible to disease outbreaks than previously thought, necessitating a broader approach to biosecurity. 

By incorporating both human and animal movements into risk assessments, farm managers can better prepare for and prevent potential outbreaks, creating a safer and more resilient farming environment. 

Photo Credit: istock-srdjan-stepic