TDK conference 2010

Since the winter of 2005/2006 dramatic losses of bats have been reported from the north-eastern part of the United States. Cave-dwelling bat populations declined with more than one million individuals, significant mortalities were observed in the case of endangered bat species, too. The mass mortality events are happening during winter, when bats arouse too often from hibernation, so they consume up their fat reserves before spring. In the course of the investigation of the mortality events, a psychrophilic fungus (Geomyces destructans) was found, which can be observed on the ears, wing membranes and on the noses of the infected specimens hence the name of this phenomenon: White-nose Syndrome. To better understand the declines in the United States, we need to find out the origin of this emerging fungal disease since no occurrences were reported from the New World before 2006.

In the last decades there were anecdotal reports from Europe on white fungal infections. In the winter of 2008/2009 an international research program started to collect precise data on European infection which has shown that the fungus occurs in different parts of the continent, including Hungary. However, no mortality events were observed or reported.

In Hungary the first infected specimens were found in an abandoned bauxite mine in the Bakony Mountains in February 2009. The microscopic and molecular investigations of the Hungarian samples showed that the fungus is identical with the American samples. The white patches on the bats make the infection easily identifiable, so nowadays we have data about the fungus from different parts of the country. In Europe there were only Myotis bats infected with the fungus, the most important hosts are the greater (Myotis myotis) and lesser mouse-eared bat (Myotis oxygnathus). In Hungary only these two species were infected. With our bat banding work we could prove for the first time in Europe, that bats can indeed survive this infection.

There are several possible explanations on the difference in the lethality of the fungus infection between the two continents. The most probably is the coevolution of the bats and the fungus so the European bats have been adapted to it. The hiatus of the coexistence in America can be the cause of the lethality of the fungus for the American bats (the first observation of WNS was reported from a cave often visited by tourists).

To stop this fungus from wiping out bat species from America and so causing ecological catastrophe there is an urgent need to widen out our knowledge about the infectiousness, the process, the spreading and the possible impacts of this emerging infectious disease.