Epidemiology of disease through the interactions between humans, domestic animals, and wildlife
Mariana Marrana
Abstract
Emergence of diseases at the interface between animals and humans has been occurring since agricultural and farming practices allowed humans to live in sedentary communities, close to their animals and crops. However, this occurrence has become increasingly relevant since the beginning of the XX century, a time since when we have seen an increase in the frequency and size of outbreaks of zoonotic diseases. Although animal-to-human diseases already cause an estimated 700,000 deaths each year, the potential for future pandemics is vast. Growing numbers of spillover events are connected to the way food is procured or produced, in order to feed a growing human population; to the way cities, agricultural, and mining lands expand to cater such population, encroaching into natural ecosystems; to the increasing globalization of trade, business and tourism; as well as to climate change and antimicrobial resistance, that generate more opportunities for disease emergence and amplify its consequences. The drivers and mechanisms that cause diseases to emerge between animals and humans are described in this chapter, as well as the mechanisms that allow animal pathogens to be transmitted to humans and eventually to evolve into a specialized pathogen of humans.