Ebola. Nipah. Rabies. Swine flu. West Nile. Dengue. All of these diseases have one thing in common: they are caused by zoonotic pathogens, or pathogens that are transmitted between different species. Today, 60% of emerging infectious diseases in humans are zoonotic. Animal pathogens can infect humans directly through contact with wild or domestic animals or indirectly by transmission through intermediate hosts that foster the genetic variation of diseases, enabling them to infect humans. Relevantly, the World Health Organization (WHO) states that all available evidence for COVID-19 points toward a zoonotic source of SARS-CoV-2.
A new United Nations report warns that more zoonotic pathogens are likely to emerge as habitats are ravaged by wildlife exploitation, unsustainable farming practices and climate change.
"We have intensified agriculture, expanded infrastructure and extracted resources at the expense of our wild spaces," UNEP Executive Director Inger Andersen said. "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."
In order to prevent epidemics of zoonotic diseases, multisectoral approaches to public health are required.
Collaboration across sectors relevant to zoonotic diseases, particularly among human and animal health disciplines, is essential for launching effective surveillance strategies. Surveillance in both humans and animals is critical for prevention; this requires expanded cooperation between human and animal health organizations such as the WHO and the World Organization for Animal Health. It is essential that there are shared quantitative tools with equal input from both sectors and frequent communication between these organizations to ensure reliable and accurate surveillance data.
The One Health Zoonotic Disease Prioritization Tool was developed by the CDC for this reason, but expansion of this program is necessary as zoonotic diseases become a greater threat to public health. For regions particularly vulnerable to zoonotic disease, such as the Eastern Mediterranean, these systems should be implemented by local governments and community health officials to ensure faster reports of concerning data and response–an essential tactic to preventing epidemics before they start.