A fungus from Asia has killed off large numbers of salamanders and newts in Belgium and The Netherlands and risks reaching North America unless the exotic pet trade is stopped, researchers said Thursday.
An international study in the US journal Science included 5,000 amphibians from four continents to determine the origins of Batrachochytrium salamandrivorans, which was discovered in Europe last year.
It was detected in amphibians from Thailand, Vietnam and Japan as early as 1861, without causing disease, suggesting that the fungus originated there.
The fungus likely traveled via the international pet trade, the researchers found.
"This study captures a pathogen's first steps out of Asia," said University of Maryland researcher Kelly Zamudio.
"The more globalized our world becomes, the more our biodiversity will be challenged by diseases moving into areas where they have never occurred before."
B. salamandrivorans is dangerous to salamanders and newts, but not to frogs, toads or caecilians, which are snake-like amphibians.
Researchers said it is only a matter of time before it spreads further.
"It's a question of when, not if, this fungus reaches North America," said University of Maryland graduate student Carly Muletz, a co-author of the Science paper.
North America is home to more than 150 of the world's 655 known salamander species.
Chinese fire belly newts are potential carriers of B. salamandrivorans, and more than 2.3 million of them were imported into the United States for the pet trade between 2001 and 2009, the study said.
Even more concerning is the lack of regulation. In the United States, there is no agency in charge of monitoring imports of salamanders or other amphibians, experts said.
"If scientists and policy makers can work together on this, we have a rare opportunity to stop an epidemic from spreading around the globe with potentially deadly effect," said co-author Karen Lips.
The study was led by professors An Martel and Frank Pasmans at Ghent University in Belgium.
"Pathogens like B. salamandrivorans that are brought to a new environment can very rapidly threaten many species with extinction," said Martel.