The fungus that causes the deadly White Nose Syndrome in bats has been discovered on the wings of four bats in caves in Minnesota, adding another state to the growing list of where the disease has spread. The discovery suggests the fungus is continuing its rapid march north, south and west across North America after being first discovered in 2007 in New York.
The Minnesota discovery was made by biologists who have been collecting DNA samples from the wings of bats in an ongoing study to learn how the fungus spreads and the disease progresses. The researchers, speaking at a Friday press conference organized by the Minnesota Department of Natural Resources, said the detection of the fungus does not automatically mean the bats from the Forestville/Mystery Cave State Park and at Soudan Underground Mine State Park will become sick with the fatal disease, but that it's the most likely outcome.
"It's not a guarantee, but that's the kind of question we are trying to answer," said Winifred Frisk, who is leading the study from her lab at the University of California at Santa Cruz.
Her NSF-funded study is aimed at determining the timing of the disease, as well as the different bat species it affects. "Our questions are very much focusing on timelines," the detection, disease and mortality of the disease, she said.
"There is a lot we don't know about the fungus," said Jeremy Coleman, national White Nose Syndrome coordinator for the U.S. Fish and Wildlife Service.
It took some time to determine that the fungus was the main disease agent and just recently even the name of the fungus has been changed as a result of better genetic analyses. "We're still trying to figure out why this is a pathogenic fungus," he said.
Researchers still have no treatment for the disease. For now they are working with land managers to control its spread, using rules and warnings for disinfecting cavers' clothing and equipment. In some cases equipment used in a cave later found to harbor White Nose Syndrome fungus are completely banned from other caves, since normal washing is usually insufficient at killing fungal spores. the researchers explained.
The more advanced genetic testing has been a boon to the researchers because it has enabled to them to detect the fungus before bats get sick, as is the case in Minnesota. However, they are a long way from halting the disease.
One of the things that researchers have been hoping to see is a difference in how some bat populations resist the disease, Coleman said. Different populations of the same species can differ widely in this way because of their different locations, foods, living conditions and climate.
Unfortunately, however, the disease has so far proven equally devastating to bats wherever it's been found, although some species are less affected than others.
White Nose Syndrome is not known to affect any animals other than bats. However, in Minnesota alone the benefits of insect-eating bats to agriculture are calculated to be $1.4 billion, said Gerda Nordquist, a mammalogist at Minnesota County Biological Survey.
"We could have serious repercussions to pest control in the future," Norquist said.