Host Community Interfaces: The Wildlife-Livestock

Abstract

The livestock compartment and its interfaces with humans and wildlife appeared after domestication. These epidemiological interfaces have constituted opportunities for horizontal transmission between species and a new space for evolution, emergence, and maintenance of pathogens. More recently, anthropogenic effects and the subsequent changes in urban areas, farming, food systems, and natural ecosystems have led to increased exposure of human and animal populations to novel pathogens and the establishment of newly shared emergent diseases. Humans, animals (both domestic and wild), and ecosystems are more tightly linked than ever. The third significant Coronavirus to emerge in humans in 17 years, COVID-19, exemplifies the increased risks for pathogens to jump from infected wild animals to humans. The world is also experiencing unprecedented emergence and spread of many diseases that in livestock have “spilled over” to wild populations and have “spilled back” to livestock. The ever-increasing role of anthropogenic drivers of change suggests a future exponential growth in interactions among wildlife, domestic animals, and humans, with important implications, including additional disease emergence at interfaces. The recent pandemic increases our certainty that we need a systems-wide holistic perspective on pathogen dynamics at the wildlife-livestock-human interface based on interdisciplinary approaches to the examination of biological, ecological, economic, and social drivers of pathogen emergence. Simply, we cannot look at any compartment in isolation from others as they are ineludibly and functionally linked through ecological and evolutionary processes underlying host jumps by pathogens. The implementation of actions (ranging from local to holistic) under this principle across the animal health, human health, and environment sectors will be a challenge. We need to understand, predict, prevent, detect, and control disease emergence at their main origin, the animal interfaces. Detecting early warning signs at the origin of pathogen emergence is imperative so it can be halted before it leads to dramatic local, regional, or global consequences. This approach is likely to be more cost-effective than adaptation to mitigate consequences. However, the wildlife-livestock interface has been often neglected and, consequently, disease spillover is largely underreported, even zoonoses. This chapter summarizes the complex wildlife-livestock interface in all its dimensions, to include changing natural landscapes and increasing anthropogenic impacts. We identify essential gaps that prevent us from better understanding and managing disease dynamics at the interface.