Salamanders throughout Europe are getting sick from a deadly fungal disease, and it threatens to spread to the United States through the pet trade unless international efforts are taken to stop it in its tracks, scientists reported Thursday in the journal Science.

The toxic fungus in question, Batrachochytrium salamandrivorans, is similar to one that has caused the extinction of hundreds of frog and toad species around the world. Now, the previously unknown fungus is killing at least a dozen European and North American salamander and newt species.

Supposedly originating in Southeast Asia 30 million years ago, B. salamandrivorans rapidly invades salamanders' skin, which plays a crucial role in their respiratory system. It also interferes with their breathing and their ability to absorb water and essential minerals. So far, more than 520 amphibian species worldwide have succumbed to its deadly effects.

Scientists believe that international trade in Asian newts, popular among amphibian fanatics, helped the fungus spread to Europe, and now they worry that the pet trade will also bring the disease to the United States.

"If even a few of these animals have the fungus, "it's a question of when, not if, this fungus reaches North America," University of Maryland graduate student Carly Muletz, a co-author of the study, said in a statement.

For example, 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. And newts, a subgroup within the salamander family, are particularly vulnerable. Lab tests showed that when the Eastern red-spotted newt and the rough-skinned newt were deliberately infected with the fungus, 100 percent of them died.

The study found evidence of the fungus in amphibians in Vietnam, Thailand and Japan, where the animals were not affected, and in the Netherlands and Belgium, where it killed numerous populations. And while the United States remains untouched by the infection, gaps in pet trade regulations make its spread inevitable, researchers say. Current US regulations focus on monitoring live animal imports to prevent the spread of diseases to humans and livestock, not to native wildlife, according to amphibian expert Karen Lips.

"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," Lips added.