As more and more natural habitats are transformed into agricultural land, the chances of viruses jumping from animals to humans — as COVID-19 is suspected to have started — is more likely, as per a Stanford University study.
The Stanford researchers' study focused on how the loss of tropical forests in Uganda created by humans now puts people at higher risk of contracting diseases from animals venturing nearer.
The study was published in Landscape Ecology.
The emergence and spread of infectious diseases
The findings of the study have pointed out that the emergence and spread of infectious animal-to-human diseases are likely in part due to deforestation trends around the world. Their study is the first one to look at landscape-level ecological factors as well as individual-level behavioral factors that impact human health.
"At a time when COVID-19 is causing an unprecedented level of economic, social and health devastation, it is essential that we think critically about how human behaviors increase our interactions with disease-infected animals," said study lead author Laura Bloomfield, an MD student in the School of Medicine at Stanford.
"The combination of major environmental change, like deforestation, and poverty can spark the fire of a global pandemic."
As more and more forests are cut away, humans move closer to them, and animals venture further out of them in order to find food. This brings the two closer together and increases the chances of zoonotic — animal to human — disease. HIV, for instance, originated from a virus that jumped from wild primates over to humans through infected bodily fluids.
Moreover, by turning deforested areas into agricultural land farmers and workers spend more time close to or in these areas, which could lead to more spillover of infections from wild primates to humans around the globe.
In order to minimize this effect, the Stanford researchers suggest that creating small buffer zones could hugely lessen the likelihood of these animal-to-human interactions. Using external sources to provide fuel and construction material or monetary supplements could also lessen the pressure on people living and working in these areas to go looking for wood in these forested areas.
"At the end of the day, land conservation and the reduction of forest fragmentation is our best bet to reduce human-wild animal interactions," said study coauthor Tyler McIntosh, a former graduate student in the Stanford Earth Systems Program.