NAIROBI, KENYA – The world is seeing a rise in diseases caused by viruses that have jumped from animal hosts to the human population, with COVID-19 just one example, a group of experts said.

Ebola, MERS as well as West Nile and Rift Valley fevers were other examples of zoonotic diseases, which are driven by the degradation of our natural environment, said the United Nations Environment Department (UNEP) and International Livestock Research Institute (ILRI).

"While many in the world were surprised by COVID-19, those of us who work on animal disease were not. This was a highly predictable pandemic," said Delia Randolph, ILRI veterinary epidemiologist.

Randolph described a "very clear trend" since the 1930s that showed that 75% of emerging human diseases stemmed from wildlife. COVID-19, for example, most likely originated in bats, UNEP and ILRI said.

Further outbreaks will emerge unless governments take active measures to prevent other zoonotic diseases from crossing into the human population, UNEP warned.

The report identifies seven trends driving the prevalence of zoonotic diseases. They include increased demand for animal protein, a rise in unsustainable farming, increased use and exploitation of wildlife, and climate change.

"The science is clear that if we keep exploiting wildlife and destroying our ecosystems, then we can expect to see a steady stream of these diseases jumping from animals to humans in the years ahead," said UNEP Executive Director Inger Andersen.

Protecting the environment can help to protect people from enduring another global outbreak as it was often human activity that was breaking down natural barriers that used to protect humans from disease pathogens, UNEP said.

Every year, 2 million people die from neglected zoonotic diseases, the report said. In the last two decades alone, zoonotic diseases have caused economic losses of more than $100 billion, not including the cost of the COVID-19 pandemic, which is expected to cost $9 trillion over the next few years, the U.N. said.

African countries, a number of which have managed outbreaks, have the potential to leverage this experience to tackle future outbreaks. "African countries are demonstrating proactive ways to manage disease outbreaks," ILRI Director General Jimmy Smith said.

Other aspects include early detection and response. "If pandemics can be caught right at the start, the costs can be reduced by 90%," Randolph said.