12.05.2024

Biodiversity loss increases epidemics of infectious diseases

Biodiversity loss is the biggest environmental driver of infectious disease outbreaks, making them more dangerous and widespread, says a new study cited by Guardian.

New infectious diseases are on the rise and often originate in wildlife. In a meta-analysis published in the journal Nature, researchers found that of all the drivers of global change that destroy ecosystems, species loss is the most damaging in increasing the risk of epidemics. Climate change and the introduction of non-native species follow.

"Biodiversity loss, climate change and introduced species increase disease," summarized lead researcher Prof. Jason Rohr of the University of Notre Dame in the US.

Four factors increase the risk of epidemics

The experts analyzed nearly 1000 studies of the global ecological drivers of infectious diseases, covering all continents except Antarctica. They look at both the severity and spread of disease in plants, animals and humans.

The team focused on five global drivers of change – biodiversity loss, climate change, chemical pollution, non-native species and habitat loss. The scientists found that all factors except habitat loss increased epidemics, with the effect being the same for both human and nonhuman diseases.

There is less disease in cities

Habitat change reduces risk due to the tendency for people to move to cities. Urban areas tend to have less disease, partly because of better public sanitation, but also because there is less wildlife.

"In urban areas with a lot of concrete, there are much fewer species that can thrive in that environment. From a human disease point of view, there is often better sanitation and health infrastructure than in rural areas,” explains Rohr.

Interest in zoonotic diseases (diseases and infections that are naturally transmissible directly and indirectly between animals and humans) has increased since the COVID pandemic, which some researchers believe came from a bat. Many other diseases currently of concern to global health authorities – including swine flu and bird flu – also originate in wildlife. Three-quarters of emerging human diseases are zoonotic, meaning they also infect wildlife and domestic animals.

Previous studies have pointed to links between these diseases and environmental change (for example, global warming may mean malaria is becoming more widespread), but until now it was not clear which environmental factors had the biggest impact. The researchers note that many of the factors are interrelated:

"For example, climate change and chemical pollution can cause habitat loss and alteration, which in turn can lead to biodiversity loss."

The researchers also say that reducing emissions, reducing biodiversity loss and preventing invasive species can help reduce the burden of disease.

"We hope that our analyzes will facilitate disease control, mitigation and surveillance efforts worldwide," the report's authors conclude.