WEBVTT Kind: captions Language: en 00:00:02.960 --> 00:00:06.170 Dr. David Blehert:  Thank you, Bill, for the very nice introduction and thanks to Hannah 00:00:06.170 --> 00:00:12.800 Hamilton for inviting me and the USGS communications group for arranging my visit. 00:00:12.800 --> 00:00:19.000 So today, I'm going to talk about bats and new bat disease.  Let's see if I can my slides 00:00:19.000 --> 00:00:20.810 to advance.  Can everybody hear me OK? 00:00:20.810 --> 00:00:21.810 Audience:  Yes. 00:00:21.810 --> 00:00:27.290 Dr. David Blehert:  Let's see.  Yeah.  The arrows.  They should work.  There we 00:00:27.290 --> 00:00:28.290 go. 00:00:28.290 --> 00:00:32.630 OK.  So let me just begin by saying a little bit about bats to get us all on the same page.  00:00:32.630 --> 00:00:42.620 Bats are the only mammals that are capable of self-powered flights.  Most are nocturnal.  00:00:42.620 --> 00:00:47.140 Perhaps these adaptations of being one of the few animals that's out flying in the night 00:00:47.140 --> 00:00:54.050 sky when there's otherwise lack of aerial predators has afforded this group of animals 00:00:54.050 --> 00:01:00.480 with the evolutionary opportunity to diverge into a huge number of species. 00:01:00.480 --> 00:01:05.300 Bats are the second most species diverse group of mammals on the planet.  Only behind rodents.  00:01:05.300 --> 00:01:12.920 There are about 1,100 species of bats out of a total 5,500 or so species of mammals.  00:01:12.920 --> 00:01:21.430 And just an amazing amount of adaptations, if you look at this giant fruit bat on the 00:01:21.430 --> 00:01:27.049 screen here, this animal consumes ripe fruit.  This is nectar-feeding bat that can hover 00:01:27.049 --> 00:01:32.369 in front of cactus flowers and lap the nectar. 00:01:32.369 --> 00:01:38.140 Here's a bat that's got both white and black fur.  It's the spotted bat in the American 00:01:38.140 --> 00:01:44.000 Southwest.  With his huge ears, I think this animal is known to forge for insects on the 00:01:44.000 --> 00:01:47.020 ground and they can say that it can actually hear their footsteps. 00:01:47.020 --> 00:01:51.780 And here we have a bulldog bat -- which actually eats fish and it catches them right out of 00:01:51.780 --> 00:01:53.570 the water. 00:01:53.570 --> 00:02:02.430 So, to transition the topic of today's talk, a disease bats, white-nose syndrome is a fungal 00:02:02.430 --> 00:02:06.780 disease.  Of all the various pathogens or disease agents that we know of, and I'm a 00:02:06.780 --> 00:02:11.610 microbiologist so I know of a lot of these, even for microbiologist, fungi are not often 00:02:11.610 --> 00:02:14.590 the first that come to mind when talking about disease. 00:02:14.590 --> 00:02:19.490 When it comes to disease of humans, there are really only six major recognized groups 00:02:19.490 --> 00:02:24.480 or genre of fungi that cause disease and to name them, maybe you've heard of some of them, 00:02:24.480 --> 00:02:31.760 includes the Yeast Candida and other fungi Aspergillus, Histoplasma, Blastomyces, Coccidioides 00:02:31.760 --> 00:02:32.770 and Cryptococcus.   00:02:32.770 --> 00:02:40.200 But, that's six out of literally hundreds of thousands of species.  Despite fungal 00:02:40.200 --> 00:02:44.660 pathogens not necessarily being the first thing that people think of when talking about 00:02:44.660 --> 00:02:49.660 disease, it's indisputable as I've outlined on this slide here, that fungi have had major 00:02:49.660 --> 00:02:55.510 impacts on the world. So for example, fungal diseases transformed landscapes by ravaging 00:02:55.510 --> 00:03:02.390 both American chestnut trees and elm trees, all within the 20th century.  The Irish potato 00:03:02.390 --> 00:03:08.220 famine caused by a fungal-like organism that's now referred to as called Oomycete, caused 00:03:08.220 --> 00:03:11.430 the death and immigration of over 2 million people. 00:03:11.430 --> 00:03:17.200 Fungi remain potent pathogens of plants, humans and wildlife today, yet fewer than 10% of 00:03:17.200 --> 00:03:21.820 all fungal species are known to science.  There are limited antifungal therapeutic drugs 00:03:21.820 --> 00:03:27.570 available and they often have associated toxicity because of terms of classes of animals, fungi 00:03:27.570 --> 00:03:32.100 are actually very closely related to people.  So when we target bacterial pathogens with 00:03:32.100 --> 00:03:37.490 antibiotics, we're targeting mechanisms of replication for that microorganism that are 00:03:37.490 --> 00:03:40.320 distinctly different than those in our own bodies. 00:03:40.320 --> 00:03:44.000 When it comes to treating a fungal pathogen, there are also what are known as eukaryotes 00:03:44.000 --> 00:03:50.500 just like us.  And so it becomes challenging to kill the fungus without harming the host.  00:03:50.500 --> 00:03:56.790 There's no antifungal vaccines.  And then when it comes in particular to plants or animals, 00:03:56.790 --> 00:04:02.540 like wildlife, that don't have intrinsic or obvious economic value, disease management 00:04:02.540 --> 00:04:09.570 can be very challenging.  Another point of interest is that fungal diseases in humans 00:04:09.570 --> 00:04:15.100 and other mammals are most commonly associated with hosts that have compromised immune systems.  00:04:15.100 --> 00:04:19.729 So there's something else going on.  Or, in cases where that host was exposed to a 00:04:19.729 --> 00:04:28.270 huge dose of the organism. Say, through, fungal diseases sometimes arise in military personnel 00:04:28.270 --> 00:04:32.990 doing training exercises where they're crawling through soil with their faces close to the 00:04:32.990 --> 00:04:39.290 soil that's enriched with fungal spores of certain disease agents. 00:04:39.290 --> 00:04:43.810 This graphic shows that with respect to human health-- and likely driven changes in host's 00:04:43.810 --> 00:04:49.780 immune status-- caused by the emergence of HIV, increased use of immunosuppressive medications 00:04:49.780 --> 00:04:56.580 like steroid treatments, other intensive care-based therapies that have people in hospitals with 00:04:56.580 --> 00:05:01.039 in-blowing catheters that are providing a conduit between the outside world and the 00:05:01.039 --> 00:05:05.889 inside of the body, incidents of systemic fungal disease and people has been exponentially 00:05:05.889 --> 00:05:09.249 on the rise since about the 1950s. 00:05:09.249 --> 00:05:13.490 As I move along through this presentation, and along these same lines, I hope to convey 00:05:13.490 --> 00:05:19.750 to you the unique world that hibernation plays in white-nose syndrome as one of these predisposing 00:05:19.750 --> 00:05:26.090 factors to this novel of disease. So what is White-nose Syndrome? 00:05:26.090 --> 00:05:30.970 It's an emerging fungal disease of bats and it's a very interesting-- or maybe insidious 00:05:30.970 --> 00:05:35.629 would be a better word -- disease because bats are specifically infected with this fungus 00:05:35.629 --> 00:05:41.800 when they hibernate; which, based on research done in other hibernating mammals, is believed 00:05:41.800 --> 00:05:45.360 to be, it's known to be in these other mammals, and we believed it to be in bats, to be a 00:05:45.360 --> 00:05:50.349 time of natural immunosuppression.  So, there is one of the potential predisposing factors. 00:05:50.349 --> 00:05:56.100 Furthermore, a large scale disease epidemic, or we'd say epizootic when we're talking about 00:05:56.100 --> 00:06:02.229 mammals, a large scale epizootic among bats like White-nose Syndrome is not only unprecedented 00:06:02.229 --> 00:06:07.379 among the bats that live in the United States, but among all of the 1,100 plus species of 00:06:07.379 --> 00:06:12.319 bats and perhaps even among all mammalian species around the world. 00:06:12.319 --> 00:06:19.189 A paper came out in the journal Science two summers ago now in which the authors predicted 00:06:19.189 --> 00:06:26.050 a 99% chance for regional extinction of little brown bats-- once the most numerous hibernating 00:06:26.050 --> 00:06:31.190 insect killer bats species in the Northeastern United States -- within about the next 16 00:06:31.190 --> 00:06:34.770 years as a result of this disease. 00:06:34.770 --> 00:06:37.479 So do I think this is a feasible hypothesis?  00:06:37.479 --> 00:06:43.580 I would say that it actually is because unlike other pathogens, say like a virus, that is 00:06:43.580 --> 00:06:49.250 not as autonomously replicating organism, or something that's capable of survival on 00:06:49.250 --> 00:06:55.379 its own, most fungi are.  Almost all fungi, including those that are pathogenic, can also 00:06:55.379 --> 00:07:01.020 live a second type of life phase, whether just existing as saprobes or decomposers of 00:07:01.020 --> 00:07:03.029 organic matter in soil. 00:07:03.029 --> 00:07:07.330 And so a fungus that's trying to compete with all of these thousands and thousands of other 00:07:07.330 --> 00:07:12.800 species for very limited nutrients in soil, if it has somehow gain the ability to infect 00:07:12.800 --> 00:07:18.650 the host, which in the case of a bat, maybe we could just think of a hibernating container 00:07:18.650 --> 00:07:24.479 of fungus food. In that case, that fungus gets a huge advantage over its counterparts 00:07:24.479 --> 00:07:29.199 in the soil and it gains the ability to replicate and make more of itself, which is effectively 00:07:29.199 --> 00:07:32.439 the evolutionary goal of a microorganism. 00:07:32.439 --> 00:07:38.300 So, now if these fungi kill all the bats in the cave, they just go back to a more quiet 00:07:38.300 --> 00:07:43.289 reserved lifestyle in the soil and it doesn't mater that they drove their host to extinction.  00:07:43.289 --> 00:07:47.759 If a virus kills all of its hosts, the virus goes with them. 00:07:47.759 --> 00:07:52.479 And so that's one of our concerns in that fungi do have this unique ability compared 00:07:52.479 --> 00:07:57.689 to other pathogens. So let me talk about a little bit about the known progression of 00:07:57.689 --> 00:07:58.960 this disease. 00:07:58.960 --> 00:08:02.660 The first evidence that we have a White-nose Syndrome comes from a photograph that was 00:08:02.660 --> 00:08:09.930 taken by a recreational caver in early 2006.  The photo which has down, what would that 00:08:09.930 --> 00:08:16.249 be your right-hand corner of the screen, shows a bat with this unusual white substance or 00:08:16.249 --> 00:08:19.210 growth of what we know now as fungus around its nose. 00:08:19.210 --> 00:08:25.640 This photo wasn't actually made widely public until the year 2008.  What's interesting 00:08:25.640 --> 00:08:33.140 is this photograph was taken in a cave, in east central New York, that is part of a complex 00:08:33.140 --> 00:08:38.479 of caves that includes a large tourist cave that entertains about 250,000 human visitors 00:08:38.479 --> 00:08:39.590 each year. 00:08:39.590 --> 00:08:45.230 We've also since learned that the fungus that causes White-nose Syndrome is surprisingly 00:08:45.230 --> 00:08:51.040 wide-spread on bats of Europe, where the bats seemingly co-exist with it.  In other words, 00:08:51.040 --> 00:08:55.160 we've never, although we've seen the fungus on the bats, we've even seen that it can cause 00:08:55.160 --> 00:09:00.380 White-nose Syndrome in European bats, there's no current or historical documentation of 00:09:00.380 --> 00:09:03.980 these unusual mortality events caused by the disease in Europe. 00:09:03.980 --> 00:09:09.390 So, it leads to the plausible hypothesis that this disease agent may have been introduced 00:09:09.390 --> 00:09:14.180 to the United States through tourism.  And that is not an unexpected scenario given the 00:09:14.180 --> 00:09:18.380 prominent role, and I'll talk more about this later, that global travel and trade are known 00:09:18.380 --> 00:09:24.820 to play in the emergence of infectious diseases worldwide. So the next winter, the disease 00:09:24.820 --> 00:09:28.520 was, let's say officially discovered, by a biologist with the New York State Department 00:09:28.520 --> 00:09:33.590 of Environmental Conservation when they were conducting routine bat hibernation survey 00:09:33.590 --> 00:09:39.260 counts for the endangered Indiana bats.  And by the time they were done doing their 00:09:39.260 --> 00:09:45.270 surveys, they had found bats with either suspicious white growth on their bodies or dead bats 00:09:45.270 --> 00:09:53.800 on cave floors at five sites within two counties encompassing about a 15-kilometer radius, 00:09:53.800 --> 00:09:56.010 near Albany, New York. 00:09:56.010 --> 00:10:01.500 The next winter, my laboratory, others at the National Wildlife Health Center, our pathology 00:10:01.500 --> 00:10:07.100 team, our field investigation team, as well as other diagnostic labs became significantly 00:10:07.100 --> 00:10:10.720 involved.  So, in another words the people from New York State, who discovered this the 00:10:10.720 --> 00:10:13.710 previous spring, had alerted us to this problem. 00:10:13.710 --> 00:10:17.210 We had some conference calls - we need to figure out what's going on; we're going to 00:10:17.210 --> 00:10:22.080 be out looking for this; we're going to be sending you bats, get ready, it's going to 00:10:22.080 --> 00:10:23.080 be ugly. 00:10:23.080 --> 00:10:29.000 And so, by the time the winter of 2007-2008 was over, we have now identified the disease 00:10:29.000 --> 00:10:35.090 of 33 sites extending to a circle with a radius of 210 kilometers from that index site near 00:10:35.090 --> 00:10:42.060 Albany, New York.  The disease now documented in New York, Massachusetts, Vermont and Connecticut. 00:10:42.060 --> 00:10:46.720 The next winter, things got much worse with the bats with the disease identified now in 00:10:46.720 --> 00:10:51.630 over a 100 sites extending into nine states all the way down to the southwestern tip of 00:10:51.630 --> 00:10:57.040 Virginia, at a distance of over 900 kilometers from the disease epicenter. 00:10:57.040 --> 00:11:03.700 And at this point, there's really no precedent for studying or responding to a wildlife disease 00:11:03.700 --> 00:11:10.160 among what we can refer to as cryptic hibernating animals like bats.  Many of us, if we didn't 00:11:10.160 --> 00:11:16.720 for other reasons, know they were there, they're just there, people don't know about them, 00:11:16.720 --> 00:11:22.610 they're doing our thing, we're doing our thing.  And there's surprisingly little known about 00:11:22.610 --> 00:11:31.130 their immune systems and their over-all biology. So then the following winter, this will be what, 00:11:31.130 --> 00:11:35.390 three winters ago now, we worked with Canadian Wildlife Health Authorities to confirm the 00:11:35.390 --> 00:11:41.920 disease at several sites in Quebec and Ontario, showing now that as disease is moving westward 00:11:41.920 --> 00:11:46.180 across the country, there's effectively two fronts for introduction into the mid-western 00:11:46.180 --> 00:11:49.750 states and on into the western states. 00:11:49.750 --> 00:11:54.930 At this time we also brought online some new, more sensitive molecular tests that we can 00:11:54.930 --> 00:12:01.780 use to find DNA from the fungus which led to these possible detections of the fungus 00:12:01.780 --> 00:12:11.120 on bats in Oklahoma and Missouri.  Thankfully, we've not been able to confirm these findings, 00:12:11.120 --> 00:12:16.920 the surveillance work that we do is opportunistic, so we don't have people out all over the place 00:12:16.920 --> 00:12:18.690 testing every bat they can find. 00:12:18.690 --> 00:12:23.940 We have people that are doing surveys in caves in this unobtrusive of a way as possible so 00:12:23.940 --> 00:12:29.220 as not to disturb the hibernating animals.  And if they see something suspicious or dead, 00:12:29.220 --> 00:12:33.930 that animal may be collected and sent to my lab or other labs for analysis. 00:12:33.930 --> 00:12:41.220 And so, despite heightened surveillance activity, we have not yet confirmed these sightings 00:12:41.220 --> 00:12:45.100 in Missouri and Oklahoma. 00:12:45.100 --> 00:12:52.470 So this takes us to last winter where we by the end winter 2010-2011 had confirmed the 00:12:52.470 --> 00:12:57.910 disease out into 16 states including these new states of Indiana, Kentucky, North Carolina 00:12:57.910 --> 00:13:05.520 and Tennessee.  And now in four Canadian provinces. Interestingly, we have not yet 00:13:05.520 --> 00:13:15.590 and this still holds true today, if I pull up our current map, current as of last Friday, 00:13:15.590 --> 00:13:21.850 we have not yet seen the high unusual mortality west of the Appalachian mountains.  And that's 00:13:21.850 --> 00:13:23.710 an area that we're actively investigating. 00:13:23.710 --> 00:13:29.700 So the question is, we know that this fungus establishes itself in environments, in the 00:13:29.700 --> 00:13:34.470 environment, and effectively can become amplified overtime and the bats then become exposed 00:13:34.470 --> 00:13:40.510 to more of it earlier each hibernation season.  So is it just a matter of time and perhaps 00:13:40.510 --> 00:13:45.340 by the end of March and in the April, as the bats are completing hibernation for this winter, 00:13:45.340 --> 00:13:51.390 we'll see things get much worse in these mid-western states like Tennessee, Kentucky, Indiana, 00:13:51.390 --> 00:13:57.320 Ohio, etc., Or, are environmental conditions different such that the disease never will 00:13:57.320 --> 00:14:00.030 become as severe west of the Appalachian mountains. 00:14:00.030 --> 00:14:07.110 So, that's perhaps one area of the hope but, the jury is still out on that. 00:14:07.110 --> 00:14:13.280 In terms of the species affected, we've documented what we in the lab would call clinical disease 00:14:13.280 --> 00:14:18.570 in six different species of bats that belong to three different genre.  When all of these 00:14:18.570 --> 00:14:23.190 bat species - the Little brown bat, the Big brown bat, the Northern long-eared bat, the 00:14:23.190 --> 00:14:28.990 Eastern small-footed bat, the Tricolored bat, which people have previously known as the 00:14:28.990 --> 00:14:34.000 Eastern Pipistrelle, and the Indiana bat, which is an endangered species, all have in 00:14:34.000 --> 00:14:39.700 common, is that these bats all hibernate to wait out the insect food shortage during the 00:14:39.700 --> 00:14:40.790 winter time. 00:14:40.790 --> 00:14:45.650 And so again, we’ll further discuss how I believe hibernation predisposes these animals 00:14:45.650 --> 00:14:51.620 to infection by Geomyces destructans-- the fungus. So with that, let's transition to 00:14:51.620 --> 00:14:54.590 a brief discussion of disease ecology. 00:14:54.590 --> 00:14:59.290 In order to understand emergence and subsequent spread of the disease, we have to understand 00:14:59.290 --> 00:15:05.440 how susceptible hosts, pathogens, and environments, come together in a way that promotes development 00:15:05.440 --> 00:15:10.480 of the disease.  So, that can be: a stomach virus outbreak among passengers that are closely 00:15:10.480 --> 00:15:15.320 housed together on a cruise ship, a cold that passes through children at day care center, 00:15:15.320 --> 00:15:21.290 or a White-nose Syndrome outbreak among hibernating bats in close proximity within an underground 00:15:21.290 --> 00:15:25.720 hibernation environment like a cave or a mine. 00:15:25.720 --> 00:15:35.720 So hopefully by now I've convinced you that bats are the host for this disease.  So, 00:15:35.720 --> 00:15:39.780 I'll talk more about the pathogen later.  But let's talk about this environment, the 00:15:39.780 --> 00:15:42.590 underground hibernation site. 00:15:42.590 --> 00:15:48.070 This is an old U.S. Geological Survey map that show the locations of caves as red dots 00:15:48.070 --> 00:15:54.990 in the Eastern United States.  And if we overlay a map showing disease occurrence, 00:15:54.990 --> 00:16:00.310 the yellow counties on the map, you can see that it exactly mirrors the cave locations.  00:16:00.310 --> 00:16:06.690 So, indicating that these caves provide that environment that brings the susceptible hosts 00:16:06.690 --> 00:16:08.410 and the pathogen together. 00:16:08.410 --> 00:16:14.310 A similar analysis I believe was done when West Nile Virus was moving westward across 00:16:14.310 --> 00:16:20.010 the country from its initial point of introduction on the East Coast.  And effectively if you 00:16:20.010 --> 00:16:25.340 could find a susceptible bird species like a crow or a blue bird, a Blue Jay, near a 00:16:25.340 --> 00:16:30.280 water source that harbored mosquitoes that harbored the West Nile Virus pathogen, that 00:16:30.280 --> 00:16:36.490 was your key for early detection of West Nile Virus in your state as the disease march westward. 00:16:36.490 --> 00:16:40.670 So to complete this discussion of the disease triad, we've covered the host, we've covered 00:16:40.670 --> 00:16:47.710 the environment: the cool underground dark cave. Let's transition to the pathogen aspects 00:16:47.710 --> 00:16:54.320 of the disease. So as I mentioned before, my laboratory and others began to investigate 00:16:54.320 --> 00:17:01.150 this outbreak in earnest in early 2008, after we were contacted by the state biologists 00:17:01.150 --> 00:17:07.539 in New York.  Because of a clinical presentation of this disease, this white stuff around their 00:17:07.539 --> 00:17:12.290 faces, we suspected a fungal disease agent. 00:17:12.290 --> 00:17:16.929 But our early disease investigation efforts were complicated in that this white material 00:17:16.929 --> 00:17:20.560 that I show you on the bats' muzzles -- and it is elsewhere on their bodies too, especially 00:17:20.560 --> 00:17:26.959 their wings-- is very fragile.  And if these bats are removed from caves it would disappear.  00:17:26.959 --> 00:17:31.960 So, by time the bat was shipped to our bio-safe, bio-secure laboratory in Madison from the 00:17:31.960 --> 00:17:36.340 East Coast, they didn't look like anything was wrong with them, except for they were 00:17:36.340 --> 00:17:39.640 dead. 00:17:39.640 --> 00:17:44.570 So an early breakthrough in the investigation came when a persistent New York state pathologist, 00:17:44.570 --> 00:17:48.960 Dr. Melissa Behr, who, to our good fortune, subsequently transferred to the Wisconsin 00:17:48.960 --> 00:17:53.649 Veterinary Diagnostic Lab, and we're continuing to work with Melissa, was also troubled by that 00:17:53.649 --> 00:17:54.850 observation. 00:17:54.850 --> 00:18:01.309 She's getting bats from a mine that was probably within 10 miles of her lab in Albany and didn't 00:18:01.309 --> 00:18:05.649 look like there's anything wrong with it.  So, Melissa went in to one of these caves 00:18:05.649 --> 00:18:11.330 and she collected samples from bats right on the cave wall of this white material and 00:18:11.330 --> 00:18:17.940 prepared them for both electron-microscopy and simple light-microscopy using a blue stain. 00:18:17.940 --> 00:18:23.499 And what she saw when she scraped this white material on to her microscope preparations 00:18:23.499 --> 00:18:31.129 was a pure culture of this unusual fungus with these hook spores that are actually a 00:18:31.129 --> 00:18:36.320 spore morphology that never had before been seen. 00:18:36.320 --> 00:18:42.850 So, in the meantime at my lab, we were culturing skin samples from the hundreds of bats that 00:18:42.850 --> 00:18:49.749 we're receiving.  And if you take an animal that lives in a cold, dark cave and culture 00:18:49.749 --> 00:18:53.639 its skin, you can imagine that it's just covered with fungi.  I mean, people probably have 00:18:53.639 --> 00:18:57.830 been in a musty basement -- and musty cave is the same way-- and that musty snow comes 00:18:57.830 --> 00:19:02.870 from all of the fungi that are present.  And so how do you figure out which one of 00:19:02.870 --> 00:19:08.000 those things growing on that bats is what's causing your problem.   Well, one of our 00:19:08.000 --> 00:19:13.000 breakthroughs and other people were doing this as well, was we had to ask the question: 00:19:13.000 --> 00:19:17.590 What do we need to do in the lab to grow something that's colonizing the skin of a hibernating 00:19:17.590 --> 00:19:23.130 bat?  And the skin of a hibernating is about the temperature of the inside of your refrigerator. 00:19:23.130 --> 00:19:28.080 And typically, when your doing microbiology work, you incubate your cultures at the temperature 00:19:28.080 --> 00:19:32.840 of the human body, like 98.6 degrees, or maybe at room temperature.  Well, it turns out 00:19:32.840 --> 00:19:38.289 that for this fungus room temperature is too warm.  Its upper cutoff for growth is around 00:19:38.289 --> 00:19:44.570 65-66 degrees Fahrenheit, around below 20 degrees Centigrade. 00:19:44.570 --> 00:19:49.629 So, my technician in the lab had put some of these skin samples on petri plates and 00:19:49.629 --> 00:19:53.970 stuck it in a laboratory refrigerator.  And very slowly, this white fungus started to 00:19:53.970 --> 00:19:58.139 grow on those plates.  And at about the time that Melissa circulated her photographs of 00:19:58.139 --> 00:20:04.820 the white scraping right off the bats, our cultures were starting to grow and we stuck 00:20:04.820 --> 00:20:11.940 them under microscope and compared them to Melissa's photos and found the same fungus. 00:20:11.940 --> 00:20:18.179 And so, the question is: What is it? 00:20:18.179 --> 00:20:24.369 It requires cold for growth, and the temperatures at which it grows unfortunately overlap perfectly 00:20:24.369 --> 00:20:29.160 with the skin and core body temperatures of hibernating bats.  The fungus cannot actively 00:20:29.160 --> 00:20:33.620 grow at warm temperatures, even the temperature of this room, as I mentioned, would be too 00:20:33.620 --> 00:20:40.889 warm for it, but that doesn't mean it would die.  And so there is a concern about not 00:20:40.889 --> 00:20:43.749 accidentally transporting it somewhere. 00:20:43.749 --> 00:20:49.779 The fungus is common on sick bats but absent from healthy bats and all of the isolates 00:20:49.779 --> 00:20:54.929 that we have subsequently characterized within some common genetic marker regions from both 00:20:54.929 --> 00:20:59.659 North America and now from Europe as well, are genetically identical.  So when you put 00:20:59.659 --> 00:21:04.799 this genetic relatedness together with this radiating pattern of disease spread from a 00:21:04.799 --> 00:21:10.070 single index site, suggest that, -- all this circumstantial evidences is suggestive, of 00:21:10.070 --> 00:21:16.539 a single point introduction and subsequent spread of an introduced pathogen. So based 00:21:16.539 --> 00:21:21.720 on DNA sequence analysis of some of these marker genes, we were able to determine that 00:21:21.720 --> 00:21:27.799 this fungus belong to a genus of common soil fungi called Geomyces, which means fungus 00:21:27.799 --> 00:21:33.919 of the earth.  But based on some of these other characteristics, its ability to infect 00:21:33.919 --> 00:21:41.710 bats, its curved spore shape, and its requirement for growth in cold, we identified it and named 00:21:41.710 --> 00:21:49.610 is as a new species which we designated destructans, so the destroying Geomyces. 00:21:49.610 --> 00:21:54.100 Some work that we've recently completed and published was demonstration according to strict 00:21:54.100 --> 00:22:01.009 criteria in microbiology known as Koch's Postulates, developed by a preeminent microbiology pioneer, 00:22:01.009 --> 00:22:08.630 Robert Koch, in the late 1800s, that definitively demonstrate the Geomyces destructans in the 00:22:08.630 --> 00:22:13.639 absence of other contributing factors is the pathogen that causes this disease. 00:22:13.639 --> 00:22:17.929 And so in order to fill Koch's Postulates, first you have to demonstrate that the microorganism 00:22:17.929 --> 00:22:23.029 is found in abundance on all organisms or all animals suffering from the disease, but 00:22:23.029 --> 00:22:27.940 absent from healthy animals.  And we accomplished that through our disease investigation work. 00:22:27.940 --> 00:22:31.440 Oops!  I jumped one ahead. 00:22:31.440 --> 00:22:37.919 The microorganism must then be isolated from the sick animal and grown in pure culture 00:22:37.919 --> 00:22:43.169 in the laboratory.  And so again we accomplish that through our disease investigation work. 00:22:43.169 --> 00:22:50.970 The cultured microorganism should cause disease when introduce into a healthy animal and then 00:22:50.970 --> 00:22:57.450 subsequently, you have to be able to re-isolate the introduced pathogen from the healthy animal.  00:22:57.450 --> 00:23:02.320 And so in order to do this, our first challenge was to develop a system whereby we could successfully 00:23:02.320 --> 00:23:11.740 maintain wild hibernating bats in our laboratory.  And so having achieved that, we were then 00:23:11.740 --> 00:23:18.691 able to conduct the experiment.    So, what I'm showing you on this slide, these 00:23:18.691 --> 00:23:25.169 two images are called histopathology, which allows us to see how the fungus interacts 00:23:25.169 --> 00:23:31.230 with tissues from the animal.  And so what we're looking at here are cross-sections of 00:23:31.230 --> 00:23:37.059 bat wing skin and the stuff in dark purple is fungus. 00:23:37.059 --> 00:23:44.230 If you think this is-- if you recognize this is bat-- and dark color is bad, you're getting 00:23:44.230 --> 00:23:48.601 to see the picture. What this fungus does is it forms these dense aggregations in a 00:23:48.601 --> 00:23:54.929 way that we haven't seen with other fungal skin pathogens of bats.  And it invades and 00:23:54.929 --> 00:23:59.950 destroys wing tissue, as well as tissue of the muzzle and elsewhere. 00:23:59.950 --> 00:24:06.629 And so based on this measure, we were able to demonstrate that by putting predetermined 00:24:06.629 --> 00:24:10.860 numbers of spores from this fungus on the skin of hibernating bats that we were able 00:24:10.860 --> 00:24:18.480 to cause the disease in 100% of animals that we treated.  We are also able to transmit 00:24:18.480 --> 00:24:23.820 the disease from bat to bat by co-housing sick with healthy bats. 00:24:23.820 --> 00:24:30.360 Interestingly, when we had bats in separate cages -- hibernating bats in separate cages 00:24:30.360 --> 00:24:36.639 within our incubators-- we did not transmit the fungal agent between bats by air.  It 00:24:36.639 --> 00:24:41.419 is an interesting result, but one of my concerns is that I think that this might stem from 00:24:41.419 --> 00:24:43.600 the way in which the experiment was done. 00:24:43.600 --> 00:24:50.200 The bats are kept in mesh cages and the mesh can obstruct the free movement of spores between 00:24:50.200 --> 00:24:57.450 cages, as well as, unlike a cave, these incubators are constantly moving air from within the 00:24:57.450 --> 00:25:02.419 incubator over the evaporator or chiller coil and recirculating it back through, so it's 00:25:02.419 --> 00:25:07.830 possible that we effectively vacuumed spores out of the air of the system as it works. 00:25:07.830 --> 00:25:14.010 And so this still remains an active area of research.  Having achieved this objective 00:25:14.010 --> 00:25:20.749 of demonstrating causality, which is important, because now we truly can focus disease investigation 00:25:20.749 --> 00:25:26.549 efforts, as well as disease management efforts around a single pathogen, and all of those 00:25:26.549 --> 00:25:30.299 various implications for control and management strategies. 00:25:30.299 --> 00:25:34.100 Another important thing that comes out of this system is our model system for maintaining 00:25:34.100 --> 00:25:38.519 hibernating bats in the laboratory.  And this can be used for additional purposes such 00:25:38.519 --> 00:25:44.519 as consideration for long term maintenance or holding of captive colonies of endangered 00:25:44.519 --> 00:25:49.210 bat species to protect them from this disease to which they might be exposed in the wild 00:25:49.210 --> 00:25:51.799 until better management solutions are developed. 00:25:51.799 --> 00:25:59.130 We can also use this system to conduct experiments to further understand how this fungus kills 00:25:59.130 --> 00:26:04.269 bats.  And as we develop a better understanding of how the fungus works and why it's a pathogen, 00:26:04.269 --> 00:26:08.289 we can then look for additional ways in which we could intervene and break this disease 00:26:08.289 --> 00:26:09.730 cycle. 00:26:09.730 --> 00:26:14.909 Also, this system could serve as a way for testing different treatment or management 00:26:14.909 --> 00:26:20.190 strategies in captivity so that we can test it in the laboratory on living bats first, 00:26:20.190 --> 00:26:27.539 before we introduce it into national systems in the wild and thus avoid unintended adverse 00:26:27.539 --> 00:26:28.539 consequences. 00:26:28.539 --> 00:26:34.249 So it's still leads to the question as to why would a skin infection like White-nose 00:26:34.249 --> 00:26:36.870 Syndrome be so deadly to bats. 00:26:36.870 --> 00:26:44.169 We get athlete's foot infection, fungal infection of our feet.  Other animals are susceptible 00:26:44.169 --> 00:26:48.820 to numerous fungi that for whatever reason fall in to a category where they call the 00:26:48.820 --> 00:26:52.840 infection ringworm.  It's not actually caused by a worm, it's caused by a fungus.  But 00:26:52.840 --> 00:26:58.330 it basically just creates an itchy red spot on your skin somewhere.  You don't die from 00:26:58.330 --> 00:26:59.330 it. 00:26:59.330 --> 00:27:04.909 All of those other fungal infections are called, those fungi are called dermatophytes.  And 00:27:04.909 --> 00:27:13.049 those fungi colonize the layer of dead skin cells on the surface of our skin. Geomyces 00:27:13.049 --> 00:27:18.820 destructans in White-nose Syndrome is different in that that fungus actually actively invades 00:27:18.820 --> 00:27:26.440 the skin of bats.  And it penetrates through that epidermal layer and destroys the epidermis, 00:27:26.440 --> 00:27:32.889 connective tissues, blood vessels, muscles, nerve fibers, oil glands, sweat glands -- everything 00:27:32.889 --> 00:27:36.020 that it encounters. 00:27:36.020 --> 00:27:40.210 Despite the name of the disease, White-nose Syndrome, perhaps the greatest damage that 00:27:40.210 --> 00:27:45.379 it causes to the bats is to their wings.  And these wings are critical to bats not only 00:27:45.379 --> 00:27:50.749 for them to be able to fly, but they also perform numerous other physiological functions 00:27:50.749 --> 00:27:57.700 shown here, including: heat dissipation, water control; so an intact wing membrane is necessary 00:27:57.700 --> 00:28:02.350 so the bats don't lose water while they're hibernating and otherwise unable to eat or 00:28:02.350 --> 00:28:03.350 drink. 00:28:03.350 --> 00:28:07.210 These wings actually allow the bat, these large wings, which the skin of the wings accounts 00:28:07.210 --> 00:28:12.299 for eight times more skin than on the entire rest of the body of the animal, also passively 00:28:12.299 --> 00:28:15.950 exchange gases while they're hibernating.  When they're hibernating they're only breathing 00:28:15.950 --> 00:28:22.690 a couple times a minute.  And even with their wings folded in on their bodies it's been 00:28:22.690 --> 00:28:28.129 shown that 10% of their CO2 exchange occurs through theses folded wings membranes. 00:28:28.129 --> 00:28:32.090 Also, remember theses animals are spending like six months of their lives hanging upside 00:28:32.090 --> 00:28:40.820 down.  These wings actually have special shunts in the blood vessels that help move 00:28:40.820 --> 00:28:45.100 blood around and function in blood pressure regulation. 00:28:45.100 --> 00:28:50.649 So numerous critical physiological functions all of which are being disrupted by this fungus. 00:28:50.649 --> 00:28:59.139    Let me tell you a little bit about another project that we did.  Fungal diseases tend 00:28:59.139 --> 00:29:03.929 to have environmental reservoirs which presents an additional challenge for managing the disease 00:29:03.929 --> 00:29:08.460 in the wild.  Even if you could cure the disease in the infected animals, if they return 00:29:08.460 --> 00:29:13.940 to their infested hibernation site the next year they'll just become re-infected.  So 00:29:13.940 --> 00:29:17.769 anything that doesn't give them life-long immunity and there are questions about whether 00:29:17.769 --> 00:29:25.309 that's even possible in a hibernating mammal, the animals potentially subject to reinfection. 00:29:25.309 --> 00:29:35.679 And so, we developed the study where we partnered with biologists as well as recreational cavers 00:29:35.679 --> 00:29:41.649 from across the eastern United States. And we were able to collect over 550 soil samples 00:29:41.649 --> 00:29:47.100 from over 120 caves on states bordering on in East of the Mississippi River. 00:29:47.100 --> 00:29:52.470 And the goal was to screen these soil samples for presence of the fungus. And first our 00:29:52.470 --> 00:29:56.910 question at this time, not yet knowing whether the fungus was causing the disease, was to 00:29:56.910 --> 00:30:01.669 just ask the basic question: Is this fungus ubiquitous in all of our sites, and the disease 00:30:01.669 --> 00:30:06.889 is only occurring in the northeast for some other reason?   Or is that fungus only restricted 00:30:06.889 --> 00:30:10.240 to areas where we find sick bats? 00:30:10.240 --> 00:30:16.139 And so, first thing we accomplished through this work was we were able to culture the 00:30:16.139 --> 00:30:21.429 viable fungus from samples with hibernating bats.  And what I'm showing here is just 00:30:21.429 --> 00:30:26.059 a preliminary work.  We're continuing to work with these samples, but this is the first 00:30:26.059 --> 00:30:28.049 bit that we were able to complete. 00:30:28.049 --> 00:30:35.730 So these stars show sites from at that time we were able to both grow the fungus and find 00:30:35.730 --> 00:30:42.009 its DNA in the soil.  We're actually able to find viable fungus in as little as 0.2 00:30:42.009 --> 00:30:47.399 grams of soil and so you can see next to a dime that's a very small amount of fungus. 00:30:47.399 --> 00:30:52.070 And if I draw your attention to the picture down here, most likely, we're growing the 00:30:52.070 --> 00:30:57.340 fungus out of soil as a result of these numerous spores, these are its reproductive structures.  00:30:57.340 --> 00:31:03.159 These are environmentally resistant structures that the fungus produces to satisfy its one 00:31:03.159 --> 00:31:08.100 goal in life again, which is to make more of itself.  And so our ability to find it 00:31:08.100 --> 00:31:12.859 viable in soil highlights the need that people be very careful -- that if they're going to 00:31:12.859 --> 00:31:18.059 a site that they don't accidentally pick up the fungus, and as a hitchhiker bring it to 00:31:18.059 --> 00:31:25.239 the next cave that they visit.   As our infectivity work showed the bats do transmit 00:31:25.239 --> 00:31:30.899 the fungus between themselves as they interact, but this work strongly infers that humans 00:31:30.899 --> 00:31:36.429 could also be mechanical vectors or transporters of the fungus.  And so we want to do all 00:31:36.429 --> 00:31:40.389 that we can so that we don't also contribute and make this problem worse. 00:31:40.389 --> 00:31:44.779 So one of our other interesting findings is that if you want to screen a lot of samples, 00:31:44.779 --> 00:31:49.660 using a labor intensive culture method, is probably not a viable approach.  And so we've 00:31:49.660 --> 00:31:53.769 developed a molecular diagnostic to detect the fungus in soil. 00:31:53.769 --> 00:32:00.059 And we tested that on the skin of bats which do have a lot of fungi on them but fewer varieties 00:32:00.059 --> 00:32:06.580 of fungi than you would find in soil.  And when we started applying our PCR test to soil 00:32:06.580 --> 00:32:12.330 samples, we were finding what we later identified as cross-reactivity with practically every 00:32:12.330 --> 00:32:15.210 sample that we analyzed. 00:32:15.210 --> 00:32:20.940 And so, as an example, these are what some of the other unknown Geomyces species present 00:32:20.940 --> 00:32:30.499 in soil from bat caves look like.   So the real challenge here is that, on this map, 00:32:30.499 --> 00:32:38.729 out of just an initial subset of 24 soil samples, we potentially have identified up to 11 new 00:32:38.729 --> 00:32:45.420 species of Geomyces.  And all of these are very very closely related to Geomyces destructans 00:32:45.420 --> 00:32:50.600 within the mark of genes that we've characterized.  So if you look at this little spot -- When 00:32:50.600 --> 00:32:54.710 you look at this “filegrams,” they’re called, the closer things are to one another, 00:32:54.710 --> 00:32:56.369 that the more closely they're related. 00:32:56.369 --> 00:33:03.100 These distances have to do with genetic changes.  So this Clade 10, Clade 11, Clade 12 are 00:33:03.100 --> 00:33:07.720 relatively distant from Clade 1, which is Geomyces destructans.  Clade 2, the little 00:33:07.720 --> 00:33:14.840 spot on the line here, only differs from Clade 1 at four nucleotide positions, out of 624 00:33:14.840 --> 00:33:17.710 that we looked at to develop this chart. 00:33:17.710 --> 00:33:22.519 And so, at this point, we're really only scratching a surface of what could very well be one of 00:33:22.519 --> 00:33:29.409 the most common groups of fungal organisms in cave soil, this cold damp environment.  00:33:29.409 --> 00:33:35.190 And that leads to another important question: What is so special about Geomyces destructans-- 00:33:35.190 --> 00:33:40.590 that it's pathogenic to bats whereas all of these other fungi that presumably bats have 00:33:40.590 --> 00:33:46.710 co-existed with for millions of years, do not cause this disease. 00:33:46.710 --> 00:33:51.389 We're actually doing some work, some comparative genomic analysis work, and maybe that will 00:33:51.389 --> 00:33:56.889 help us to begin to identify virilants determinants in Geomyces desrtuctans. 00:33:56.889 --> 00:34:00.479 This slide just shows what some of these guys look like when we grow them on petri plates.  00:34:00.479 --> 00:34:06.480 Here is our type isolate of Geomyces destructans, here's an isolate Geomyces destructans cultured 00:34:06.480 --> 00:34:11.280 directly out of cave soil.  Here are some of the relatives and you can see they're kind 00:34:11.280 --> 00:34:12.369 of similar looking. 00:34:12.369 --> 00:34:17.099 But interestingly this one that looks like shag carpeting, genetically, is the most closely 00:34:17.099 --> 00:34:22.740 related fungus to this one.  So it's also interesting how these visual or phenotypic 00:34:22.740 --> 00:34:28.970 traits don't seem to necessarily correspond to genetic relatedness or differences. 00:34:28.970 --> 00:34:34.740 And here's a point; I have touched on this already, but a question that frequently arises 00:34:34.740 --> 00:34:39.200 is: Where did Geomyces destructans come from and why did White-nose Syndrome emerge in 00:34:39.200 --> 00:34:46.169 North America in 2006-2007, approximately?  So we don't yet have a definitive answer to 00:34:46.169 --> 00:34:51.039 this question.  But there's anecdotal references in scientific literature to bats with white 00:34:51.039 --> 00:34:55.129 fungus on their muzzles in Germany, dating back to the early 1980s. 00:34:55.129 --> 00:35:01.190 And recent surveillance work in Europe has indicated that this fungus, Geomyces destructans, 00:35:01.190 --> 00:35:06.710 genetically and morphologically indistinguishable for isolates in the United States is widespread 00:35:06.710 --> 00:35:11.359 as shown in this map, in at least bats in at least 12 countries. 00:35:11.359 --> 00:35:16.309 But as I mentioned previously again, these unusual mortality events, associated with 00:35:16.309 --> 00:35:21.880 infection in the United States, have not yet been observed in Europe.  We don't yet have 00:35:21.880 --> 00:35:26.890 an answer for that, but it may stem from differences in environmental conditions that we hope to 00:35:26.890 --> 00:35:31.510 better characterized, as well as differences in population levels. In the northeastern 00:35:31.510 --> 00:35:37.880 United States, there used to be many very large aggregations of these bats; thousands, 00:35:37.880 --> 00:35:42.930 tens of thousands, even hundred of thousands.  So if you imagine you get a fungus into a 00:35:42.930 --> 00:35:48.490 colony of 10,000 bats and each of those bats serves an amplifying host for the fungus, 00:35:48.490 --> 00:35:53.050 within a very short period of time, one or two years, there's great potential for that 00:35:53.050 --> 00:35:58.070 fungus to make a lot of itself-- remember it's goal in life-- and infect a lot of bats 00:35:58.070 --> 00:36:01.799 heavily and early in hibernation and cause heavy mortality. 00:36:01.799 --> 00:36:07.400 In Europe, as far as people have recorded back, the bat populations tend to be very 00:36:07.400 --> 00:36:14.329 much smaller - 10 bats, 30 bats, in some instances 100 bats. And in a couple rare instances, 00:36:14.329 --> 00:36:21.180 thousands.  But among these smaller populations, there's fewer animals-- potentially less chance 00:36:21.180 --> 00:36:27.130 for fungal amplification, less chance for bat-to-bat interaction and spread lower fungal 00:36:27.130 --> 00:36:32.330 burdens in the environment, lower infectious doses; and, whereas these bats get colonized, 00:36:32.330 --> 00:36:35.569 perhaps the disease just doesn't progress to the point where it kills them. 00:36:35.569 --> 00:36:40.670 People have, most recently, even documented these lesions that we see on the skin of North 00:36:40.670 --> 00:36:46.380 American bats that we considered diagnostic for the disease in European bats.  But again, 00:36:46.380 --> 00:36:48.150 they're not dying. 00:36:48.150 --> 00:36:52.109 Some other work that we've done is showing that if you remove a bat from hibernation 00:36:52.109 --> 00:36:57.030 or take a bat that's not yet dead from the disease and just provide it with a warm environment 00:36:57.030 --> 00:37:02.890 and food and water, they'll make a full recovery, actually remarkably quickly.  They have full 00:37:02.890 --> 00:37:07.400 capacity to regenerate the skin of their wings and microscopically, it looks like there was 00:37:07.400 --> 00:37:10.270 never anything wrong with it. 00:37:10.270 --> 00:37:14.960 And I think a lot of that just has to do with turning back on their physiology, their immune 00:37:14.960 --> 00:37:20.660 system and they can mount a recovery.  And so effectively in Europe maybe things just 00:37:20.660 --> 00:37:24.240 never progressed to the degree that we see them in the United States.  But again, an 00:37:24.240 --> 00:37:29.420 active area of research. But still does lead to that question of: Wow did the disease get 00:37:29.420 --> 00:37:30.420 here? 00:37:30.420 --> 00:37:35.270 So this slide depicts civilian global aviation networks among the 500 largest international 00:37:35.270 --> 00:37:42.650 airports in 100 countries, most intense air traffic shown in yellow.  And what this slide 00:37:42.650 --> 00:37:48.119 shows is that: we humans, have succeeded widely in breaching historic barriers to the spread 00:37:48.119 --> 00:37:53.410 of infectious diseases around the world, namely oceans and mountain ranges. And given our 00:37:53.410 --> 00:37:57.980 incredible capacity for mobility, there's almost no place where we and our hitchhiking 00:37:57.980 --> 00:38:02.570 pathogens cannot be on this planet, within just a matter of days --if we set our mind 00:38:02.570 --> 00:38:03.570 to it. 00:38:03.570 --> 00:38:08.410 And indeed, global travel and trade are widely recognized as the most significant drivers 00:38:08.410 --> 00:38:14.539 in global spread of infectious diseases. 00:38:14.539 --> 00:38:20.220 So at this point I'll start to sum up. This next series slides were developed with a colleague 00:38:20.220 --> 00:38:26.349 from USDA Wildlife Services, Tom DeLiberto, who's a wildlife disease specialist with that 00:38:26.349 --> 00:38:32.309 agency.  When we think of White-nose syndrome, it's not an ordinary disease.  Few diseases 00:38:32.309 --> 00:38:37.760 have affected as many species, over such a large geographic area, in such a short period 00:38:37.760 --> 00:38:42.150 of time, with as much impact on populations. 00:38:42.150 --> 00:38:47.170 Confounding factors contributing to the severity of White-nose Syndrome likely include: high 00:38:47.170 --> 00:38:52.289 density clusters of susceptible individual animals during hibernation, the time to which 00:38:52.289 --> 00:39:00.170 they're uniquely susceptible to this disease, both high infection and mortality rates, transmission 00:39:00.170 --> 00:39:06.710 between bats and the environment, and likely the other direction as well, and environmental 00:39:06.710 --> 00:39:07.760 persistence.   00:39:07.760 --> 00:39:12.359 Even though these animals are hibernating, they on somewhat regular intervals, like every 00:39:12.359 --> 00:39:17.251 two weeks or so, they do arouse out of hibernation, briefly, for maybe an hour at a time, get 00:39:17.251 --> 00:39:23.600 a drink of water, urinate, various things. I would just say go to the bathroom, but I 00:39:23.600 --> 00:39:28.109 don't think there are bathrooms in these caves.  So, even though they're hibernating, there 00:39:28.109 --> 00:39:32.810 are frequent movements of individuals both within their clusters, among clusters. And 00:39:32.810 --> 00:39:36.900 these animals, even though they're not officially recognized as migratory, they are known to 00:39:36.900 --> 00:39:41.200 move distances between summer and fall of up to 200 miles. 00:39:41.200 --> 00:39:47.010 And so also the tendency for these, or the potential ability, for these animals to spread 00:39:47.010 --> 00:39:53.580 viable spores of this agent over relatively large distances.  And then couple that with: 00:39:53.580 --> 00:39:58.369 These animals have a very low and natural reproductive rate.  These are not flying 00:39:58.369 --> 00:40:07.289 mice or flying rodents that have many, many babies.  Bats exhibit very high degree of 00:40:07.289 --> 00:40:14.539 care for their young and an insectivorous bat, on average, has one pup per year. 00:40:14.539 --> 00:40:23.289 And so the potential for these species to recover is a long-term problem. These animals 00:40:23.289 --> 00:40:29.109 are important even though we may not even see them.  A bat can eat its body rate in 00:40:29.109 --> 00:40:34.440 insects each night.  Insects consumed by bats include those that cause vector-born 00:40:34.440 --> 00:40:40.720 disease, as well as those that impact crop and forest health. 00:40:40.720 --> 00:40:46.110 A bat biologist at Boston University estimated that for the millions of bats that have been 00:40:46.110 --> 00:40:51.809 estimated to die from White-nose Syndrome, to date that numbers around 5 million, that 00:40:51.809 --> 00:40:57.510 would literally amount of to thousands of tons of insects per year.  And a recent modeling 00:40:57.510 --> 00:41:03.270 paper estimated that the pesticide, the free pesticide, or ecosystem services provided 00:41:03.270 --> 00:41:08.940 by bats, and these a.) Don’t cause us any money; and b.) Don’t involve any import 00:41:08.940 --> 00:41:14.609 of potentially toxic chemicals, are value between $4 to $50 billion per year to the 00:41:14.609 --> 00:41:17.720 U.S. agricultural industry. 00:41:17.720 --> 00:41:23.440 So some final thoughts: Why don't we just go out and treat these animals with antifungals? 00:41:23.440 --> 00:41:28.400 Unfortunately, there's no precedent for using antifungals or any sort of pharmaceutical 00:41:28.400 --> 00:41:33.940 compound --short of a vaccine-- for treating disease in free-ranging wildlife.  Especially 00:41:33.940 --> 00:41:37.500 for a disease with an environmental reservoir, where the animals are likely to pick it up 00:41:37.500 --> 00:41:41.010 again from the environments in which they hibernate. 00:41:41.010 --> 00:41:45.200 So managing disease in these animals is very different than strategies that we would use 00:41:45.200 --> 00:41:50.690 for our pets, for people, or for our farm animals.  As I said, this environmental reservoir, 00:41:50.690 --> 00:41:56.280 as well as a very sensitive and unique ecology in every cave that these bats inhabit, presents 00:41:56.280 --> 00:41:57.280 unique challenges. 00:41:57.280 --> 00:42:02.390 And so what I think we're challenged with is thinking outside the box to identify practical 00:42:02.390 --> 00:42:08.580 solutions that can benefit these animals, that the population level, while first and 00:42:08.580 --> 00:42:12.460 foremost, not doing any harm to the populations. 00:42:12.460 --> 00:42:18.760 And so, I'll conclude here.  This slide acknowledges numerous people that have worked with me on 00:42:18.760 --> 00:42:25.480 this problem - graduate students, our pathologists at the health center, technicians and people 00:42:25.480 --> 00:42:30.920 from numerous other institutions, as well as our funding source, funding from U.S. Geological 00:42:30.920 --> 00:42:37.150 Survey, United States Fish and Wildlife Service, Bat Conservation International, and others. 00:42:37.150 --> 00:42:41.180 And I'll just transition to this last slide and be happy to take questions.