Life - US bat killer strikes in Europe

White nose syndrome is contagious in North American bats (Image: Nancy Heaslip, New York Department of Environmental Conservation)

White nose syndrome has been diagnosed in a European bat for the first time. The disease, caused by a fungus, Geomyces destructans, has wiped out millions of bats in the US since it was discovered there in 2006.

The single case, in a living bat, signifies that the disease may occur sporadically in European populations. Other European bats carry the fungus but do not develop white nose syndrome.

"There's definitely no disaster in Europe, and no mass mortality, and the long-term data suggest the situation remains stable," says Natália Martinková of the Czech Institute of Vertebrate Biology in Brno, who led the research.

Martinková studies greater mouse-eared bats (Myotis myotis) in a cave in the Czech Republic. She found crescent-shaped cavities filled with fungal spores and hyphae – the defining symptom of the disease – in the skin of one bat. "The pathology of the skin infection is diagnostic of white nose syndrome," she says.

Two dead bats on the cave floor were also found to be carrying the fungus, but there was no evidence that they had been killed by the disease.

The solitary case strengthens the argument that European bats have long acclimatised to the fungus. North American bats succumb because they have yet to develop resistance. The fungus is thought to have arrived recently in the US from Europe.

No ill effects

Last year Emma Teeling of University College Dublin in Ireland found in a study that bats in 12 European countries are carrying the fungus without any ill effects. She agrees that the isolated case of white nose syndrome is no reason to panic.

"To say that white nose syndrome is in Europe could be a bit premature," Teeling says. If anything, she says, the single case highlights the difficulty of defining when a bat has the disease and when it is harmlessly colonised by the fungus.

"An understanding of the susceptibility [of European bats] may help us understand where we can interrupt the disease cycle and slow or contain the spread of the disease in North American populations," says Ann Froschauer, a spokeswoman for the US Fish and Wildlife Service.

Martinková shares that hope. She adds that European monitoring will reveal environmental factors that suit the fungus. "We have sites where about half the bats are infected, and others where there are far fewer, so we're trying to figure out environmental factors that affect prevalence."

This, in turn, may help to explain how the disease is spreading in the US, and ways to prevent it by modifying the environment within caves.

Journal reference: Journal of Wildlife Diseases, vol 48, p 207

http://www.newscientist.com/