White-nose syndrome, a disease that affects insect-eating bats, is one of the most devastating wildlife diseases on record. But there may be a relatively simple way to stop it, according to new research: UV light.
As New Atlas reports, a new study from the U.S. Forest Service and the University of New Hampshire has found that only a few seconds of exposure to ultraviolet light causes permanent damage to the fungus that causes white-nose syndrome, Pseudogymnoascus destructans. The results were published in Nature Communications on January 2.
White-nose syndrome has killed millions of bats in the United States and Canada over the past decade, according to the USGS. Bats infected by the fungus use more energy during their winter hibernation than healthy bats, meaning they might run out of their energy reserves and die before spring comes. The infection causes dangerous physiological changes including severe wing damage, weight loss, and dehydration.
The P. destructans fungus can grow only in temperatures ranging from 39°F to 68°F, so it infects bats only when they're hibernating. But it's also hard to treat diseased bats as they hibernate, making it even more difficult for scientists to stop the disease. And stopping it is a big deal, not just for wildlife organizations but for governments and farmers, since the bats at risk are important predators that feed on crop-destroying insects. Previous research has shown that UV light can screen hibernating bats for white-nose syndrome—the skin lesions that form on the wings of infected bats glow orange-yellow under UV light—but this is the first study to show it can also be a treatment.
The researchers exposed six closely related Pseudogymnoascus species to UV light for a few seconds to see how the fungi would react. (P. destructans was the only pathogenic species involved.) They found that P. destructans lacked a key enzyme that helps it repair the DNA damage inflicted by exposure to UV light. Whereas other species weren't affected by the light, P. destructans exposed to a low dose of UV light had only a 15 percent survival rate. When that dosage was doubled (to what was still a moderate dose), the species had less than a 1 percent survival rate.
This extreme sensitivity to UV light could be a way for scientists to battle white-nose syndrome. But first they'll have to test the effects of the light on infected, hibernating bats, instead of just working with samples of the fungus in the lab. It's possible that the light could damage the bats' skin, killing off important species in their microbiome, or have some other unintended effect. But even as a preliminary finding, this is a hopeful step.