Increasing Incidence of Geomyces destructans Fungus in Bats from the Czech Republic and Slovakia

BACKGROUND: White-nose syndrome is a disease of hibernating insectivorous bats associated with the fungus Geomyces destructans. It first appeared in North America in 2006, where over a million bats died since then. In Europe, G. destructans was first identified in France in 2009. Its distribution, infection dynamics, and effects on hibernating bats in Europe are largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: We screened hibernacula in the Czech Republic and Slovakia for the presence of the fungus during the winter seasons of 2008/2009 and 2009/2010. In winter 2009/2010, we found infected bats in 76 out of 98 surveyed sites, in which the majority had been previously negative. A photographic record of over 6000 hibernating bats, taken since 1994, revealed bats with fungal growths since 1995; however, the incidence of such bats increased in Myotis myotis from 2% in 2007 to 14% by 2010. Microscopic, cultivation and molecular genetic evaluations confirmed the identity of the recently sampled fungus as G. destructans, and demonstrated its continuous distribution in the studied area. At the end of the hibernation season we recorded pathologic changes in the skin of the affected bats, from which the fungus was isolated. We registered no mass mortality caused by the fungus, and the recorded population decline in the last two years of the most affected species, M. myotis, is within the population trend prediction interval. CONCLUSIONS/SIGNIFICANCE: G. destructans was found to be widespread in the Czech Republic and Slovakia, with an epizootic incidence in bats during the most recent years. Further development of the situation urgently requires a detailed pan-European monitoring scheme

Histogram showing the distribution of individual fish directional bearings in circular tubs.

<p>Note preferential alignment in the North-Southern direction.</p

No fish alignment relative to light.

<p>(<b>A</b>) Distribution of the nearest or the strongest light source positions. (<b>B</b>) The tub mean bearings plotted relative to the position of the light source (light positions standardized to 0°). See caption to Fig. 2 for explanation. (<b>C</b>) The tub mean bearings plotted relative to the magnetic North. Each pair of dots (located on the opposite sites within the unit circle) represents the direction of the bimodal mean tub vector (see Methods). The double-headed arrow indicates the grant mean axial vector calculated over all tubs; the length of the grant mean vector provides a measure of the degree of clustering in the distribution of the tub mean vectors.</p

Graphic demonstration of the measuring of carps’ bearings.

<p>(<b>A, B</b>) Arrows were drawn along the median axes of all the fish visible in the photograph (the arrow axial course was marked unambiguously by the long dorsal fin, its direction by the head position). (<b>C, D</b>) The underlying photograph was removed and replaced by a compass rosette divided radially into 36 ten-degree segments. (<b>E</b>) Each arrow was moved to the center of the rosette and its azimuthal direction was determined by the nearest 10° mark. (<b>F</b>) Mean unimodal, bimodal and quadrimodal vectors were calculated for the photograph.</p

Fish alignment relative to water inlet flow.

<p>(<b>A</b>) Distribution of the water inlet flow directions. (<b>B</b>) The photograph mean bearings plotted relative to the direction of the water inlet flow (standardized to 0°). Arrows indicate the mean vector for the distribution, the length of the mean vector provides a measure of the degree of clustering in the distribution. The inner dashed circles mark the 5% significance border of the Rayleigh test; the arrows exceeding these circles indicate significant directional orientation. The bars outside of the circles delimit 95% confidence interval for the mean bearings.</p

Circular diagrams of tub mean vector distributions demonstrating the North-Southern alignment in carps.

<p>(<b>A</b>) Raw data plot. Each pair of dots (located on the opposite sites within the unit circle) represents the direction of the bimodal mean tub vector. The double-headed arrow indicates the grant mean axial vector calculated over all tubs; the length of the grant mean vector provides a measure of the degree of clustering in the distribution of the tub mean vectors. The inner dashed circle marks the 5% significance border of the Rayleigh test; the bars outside of the circle delimit 95% confidence interval for the grand mean bearing. (<b>B</b>) Scatter plot summarizing statistics weighted by the length of the mean vectors for individual tubs. The position of each pair of dots within the circle represents both the direction and the length of the bimodal mean vector for one tub. The double-headed arrow indicates the weighted grant mean axial vector calculated over all tubs.</p