Julie Shaffer: Ticks in the Great Plains
This episode of the Paul A. Olson "Great Plains Anywhere" series features Dr. Julie Shaffer, professor and chair in Biology at the University of Nebraska at Kearney. Shaffer's recent research involves assessing tick-borne diseases in central Nebraska and the recent changes in these disease patterns.
Special thanks to Margaret Huettl for providing a video land acknowledgement for this episode. To listen to the podcast version, visit: https://anchor.fm/gp-lectures
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[00:00:00.170]Welcome to Great Plains: Anywhere,
[00:00:01.990]a Paul A. Olson Lecture
[00:00:03.770]from the Center for Great Plains Studies
[00:00:05.420]at the University of Nebraska.
[00:00:07.216](calm guitar music)
[00:00:08.290]For today's episode, we spoke with Dr. Julie Shaffer,
[00:00:11.260]a professor and chair in biology
[00:00:13.200]at the University of Nebraska at Kearney.
[00:00:16.297]Schaffer's recent research
[00:00:17.930]involves assessing tick-borne diseases in Central Nebraska
[00:00:22.057]and the recent changes in these disease patterns.
[00:00:26.120]On behalf of the Center for Great Plains Studies,
[00:00:28.280]I would like to begin by acknowledging
[00:00:30.440]that the University of Nebraska is a land grant institution
[00:00:34.130]with campuses and programs on the past, present,
[00:00:36.930]and future homelands of the Pawnee, Ponca,
[00:00:39.670]Otoe-Missouria, Omaha, Lakota, Dakota,
[00:00:43.670]Arapaho, Cheyenne, and Kaw peoples,
[00:00:46.670]as well as the relocated Ho-Chunk, Iowa,
[00:00:49.380]and Sac and Fox peoples.
[00:00:51.340]Please take a moment to consider the legacies
[00:00:53.570]of more than 150 years of displacement, violence,
[00:00:57.950]settlement, and survival that bring us here today.
[00:01:01.400]This acknowledgement and the centering of indigenous peoples
[00:01:04.410]is a start as we move forward together
[00:01:06.900]for the next 150 years.
[00:01:10.220]Hi, I'm Katie Nealon, the assistant director
[00:01:12.250]for the Center for Great Plains Studies.
[00:01:14.240]My name is Dijon DeLaPorte.
[00:01:15.460]I'm the events coordinator
[00:01:16.920]at the Center for Great Plains Studies.
[00:01:20.290]All right, thank you, Dijon.
[00:01:22.040]This is some research that I've been working on
[00:01:24.950]for about six or seven years now,
[00:01:27.590]one of my primary project areas.
[00:01:30.380]And people are very interested in ticks.
[00:01:33.010]Ticks are creepy-crawly and gross,
[00:01:36.880]but they also are able to transmit diseases.
[00:01:40.540]And so, you know, we need to talk about,
[00:01:43.350]is the risk real in Nebraska?
[00:01:48.440]So most people, when I bring up that we study ticks,
[00:01:52.010]are just really grossed out by it.
[00:01:54.560]People don't like ticks, ticks are creepy.
[00:02:00.040]They are blood feeders.
[00:02:02.070]They get all fat and gross.
[00:02:05.150]And so we tend to try to stay away from them
[00:02:09.360]and it just causes unnecessary fear or disgust in us.
[00:02:15.510]But ticks are really important,
[00:02:17.940]as they are able to transmit disease to people, to animals,
[00:02:22.670]and we need to know the facts about that
[00:02:26.010]and understand what ticks are really doing
[00:02:28.900]and what the risk is really to us.
[00:02:31.130]Here are the three ticks
[00:02:34.010]that we have been finding in Nebraska.
[00:02:36.200]The one that most people will be familiar with
[00:02:38.790]is the one in the middle, the dog tick.
[00:02:41.070]The dog tick is found across the entire state,
[00:02:46.170]and the most common tick that we have.
[00:02:49.810]Now in about the past decade,, or maybe a little more,
[00:02:53.140]we've had an increase or an encroachment
[00:02:55.700]of the lone star tick, especially along our river systems.
[00:02:59.616]You'll see it along the Platte
[00:03:01.500]and we've found it on the Elkhorn River now.
[00:03:04.870]This tick has one white spot on its back.
[00:03:08.500]So it's pretty easy to tell the difference
[00:03:10.510]between the dog ticks and the lone star ticks.
[00:03:13.250]But these lone star ticks have migrated up here from Texas
[00:03:16.830]and they are voracious feeders.
[00:03:19.740]So they run fast, they are hard to get ahold of.
[00:03:23.240]They are a little more nasty
[00:03:29.650]than I would say the dog ticks are,
[00:03:32.040]but they're more limited in their range across Nebraska.
[00:03:35.470]And then the deer tick or the blacklegged tick
[00:03:38.440]is something we've been looking for in Nebraska.
[00:03:41.630]This is a tick that can carry Lyme disease.
[00:03:45.600]And so we've been very concerned
[00:03:47.240]about its presence in Nebraska.
[00:03:49.600]We found it, some people found it last summer out east
[00:03:54.500]along Mahoney State Park kind of area, in that region.
[00:03:59.460]And so we know it's here now.
[00:04:01.460]And we had been seeing cases of Lyme disease in Nebraska
[00:04:05.257]and were wondering where it came from.
[00:04:06.940]So we were really interested in finding this tick,
[00:04:09.480]and it does seem to be around Nebraska.
[00:04:12.750]Now ticks have multiple life stages.
[00:04:16.340]This shows two of the three.
[00:04:18.358]They will hatch from eggs as larvae,
[00:04:21.200]and then they will form this small nymph stage.
[00:04:25.000]And then the adults,
[00:04:26.290]males and females generally look different.
[00:04:28.640]So they're pretty easy to identify
[00:04:31.240]when you see them in nature.
[00:04:35.580]Ticks have a three host lifecycle,
[00:04:38.300]meaning they go through...
[00:04:43.170]Here's the hatch from the eggs to the larval stage.
[00:04:46.860]You always know you have a larvae
[00:04:48.690]because they have three legs instead of four legs
[00:04:51.550]like a normal adult tick.
[00:04:55.170]And they will feed on some small animal,
[00:04:57.940]typically a mouse or something like that.
[00:05:00.680]And then once they feed,
[00:05:02.160]they will molt into the nymph stage.
[00:05:04.880]You see the nymphs now have the four legs.
[00:05:07.500]These are very small.
[00:05:08.980]They're maybe the size of a pinhead or a little bit larger.
[00:05:13.160]And these are pinhead or a little bit smaller.
[00:05:15.960]So very small.
[00:05:17.620]Then they feed again on a, could still be a mouse,
[00:05:22.260]but could be a little bit larger host,
[00:05:24.890]rabbits or dogs, anything like that.
[00:05:27.960]And then they will molt again
[00:05:30.360]and they will form the adult tick.
[00:05:32.460]And then the adult tick typically feeds on larger prey
[00:05:35.350]such as humans, deer, dogs, but larger prey.
[00:05:40.270]And when they feed, only the females will feed,
[00:05:43.300]and the females will engorge to this, you know,
[00:05:47.670]that nasty balloon-shaped tick
[00:05:50.860]that we all think is so gross to even touch
[00:05:53.660]that gets on your dogs or hopefully not in your hair.
[00:05:56.720]But then they will lay eggs
[00:05:59.150]and then start the life cycle again.
[00:06:01.210]So this can last for two years
[00:06:03.810]and they'll overwinter during that time.
[00:06:07.480]And so ticks are something we keep close track on
[00:06:11.890]because they can transmit disease
[00:06:16.200]through all of those stages.
[00:06:18.170]So here is how a tick works.
[00:06:20.470]We tend to have, and I remember this as a kid,
[00:06:23.540]you know, them falling in your hair,
[00:06:25.160]they fell in your hair from a tree.
[00:06:26.590]Well, that doesn't really happen here.
[00:06:28.420]That's not how ticks feed.
[00:06:30.553]When they're questing for food,
[00:06:32.590]they'll crawl up blades of grass
[00:06:35.470]and then grab on when you walk by.
[00:06:37.650]So the dog tick, which is the most common,
[00:06:40.330]and here's a female dog tick crawled up
[00:06:42.630]on a blade of grass or a plant,
[00:06:45.160]and you can see it's reaching out.
[00:06:47.070]So when something walks by, it'll grab on
[00:06:49.890]and then it can get on the host.
[00:06:53.350]And we call that questing.
[00:06:55.890]They all do it.
[00:06:56.830]It's how they find their hosts.
[00:06:58.980]Dog ticks are in grasslands.
[00:07:01.090]So that's why we are so exposed to them.
[00:07:04.020]They can be in parks, they can be in pastures.
[00:07:06.440]They can be in your yard depending on the year.
[00:07:09.463]They can be pretty much everywhere.
[00:07:11.700]Deer ticks are at that tree/grassland interface
[00:07:15.560]and can grab onto you there.
[00:07:18.610]And then lone star ticks are kind of the same,
[00:07:21.010]but they stay along,
[00:07:22.220]at least so far, they've stayed along the waterways
[00:07:25.300]and do seem to like to be around cedar trees.
[00:07:30.330]They're not necessarily in the tree.
[00:07:32.540]They may be in the grass around the tree,
[00:07:34.860]but we have had really good luck finding them around cedars.
[00:07:41.030]So the question then at UNK has been,
[00:07:45.300]what is the real risk to citizens of Nebraska
[00:07:48.860]when they're exposed?
[00:07:50.670]Ticks have three different ways disease can be transmitted,
[00:07:56.960]but different diseases are transmitted different ways.
[00:08:00.340]Different ticks use different techniques.
[00:08:02.430]So there are really three different ways
[00:08:04.490]that infectious bacteria can be transmitted
[00:08:07.660]through the ticks.
[00:08:08.870]One is transovarial transfer,
[00:08:11.130]which would be the mother has the disease,
[00:08:14.440]and then the infectious agent is in the eggs.
[00:08:17.590]That's what we see
[00:08:18.800]with the main organism we've been studying, Rickettsia,
[00:08:22.490]which causes Rocky Mountain spotted fever.
[00:08:26.466]It can be in all the offspring, right?
[00:08:28.810]It can be in all the eggs then.
[00:08:30.440]And so you see,
[00:08:32.820]you could see, I would think,
[00:08:34.030]hotspots where you'll have large numbers of infected ticks
[00:08:37.630]in one area and not in others.
[00:08:39.240]So that's kind of what our hypothesis was
[00:08:41.650]when we started studying this.
[00:08:43.420]It can be transstadial, meaning it's in there from feeding,
[00:08:48.110]but it can overwinter and it can go through the molt
[00:08:51.310]so that all the ticks from larvae to nymph
[00:08:54.550]to adult may have the disease.
[00:08:57.820]But it can go from one to the other through the molt.
[00:09:01.700]And then the last one is intrastadial transfer,
[00:09:04.300]and that's when they bite someone, generally an animal,
[00:09:08.390]and they pick up the disease,
[00:09:09.870]the infectious agent from them.
[00:09:11.890]So we have three different ways diseases can be transferred.
[00:09:16.270]And it's important to understand that
[00:09:19.810]so that you can understand the risk
[00:09:22.010]when you're exposed to these ticks.
[00:09:26.490]So here are the primary tick-borne diseases
[00:09:31.080]that we are concerned about in Nebraska
[00:09:33.570]because of the tick species we have here.
[00:09:35.610]Different tick species carry different bacterial
[00:09:40.750]And what you should notice is most of these
[00:09:43.880]have been found fairly recently.
[00:09:46.310]And that's what our big concern has been.
[00:09:48.910]So Rickettsia rickettsii, which is the causative agent
[00:09:52.480]of Rocky Mountain Spotted Fever, was found in 1909.
[00:09:56.070]It's in dog ticks primarily.
[00:09:58.610]And so it has been a big concern
[00:10:00.810]across the state of Nebraska for a very long time,
[00:10:03.866]as also has...
[00:10:06.820]As has Francisella tularensis, which causes big ulcers
[00:10:12.710]and can cause septicemia and death.
[00:10:15.770]And that one is also associated with rabbits.
[00:10:20.780]And you can see it was discovered in the early '20s,
[00:10:23.900]but it's found in both of our primary tick species,
[00:10:27.270]hard-bodied tick species in Nebraska.
[00:10:30.360]Babesia is less common here.
[00:10:33.190]It's a little more in the northeast
[00:10:37.120]in I think Minnesota and Wisconsin and those areas,
[00:10:41.040]but we could have it here if we have the deer tick.
[00:10:43.830]And of course we are most concerned
[00:10:46.280]about Borrelia burgdorferi.
[00:10:47.950]Borrelia burgdorferi is the cause of Lyme disease,
[00:10:52.200]and Lyme disease makes up about 70%
[00:10:55.530]of all infectious disease vectored in the United States.
[00:11:00.310]It is a real problem,
[00:11:02.180]and is a primary area of concern in the US.
[00:11:06.700]Ticks are considered the number one vector
[00:11:09.410]of infectious disease in the United States,
[00:11:12.030]higher than mosquitoes,
[00:11:13.650]and Lyme disease is a primary reason for that.
[00:11:17.720]But you notice we discovered it in the '80s
[00:11:19.940]and it is carried only by the deer ticks in Nebraska.
[00:11:25.570]And then the last ones will be less familiar to you.
[00:11:28.640]These have been discovered more recently.
[00:11:31.150]Ehrlichia chaffeensis and Ehrlichia ewingii
[00:11:34.540]cause ehrlichiosis, which is high fever and rash sometimes,
[00:11:39.790]and less mortality associated with it.
[00:11:44.507]But it's found in those lone star ticks,
[00:11:47.410]and so it's a more recent movement into Nebraska.
[00:11:51.110]And then the other one is Anaplasma phagocytophilum.
[00:11:54.811]We don't have a lot of anaplasmosis
[00:11:57.680]in Nebraska that we have recognized,
[00:12:00.730]but we have had studies done on it in Nebraska in dogs,
[00:12:04.390]and we find the antibody in dogs.
[00:12:06.400]So we know it's here.
[00:12:07.780]We know we have seen it, the disease, in pets.
[00:12:11.410]And it's in the deer tick again.
[00:12:13.020]So another reason we thought
[00:12:14.820]that the deer tick had to be present in Nebraska.
[00:12:21.960]So why do we care about these diseases
[00:12:24.420]that seem so uncommon or unusual?
[00:12:27.630]Other than Lyme disease, right?
[00:12:29.480]This is a 2016 data set showing the number of cases
[00:12:35.600]of tick-borne disease in the United States.
[00:12:38.440]That's the light blue bar, the bar on the right.
[00:12:41.510]And you can see it's going up and up and up.
[00:12:44.990]It's really a huge problem in the last 20 years.
[00:12:49.280]It's just been increasing.
[00:12:51.760]And so it's a big concern and we are more and more aware
[00:12:57.020]of tick-borne illnesses and the needs
[00:12:59.920]to understand them better.
[00:13:01.570]And you can see the dark blue bars
[00:13:03.640]are the mosquito-borne cases.
[00:13:05.190]So in general, mosquitoes are not the problem in the US
[00:13:09.970]as much as ticks.
[00:13:15.560]So why do we care about Nebraska, right?
[00:13:18.050]I mean that becomes the central question
[00:13:21.520]for why we would want to do so much study here.
[00:13:24.090]Here's a graph that shows you kind of the distribution
[00:13:28.440]of infectious diseases transmitted by ticks.
[00:13:31.700]And you can see most of it is to our east.
[00:13:34.680]But what I want you to notice is Nebraska
[00:13:36.970]is right on that border, right?
[00:13:39.310]We are right in an area where ticks are coming in
[00:13:44.280]and diseases will be moving in as well.
[00:13:47.510]So that's why, in Nebraska, we've become more
[00:13:50.900]and more concerned about tick-borne studies.
[00:13:54.230]Some ticks are blocked by the Rocky Mountains,
[00:13:56.850]you know, on the west side.
[00:13:58.530]And so we're really getting some of this tick-borne studies
[00:14:05.280]because we're concerned about the tick movement.
[00:14:11.070]So here's the distribution of those ticks
[00:14:13.860]just to show you in another figure.
[00:14:16.540]Here are the lone star ticks.
[00:14:18.370]And this has actually moved
[00:14:19.938]even a little further west, as I said.
[00:14:22.430]They're all along the Platte River, for sure,
[00:14:24.730]we've been finding them.
[00:14:26.470]And so we know that they are in Nebraska.
[00:14:29.950]Here is the blacklegged tick.
[00:14:31.850]And as I said, we found some over by Lincoln this summer.
[00:14:36.970]And so we know they're in the state.
[00:14:38.670]We had known for a long time
[00:14:39.810]they were in the farthest southeast corner,
[00:14:42.560]but now they are moving west.
[00:14:44.920]And then the dog tick has really been a problem in Nebraska
[00:14:50.670]for long as we remember.
[00:14:54.170]It's been the number one tick.
[00:14:55.550]So we are really interested in the distribution
[00:15:01.090]of the ticks and what diseases they carry.
[00:15:04.880]And then a third thing that we are very interested in now
[00:15:09.490]is now that the lone star tick has come into the state,
[00:15:13.370]are we going to see spillover where the infectious diseases
[00:15:18.511]that are carried by the lone star ticks
[00:15:21.290]are going to move to our dog ticks
[00:15:24.830]that are very common across our state?
[00:15:27.160]Are we gonna see changes in infectious disease transmission?
[00:15:31.000]And so spillover is a really important thing
[00:15:34.430]that we are just starting to look at,
[00:15:36.510]and another reason we study Rickettsia at UNK
[00:15:41.380]is because Rickettsias, different ones are found
[00:15:44.880]in the different ticks.
[00:15:45.870]And then we can look for the different species
[00:15:48.830]and what they're doing.
[00:15:52.000]So here's the study that we just published
[00:15:57.040]fairly recently at UNK.
[00:15:59.150]We were looking at the Rickettsias in the American dog ticks
[00:16:03.320]along the Platte River in central Nebraska.
[00:16:06.030]And I just want to point out,
[00:16:07.600]at UNK, we are really involved in student mentoring
[00:16:12.820]and getting students involved in research.
[00:16:15.660]So Estrella Monrroy, who you see listed here,
[00:16:19.030]helped with even the paper writing
[00:16:21.070]for this particular publication.
[00:16:24.050]But there are many other students too
[00:16:25.930]that helped either collect ticks
[00:16:27.580]or do PCRs or things like that.
[00:16:30.380]So students are essential for us in our research.
[00:16:36.490]So here's kind of where we focused
[00:16:38.820]for this particular research study.
[00:16:41.710]We were just going along the Platte River
[00:16:44.740]in Dawson County, Buffalo County.
[00:16:46.720]We had one area in Phelps County.
[00:16:49.100]The students didn't know it was Phelps County
[00:16:51.690]when they were collecting, but we went ahead
[00:16:53.530]and put the ticks in the study as well.
[00:16:57.556]So all along the Platte River.
[00:17:02.900]Now, one of the fun things, I think, about studying ticks
[00:17:06.650]is the collections of ticks.
[00:17:09.150]And here you can see an undergraduate student,
[00:17:12.160]Taylor Stillwater, she was collecting ticks
[00:17:15.510]out at Cottonmill Lake at Kearney.
[00:17:18.890]And she has a big piece of white felt.
[00:17:21.590]We use these, like a yard of white felt,
[00:17:24.020]and we just attach it to a stick and a dowel with string.
[00:17:28.720]And then we drag it behind us through the tall grass,
[00:17:32.230]and then the ticks will grab on from their questing.
[00:17:35.130]And then you can see them on that white felt
[00:17:38.080]and pick them off, and then we bring them back to the lab
[00:17:40.450]to identify them and to study them.
[00:17:44.350]So it's actually a lot of legwork to collect enough ticks.
[00:17:48.980]We collected about 1,000 ticks for this study,
[00:17:51.420]and all these students,
[00:17:54.140]Taylor and Sarah Bulan and several others,
[00:17:57.630]really spent a lot of time collecting ticks.
[00:18:00.910]The other way you can collect ticks is through dry ice.
[00:18:04.850]So they are attracted to carbon dioxide gas.
[00:18:07.830]And so what you can do is take a cooler
[00:18:10.760]and punch holes in the side,
[00:18:12.600]put dry ice in here, and set it on something white.
[00:18:15.150]This is just a white towel that a student had.
[00:18:18.030]And you can see the little,
[00:18:19.540]hopefully you can see the little ticks
[00:18:20.910]have crawled onto the white towel
[00:18:23.580]and then you can just pick them off as well.
[00:18:25.250]So then you can set up stations
[00:18:27.520]and you don't have to keep walking.
[00:18:28.940]Perhaps you can go drop it off and then come back
[00:18:31.388]in an hour or two and collect the ticks.
[00:18:34.340]So there are a couple of ways we have done it.
[00:18:39.710]Once we get them back to the laboratory,
[00:18:41.550]then the student will identify them by species and by sex.
[00:18:45.940]And then we will sort them
[00:18:48.020]and save them until we're ready to process the ticks.
[00:18:51.270]The first thing you have to do,
[00:18:52.720]and I don't know if you can see in here,
[00:18:54.160]we put them in a little test tube full of metal beads
[00:18:57.480]and then crunch them up.
[00:18:58.730]It shakes them really hard and crushes the tick
[00:19:01.300]so we can extract the DNA, total DNA from the tick.
[00:19:05.230]And then we will do PCR, polymerase chain reaction,
[00:19:09.420]where we amplify the DNA
[00:19:12.020]of the specific bacteria that we are interested in.
[00:19:15.660]And so it's very specific
[00:19:17.610]for those bacteria and only identifies the bacteria.
[00:19:22.050]It doesn't get messed up
[00:19:23.450]with the tick DNA or anything like that.
[00:19:25.440]So we can look for these specific species of bacteria.
[00:19:30.400]And then we run it out in a gel.
[00:19:33.070]That's what Nathan Harms is doing here.
[00:19:35.520]Nathan Harms is a medical student
[00:19:38.270]right now at the med center.
[00:19:39.510]And he did a lot of work
[00:19:41.350]on our next publication that we're going to put out,
[00:19:44.300]but you can see him doing gel electrophoresis
[00:19:47.910]in the laboratory.
[00:19:49.530]And then here is one of those gels,
[00:19:51.800]or what the gels look like
[00:19:53.240]when we run them out to separate the DNA.
[00:19:55.480]So in this lane, we put the marker.
[00:19:59.260]The marker tells us what size
[00:20:01.210]of a piece of DNA is in that sample.
[00:20:04.650]And then you can see, in each lane,
[00:20:07.400]we use control DNA from the different bacteria
[00:20:11.750]with our different primers.
[00:20:13.540]And so you can see that-
[00:20:15.960]Why is that going back?
[00:20:16.820]Coxiella burnetii is a larger size
[00:20:20.810]than Francisella tularensis, A. phagocytophilum.
[00:20:24.150]And we can identify each bacterium then from that tick.
[00:20:29.330]And it's really quite easy to tell
[00:20:33.330]if you have a tick that has different infectious bacteria,
[00:20:36.600]and then we can study them further.
[00:20:39.670]So let's look at the data that we got from that study.
[00:20:45.030]That was three years worth of work.
[00:20:47.220]And you can see, we had just short of 1,000 ticks
[00:20:50.252]that students collected during those three years,
[00:20:53.280]all along the Platte River.
[00:20:55.210]And we had, these are all dog ticks, Dermacentor variabilis,
[00:21:00.270]and we can see males and females were close to the same,
[00:21:03.870]which you would expect, about 50% males and 50% females.
[00:21:08.120]And we had about 4% positives for Rickettsia in both.
[00:21:13.830]So equal, we're not seeing higher levels
[00:21:16.840]in males than females.
[00:21:18.800]And they're all about the same.
[00:21:21.200]This percentage is similar to what they have reported
[00:21:24.950]for dog ticks in Missouri and in some other areas.
[00:21:28.990]So this is about what we expected to see.
[00:21:33.510]When you divide the ticks up by county then,
[00:21:36.710]you can see we had the most ticks
[00:21:40.270]from Buffalo County, being close to Kearney, obviously.
[00:21:43.660]But we had quite a few in Dawson as well
[00:21:46.010]and a few and Phelps.
[00:21:48.170]And you can see we do have slight differences
[00:21:52.230]in the numbers of positives,
[00:21:54.100]with Phelps being a little lower,
[00:21:55.820]but we had quite a few less ticks
[00:21:58.340]in only one location that we looked at.
[00:22:00.370]That was the location that students didn't know was Phelps.
[00:22:03.610]They had just gone across the border
[00:22:07.360]from Dawson into Phelps and didn't know it.
[00:22:09.280]So we had to separate those out,
[00:22:11.180]and they're a little lower,
[00:22:12.030]but I think if we had greater numbers,
[00:22:14.030]we would see more similarity.
[00:22:15.810]We don't seem to see big differences
[00:22:18.150]or hotspots in the different areas.
[00:22:22.100]And here is the data broken down by year
[00:22:25.670]because we thought maybe, you know,
[00:22:27.290]certain years when you have more ticks,
[00:22:29.130]you might have a higher percentages.
[00:22:31.770]Or less ticks, who knows?
[00:22:34.480]I mean, we were not sure.
[00:22:36.440]Rickettsia rickettsii, which is the causative agent
[00:22:40.351]of Rocky Mountain spotted fever, is toxic to the ticks.
[00:22:46.920]So the ticks are not very healthy, you know?
[00:22:49.750]So could that be impacting year to year as well?
[00:22:53.830]Well, what we saw was there's really not much difference
[00:22:57.670]from year to year.
[00:22:59.220]In 2015, we did have a little lower number,
[00:23:03.160]and it was a little wetter that year.
[00:23:04.700]We had a few more ticks
[00:23:06.010]in the areas that we were looking at.
[00:23:08.292]So we could collect longer.
[00:23:10.280]Ticks seem to disappear when it gets really hot and dry.
[00:23:14.210]So we collected longer, got more ticks,
[00:23:16.250]and we did have fewer cases.
[00:23:17.870]So we need to look at that further
[00:23:21.750]because we had fewer positive.
[00:23:25.990]Now once we had the DNA for the ticks,
[00:23:28.930]we would sequence it to find out
[00:23:31.110]what type of Rickettsia we had.
[00:23:34.100]Different species are found in different ticks.
[00:23:37.370]Different species have different ability to cause infection.
[00:23:40.870]As I mentioned, Rickettsia rickettsii
[00:23:44.880]has a much higher pathogenesis, a much higher virulence.
[00:23:48.026]So that's the one that causes
[00:23:49.110]true Rocky Mountain spotted fever,
[00:23:51.270]and is the most lethal or the most concern to us.
[00:23:55.090]We did not find it.
[00:23:56.410]Thank goodness, we were happy.
[00:23:57.940]We didn't find it.
[00:24:01.080]But we did find several other species.
[00:24:04.676]Rickettsia montanensis we found in the highest amount.
[00:24:09.110]That one is not known to cause
[00:24:11.860]Rocky Mountain spotted fever type illness.
[00:24:14.710]So it may not cause illness at all,
[00:24:17.270]but we did find it in a lot of ticks in Nebraska.
[00:24:20.360]Rickettsia bellii has been shown to cause cankers
[00:24:24.720]or, you know, lesions on people's skin.
[00:24:28.260]And we did find it in small amounts.
[00:24:31.450]And then Rickettsia amblyommatis is the form
[00:24:35.130]of Rickettsia that we find in lone star ticks.
[00:24:38.430]And it is able to cause
[00:24:42.080]Rocky Mountain spotted fever type illness.
[00:24:44.230]It's not Rocky Mountain spotted fever
[00:24:45.970]because it's not as virulent as the original,
[00:24:50.250]but it still can cause illness
[00:24:52.170]and is able to make people more sick
[00:24:58.420]than the Rickettsia bellii.
[00:24:59.960]So it is of concern.
[00:25:01.940]Now what was interesting to us is Rickettsia amblyommatis
[00:25:05.990]is normally found in the lone star ticks.
[00:25:08.410]So it does seem to be jumping.
[00:25:12.160]As I talked about earlier.
[00:25:13.410]From the lone star ticks feeding on a mouse or something,
[00:25:18.640]causing the infection in that animal,
[00:25:20.650]and then a dog tick feeds on that same animal
[00:25:24.770]and picks it up.
[00:25:25.880]So it does seem that we are seeing spillover in this state
[00:25:29.560]at least of the Rickettsias.
[00:25:31.440]Now is this a concern?
[00:25:33.090]I would say yes because the rickettsia amblyommatis
[00:25:36.780]can cause disease.
[00:25:38.390]So if we're gonna see it spreading
[00:25:40.200]into the dog tick species, we will have it
[00:25:43.200]across pretty much the entire state or, you know,
[00:25:46.870]three fourths of the state where we have dog ticks commonly.
[00:25:50.830]So it could be part of the reason we're seeing an increase
[00:25:54.730]in Rickettsia type illnesses in Nebraska.
[00:26:00.280]So just to wrap up, to give you just the key points
[00:26:03.760]of what we've been doing and what we're interested in
[00:26:06.480]is Rickettsia species are found in ticks in Nebraska,
[00:26:10.220]but not all of the ones we find cause disease.
[00:26:13.170]In fact, we didn't find Rickettsia rickettsii,
[00:26:15.840]which is traditionally the cause
[00:26:19.270]of Rocky Mountain spotted fever.
[00:26:21.170]And we do know that there were a couple
[00:26:23.460]of cases in North Platte that year,
[00:26:25.870]one of the years we were sampling.
[00:26:27.780]We didn't go clear to North Platte obviously,
[00:26:30.470]but there were cases.
[00:26:31.700]So we do know it is around,
[00:26:33.940]but we have not been able to find it.
[00:26:35.780]But as I said, it makes the ticks kind of sick.
[00:26:38.340]So it probably has some trouble
[00:26:41.340]staying in the population for transmission.
[00:26:44.410]So we'll continue to look for it.
[00:26:47.040]We did find Rickettsia amblyommatis
[00:26:50.190]in our dog ticks, which we did not expect.
[00:26:53.170]And it seems to have gotten there through spillover.
[00:26:55.640]And this can cause illness,
[00:26:57.980]not as severe as Rickettsia rickettsii,
[00:27:01.210]but people would have fever, they could have rash.
[00:27:04.079]They could have, you know, your normal tick-borne illness.
[00:27:10.080]Now, the other thing that was really interesting to us
[00:27:12.950]is it does seem to be evenly distributed
[00:27:15.420]along the locations that we tested.
[00:27:18.290]And so it does seem to be pretty common.
[00:27:21.796]And Rickettsias are not unusual in our dog ticks
[00:27:26.650]along the Platte River and through these two counties.
[00:27:31.110]So more research really needs to be done.
[00:27:33.850]This is just, you know, a blip, a tiny photograph
[00:27:37.946]of what's happening with ticks in Nebraska.
[00:27:41.000]So we continue to look for tick distribution
[00:27:44.640]and the infectious diseases.
[00:27:46.840]We're looking more at the total picture now.
[00:27:51.940]We have a technique that allows us
[00:27:54.530]to look at six or seven bacteria at the same time
[00:27:58.500]from every tick, and so that will be our next publication.
[00:28:01.940]And hopefully that will make us able
[00:28:04.850]to study more ticks more quickly
[00:28:09.340]and know what infectious diseases
[00:28:11.830]are problems in different areas.
[00:28:14.440]We've also increased our area of study.
[00:28:17.830]So we've looked up the Elkhorn River now
[00:28:21.140]and we have found different infectious agents in that area.
[00:28:26.400]There's more Ehrlichias in that area
[00:28:28.310]than we had seen along the Platte River.
[00:28:31.470]So we expect to see differences around the state
[00:28:34.590]when we look at different areas.
[00:28:36.400]And the third thing we've really been doing
[00:28:38.760]is trying to get a group together so we can study more ticks
[00:28:44.287]in a way that makes sense for Nebraska.
[00:28:47.340]We have collaborators now at UNL and at Creighton.
[00:28:51.900]And we have been talking with health and human services
[00:28:55.160]and their entomologists there in Nebraska.
[00:28:57.860]And we've even been talking
[00:28:59.520]to some USDA veterinarians in the state.
[00:29:02.640]So, you know, the better team, stronger team we have,
[00:29:05.500]the more interesting findings we'll have,
[00:29:09.320]the more information we'll have
[00:29:10.960]and be better able to guide doctors
[00:29:14.610]and other healthcare providers around the state
[00:29:17.550]as to what the risks are for tick-borne disease.
[00:29:20.690]What should a person do to avoid a tick that's questing?
[00:29:27.200]So ticks generally are in the grass.
[00:29:31.470]So I would spray my legs with insect spray.
[00:29:38.050]The other thing you can do
[00:29:39.320]if you know you're going to be exposed or out in the area
[00:29:42.380]is to wear light colored clothing.
[00:29:44.700]You know, if you have on white pants, much like our felt,
[00:29:47.570]you can see them and you can get them off.
[00:29:50.516]It's a really good idea to check when you've been outside.
[00:29:56.190]I mean, even some years, you know,
[00:29:58.260]they're even in your yards and things,
[00:30:00.070]especially if you have pets.
[00:30:01.450]So it's important to always check yourself at night.
[00:30:04.810]If you get the ticks off,
[00:30:06.120]and there's some argument about this, but in general,
[00:30:08.290]if you get the ticks off within the first 24 hours,
[00:30:11.290]your chance of getting an infectious disease is lowered.
[00:30:15.530]So get them off pretty quickly,
[00:30:17.860]then you don't have to worry about it.
[00:30:19.710]And then when they get engorged, you want to be sure
[00:30:22.670]you're really careful how you remove them,
[00:30:24.810]because if you squeeze them, right?
[00:30:26.350]You force all that blood back into the wound
[00:30:30.030]and you can be exposed to more infectious agents.
[00:30:32.310]So, you know, you want to grab them really close to the head
[00:30:35.220]maybe with a tweezer and pull them off that way
[00:30:37.720]so that they don't introduce
[00:30:41.340]more infectious disease into your skin.
[00:30:44.910]Right, that makes sense.
[00:30:45.930]And generally, is there a time of year
[00:30:48.310]that people should generally watch out for them more?
[00:30:51.400]In Nebraska, we have seen them as early as March
[00:30:55.970]in pretty high numbers.
[00:30:57.520]And then through July, typically,
[00:31:00.200]because July gets hot and dry,
[00:31:01.820]and then typically they kind of disappear.
[00:31:04.271]But as I said, that year that it was pretty moist
[00:31:07.790]and not super-
[00:31:09.270]I mean, the temperature doesn't really
[00:31:11.690]create a problem for them.
[00:31:13.120]They like heat, but they don't like dry.
[00:31:15.020]So the year, that year that it was really wet,
[00:31:18.370]they were around through September.
[00:31:20.080]We were still collecting.
[00:31:21.950]And then sometimes if it gets nice again,
[00:31:24.890]like this year it's not,
[00:31:26.210]it's very dry and we don't have ticks,
[00:31:28.610]but if it gets wet again in the fall,
[00:31:31.030]they'll come back out again as well.
[00:31:33.110]So what I would do, or you know,
[00:31:36.250]is kind of watch your animals.
[00:31:37.890]If you have pets, you can kind of tell
[00:31:39.870]because they'll get on your pets first
[00:31:41.620]who are running through the tall grass.
[00:31:44.078]And that's usually a sign to us
[00:31:47.103]when we can really be concerned about ticks.
[00:31:52.468]It was good to know that they don't really drop from trees
[00:31:56.010]because that's really what you hear about.
[00:31:57.660]And you're always like, "I'm gonna wear a hat
[00:31:59.060]if I'm going to the forest,"
[00:32:00.240]or whatever, but that's good to know.
[00:32:01.630]Nope, they're crawling up your back.
[00:32:03.340]Yeah, that's way good to know,
[00:32:05.260]and, you know, slightly terrifying.
[00:32:08.680]You talked about infectious diseases, a lot about,
[00:32:12.090]you mentioned Lyme disease and Rocky Mountain spotted fever.
[00:32:17.010]I hadn't heard of that before.
[00:32:18.820]Can you share a little bit more about that disease?
[00:32:22.780]Well, Lyme disease is kind of its own thing
[00:32:26.150]and you get different symptoms.
[00:32:27.530]Your symptoms are more related to joint pain
[00:32:30.960]and that bullseye rash probably everybody's familiar with.
[00:32:34.940]Rocky Mountain spotted fever and other tick related diseases
[00:32:38.500]like ehrlichiosis and anaplasmosis
[00:32:41.300]have very similar symptoms.
[00:32:43.350]So you can have a fever, you can have a rash.
[00:32:47.330]You know, a lot of tiredness.
[00:32:50.220]Now for ehrlichiosis and anaplasmosis,
[00:32:54.470]oftentimes that doesn't get very severe
[00:32:56.580]and you can fight it off yourself.
[00:32:58.490]It's easier to treat with antibiotics.
[00:33:03.300]Rocky Mountain spotted fever is the same symptoms,
[00:33:06.770]but it can become septic
[00:33:09.260]and then you can lose your life from it.
[00:33:11.990]So it's really important
[00:33:13.870]if you think you have Rocky Mountain spotted fever
[00:33:16.230]to get to the doctor and get antibiotics
[00:33:19.320]as quickly as possible.
[00:33:20.530]It's a life-threatening infection,
[00:33:23.320]whereas the others are not as.
[00:33:25.290]You might still want an antibiotic,
[00:33:27.200]but you would just go to your general practitioner
[00:33:31.650]and get treatment potentially,
[00:33:33.770]or you might fight it off yourself as well.
[00:33:36.644]You've often described ticks as nasty.
[00:33:39.652]That was a term you used a lot.
[00:33:41.988]What attracted you to this this research
[00:33:45.750]in such a nasty topic?
[00:33:47.940]Well, I am a microbiologist,
[00:33:50.700]but I am an indoor/outdoor scientist, I would call myself.
[00:33:54.890]I love to be in the field, I love to be collecting,
[00:33:58.110]and then I also like the lab work as well
[00:34:00.770]and doing all of that.
[00:34:02.280]So when I first came to UNK,
[00:34:04.923]I was working with another faculty member.
[00:34:07.530]We were looking at insects and the role insects were playing
[00:34:12.810]with microbes and microbial control,
[00:34:17.570]some of those sorts of things.
[00:34:19.540]And another faculty member was working with,
[00:34:23.550]had a student who was really interested in ticks.
[00:34:26.210]And he started working with the tick side of it.
[00:34:28.850]And I got interested in helping him.
[00:34:31.900]And then he actually left UNK and left the students.
[00:34:36.210]And so I just was helping them
[00:34:39.000]with their projects and finding, you know,
[00:34:41.420]more and more information about how it was going to work
[00:34:45.300]and the huge need that we have in the state to study ticks
[00:34:50.710]and understand how disease transmission is happening.
[00:34:53.550]So I just, I really switched gears in what I was doing
[00:34:57.540]because of the need that we had in that area.
[00:35:01.897]You mentioned a little bit,
[00:35:03.910]in one of the graphs you had,
[00:35:05.163]you showed tick-borne diseases
[00:35:08.530]overtaking mosquito-borne diseases
[00:35:12.370]at least in the past decade, maybe two decades.
[00:35:14.730]I couldn't remember how far back it went.
[00:35:16.980]Why do you think mosquito-borne diseases
[00:35:21.682]have gotten a lot more attention
[00:35:23.901]than some of the tick-borne?
[00:35:26.436]Well, you know, mosquito born diseases are also serious.
[00:35:30.070]We shouldn't downplay that
[00:35:32.630]because West Nile was a huge problem
[00:35:35.490]and it created a lot of issues for us health-wise.
[00:35:41.660]But in general, we've done a pretty good job
[00:35:44.010]of controlling mosquitoes around the state,
[00:35:48.890]from spraying to more biological control of mosquitoes.
[00:35:55.470]And so I think we've just been better at controlling them,
[00:35:58.260]whereas ticks, we don't really have any control
[00:36:01.990]of ticks or how to control them.
[00:36:04.290]And so, you know, when Lyme disease
[00:36:06.770]first popped up in the early '80s,
[00:36:09.690]it spread very quickly and has become a huge problem
[00:36:14.660]because the disease itself is hard to treat as well.
[00:36:18.060]So if you don't know you have it
[00:36:19.740]and you can't get treatment early, it's really hard to treat
[00:36:23.440]once you've gone several years without treatment
[00:36:26.150]and it's in your joints
[00:36:27.990]and it's hard to target with antibiotics.
[00:36:30.460]So I think that tick-borne diseases are a problem
[00:36:34.820]because of our inability really to control them.
[00:36:38.910]But also, you know, the climate is changing a little bit
[00:36:43.430]and Nebraska is getting warmer.
[00:36:45.290]And so we're seeing ticks
[00:36:47.260]maybe that we hadn't seen here before
[00:36:49.110]because they can overwinter now,
[00:36:50.950]whereas they couldn't before.
[00:36:53.030]So we have the lone star tick.
[00:36:55.070]We've been watching for deer ticks for many years.
[00:36:58.360]And there's a third tick called the gulf coast tick
[00:37:01.540]that we have been finding in central Nebraska
[00:37:05.000]that is a problem for disease transmission in cattle.
[00:37:09.400]And it's moving into the area, we're afraid, too.
[00:37:13.010]So we've really been monitoring it as well.
[00:37:15.340]So I think it's just several things working against us
[00:37:20.862]to increase the tick-borne disease.
[00:37:24.700]If people would like to learn more about your research,
[00:37:27.040]where should they go?
[00:37:28.560]Well, they can contact me.
[00:37:31.250]My email is shaper email@example.com
[00:37:35.795]We are trying to get some money, grant money, federal money
[00:37:40.850]for creating a web-based page that people can ask questions
[00:37:48.380]or people can find more information.
[00:37:51.060]We'd like to be able to have people send us ticks
[00:37:54.580]and then add those to our collection points.
[00:37:58.080]So hopefully we will have more information soon
[00:38:04.540]from this research group that we have created
[00:38:07.630]and more information available for the state.
[00:38:14.030]Great, well thank you so much for joining us today.
[00:38:16.440]We really appreciate it.
[00:38:20.660]We'd like to thank Julie Shaffer
[00:38:22.230]for speaking with us today.
[00:38:24.000]Find all of our short Great Plains talks and interviews
[00:38:27.230]as videos and podcasts at go.unl.edu/gplectures.
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