Emerging diseases on the rise, study finds

Posted: 11 March 2008

Outbreaks of emerging infectious diseases such as Ebola, SARS, HIV and avian influenza are on the rise around the world, researchers report in the journal Nature. The new study presents the first scientific evidence that zoonoses - diseases from wildlife - are the prime emerging disease threat, due to encroachment of wild areas by human population growth and related impacts.

Scientists analysed 335 diseases that emerged between 1940 and 2004, and found the rate of new infectious diseases is increasing. More than half of the diseases jumped from animals to humans.

By assembling data collected over decades from hundreds of different disease outbreaks, researchers have mapped out likely "hot spots" for these diseases.

The team found that the developing world was a key ground for emerging diseases, especially in areas in which humans and animals are in very close contact.

Disease hotspots map
Disease hotspots map
Researchers say that areas in which humans and animals come in very close contact are a key grounds for emerging diseases. Above, a world map highlights hot spots for diseases passed from animals to humans. Click on map for full-size image. Credit: © Nature
"These maps show that the key threat to public health is where human population growth and wildlife diversity clash," says Peter Daszak, one of the authors of the report.

Marc Levy, from the Center for International Earth Science at Colombia University (CIESIN), a co-author of the study, said "Overlaying maps of where the zoonotic diseases have occurred, with population maps, allows a pattern of relationships to emerge." He said it was a first step in predicting the risk of future diseases.

"The result is a global map of emerging disease 'hotspots' that shows a pattern of growing vulnerability to new diseases in rich as well as poor nations, with implications for further prediction and prevention."

The study also offers insights into the role of conservation in preventing new diseases and the importance of reviewing approaches to allocation of public health resources in order to reduce risk.

More about the study Global Trends in Emerging Infectious Diseases which built a predictive model by correlating socio-population data from NASA,can be heard in an NPR interview Study Finds Emerging Diseases on Rise.