White Nose Syndrome

A serious disease is attacking bats worldwide.



by Daksha L.

Lately, a disease called White-Nose Syndrome (WNS) has been killing bats all across the world.  Bats are a very important part of ecosystems. If there were no bats, the world would practically be swimming in insects. Each year individual farmers and cities save a lot of money on pesticides because bats keep their numbers in check.

What is WNS?

White-Nose Syndrome is a fungal disease killing bats in Eastern North America, Europe, and Asia. Named for the white fungus on the noses of affected bats, WNS is caused by Pseudogymnoascus destructans (Pd). Pd is an airborne fungus that thrives in cold and humid conditions.

How is WNS spread?

WNS is spread mainly by two agents: bats and humans. Bats spread the disease by contracting it while hunting and may spread it to the other bats in the hibernaculum (the location where bats hibernate over the winter). Humans are actually the main cause of the spread of WNS. Hikers may wander into caves containing bats and unknowingly may have Pd spores on their clothes. The spores may fall off, causing the fungus to spread to the resident bats.

Where is WNS?

WNS was spread to North America from Eurasia. Scientists think that bats in Europe might have had WNS more than 20 years before WNS was found in North America. WNS has been confirmed in these four European countries: Hungary, Germany, Switzerland, and France. WNS is also found in China.

WNS has been confirmed in North America in twenty-two US states and five Canadian provinces. It is suspected in two other US states. WNS is mostly found in Eastern North America but some cases have been found in Washington state.

What bats are affected by WNS?

In North America seven species of bats have been diagnosed with WNS and five other bat species have been found with Pd but have not yet developed the disease (see underlined). There are 11 species of bats affected by WNS in Ohio (*).

  • Big Brown Bat Eptesicus fuscus*
  • Eastern Small-Footed Myotis leibii*
  • Gray Bat (endangered) Myotis grisescens *
  • Little Brown Bat Myotis lucifugus*
  • Indiana Bat Myotis sodalis (endangered)*
  • Northern Long-Eared Bat Myotis septentrionalis (threatened)*
  • Tri-Colored Bat Perimyotis subflavus*
  • Southeastern Bat Myotis austroriparius*
  • Silver-Haired Bat Lasionycteris noctivagans*
  • Townsend’s Big-Eared Bat Corynorhinus townsendii*
  • Eastern Red Bat Lasiurus borealis*
  • Rafinesque’s Big-Eared Bat Corynorhinus rafinesquii*

What are the symptoms of WNS?

Symptoms of WNS include: white fungus on nose ears and wing, wrinkled or damaged skin on wings, and loss of body fat. Bats usually die of loss of body fat or fly out of the hibernaculum in freezing conditions and die of hypothermia.

How deadly is WNS?

WNS usually kills 70-90% of bats in an affected hibernaculum. In some caves the mortality rate is 100%.

What can I do to help?

If you see a dead bat with signs of WNS outside in winter or a bat flying outside in winter, report your sighting to your state natural resource agency. If you see a dead bat DO NOT TOUCH IT.

Is there a cure for WNS?

Yes, the University of Georgia is using Rhodococcus rhodochrous, a bacteria used to prevent fungal growth on fruits and vegetables, to prevent fungal growth on bats. Rhodococcus rhodochrous is also being used to cure bats of WNS. In Hannibal, Missouri on May 19, 2015 bats cured of WNS using Rhodococcus rhodochrous were released. It can be hard to reach the bats in their natural hibernaculum so this treatment is better than previous treatments in that you don’t actually have to handle the bats. Instead, the treatment is given by releasing the air given off by the volatile organic compounds.

Also, researchers from the University of California at Santa Cruz have found bats in China to be more resilient to WNS than bats in North America. They found fewer bats affected and less fungus on the bats that were affected.

So, even though this disease is so devastating, there is hope!