Snake-Killing Fungus in Eastern U.S. Identified

Snake fungal disease (SFD), a frequently deadly skin infection found in snakes in the eastern half of the United States, now has a known cause: a fungus called Ophidiomyces ophiodiicola.

That's according to new research published in the online journal mBio by scientists from the U.S. Geological Survey (USGS).

Since 2009, SFD has been documented by the USGS in seven snake species across nine eastern U.S. states. The infection in some species, such as the massasauga rattlesnake in Illinois, is almost always fatal, researchers say, while in other species the impact is not always so dramatic.

Scabs, scales, and opaque eye cloudiness not related to skin molting are among the typical clinical signs of SFD, according to the USGS.

By inoculating laboratory snakes with cultured O. ophiodiicola, a research team led by USGS National Wildlife Health Center microbiologist Jeffrey Lorch was able to prove definitively that the fungus was behind SFD.

SFD is reminiscent of other fungal diseases currently ravaging animals such as bats, with white-nose syndrome, and frogs, with chytridiomycosis. For some snakes, then, the stakes could not be higher.

"There is a fear that Ophidiomyces could drive at least some populations of snakes to extinction," said Lorch, in a statement.

It's still not certain exactly how the disease causes death in the wild, though Lorch thinks a number of factors combine to kill the animal.

"It could be due to predation or exposure if snakes are out and about when they shouldn't be," he said. "They could be getting secondary skin infections if bacteria get in."

Meanwhile, the mortality rate of FSD has been tough to peg, thanks to a lack of long-term data on the condition as well as the difficulty in studying the solitary, often inscrutable nature of snakes.

Read more at Discovery News