Zoonoses are infectious diseases that spread between animals and humans. They account for more than two-thirds of human emerging diseases.
The most significant burden on human health and livelihoods comes from epidemic and endemic zoonoses, which globally cause about 1 billion cases of illness and millions of deaths every year. These diseases are persistent regional health problems around the world. Zoonoses originate in pathogens hosted by animals (wildlife and domestic animals) and are a substantial threat to global health and security. They have caused economic damage exceeding hundreds of billions of US dollars over the past 20 years, and this number will continue to rise with the COVID-19 pandemic, which has already cost more than 11,700 billion dollars. Zoonotic agents also represent the most significant number of infectious disease agents in humans, and projections indicate that their number might increase significantly.
It is therefore crucial to act far ahead of epidemic and pandemic crises by implementing ambitious scientific and operational programmes dedicated to preventing the emergence and spread of zoonotic diseases.
The exponential rise of zoonoses
Rabies, Severe Acute Respiratory Syndrome (SARS), Nipah virus, Influenza viruses, Zika disease, Yellow fever, Chikungunya, Ebola, Middle East Respiratory Syndrome (MERS-CoV), Rift Valley fever, SARS-CoV-2… In recent decades, the frequency and number of zoonoses have exponentially increased along with the number of sporadic spillover events, posing a significant threat to the global economy and public health.
Land-use changes, degradation, unsustainable agricultural practices, and deforestation, among other factors, have heightened the human impact on nature, leading to significant biodiversity loss on land and seriously threatening the balance of ecosystems at the interface of humans, animals, plants, and the environment. These risks are worsened by the expansion of urban areas, international trade, and travel, including the transboundary movement of animals, as well as climate crises. As the planet heats up, infectious diseases that were once confined to warm latitudes are expanding into new geographical regions. Vector-borne diseases – such as Crimea Congo Hemorrhagic Fever, Rift Valley fever, West Nile virus, etc. – are now being found in new areas.
International and multi-sectoral collaboration is critical for understanding the emergence, prevention, risk reduction, and early detection of zoonoses, as well as for tackling the risks of spillover and preventing pandemics.