Perhaps it's already in play, and this why the parks are closed...

“This disease is taking a terrible toll on America’s bats, so it’s deeply alarming to see it show up in more and more places,” Matteson said.

Bats are the primary vector of the fungus, which attacks them as they hibernate in winter. But biologists have documented that people can also transport the fungus on their clothing, shoes or equipment. The fungus appears to have originated in Europe, where scientists have found it on bats in caves throughout the continent. However, European bats do not fall ill from the fungus. Most scientists believe that people are responsible for inadvertently transporting the fungus from a European cave to the site where the bat disease was first discovered in 2006, at a cave connected to a popular tourist cave in upstate New York.

Land-management officials have closed caves in much of the eastern and southern United States, as well as in a few locations in the West, as a precautionary measure to help slow the human-facilitated spread of the disease. However, thousands of caves on western public lands remain open to recreational use. Earlier this month, the U.S. Forest Service loosened restrictions on recreational cave access in Colorado, Wyoming Kansas, and South Dakota, reversing a three-year closure order aimed at reducing the risk of human transmission of the bat disease into the West. [link to www.biologicaldiversity.org]
[link to www.upi.com]

fungus = vampire