Researchers have found the organism that causes deadly white-nose syndrome can survive in soil inside caves for month or even years, the University of Wisconsin-Madison reported Monday.
White-nose syndrome has killed millions of bats of at least seven species since it was first detected in New York State in 2006, researchers said.
The fungus, Geomyces destructans, cannot grow at warm temperatures, scientist said, but the study shows it can survive over the summer in the cool soil where bats hibernate.
"We have found that caves and mines, which remain cool year-round, can serve as reservoirs for the fungus, so bats entering previously infected sites may contract white-nose syndrome from that environment," said researcher Jeff Lorch of the university's Department of Forest and Wildlife Ecology. "This represents an important and adverse transmission route."
White-nose syndrome, named for a distinctive white fungal growth around the muzzles and on the wings of hibernating bats, has spread into New England, West Virginia, Missouri and Canada north of Michigan's Upper Peninsula, the researchers said.
"A lot of people were wondering whether the bats would eventually recolonize caves they had disappeared from due to the disease," Lorch said. "It now appears as though this may be a challenge for susceptible bats because the pathogen is living in the soil."