Bats, Whitenose Fungus, Chikungunya, and Parasite Vectors of Disease by Dr. Luis Escobar


Hey folks. How’s it going tonight?
Hi. Thank you. Thank you all for being here at Cafe Scientifique. I can’t
believe that it is our second-to-last Cafe of the season. How many folks in the
audience have been to almost every Cafe this season? That’s great. Thank you so
much for your support. It just means so much to us. So, I’m gonna go ahead and
introduce our speaker now. Dr. Luis Escobar’s research interests include
macro-ecology and ecological niche modeling using climate and remote
sensing data. He aims to investigate areas of potential invasion of micro, or
disease, and macro, fish, species. His goal is to validate tools and theory from
invasion biology into disease ecology to enhance the field of spatial
epidemiology, which I imagine he might explain while he’s up here He also
assesses methods and variables for assertive predictions of biological
invasions in Minnesota freshwater ecosystems at coarse and fine geographic
scales. And tonight, you’re like, what does that have to do with bats? Tonight, he’s
gonna be talking about bats. But the way that I was introduced to Dr. Escobar’s
work was because he was working within the area of aquatic invasive species and
presenting on modeling techniques that can be used in a variety of different
ways, which I think again he may speak to somewhat tonight. And he was
presenting to some folks at the DNR, and we actually have some DNR folks in the
audience tonight, as well, but he came very highly recommended, speaking on the
topic of bats. So, I’m looking forward to introducing him to you, Dr. Luis Escobar…
and he just got married, like, this week, so… And he’s sitting next to his lovely wife,
Joanna. So come on up doctor. Thank you for that cool introduction. My wife
says that I love her but that my heart is with the bats. Thanks for
this invitation. It is an honor to be here. And please forgive my my accent. I’m
from Guatemala. So, if you don’t understand something,
just raise your hand and I can repeat, even if I commit the same
mistake. I work with bats. That’s most of my background. And I have been studying
diseases in bats. Bats are a very complex system, a very complex group. And, because
I has been gaining a lot of knowledge from that group, now I’m applying that
knowledge to diseases in fish. That’s why I’m here. At the end of the of the
talk, you are going to understand what’s the link between bats, between parasites,
and chikungunya – it’s a novel disease, and white-nose syndrome. This is a picture of
Batman and Superman. This is a new movie. So my goal here is that, at the
moment that you watch this movie, you are going to be on the side of Batman. Let’s see if I can achieve that. This was my training in Guatemala.
I’m from Guatemala. My wife, also. And the idea was to work with the CDC looking
for novel diseases or novel pathogens in bats. So, we were looking in healthy bats
for potential parasites that can jump from bats to people. Okay, let’s see, this
is me some years ago and we made some necropsy… sorry for for the pictures. Okay,
there were some accidents sometimes. Okay, we use mist nets that are used to
capture birds, but we use that for bats also, at night. And it’s very
interesting because, when you put the nets, it depends of the bat species to
the time that we capture them. So they have different times to forage and
also it depends of the level in which they are flying. We capture them. For
example, if we put the nets very high, we are going to capture insectivorous bats.
But, if we put the nets in the bottom of the floor, we’re going to capture bumper
bats. This is a bumper. But we’re going to talk about parasites in natural
ecosystems. We are going to use bats as a model. We are going to talk
about parasites in disturbed ecosystems systems, and then we are going to show
the example of chikungunya in a disturbed ecosystem, and the White Nose Syndrome that is affecting bats. So, in this one, bats are going to be the bad guys. And here
they are going to be the victims. This is the type of animals that my colleagues used to work with when I was studying my PhD. They used to work with very fluffy and beautiful animals, while I was working
with another group of animals. So, the goal here is that the end of the talk
you are going to be loving the bats. There are some beliefs that are not
correct. I remember that I heard this question in
one of the talks I gave a couple of years ago. People think that some bats attack
and when they are flying they get stuck in your hair. People also, when you say “bat,” they immediately think of Dracula. There are some kids also that think that bats are blind, but they can
see very well. The flying foxes that I showed, the babies, They fly during the day so they have vision like us. Others fly at night. All the bats that
are in the Americas fly at night. And they have a very good view, vision,
and they also have a collocation. Not all the bats eat blood, so that’s an incorrect
belief. They are not flying mice. And they are not bad animals. They are really cute,
beautiful, nice animals. Okay, and this means, this is a kind of book, so here we
measure the distance of how familiar are the animal. So more distance, more different or less history of evolution they have. And, for example,
in this group we can find the bats, the horses, and the dogs. And you can see
that, for example, humans are far from mice, from rodents, and bats are even more
far from rodents. And this is the, what bats provides to people. We call that
“ecosystem services.” For example, they eat insects. And a colony of bats in the US
can remove per night 50 pounds of insects. So, they are providing a lot of
services to the agriculture. They also eat mosquitoes. One bat can eat per hour
one thousand mosquitoes, but they don’t eat 24 hours. Like, a couple of hours. The species that eat mosquitoes is a
myotis, and they are in danger now due to the white nose syndrome – we are going to
talk later about that – and they also eat nectar. And, because they eat nectar, they
have pollen in the hair. And they pollinize the flowers. What else?
Indeed, there are some plant species of plants that quibble with bats. And the
plan has exactly the form of the anatomy of the head of the of the bats. And they
also eat fruit, so when they move it to in trees, they spread the seeds and they
provide this kind of service to generate the forests. Okay. If you want more
information about bats, there is this link, but we are going to talk most of
the things that are here, for example, that they live a lot and
that they are not related to rodents. They are more close to humans than to
rodents. This is a bat that is capturing an insect, and what they do is that they
have some kind of skin here between the legs. And, when they are
flying, they capture the insect with that, with a kind of net. I was mentioning
echolocation and what they do is that they emit a song. This song travel and
crash with the insect, so the bat can know the: where is the insect, what’s the
speed, and what’s the size of the insect. When it detects one insect, it is going to
emit a lot of more frequent echolocation to know exactly where it is
and it is going to capture the the insect. We are going to talk about coevolution, and that means that the species has been
living together at the point that they know
them. For example, there are some moths, these butterflies that fly at night. And
when they, when they feel the echolocation, they stop flying and just…
they just drop. They just fall. So the bats come is not going to be able to
identify where it is. This is a kind of family tree, and more far we are, less
close are the species. And this tree is very cool, because it shows the family of
bats and how far they are, how similar they are, but most important: what they
eat. i’m going to show you here what they eat. For example, this is a small (?) and they eat blood. This one is the bat that eats
other bats, or frogs, or rodents, or even birds. And, they, this one, yeah, I
always have problems with that one, sorry. This one eats nectar, and this one eats
fruits, and this one is there are two species that eat fish. They have some
claws in the legs. So, they are flying very close to the water, almost
touching the water, and they are going to capture the fish that is, like,
swimming in the surface. It’s very cool. I remember that we were in the field, and
there was a fisherman waiting for the fish at night, and he feels like a fish pulling. He’ll take the line and there was a bat. Poor
bat. Ok there is a big diversity of this species. We have this flying fox in
the old world, and we have this species here in the Americas.
A tiny, tiny bat species. So, this group is very diverse in terms of what kind of
habitats they live in. We have been studying all the diversity of what
species (live) across Latin America and here, in Venezuela and Colombia, there are
some areas in which you can find even 1020 species of bats in the same place.
So, this is the area in the Americas with the highest diversity, the highest
richness of bat species. I like this one. This is centurio senx, and it eats
fruits. This is a male. They have these white spots here, because apparently
that’s attractive to the females. And this face, (does) somebody (have) a clue
about why they have this form in the face? No? That’s because they usually are
hanging and, when they eat the fruits, all the juices of the fruits are
going to fall and this allows them not to breathe or inhale the liquids, the juices. This is the vampyrum spectrum. I don’t like the name because
it’s not a vampire bat. The don’t eat blood. They are carnivorous bats. People
compare them with the jaguars or the cougars, the pumas, because they are
really rare. They are solitary animals and they are at the top of the chain, at
least in the in the bat world. They’re the biggest bat in the in all the
character group in in the Americas. But it’s not a very big bat like the flying
foxes, right? And here one is eating a lizard. Yeah, so now you can understand this. Okay, usually when we see the news or we read a paper about bats, they are very
linked with diseases. I have been working in this project a in which they
found the oldest ancestor of the avian flu. It was discovered in Guatemala. This
is the paramyxoviruses, they are close to the nipah virus that was very famous. They
even did a movie about nipah virus in Asia. So, a lot
of things link emerging diseases to bats. For example, MERS – that is a disease that was found in camels, also is linked to
bats. This are all the family of viruses that has been found in bats. Rotovirus are the big group of rabies. Most of research has been done in
in that group of viruses. Coronaviruses is linked to SARS –
that was a pandemic, like, in 2003. Paramyxovirus is nipah, hendra. Ortho is
the flu. So, they have a lot of viruses but also they have a lot of bacteria.
These are all these species of bats that were found with some kind of bacteria
that could be pathogen to people in different countries here in the Americas.
So, we can find a lot of bacteria, a lot of a viruses on them, but I remember that
we never found a sick bat. They were apparently healthy. We usually have this perception of
the pathogens: they are bad, we should remove them, our lives would be better if
there were no pathogens, for example. And we even think, or I was thinking, or my
mom thinks that this is more acceptable than having parasites. When I mention
parasites, there are two groups: the microparasites – the tiny one that we I
need a microscope to see them. For example, viruses, fungi, bacteria,
or the macro parasites like the tics, the fleas. Okay, so my second goal here is
to change your minds, so you are not going to perceive the pathogens. as you
were thinking. Maybe not like this, but at least you are going to think different
about diseases and about parasites. I’m going to pull all the parasites, the micro the macro, so keep that in mind. What’s the role of parasites in in the
in the ecosystem? And I’m going to mention some parasites in bats, so you
can be thinking on them. This is this is a juvenile male of the smalls rotundus,
the vampire bat, with some injures. They fight a lot. They are very territorial.
There is one male with twenty five females in the group and they fight for
for the females and for the area. And this one was in very good health
apparently. I am (a) veterinarian and there were a group of veterinarians and my
speciality is wildlife, so it apparently was very healthy, but it has a lot of like kissing box around him a lot. Even when they have lot of ectoparasites, they look very healthy. I didn’t mention that this was a juvenile, because the testicles were really tiny
and it’s very evident when they are mature male. So you are going to be
experts in bats after this. One of the benefits of the parasites
in nature is to remove the weak animals. This is a picture of a colleague in
Mexico. These are a kind of lice. This bat eats insects and it
was also, apparently, healthy. This is a kind of worm, in which the the fly put
the eggs into the skin, the worm opens a tiny, tiny injury and lives inside. So it has
three kinds of these worms in the skin and, again, this is a picture of a
fruit bat in the Philippines from a colleague. And the bat was very healthy.
So, what if the parasite kill the host? The parasite is going to die also
because, in this case, these tiny worms are eating the fluids. And here they
are eating the blood. So they need a host that is alive. This is another picture.
This is from more fieldwork in Guatemala. And this was a mouse with a huge cuterebra worm living inside it. And again, It needs the mice living. So, what if
the parasite kills the host? If the host is dead then the
parasite is going to be dead also, so they don’t want to kill the host.
They co-evolved. I’m going to do an exception here, and this is the
only report we know that exists. I know the researcher and this is a parasite
that is a specific to a species of snails.
This species of snail, was in critical danger, so the zoo of London collect
the last population in nature and put them in a fish cage. So they were raising
these these snails there and then because of the stress of changed
temperature, for example, there was a rise in the number of parasites and the
parasites killed the host. This is the only evidence that we have,
and we know that the population of snails was really, really small at that
moment, but for different circumstances, but usually parasites only
kill the host if it is not the original host. For example, if there is a jump to
another host that is not the the natural one. Another benefit of parasites is
that they remove the top predators. For example, I remember that, when I was
in school, my teachers told me that the Jaguar was the top predator in
the Americas they kill other cats, they kill a cockatrice, they kill anacondas,
and they even kill turtles. And the turtles are a
special group because, usually, when they are adults, they don’t have predators.
So, the jaguars kill and eat everything below them. So they are the top of
the food chain, apparently, right? Then we know that there are some bat species
that eat blood. For example, here there is a tiny desmodus on the back of this deer,
looking for food. We know from some evidence that vampire bats can eat on,
can feed on Jaguars. So they can transmit rabies. Rabies is a very common
disease in bats. They have rabies in their saliva. They are healthy with rabies. They
develop rabies, the symptoms, only if they are babies when they are infected.
But if they are old, they are resistant to rabies. So what if there is a bat eating or biting a Jaguar? The jaguar is going to be infected with rabies and then there is not going to be more
jaguar and then all the other animals below the jaguar are going to receive
benefits. So apparently the diseases that can remove some of the predators can
have some effects in the rest of the chain. So the jaguar is not anymore the
top the predator the top the predator are the diseases. And that’s very
easy to me to understand if we think that humans are the top-top-top, the
predators in nature. But the only the player that really can kill thousands of humans are diseases. Another service of parasites to ecosystems is
that they can regulate the number of individuals. They can control populations.
Bats can live, depending on the species and the environment, between 10 and 40
years. And they have a very complex immune system. And they are very
resistant to parasites. Indeed, there is a research study in which they inoculate
rabies that is the most mortal of all diseases. If you receive an injection of
rabies, there is 100 percent sure that you are going to die. There are six
exceptions, but there are some questions about that. And then, bats can survive. If
they are adult bats, they can survive rabies. And they are also have here some
ticks. I guess that we found 20 ticks in this vampire bat and this is, I don’t know,
but maybe equivalent that if I have like a guinea pig here sucking
for blood. This is a very huge parasite for the poor bat. Bats are an
exception to the rule, in terms of how long they live. For example, if we have an
elephant, they if they say that they live 60 years, that’s fine. A mice, they can
survive, like, two years. And when we draw a line, we expect that bats survive, like,
three years, but no they are an exception to this rule and they live more than
what they should. If they were humans, they should survive around
500 years. They have one baby per year and the baby is as big as a six year old
kid when they have the baby at the moment of the birth. I don’t know how to
say that and the babies develop very fast. They can fly one year after they
are born. There are nurseries. This is very weird in nature. That’s not
usual and this means that all the all the mothers put the babies in one place
in one corner in the cave. So there is going to be one mother that is going
to feed the babies, even if the babies are not from from that mother, and
usually that doesn’t occur in in nature. And because she was not hunting there
is going to be another mother that is going to come and is going to feed this
other mother. They are very altruistic. So, for example, this nose rotundus, the
vampire bat, when there is one of the bats that is sick or injured or is a mother
in the nursery and cannot go to to collect food, there are other bats come and put, like, vomit blood into the
mouth of the other bat. So, that is also weird in nature. We don’t expect to see that in other animals. So, also, they live in the
roofs. They are the only animals that do that. And I remember that we collected some dead bats that were hanging, so they don’t need to do any effort to do this
when they are in the roof perching. But they are in the in the roof. So,
indeed, they need to do to invest some energy to open the hands. So, because
they are living in the roof, they are not a lot of the predators for them like a
fox or a cat. It’s very hard to to to reduce the
populations in nature. They are really resistant to diseases (and) to the predators. They live a lot so why are there not so many bats? And that’s because
diseases can kill most of the babies the first year. So thanks to these diseases
we don’t have like a pest of bats everywhere. Diseases also are
engineers in the eco-… in the nature. I’m going to give this example. I didn’t
found an example in bats, but this is rinderpest. This was or is a virus that
was affecting Africa and it was common in leaf stalk and the leaf stalk
transmitted the virus to the wild deer and the other herbivores
because there were no more herbivores at the time, there was more grass in the summer, in the dry season in Africa there are… the fires… the wildfires are common. The fires were bigger than
expected. Bigger than the previous years. So the trees were removed for the fire.
So diseases… just the presence of disease changed completely the
landscape. There were no more… The few trees that were there were gone. Finally, parasites regulate the food webs. I have this nice example. This
is a snail. Usually, as nails don’t want to be killed for the predator.
So to survive they look for the dark areas. But there is a parasite
that need for some stage to be in the snails and for the other stage in the
predator birds. And when the snail has this parasite, it’ss not
going to look for the dark areas anymore. It’s going to look for the light. They
call it a post-positive tropism. And so, the rates of the predation are going to increase. So, thanks to the parasite, this guy is
eating. This is something very similar. There is a parasite that needs to have
babies. It needs to be in this animal. To grow up. it needs to be in one
stage in snails. In an another stage, in frogs. And something cool is that,
when the parasite is in the tadpoles, it’s going to be here and it’s
going to produce some chemicals to change the hormones and this frog is
going to have several legs and that’s going to make this frog more susceptible
to predation. So, he’s happy with parasites. So, parasites are really
important in nature and they have a strong impact in the food webs. The
final example of how parasites impact in the food webs is with
toxoplasma. Toxoplasma, so this is that usually is linked to pregnant women and
is found in mice or in cats, because for some stage it needs to be in mice, and
for other stage to reproduce it needs to be in the cats. But I remember that when
I was in the first year of the University, they were thinking why a
parasite wants to be in these two guys if this one wants to be as far as
possible off of the other’s stage. So, when there are plenty of… (when there’s a) good level of
parasites, some parasites are going to move to the brain and the
behavior of the mice is going to change. And it’s going to be fearless
to the cats. For example, the mice usually don’t see very well and they need
to touch the walls with the mustache to know that the wall is close. But
when they have the parasites, they cross this room, so it’s easier. Okay, this is a
story developed for one of my teachers in the PhD, Marcel Aldana, in Chile. And
she was looking for diseases in fish, for some parasites in fish, and she compared
areas with a lot of disturbance a lot of the perturbation. For example, areas with
a lot of tourism and wild areas. And she found more parasites in areas that were
more wild. So people is proposing, you cannot see that here, but they are
proposing that parasites can be like an indicator of ecosystem health. And that’s
what we expect in a very healthy ecosystem. Parasites are good. But what
about that in ecosystem that is with perturbation? I’m going to provide a
couple of examples and I’m going to include chikungunya. First, we expect this
in in the wild. This is a bond pairs… sorry, a bat species, that is found in the tropics in Latin America. They look like cotton and they live under the
leaves of the banana. They plant banana trees. What they do is that they
coat these areas so the leaves are going to fall. The walls of the
leaves are going to fall and they can live here, like, six days. They then are
going to look for another (place to) live. So they need an area with a lot of this tree species, right? But what if I change the landscape? I’m going to lose those
species. So, this emerges when we change something in the habitat of the
species, due to habitat loss or pollution, for example. I like this cartoon because it
explains exactly what is happening with emerging diseases. For example, here there is the bear and he has been living in this forest, then we caught the forest,
we develop an urban area, and with the people, we are going to think that “Wow, this is an emergent animal,” and maybe it has been here before us.
That’s the example of Lyme disease. That’s not an emerging disease. That’s an
ancient disease. The issue is that we have been entering in wild
areas. And that’s happening. That’s not a cartoon. I have this, going back to the
bats, I have a cool example, because this species… you say that only three
species of bats eat blood. That’s true. I only know this one the
other two are very rare. Even if you work a lot in the most wild areas, the populations are very small of the other two species. This one can eat
a lot of preys, but the other ones, for example, one of the other vampire bats, they eat a specific group of birds. Okay, animals with
feathers. Okay, for example, the smallest … some studies show that they can eat
snakes, iguanas, these animals, amphibians, and turtles. For example, there are some research in which they inoculated rabies in these animals and they
didn’t develop the symptoms. But if we think, in the mammals, they are
susceptible to the to the rabies virus. So, in nature, mammals are not the
most dominant in the landscape. Usually, at least in ecosystem that has no
perturbation. But this is what we see currently, that we change the entire
habitat so we are going to provide more preys to the vampire bats and, due to
that, we are going to find more animals that are going to acquire rabies.
We have been doing research on that and we found that only with changing the
vegetation, we can explain the presence of rabies in different areas. And now I’m
going to introduce you to the dilution effect a term and this is what we see in
nature. When I have an animal that is infected,
for example, a wild beast that is sick, I expect that that’s going to be the
most easy prey to the lions. When I have a sick bat, I’m going to… this is going to
be the most easy to kill. But also, these kind of toads, they eat everything in
nature, so they remove the sick bats. And, as you remember, bats cannot infect
the toads so they are providing a service. They are, like, cleaning the
ecosystem and the problem is when we remove these animals and in a normal area, for example, there is going to be mammals that are susceptible to bats. This cat has a bat here. Something of concern, is that if I see a bat in my
house, maybe that’s normal. But if, for example, the Americas, if I see a bat in
the day, that’s dangerous because the bats that we have in this continent,
they fly at night. Usually, the bats, if I enter into a
cave, they are going to fly. They’re going to go away. But if I found a bat that
doesn’t have fear, maybe that bat is sick. So, those those
bats that do not fly, that they walk, that they do not have fear, that they are
(out during the) day, at the day, maybe they have rabies. So we don’t need to touch, we
should not to touch them. Usually, they they do that. So we
call it the amplifiers to those animals that, if they are present in the
ecosystem, instead of removing the disease, they are going to increase the
probabilities of diseases. So, when there is land use change, some bats are going
to live more close to us. I have this example. We have a forest with different
species of of bats like those cotton bats that I showed you, the white ones,
but, if I remove the forest, I’m going to change the ecosystem. And, if I put some
houses and some people, I’m going to change the ecosystem. Some of the
bats do not like or do not support these changes, but there are going to be
authors that say, “I can survive here,” and they are going to increase the
population, because there are no more competition. And we are going to increase
the rates of the risk of rabies in the system. My thesis was with this bat,
tadarida brasiliensis. It has a naked tail. They live from Canada to
South Chile and they eat insects. Okay, if I have a colony here of bats of this
species, all of them are adults. Could somebody
tell me how many of these bats are going is going to be. or are going to be sick
with rabies?
(someone from the audience) None.
Who else? Wow. Almost. Very close. It’s very rare
to find rabies on them. The problem is, when you look for those that have rabies,
and you touch them. So the risk increases. I don’t know why, but in Latin America,
when you find a bat, the people used to put them to smoke. Okay, so even when
there is the risk of finding a sick bat with rabies is very low, if you increase
the number of bats, the probabilities for the number of infected bats also are
going to increase. This case was in South Carolina, was a report from the CDC, and
this was a house in which there was a lady who loved bats. And
she always left them to live in the house, even when it was very easy
to remove them. One way to remove them was to put light here, because they don’t
like the light. They have a lot of oil in the hair, so you can see these
spots here, and she was working under under this area, and she got rabies.
Because bats – to generate the echolocation, they generate also some
tiny drops of saliva and release the saliva. So, I remember one research (study) from
Dr. Constantine, who, he is, he was a heavyweight in rabies in bats. And he
here and some speleologists, these people that like to go into the caves,
they got sick with rabies. And, under the interview, to the survivors,
he asked if they were bit and they say that no one was bit by a bat. So, he
was thinking in the in the spit or the air for transmission.
He went to the cave. He put some raccoons and dogs and cats into a tiny
cage with tiny holes, expecting that no bats can bite through the cage. And some
days later, the animals resulted positive for rabies. So, that was the confirmation
of rabies by tiny drops of saliva. So, if you find a bat,
please don’t touch it because they can bite you. You cannot see a bite. I don’t
remember. I guess that the bite is here or like
this. So, if you touch a bat, please go to the health center to
acquire the rabies vaccine. And, if you found a bat in your house, maybe it’s not
sick. Maybe it’s a juvenile. The juveniles, when they are starting to fly, they used
to have difficult to fly and they can be into the house. Just put a box and
release the bat outside the house. And if the bat cannot fly, maybe it is sick and
you need to call to the health agency. Here. I don’t know which one, huh, I
remember in Chile – I was doing my PhD in Chile, and there was the first case of
rabies in people in Chile. Rhere was a kid of six years old killed.
And I remember that all the physicians, they say, “We don’t know what
it what it is,” but the old pediatrician, of the model of the kill, he said, “I
suspect of rabies.” And all the junk physicians they say, “No, that’s
impossible. We don’t have rabies here in Chile.” And then they collect the brain
of the kid, because he died. They found rabies. So, rabies is the
only disease in which, after you are bit, you can have the vaccine and you are not
going to develop the symptoms. And then the mother. like four months
after the kid died, she was cleaning the room and she found a dead bat in
the box of the toys, of the kid. So maybe you are not going to see the big bites,
but be aware of that. Now, I’m going to talk briefly about chikungunya this is
something that we just published. And, chikungunya is a disease from Africa and
Asia. It was not present here, like, three years ago. Chikungunya is a
kind of invasive species. Here at the University of Minnesota I work with
invasive species. And invasive species are those species that are from other
side, live here, and they found a fertile ….. everything is perfect
and they increase the population even more, or even higher than in the native
areas. Okay, now that we have that in mind, we are going to think on mosquitoes as
invasive species also. In the Americas, we have is aedes aegypti and aedes albopictus, and
they are very aggressive species of mosquitoes, and they are not native from
the Americas. For example, this aedes is in the t-shirt
of a man in Ecuador. This is a picture from my colleague, Daniel Romero, and you
can see that it penetrates the clothes. So, if you use repellent,
please don’t only put repellent in the skin. I used to do that. Now, I use
repellent in the clothes also. And you can see how aggressive is the species because here is empty and here is full of blood after a couple
of seconds. So, this is the potential distribution of aedes albopictus. Here aedes aegyptive. They can transmit chikungunya and Zika virus and
dengue. And something of our concern is that, given that we have all
these species of mosquitoes in the Americas, and we have high flow
of people, there are some chances or some opportunities to move the diseases also.
So, we were doing research on that and we were thinking in people infected as, when
you think in the immigration of animals, movement of people, so we established the
amount of people flying between countries potentially infected with
chikungunya. This is the situation of chikungunya in September of 2012. This is
in March, in August, in 2015. It was not present in the Americas and then it
appears in December of 2015 in summertime here in a tiny island in the
Caribbean. And after that it is spread as fire across the Americas. This is San
Martin. Apparently, that was the patient the patient zero of chikungunya in the
Americas. And from here we estimated how many people spread it to other countries.
And because, for example, Canada had a high amount of people infected they do
not have mosquitoes there, so there were not the same spread of the disease like
here, for example. So, this is an example of the flow of people from Canada to
other countries in the Americas and you can see that Canada do not have direct
connection of flights to Chile, for example. You need to go to the US for
most of the flights. And this is an example of the United States. We did this
to understand how chikungunya move between the countries. And, this is the
United States, and each arrow means a flight. So if you are in the United
States and you need, you want to go to other countries in the Americas, you need
to take only one flight only. For two countries, you need to take three flights.
For Venezueal, for most of the countries, if you
departure from the United States, you need to take two flights. And now, the
interesting thing is the, in Sint Maarten the share, the the area in which the
epidemic started, if you departure from the from Sint
Maarten, you need to take three flights for most of the, to visit most of the
countries. So, there are more chances of transition of chikungunya here and
that’s what we saw. If there was a… this is the patient that arrived in a flight
in Colombia. And once the patient transmitted the disease to the family,
there was an explosion of cases in the country. And we saw the same in Venezuela, in Dominican Republic, Guadalupe. An exponential growth. A lot of cases in
a very short time. So, that’s what invasive species do. So now that we know
about bats, about parasites, and about invasions, I’m going to talk about
white nose syndrome. This is a normal disease here. It has ten years. This is a
very brief presentation about this disease. This is what we see under the
epidemics: a carpet of dead bats in the floor of the caves. And usually we are
going to see that these bats are going to be without fat, with a lot of this
fungi in the areas without hair. And, as I said, maybe they are dead, but
they are still hanging. This fungi, it can be found in the ears, in the wings of the
bats. If this fungus is very close to other
fungi that eat dead plants, for example. It was fun in the winter of 2006 in
New York and the mortalities go from 73 to 100%. It depends of
the species. There was a species that was very
abundant in some states that now is critical in danger, because the rates of
mortality for that species is 100%. There… Most of the caves with that species, if
they acquire the fungi, are going… the fungi is going to kill all the
individuals in the cave. Now it’s found in 30 states in the United States.
Apparently, it’s native from Europe and there are some studies infecting with
the same fungi from the United States some bats in Europe and the bats are
healthy. Why? Co-evolution. Perfect. So the the bats in Europe, they have been
living with the fungal that they say, “I know you, so I can respond. My body can
recognize you.” But in the Americas, it is novel, so the body of the bats
cannot recognize the parasite. This is what we see. This is a healthy tissue. And
this is an infected tissue. And you can see that all this layer of tissue is
gone. This here, we should be looking, some inflammation. But, in this case, there is
no inflammation. So, the fungi is eating the live animal and the animal do not
respond. The tissue does not respond. So that’s very interesting in this case. So, I found this joke in in Facebook and they say
that there is a diet for the bats. So you can take this diet. This is the
PD, the acronym of the of the species name, and some of the side effects is
death. That’s because, the bat, when the bat is
being depredated for the fungi, it is going to invest some energy to compensate the
tissue that is lost, the heat that is lost, and is going to spend all the fat that the bat has to maintain the hibernation. So, at the moment, there are some bats that wake up too early and, when they wake up, because they are starving,
there is only snow. There are some evidences that support the idea of
the origin of this fungi in France.Tthey even identified the cave in France, because
the fungi that is in the US is exactly the same as the fungi in this
cave in France. So, what they suggest is that this cave received some tourists and the tourists transmitted this disease to North America. Indeed, the cave here is an attraction and the cave here in New York is the most visited cave in the
U.S. From there, the disease is spread. And this is the distribution of the bat
species that are in the higher risk of extinction due to this fungi. The Indiana
bat is the the most in danger at this moment, because it’s the most susceptible.
That was in the winter to 2006, and then it spread faster and faster, and now this
is the situation by this month. So, this this is the origin of the
epidemic currently there are some evidences here.
And here, there are some bats that were there for this fungi in Minnesota
and there are some reports here also in Washington. Something interesting is that
there is a gap between the fungi reports in both areas, in this country, and a
there is a match between the areas without bats. So, there is no disease there maybe because there is no bats there. Okay, so
this is the map of which the number of species in the US. We developed a tool to
understand why this invasion from Europe to the US was so successful. And we found
that this is the distribution in terms of climate, temperature, humidity,
rain. These are infected bats. The environments used by infected
bats in Europe. This is the cave in New York and, from here, the fungus
has been spread into novel environments. So it’s like in the case of the zebra mussels. The fungi arrived here to a fertile soil and
everything is perfect. Even if the environment is different to Europe. it is
very suitable for the fungi. So out novel discovery now, or our proposal, is
that we collected information from the current distribution here and here of
the fungi. And we, our question is that, given that the fungus is above the Tropic
of Cancer, what if we move the fungi in the Tropic
of Capricorn? What do you think that is going to happen if I have that here?
Can survive? Let’s see. Okay. We collect information about the environmental
conditions in which I found the fungi here and here, and we identify if such
conditions exist here. So, we made the projection, the modeling, and we found
this. There are a lot of conditions here in Chile, in Uruguay, and Argentina that
are suitable for the fungi. So conditions exist, if I’m researcher and
I’m going to work here with bats, I should not move to Chile with the same
clothes or shoes, for example. There are some studies showing that, in the shoes,
they isolated the fungi. And, here in Chile, we have so many species that
also hibernate. For a shorter time, but they hibernate. So we found that the
disease is not in ecological equilibrium. Sadly, this means that the disease is
going to keep spreading here in the US. There is one treatment, maybe not
treatment. This is a bacteria and they they put the bacteria in some infected
bats and then they release the bats because the bats were healthy, in Missouri.
This bacteria was developed to kill some fungi in the fruits. The idea was to
keep fruits surviving for more time in the stores. And then they apply this
bacteria to bats and they discover that the bacteria kills the fungi.
Something nice is that it kills the fungi. Something not nice is that it’s not a
treatment. I mean, if I’m a bat and I’m already sick, it’s not going to recover me.
It’s going to kill the fungi. Okay. So message to take home, is that bats
are good for the ecosystems. Parasites are good for ecosystems. We are going to
have novel diseases if we disturb the environment. For example, with
habitat lost or species invasion. Thank you (moderator) Thank you so much. we’ll take questions from the audience if that’s all right with you.
Let’s see. Raise your hand if you do have a question. You may have been so
thorough that you have answered most of our questions! (laughs) Here! Right up here. I’ll be right there.
(audience member) I have one question. I forgot the pronunciation of the disease you talked
about Shoop what Suganya… chikungunya. What are the symptoms to that? I guess.
(Dr. Escobar) Cikungunya is a disease that was found in Africa and in a in a village with people in Mikondo, is this tribe of people. And the
meaning of the word in mikondo means “that that makes you twist” and that’s
because the the pain is so hard, so high, that people cannot even
stand up or things like that. And they compared the pain with advanced
arthritis. And so you are going to, if you are infected, around six days later you
are going to have headache, a fever, and then a lot of pain in the joints. And
this pain can last for 3 years. Yeah. Yeah. It’s very nasty.
(moderator) Can I just ask, maybe, if you could connect the research that you’ve done with
bats and how that carries over to aquatic invasive species and fish
diseases, which is what you’re currently involved with at the University of
Minnesota as a postdoctoral research associate.
(Dr. Escobar) Yes. Okay, yeah we were…the idea is that we have been trying to understand why the white nose syndrome is very good survivor here. It is dominating the complete in landscape and is changing all
the community of bats in the United States. So we use those tools to apply to
a disease that is affecting fish. There is a disease in fish that generates a
lot of hemorrhaging, bleeding, across the fish. Inside and
outside the fish. It’s from Denmark. It is from Europe but was discovered in Denmark and for some reason it appeared here in New York. Currently, the
last report for Minnesota is in Lake Superior and it is devastating, it is killing a
high number of species, native and invasive species of fish here. So we are
using these tools to understand invasions and the spread of diseases, but
we are applying that to lakes.
Yes? (audience member) Since currently in the United States the
disease and the bat are not in equilibrium, do you think that there’s
something that humans are obligated to do because we brought the disease from
Europe over? Or is this something that we just are going to let nature take its
course and the species that are fit survive and those that are not die out?
Is there is there an answer to that? Is there an ethical, or a community-like
attitude towards that?
(Dr. Escobar) Thanks for the question. Good question. In my opinion, I
remember that when I was in a study, my master in wildlife management, one of the
question was what if I found a chicken that fall from the nest? Should I take it
again into the nest? And the answer was “No, let the nature keep the course,” as you
said. But, in this case in which apparently was due to human intervention,
I guess that the best idea is to try to solve it. There is one NGO, the Nature Conservancy, and they made a huge
artificial cave. And at the moment that was a kind of joke because, why a
cave? And then they move a lot of bats, healthy bats there, and now that cave is
a model, and they are curing a lot of bats there, and they have a healthy
colony of these bats that are critically in danger now, thanks to the white nose
syndrome. And it’s one huge effort to maintain that population. Apparently, if
we do not do an intervention, the Indiana bat is going to
disappear. The reduction is too fast. There are not comparisons with other
species. In a couple of years, the the number of individuals was like 50%.
That’s too fast. Yes.
(Moderator) Thank you. I was gonna say… I don’t know… I almost… I feel
like that the information that you’ve given us is so dense and so rich, that… no
no! This is good! (laughter) …that I, like almost, my brain is just taking all that in. Is
there any last question? Ope! We got one right here.
(audience member) If it looks like we’re
gonna lose some of our most common bat species, little brown bat, for example
myota species here, which are very important to our ecosystem…. yeah, are
there related species in Europe that are resistant? Is anybody talking about, if
they completely die out, is there any talk about trying to introduce the
resistant species from Europe to fill that ecological role?
(Dr. Escobar) Good point. I guess that, if we are with old bats that’s going to be one one option. There
was, I guess that it was in Kansas maybe? They were using a lot of pesticides for
the crops and, because the insects, they have a very high reproduction rate, they
were having a lot of babies and the babies were resistant to the pesticides.
So, when they were flying and putting the pesticides in the insects they found
that the insects were resistant and the bats started to eat resistant insects
with the with pesticides. So they, a lot of bats started to die. And
then when they notice that, once the the population of bats fall, the pesticides
were not doing anything. The real control was developed for the
bats. So, I guess that the first people that is going to move if bats
disappear, are going to be the farmers. Like in the case of bees, for example, we
use a lot the bees because, even if we have a greenhouse,
we put bees inside just to to develop a role. I guess that we are going to do
that if bats disappear here, but I never hear that currently in the community.
Thank you.
(audience member) Good evening, and back to the original discussion you had about snails
in London that are now extinct, is anybody doing anything about those poor
creatures?
(Dr. Escobar) No.
(MC) Not that we’re aware of. (Dr. Escobar) I remember that the person that was working with that species, and he said that there was the last single
individual and he had that individual in his hand, and he said he
felt like Paul, where he was very sad, saying, “Well, I have in my
hand the entire species.” Yeah, it’s very sad, even if it’s a nice snail. It’s very sad.
(MC) We have time for one more question right up here.
(audience member) Thank you. I was wondering about the transmission of chikungunya. You showed
that it was transmitted by mosquitoes initially, but then, is it after that
transmissible person to person? Or by aerosol? Or is it only if one mosquito
bites an infected person and then goes to another person? How is it
transmitted after the mosquito?
(Dr. Escobar) To my knowledge, only is a vector borne
disease. It needs mosquitoes, but there is another disease, Zika virus, that is
a hot topic now. We are writing proposals to that, because
when there is a an emerging disease, everybody wants to pay to understand
that. Zika virus is now the hot topic and, in the case of Zika virus, there are a
sexual transmission. But for chikungunya, there is no evidence of transmission, even
if both are transmitted by mosquitoes, but the same species of mosquitoes.
(MC) So in the case of chikungunya, you’re saying that an infected person is bitten, and
then that virus is transmitted that way. (Dr. Escobar) Yes, yes, yes.
They are are very different diseases because, for example, one mosquito can
infect, I don’t know, like 700 people of chikungunya. But in the case of Zika
virus, it could be like around 10, for example. The rates of transmission
between both viruses are very different. The burden of chikungunya
was very dramatic, but Zika virus is low, even if the same
mosquito is the species that is transmitting diseases. So don’t go to
Brazil for the Olympics.
(laughter)
(MC) Ope, one more question up in the front, we can squeeze it in.
(Audience member) Are you saying that the Zika virus then is transmitted from person to person? Once
one person has it, can give it to another person without a mosquito? Yes, there is
an article in the New England Journal of Medicine saying that. There were some…
about that journal, because the journal is a very prestigious journal in
diseases. They also confirmed the Zika virus is developing this damage in
the babies. The microcephaly? Yeah, so this is a, people is saying that this is worse than
chikungunya for the long-term effects. (MC) Well, on that (laughter) on that note, thank you so much for being
here, Dr. Luis Escobar. Let’s give him a huge hand. You just got back from Guatemala a few days ago – thank you for making this one of your first stops back in the
States. you

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