The global transformation of the natural environment for agricultural, livestock or urban use has upset the balance of wild animal communities. A study led by several British institutions has shown that the species they carry zoonotic diseasesKnown to infect humans, they benefit from these changes in land use.
The destruction of nature caused by human activity multiplies new diseases such as COVID-19
“It is difficult to know if the risk of these types of ailments is higher now than in the past. However, at this time there are many factors that increase the likelihood that disease outbreaks isolated to become epidemics important. For example, the world is much more connected by road and air than ever, so it is easy for diseases to spread more quickly to more densely populated areas, “he tells SINC. Rory Gibb, co-author of the study and scientist at the Center for Biodiversity and Environment Research at University College London.
For the study, the researchers agreed to PREDICTS, a database that collects information on local species from hundreds of studies on ecological communities, along gradients of landscape disturbance, from natural vegetation to ecosystems agricultural and urban.
The team used 6,801 locations around the world to analyze how populations and communities of host species zoonotic, on average, as landscapes change from natural vegetation, to agricultural, grassland, and urban ecosystems.
“We found that, under increasing intensities of human land use, ecological communities shift to become increasingly dominated by zoonotic host species, particularly in habitats secondary (recovered), managed (agricultural and plantation) and urban ”, emphasizes Gibb.
The work, which is published in the magazine Nature, can help prevent future contagion of diseases caused by guests of animals. “There is some evidence that the new zoonoses [patógenos nuevos y antes no descubiertos] are emerging at an ever-increasing rate and that this may be due to increasing rates of human-driven impacts on the environment and biodiversity” says the co-author.
But, he adds, “this trend is difficult to measure conclusively. Without a doubt, the use of diagnostics improved and new genomic technologies will help us advance in the detection of new diseases ”.
However, these responses depend on the grouping of some species in particular: rodents, passerines and bats show a particularly clear and strong divergence between host and non-host species, while in carnivores and primates it is not detected, according to the study.
The researchers stress that we may need to alter the way we use land around the world to reduce the risk of future contagious effects of infectious diseases.
The global change in land use is mainly characterized by the conversion of natural landscapes for agriculture, in particular for food production. “Our findings underscore the need to manage agricultural landscapes to protect the health of the local population while ensuring their food security.” Kate Jones, co-author and researcher at University College London (UCL).
These zoonotic ailments like Ebola, the lassa fever and the Lyme’s desease, which are caused by pathogens that spread from animals to people and have a high health cost.
“He malaria Zoonotic, for example, is transmitted between primates, mosquitoes, and people around forest margins in Southeast Asia. The Nipah virus emerged, for the first time, in association with interactions between livestock and bats in agricultural landscapes. Another important and widespread disease is Lyme disease, the incidence of which is often higher in fragments of modified and recovering forests, where the ecological community is particularly effective in transporting and transmitting the bacteria, ”says Gibb.
The researchers emphasize that while there are many other factors influencing disease risks, the results point to strategies that could help mitigate the risk of outbreaks of infectious diseases comparable to COVID-19.
“As agricultural and urban lands are forecast to continue to expand in the coming decades, we should strengthen disease surveillance and disposition in those areas that are experiencing a large amount of land disturbance, as it is increasingly they likely have animals that could be harboring harmful pathogens, “adds Jones.
For its part, David Redding, another of the UCL authors, stresses that the work “provides a context to reflect on more sustainable changes, so that potential risks are taken into account, not only for biodiversity, but also for human health”.