Scientists predict that diseases transmitted from animals to humans will likely cause next pandemic, according to media reports Friday.

Scores of infectious diseases have emerged to threaten humans in the past decades as viruses leap the species barrier from wild animals and bacteria mutate into antibiotic-resistant strains, scientists have reported.

A three-year investigation led by four major institutions tracked 335 incidents since 1940 when a new infectious disease emerged.

The category includes HIV/AIDS, which has slain or infected more than 65 million people around the world, and outbreaks of severe acute respiratory syndrome (SARS) and H5N1 bird flu, which have cost tens of billions of dollars to contain.

The emergence of new diseases have roughly quadrupled over the past 50 years, 60 percent of them are so-called zoonoses, or diseases that have been transmitted from animals to humans.

Most zoonoses come from wild animals, especially mammals, which are the most closely related species to humans. Novel pathogens that adapt to humans can be extremely lethal, as humans have no resistance to them.

"We are crowding wildlife into ever-smaller areas, and human population is increasing," said Marc Levy of the Center for International Earth Science Information Network, affiliated to Columbia University's Earth Institute in New York. "Where those two things meet, that is a recipe for something crossing over."

Areas that present the biggest potential source for a new zoonose are "the whole of the East Asia region, the Indian sub-continent, the Niger delta (and) the Great Lakes region in Africa," he said.

(Agencies via Xinhua February 22, 2008)