A detailed map highlighting the world’s hotspots for emerging infectious
diseases (EIDs) has been released.
It uses
data spanning 65 years and shows the majority of these new
diseases come from
wildlife.
Scientists say conservation efforts that reduce conflicts between humans and animals could play a key role in limiting future outbreaks.
Writing in Nature, they said their map revealed that global anti-EID resources had been poorly allocated in the past.
Researchers from the Zoological Society of London (ZSL), and the US-based University of Georgia and Columbia University’s Earth Institute analysed 335 emerging diseases from 1940 to 2004.
They then used computer models to see if the outbreaks correlated with human population density or changes, latitude, rainfall or wildlife biodiversity.
Finally, the data was plotted on to maps to reveal the “hotspots” around the globe.
“Our analysis highlights the critical importance of conservation work,” said co-author Dr Kate Jones, a research fellow for ZSL.
“Conserving areas rich in biodiversity from development may be an important means of preventing the emergence of new diseases.”
The researchers found that 60 per cent of EID events were caused by “non-human animal” sources.
They add that 71 per cent of these outbreaks were “caused by pathogens with a wildlife source”.
Among the examples listed by the team was the emergence of Nipah virus in Malaysia and the Sars outbreak in China.
Others included the H5N1 strain of bird flu, Ebola and West Nile virus. The number of events that originated from wild animals had increased significantly over time, they warned.
“This supports the suggestion that zoonotic EIDs represents an increasing and very significant threat to global health,” the paper’s authors wrote.
They added that it also highlighted the need to understand the factors that lead to increased contact between wildlife and humans.
“We are crowding wildlife into ever smaller areas, and human population is increasing,” explained Dr Marc Levy, a global change expert at Columbia University’s Earth Institute. “Where those two things meet, that is the recipe for something crossing over.”
He added that the main sources were mammals that were most closely related to humans.
While some pathogens may be picked up while hunting or by accident, others - such as Nipah virus - are transmitted to humans from wild animals via livestock.
Because humans had not evolved resistance to these EIDS, the scientists said the results could be “extraordinarily lethal”.