White-Nose Syndrome: Human Activity in the Emergence of an Extirpating Mycosis.

In winter 2006, the bat population in Howe Cave, in central New York State, USA, contained a number of bats displaying an unusual white substance on their muzzles. The following year, numerous bats in four surrounding caves displayed unusual winter hibernation behavior, including day flying and entrance roosting. A number of bats were found dead and dying, and all demonstrated a white, powdery substance on their muzzles, ears, and wing membranes, which was later identified as the conidia of a previously undescribed fungal pathogen, Geomyces destructans. The growth of the conidia gave infected bats the appearance of having dunked their faces into powdered sugar. The disease was named white-nose syndrome and represents an emerging zoonotic mycosis, likely introduced through human activities, which has led to a precipitous decline in North American bat species.