The fungus associated with WNS is a newly described, psychrophilic (cold-loving) species (Geomyces destructans). It is closely related to G. pannorum, which causes skin infections in humans.
Although it is not known whether the fungus is primarily responsible for deaths of bats or is a secondary infection, it is directly associated with deaths of bats. Bacteriologic, virologic, parasitologic, and postmortem evaluations of the cause of death did not identify any other agents, which reinforces the suspicion that this fungus is the causative agent.
During intensive monitoring of bat hibernation in France, 1 bat (Myotis myotis) found on March 12, 2009, near P?rigueux showed a powdery, white fungal growth on its nose, which is characteristic of WNS.
We suggest 3 possible scenarios for our findings:
The first scenario is that the fungus has only recently arrived in Europe and all bats in Europe are now at risk for infection. Thus, conservation steps must be taken to minimize the spread of this disease, especially because this disease is specific for hibernating bats. After the hibernation period, M. myotis bats may migrate up to 436 km to reach their summer roosts, a behavior that could quickly increase the chance of fungus transmission.
A second scenario is that the fungus has been present in Europe for a long time. Because mass deaths have not been observed in bats in Europe, these bats may be immune to WNS. Therefore, identification of mechanisms of this immunity will advance understanding of this disease and fungus resistance in mammals.
The third scenario is that the G. destructans fungus is not the primary cause of death but acts as an opportunistic pathogen in bats already immunocompromised by other pathogens such as viruses or bacteria. Comparison of pathogens in bats in Europe and the United States infected with G. destructans should identify the primary causative agent.
The bat in our study showing fungal growth was not underweight, as is typical of bats in the United States with WNS. This finding favors the second or third scenarios. Also, a 6-year (2004–2009) annual monitoring program of wintering bat populations at the site and 5 sites within a 2-km radius did not show any cases of WNS or deaths and showed stable bat populations. The 3 scenarios indicate that studying G. destructans in bats in Europe and the United States is necessary to understand and control this disease.
http://www.cdc.gov/eid/content/16/2/pdfs/09-1391.pdf
Puechmaille SJ, Verdeyroux P, Fuller H, Ar Gouilh M, Bekaert M, Teeling EC.
Although it is not known whether the fungus is primarily responsible for deaths of bats or is a secondary infection, it is directly associated with deaths of bats. Bacteriologic, virologic, parasitologic, and postmortem evaluations of the cause of death did not identify any other agents, which reinforces the suspicion that this fungus is the causative agent.
During intensive monitoring of bat hibernation in France, 1 bat (Myotis myotis) found on March 12, 2009, near P?rigueux showed a powdery, white fungal growth on its nose, which is characteristic of WNS.
We suggest 3 possible scenarios for our findings:
The first scenario is that the fungus has only recently arrived in Europe and all bats in Europe are now at risk for infection. Thus, conservation steps must be taken to minimize the spread of this disease, especially because this disease is specific for hibernating bats. After the hibernation period, M. myotis bats may migrate up to 436 km to reach their summer roosts, a behavior that could quickly increase the chance of fungus transmission.
A second scenario is that the fungus has been present in Europe for a long time. Because mass deaths have not been observed in bats in Europe, these bats may be immune to WNS. Therefore, identification of mechanisms of this immunity will advance understanding of this disease and fungus resistance in mammals.
The third scenario is that the G. destructans fungus is not the primary cause of death but acts as an opportunistic pathogen in bats already immunocompromised by other pathogens such as viruses or bacteria. Comparison of pathogens in bats in Europe and the United States infected with G. destructans should identify the primary causative agent.
The bat in our study showing fungal growth was not underweight, as is typical of bats in the United States with WNS. This finding favors the second or third scenarios. Also, a 6-year (2004–2009) annual monitoring program of wintering bat populations at the site and 5 sites within a 2-km radius did not show any cases of WNS or deaths and showed stable bat populations. The 3 scenarios indicate that studying G. destructans in bats in Europe and the United States is necessary to understand and control this disease.
http://www.cdc.gov/eid/content/16/2/pdfs/09-1391.pdf
Puechmaille SJ, Verdeyroux P, Fuller H, Ar Gouilh M, Bekaert M, Teeling EC.