White-nose syndrome
[11][12] Alan Hicks with the New York State Department of Environmental Conservation described the impact in 2008 as "unprecedented" and "the gravest threat to bats...ever seen.
[16] The once-common little brown bat has suffered a major population collapse in the northeastern US,[17] although some individuals may be genetically resilient to the disease.
[26] The Fish and Wildlife Service has been partnering with the Northeastern Cave Conservancy to track movements of cavers that have visited affected sites in New York.
One Virginia scientist stated, "If it gets into caves more to our south, in places like Tennessee, Kentucky, Georgia and Alabama, we're going to be talking deaths in the millions.
"[19] In March 2012, WNS was discovered on some tri-colored bats (Perimyotis subflavus) in Russell Cave in Jackson County, Alabama.
[22] Early laboratory research placed the fungus in the genus Geomyces,[22][30] but later phylogenic evaluation revealed this organism should be reclassified within Pseudogymnoascus.
[39] Research has shown the fungus can persist on human clothing and thus could be carried between locations by people, but as of 2016 it has not been demonstrated that this has played any role in the spread of the disease.
[40][41] The visually most obvious indication of infection is the presence of white fungal growth on the muzzles and wing membranes of affected bats.
However, P. destructans may also be present in lower concentrations without leading to obvious visible cues, persisting as a cryptic infection; this appears to be more likely in some species than in others (e.g., the gray bat).
[43] A 2014 study found that while bats can successfully fight off the fungus between mid-October and May, their resistance falls to near zero once they begin to hibernate when the animals shut their metabolism down to save energy.
Some bats will even leave their winter shelters in search of absent insects and risk dying of exposure in the cold.
Consequently many infected bats don't make it until spring when their immune systems and body temperatures ramp up and insect food sources again emerge.
This causes increased energy expenditure, and an elevated blood pCO₂ and bicarbonate called chronic respiratory acidosis, possibly due to diffusion problems.
The damaged wing epidermis might stimulate increased frequencies of arousal from torpor, which removes excess CO₂ and normalizes blood pH, at the expense of hydration and fat reserves.
With worsening wing damage, the effects are exacerbated by water and electrolyte loss across the wound (hypotonic dehydration), which stimulates more frequent arousals in a positive feedback loop that ultimately leads to death.
[59] In the winter of 2011–2012, Alabama,[27] Delaware[60] and Arkansas[61] confirmed the disease in bats and new cases showed up in northeastern Ohio,[62] and Acadia National Park in Maine.
[63] Confirmed cases appeared in 2013 in Georgia,[64] South Carolina,[65] Illinois,[66] and the Canadian province of Prince Edward Island.
[71] A little brown bat (Myotis lucifugus) was found in Washington state infected with white-nose syndrome in March 2016.
[76] In May 2019, the fungus was found in the home of the largest colony of bats in the world, Bracken Cave, near San Antonio, Texas.
[81] In May 2015, based upon laboratory tests, a recommendation was issued to increase the temperature of the hot water treatment for submersible gear to 60 °C (140 °F) for 20 minutes (up from 50 °C (122 °F)).
[84] According to New York State Department of Environmental Conservation Commissioner Basil Seggos, "Research ... demonstrates that white-nose syndrome makes bats highly susceptible to disturbances.
[85] A 2019 study found that bats treated with Pseudomonas fluorescens, a probiotic bacterium previously used in chytridiomycosis treatments, were five times more likely to survive post-hibernation.
