Rare fungus kills endangered rattlesnakes in southern Illinois

Chrysosporium also is emerging as a dangerous infection in humans with weakened immune systems, he said.

Shortly after he first presented his findings at a meeting of the Fish and Wildlife Service, Allender heard from other biologists about similar infections in snakes in the northeast United States.

"They seem to be having a similar problem in timber rattlesnakes in New Hampshire and Massachusetts," Allender said. Although biologists have sporadically identified Chrysosporium in those snakes, the symptoms they report -- facial swelling and ulcers and malformations of the jaw -- are the same, he said. These infections also occurred only within the last five years.

"Fungal pathogens have been increasingly associated with free-ranging epidemics in wildlife, including the well-known effects of Batrachochytrium dendrobatidis on frog populations globally and white-nosed syndrome in bats," Allender wrote in a December 2011 report in Emerging Infectious Diseases. "Both of these diseases cause widespread and ongoing deaths in these populations that seriously threaten biodiversity across the United States."