LANSING - The Michigan Department of Natural Resources and a consortium of partners announced the fungus known to cause significant rates of illness and death in North American bats has been detected for the first time within the state's borders. White-nose syndrome (WNS) has been found in three Michigan counties: Alpena, Dickinson and Mackinac.
"These are the first confirmed WNS cases in Michigan. Even though we've known this disease was coming, it is a disappointing day," said Dr. Dan O'Brien, DNR wildlife veterinarian. "We will now shift gears and try to stop the spread of this serious disease."
Five little brown bats (Myotis lucifugus) showing disease characteristics were collected in February and March during routine WNS surveillance by Dr. Allen Kurta and Steve Smith, researchers from Eastern Michigan University. White-nose syndrome was diagnosed by Michigan State University's Diagnostic Center for Population and Animal Health (DCPAH), in cooperation with the DNR Wildlife Disease Laboratory.
"At DCPAH we have to have our eye on emerging diseases and prepare our test capabilities early on so that we are ready when the need for testing arises," said Dr. Tom Mullaney, DCPAH's interim director. "We identified the fungus by PCR and through histopathology due to the specific presentation of the lesions. While we regret that this disease has arrived in Michigan, we will work closely with our DNR partners as they continue the next phase of their work."
The diagnosis was then confirmed by the U.S. Geological Survey's National Wildlife Health Center in Madison, Wis. The bats tested positive for Pseudogymnoascus destructans, the fungus known to be the causative agent of skin lesions observed in WNS-affected bats.
The disease was first documented in 2006 in a cave in upstate New York. Eleven species of bat have been infected and over 6 million have died.
In 2010, the DNR, along with the agency's federal and non-governmental partners, developed Michigan's WNS Response Plan. The plan outlined two main pillars: 1) prevent the arrival and spread of WNS as long as possible by mitigating the human-assisted movement of the fungus that causes the disease; and 2) conserve whatever bat populations remain after the disease has arrived by preserving abandoned underground mines and caves.
In northeastern states, where the bat disease has been present the longest, summer bat populations are down by 70-80 percent, and winter die-offs in some specific caves have been greater than 90 percent.
While there is no connection between WNS and rabies, the DNR and Michigan Department of Community Health caution the public to avoid handling bats because of the risk for exposure to rabies. Bats in Michigan can carry rabies, a virus that infects the central nervous system of mammals, including people, and causes death in almost all cases. Rabies is most commonly spread by the bite of an infected animal. There are no known harmful effects to humans from WNS.
"At this point, there is no effective treatment for WNS and no practical way to deliver the treatment to millions of affected bats even if treatment existed. Rehabilitation of bats is prohibited in Michigan because of the potential for the exposure of humans to rabies," said O'Brien. "The best thing the public can do when they find a dying or dead bat is to leave it alone and keep children, livestock and pets away from it."
Bat die-offs can be reported through an observation report on the DNR website at www.michigan.gov/wildlife or by calling the DNR at 517-336-5030.
The U.S. Fish and Wildlife Service requests that cavers refrain from caving in all WNS-affected states and adjoining states. Cavers also should refrain from caving anywhere during the hibernation period (September May) to minimize disturbance and mortality to bats.
The loss of bats due to WNS could be economically significant for agriculture and commercial forestry. A reduction in the bat population could lead to an increase in pests that are harmful to crops and trees.
Learn more about white-nose syndrome at the DNR website www.michigan.gov/wns.