A new study identifies several regions around the world with the highest number of unknown viruses likely to infect people, and which species are most likely to carry them.

Researchers from New York-based environmental non-profit EcoHealth Alliance published a study Wednesday in the journal Nature they say is the first comprehensive analysis of all viruses known to infect mammals.

The world has seen a rise in the number of zoonotic viruses, or viruses that can be transmitted from animals to humans. The goal of the study is to try to predict where the next pandemic is likely to occur, and which species are most likely to carry it, said the study's senior author, Peter Daszak, who is president of EcoHealth Alliance.

"If you are an organization that is doing surveillance to stop the next Ebola — and we know there are a hundred other Ebola viruses we have not discovered out there on the planet — this paper says where they would be," Daszak said. "And then you can target your programs to go an look for them. And if you find them you can determine whether it is likely something that can infect people.

Geographically, the biggest hotspots are the tropical regions of the world, such as Central and South America, West and Central Africa, and Southeast Asia.

Apart from being some of the most biodiverse places on the planet, they are also the regions that are home to the greatest number of species that have the highest risk of carrying and transmitting viruses to humans.

One of the most striking findings is that bats carry a significantly higher proportion of zoonotic diseases than any other group of mammals.