Zoonotic Disease and Environmental Change

A zoonotic disease is one transmitted from a non-human animal to humans, and a widely cited 2008 analysis by Kate Jones and colleagues, published in Nature, found that roughly 60 percent of emerging infectious diseases identified between 1940 and 2004 were zoonotic in origin, with the large majority of those originating in wildlife rather than domesticated animals — a proportion that has made zoonotic spillover the central organizing concept in contemporary emerging-disease surveillance. The geographic distribution of zoonotic disease emergence is far from random: the same 2008 study, along with subsequent research, identified tropical regions with high wildlife biodiversity, rapid land-use change, and expanding human-wildlife contact — notably Central and West Africa, South and Southeast Asia, and parts of Latin America — as disproportionate global "hotspots" for the emergence of new zoonotic pathogens, a finding that has directly shaped where international surveillance investment, such as the US Agency for International Development's PREDICT program (active 2009–2020), has been concentrated.