This is Gulf Coast Life Im Mike Kiniri.

Thanks for joining us.

The New World screw worm has been in the news lately because it turned up in southern Texas in early June.

These parasites are endemic to Central and South America.

These days they were once present in the southern United States, but were eradicated in the mid 1960s.

The parasite is actually a fly whose larvae burrow into and feed on the living flesh of warm blooded animals.

Cattle.

Primarily.

In the Texas cases, unchecked screw worm outbreaks can be economically devastating for cattle and other livestock farmers.

There was actually a localized outbreak of New World screw worms in the Florida Keys in 2016, but it was contained using what's called the sterile insect technique, where millions of sterile flies are released with the goal of them mating with wild females, which crash the population.

Because a screw worm outbreak is potentially a big deal for the entire United States, including here in Florida.

I'm joined today by Doctor Juan Campos Krauer.

He's clinical assistant professor in the Department of Large Animal Clinical Sciences and Department of Wildlife Ecology and Conservation at University of Florida.

Doctor Campos, welcome to the show.

It's a pleasure.

Thank you very much for inviting me.

So, for starters, can you just tell us a little bit about yourself and your background?

Yes, as you said, I remember here in the University of Florida, I specialize and mostly work with a captive whitetail deer or deer in general, but I also have a lot of experience with wildlife.

I have worked with hogs, peccaries, tapirs, mostly animals from South America, and lots of experience also with cattle ranching and everything related small remnants.

And I did a lot of work in South America, so I actually have a lot of experience with this fly that you have been talking about.

I saw on your CV that you did a degree in Paraguay.

Are you from there?

Yes.

I grew up in Paraguay.

I am from Berlin.

Yeah.

And you were a Fulbright scholar in 2004?

Fulbright scholarship and I that's when I was able to do my PhD in Kansas State University.

Interesting.

So how long have you been at UF?

I have been right now it's almost ten years.

Almost ten years.

So you're an extension veterinarian with UF's Serve a Day health research initiative?

I saw that on your website.

Can you explain what that is and does?

I want to talk a little bit about that.

And deer before we get to screw worm, because there there's some lessons to be learned I think.

Oh yes.

Yes.

So yes, my position is clinical position.

But I also where I work as an extension and researcher in the Survey Health Research Initiative.

So the Survey Survey Research initiative is a program that started because as maybe you don't know, there's lots of deer farms here in Florida.

And they were really concerned about many of their animals dying because of an MRI disease.

It's a virus.

It's called episodic memory disease.

We probably heard it or seen pictures of these deer going to the water and dying in the water in many parts of the United States.

And there was a big problem here in Florida.

And that's how this program started.

And the main objective was to better understand this disease and be able to mitigate, find ways to manage the animals.

And also, one of our big success, I think, is that through the work we have been doing, we were able to get private companies to work together with us and produce a vaccine.

So right now there's a vaccine that can be used that prevents that very deadly disease in white tailed deer.

And we are very concerned in terms, especially myself, being a person that worked with wildlife and had that has experience with screw worms, is that wildlife is going to be a big component if we ever get this crew worm back, which I hope we never do.

The Florida deer farms, more than 400 that you mentioned is partly why I brought that up, because I grew up in Florida, and I've been talking on the radio about interesting wildlife stuff for a long time, and that was a new concept to me.

These aren't farms like old MacDonald.

These are farms like like managed areas where people can can hunt deer or just have deer live.

Right?

There's there's two ways.

Yes.

These are deer that are grown or produced in high fences.

So they have pens.

That's where these animals are.

They reproduce now.

They can be small or they can be very big.

There are depending there's a big variety.

But the the thing is, many times people think about their farming as an industry where there's these very tame deer in these bands and, and then people send them out and for hunting, because most of the big majority of the produced bugs in these farms are for trophy hunting.

Are deer and managed areas like that more susceptible to say screw worms if they were to show up because they're less attended to or focused on than cattle would be.

It will really depend.

And they're different in terms of their behavior.

So there are a lot more sensitive to flies or other things they don't get.

I mean, let me see how I can explain this.

There are two the species are different, right.

So there are a lot more delicate.

So it can be a problem if these deers are being cut.

Thieves race.

There's two advantages.

One, you can see the animals that are right there and second, you have the chance of treating them.

You can use darts or you can have facilities to bring them in, but you can treat them.

It will be very different from a deer that's out in a big preserve, running free or a completely wild year.

Those will be very challenging to treat or even to see, because that's one of the things that's always tricky with wildlife is that most of the wildlife will never show their weakness, even if they're super, very, very sick.

If humans come by or they notice that there's a predator or humans, they will always show themselves as they're perfectly healthy and strong.

They'll never show weakness.

So that's why, especially in case of screw up, it can be.

It will probably be challenging to identify animals that are very sick.

Unless they're at the point where they're really sick.

And so a little bit different.

We will have to see how how exactly that's going to work out.

But I assume that deer will probably be less likely to get infected unless they have a lesion.

And that also will depend if they're bugs and they're growing there, for example.

And there's can bleed very easily.

And this screw worm, the fly is searched for those little lesions, blood cuts, things like that to lay their eggs.

So it will all depend on the season, the category of the animal and the situation and where they're being raised.

So explain, you know, describe what a screw worm is for our listeners.

Okay.

Yeah.

I'll describe it in a very simple terms.

A screw worm is a fly that's native for most of the Americas, South Central America, southern United States.

It was around for a long time until it was eradicated in the southern United States.

The big difference between this fly and any other fly that leads eggs and they produce llamas or maggots, is that most of the other flies will lay their eggs on rotting or dead things to for the larvae to for these eggs to hatch, the larva to come in and start feeding on that.

The big difference with the screw worm is that the screw worm doesn't feed on dead animals or things.

It feeds on live animal, generally warmblood animals tissue.

That's the big thing.

And the other thing is also you have to understand this is not a pathogen, is not a disease, it's a parasite.

So this fly tends to search for animal.

It's always searching for animals that have small lesions, cut bruises and that attracts this fly.

And that's where it's going to lay it's eggs they can they can if left unchecked they could kill a cow that they got into.

At the point.

Yes.

So generally this this fly has around and I'm not an entomologist, so I could make some mistakes.

I want to clarify that.

But generally it's not that the cycle for this fly is 21 days, generally from egg to to developing its 21 days.

So three weeks when this when the female fly produces eggs and they lay them on the, on the, on the lesion or on an area that has a little bit of blood on an animal, these eggs will hatch in a couple in generally in a couple hours up to 24 hours.

And they'll start growing and feeding, feeding, feeding, feeding for around 5 to 7 days.

Then these eggs will jump at once.

They're they're fully developed.

They will jump out of that lesion, go in the ground poopy.

And then for another almost another week and then the mature fly comes out and lives again another week or ten days trying to reproduce and lay more eggs.

I just wanted to kind of show the cycle because it's really important.

The big other, the other big difference between this fly and other flies is that these lavas will feed on that animal and grow in 5 to 7 days.

So depending on the amount of eggs that hatch, an amount of lavas, that wound can grow from day one being a quarter inch day to being five inches, day three being six seven inches.

And that's an area that all the muscle, the tissues and everything was already consumed.

So imagine it's very, very bad.

At the same time, if there are more screw worm flies flying around, they smell because that doesn't smell very nice, because it's all this tissue decaying, all this liquid fluids, blood, more flies lay their eggs.

So you have lavas, some that are finishing their their their stage, some that are in half and some new eggs.

So it's something that could keep going.

So you're absolutely right.

If not treated completely, the animal can be killed.

These lavas will bore into the soft tissue.

Sometimes they'll go through the brain, sometimes they'll go the mouth, they'll eat up the tongue.

And they're really they're very worried.

They very, very aggressive eaters.

They can even go into the domino cavity and start feeding on organs, the chest.

So what starts with a little tiny lesion and a couple eggs can get very bad fast.

So they were eradicated in the mid 60s in part or maybe primarily using sterilized flies released into the wild.

Is that still how they're controlled today?

Yes, yes.

So they were in the late 60s from the United States.

A Florida eradicated its population earlier than that.

I think it was in the in the mid 50s.

And then it took a couple years to eradicate it completely from the United States.

Then the objective was, okay, we have cleared the United States.

Where can it come from?

Most likely Mexico.

Right.

So then there was the project continue.

And they started under the program to eradicate the flight completely from Mexico.

They went down to the Central America as well.

And in the 90s they reached Panama and all the north part, it was eradicated.

That's what changed in 2022, I believe, if I'm remembering correctly, there was a couple outbreaks in Panama.

Then it moved to Costa Rica and it started moving up to to southern Mexico.

I think in 2004, 2005, it started coming up.

And now we have some cases in in southern Texas.

So yes, it's the same method, the unique characteristic that this fly has, that it's an advantage to be able to eradicate them is that the female fly one comes out of the poop poop, and it's an adult animal, animal, insect, sorry.

They will go out and they will just copulate with one male in its life, and then it will search a place where to lay those eggs so it doesn't search for multiple males, just one male.

So that's a big advantage.

And that's why this method works.

Because what what happens is that this big labs are are made where they can reproduce millions of male flies, treat them with gamma ray to make them sterile, and then fly with planes or release them in an area where there's there's an outbreak.

And what happens is that we know that the female flies, the wild ones will only reproduce with one male.

And what happens there reproduces with a sterile male.

She will still produce eggs, so she thinks she's perfectly fine.

She'll lay those eggs, but those eggs are infertile and they will not hatch.

And that's how you break the cycle.

And that's how you can slowly, you know, it's terminated, reduce the population until its banks.

This is Gulf Coast life.

Our guest today is Doctor Juan Campos Krauer.

He's clinical assistant professor in the Department of large animal clinical Sciences and Department of wildlife Ecology and Conservation at University of Florida.

We don't have a bunch of time, but can you just tell us a little bit about the 26 outbreak down in the keys?

Was that mostly in Key Deer?

Yeah, there was an outbreak that I remember correctly occurred in 2016, I believe.

Yes.

It was only in the key.

That was a big advantage, that it was perfect because the key has one road coming in and out.

Right.

So it was easy to control to check.

I know Department of Agriculture, Florida Department of Act did an excellent job coordination with Fish and Wildlife to be able to control and not have any infected animals come out because as you know, this, this, this fly will also affect pets.

It can affect dogs.

It can affect many other.

Any warm animal can be affected by this.

So there was a big concern that anything can move out.

So yes it only affected the key.

They were able to keep it there.

It killed many many key deer which is in the species of deer that's in danger.

There's only around eight an estimation about of around 800 left in the keys.

They're really tiny, really beautiful deer.

And around 200 died because of this infection.

Until they were able to manage it and reintroduce the sterile flies and and and the outbreak.

How concerned are Florida cattle farmers and other livestock farmers?

And I guess, dear farmers, about these flies potentially showing up in Florida right now.

Well, everybody, everybody is always worried when you're going to be dealing with something that you don't have experience.

Probably the older, older producers had a little bit of experience before it was gone, but a newer producers have never seen these cases and it's always challenging.

But I can tell you that we have a group here in the University of Florida.

We there we're working in coordination with the Department of Agriculture.

We're working in coordination with Fish and Wildlife to be able to prevent this fly from coming in.

And if it commands, there are also ways to treat it.

So that's the other thing.

It's not the end of the world.

There are treatments to prevent the infection and also to cure the Is the supply of sterile flies adequate?

I learned in researching for this that after the eradication in the United States, we don't really produce them domestically anymore, as from what you know.

Are they able to make enough flies to keep up if things were to spread here?

I don't know exactly at this moment, but I do know that the that Texas has a brand new lab and they're ramping up production there, ramping up production and super fast.

I know that now they're working and they have labs in Texas, and I know they're working hard to get as many flies as possible.

One thing I learned in reading up for this is that the first sterile fly production facility was built in Sebring, Florida, in 1958.

I just thought that was interesting for Southwest Floridians.

Yes, yes, yes, yes.

It started very early here in Florida.

It started very early.

That's why I say there's still I still know some producers there are old enough that remember the time before the screw worm was eradicated.

And they always say that it was hard times.

There was not as many products as we have now.

And to treat that in those parasites.

But yes, a big, a big part of it was here in Florida.

And just to be clear, these are potentially something that if you had an open wound as a human and didn't really pay close attention, they could infect you or lay eggs on you.

But it's really, really a very, very low risk for humans unless they aren't paying attention.

Yes.

Like I said, any warm animal, a warm blood animal can be affected.

Humans were warm animals.

If if a person has reason and you may hear in those in cases, for example, of people that fall or have accidents or get lost, like in the jungle in central South America, that they, they have lesions or cuts and then they can get infected with worms.

Yes, that's the case.

If you have a lesion, you may get infected if these flies are around.

But I mean, in a more open area where you have other people and where you have access to to health care, it should not be a problem at all.

And unless you're stranded somewhere, you know, in in a very bad situation, that could be a different story.

If you see an animal out in the wild that has the kinds of wounds that you've been describing, who should you report it to?

Yes.

So one thing I encourage everybody report, report.

If you see anything strange and talking about wildlife, and I'm so glad you brought this up, one of the things that we will see if it ever comes back to to Florida, hopefully not.

And wildlife is affected.

One of the things that wildlife does is they will change their behavior.

So if a deer, for example, one of the animals that I'm worried that is feral hogs, for example, it's affected, it's likely that this animal will change its behavior.

So if you happen to see, let's say the fly is around, there have been some cases in Florida which hopefully not ever.

And you see a deer just coming out and going in circles acting strange.

Maybe.

It seems it looks like it has a hump or something in his back or anything strange.

It's always important to reach out to the fish and wildlife, and to let them know so that they can come and take and take a look and see if it's a screw one case or not.

You can also one if you're interested in getting more information.

A really nice web page where you can go is the www.screwworm.gov.

You will have.

You will find lots of information there.

That's why including all the United States everywhere.

And you can also go to the Florida Department of Agriculture where you can find just type down screw worm.

You'll find all the updates for veterinarians.

It's important that they go there because there are new products.

There are there are now available that will work against screw worm.

And it's important for them just to be prepared and have those products in their head in case they need to use them in the future.

And that's for small animals, large animals and horses.

Well, that is unfortunately all the time we have.

I want to thank my guest.

Doctor Juan Campos Krauer is clinical assistant professor in the Department of Large Animal Clinical Sciences and the Department of Wildlife Ecology and Conservation at University of Florida.

Thank you so much for your time, Doctor Campos.

I really appreciate it.

You're welcome.

It's been a pleasure.

And anytime, if you have any questions, please just reach out.

Thank you very much.

You can find links to more information about New World screw worms, including the link he mentioned and the work he does on our website, WGCU.org/GCL You can also find all of our past episodes there.

Our show today was produced by Emma Rodriguez and myself.

We had audio production today from Jared Gonzalez and video production from David Oquendo.

For now, thanks for listening.

I'm Mike Kiniry.

This is WGCU-FM Fort Myers 90.1 WMKO Marco Island 91.7 FM.

We are NPR for Southwest Florida.