UV Light May Save Bats with Deadly White-Nose Syndrome: New Tool to Detect Disease

White-nose syndrome is impacting bats across the United States. This disease can slowly kill off entire bat colonies, as it rapidly spreads through clustered populations. Now, though, scientists have found a new tool for helping them identify bats with this condition--UV light.

Millions of bats in the United States have already died from the fungal disease known as white-nose syndrome. This disease is caused by the fungus Pseudogymnoascus destructans, and has spread to 25 U.S. states and five Canadian provinces. Yet one of the problems with studying this disease is that there's an unreliability of visual cues for scientists when they check for white-nose syndrome in bats during hibernation. Until now, the only way to check for the disease was to euthanize the bats and send them back to a lab for testing.

Now, though, it looks as if there may be another method to test for white-nose syndrome. The researchers have found that if long-wave UV light is directed at the wings of bats with the disease, it produces a distinctive orange-yellow fluorescence. This glow corresponds directly with microscopic skin lesions that are the current "gold standard" for diagnosing bats with white-nose syndrome.

"When we first saw this fluorescence of a bat wing in a cave, we knew we were on to something," said Greg Turner, one of the researchers, in a news release. "It was difficult to have to euthanize bats to diagnose WNS when the disease itself was killing so many. This was a way to get a good indication of which bats were infected and take a small biopsy for testing rather than sacrifice the whole bat."

In order to see how effective UV light actually was, the scientists examined bats with and without white-nose syndrome. In the end, they found that 98.8 percent of bats with the orange-yellow fluorescence tested positive for white-nose syndrome; in contrast, 100 percent of those that did not show the fluorescence tested negative.

The findings reveal a new way to test bats for this disease. This could greatly help researchers protect bat colonies in the future.

"Moreover, the technique hurts the animal minimally and bats fly away after providing data for research," said Natalia Martinkova from the Academy of Sciences of the Czech Republic in a news release. "This makes UV fluorescence an ideal tool for studying endangered species."

The findings are published in the Journal of Wildlife Diseases.