Bird flu continues to affect egg and poultry producers in Maricopa County and elsewhere; Hickman’s Family Farms says it’s lost nearly all of its birds to the disease. But it’s not the only potential threat to Arizona livestock.
The U.S. Department of Agriculture last month stopped the movement of cows, horses and bison between Mexico and the U.S. because of a parasitic fly that lays hundreds of eggs in the animals. The New World Screwworm can affect any warm-blooded animals – including humans. And it’s got this guest concerned.
Bas Aja, executive vice president of the Arizona Cattle Feeders Association, joined The Show to discuss, starting with the fact that once the eggs hatch, the worms themselves start eating away at the flesh of the host.
Full conversation
BAS AJA: The screwworm actually has two like tentacle knives, claws, on its mouth, and it twists and eats its way in, which is why they call it the screwworm.
MARK BRODIE: Does it kill the cow?
AJA: It can, it can. Undetected, untreated, it will kill the animal.
BRODIE: So, what kind of treatment options do you have?
AJA: Usually, you have to physically handle the animal, you know, rope them or catch them. And then, you put a topical treatment on that's a parasitic killer and, there, there's various names for them all, and one of them is like a pine tar oil thing they call it, and that's what you use to treat it.
BRODIE: So this is not the first time that this has been an issue, right? I mean, the screwworm has not been a concern for many, many years, but am I right that in your younger days, this was something that you had to deal with on a not infrequent basis?
AJA: Yes, my family's been raising sheep and cattle in Arizona for over 100 years and in the '60s, we were treating hundreds of sheep and cattle for screwworm.
BRODIE: And like how easy or difficult was it to do?
AJA: It's not like it's difficult to treat, it's difficult to detect. With the screwworm, you'll smell it before you see it, and that means that it's already kind of gotten in the host a little bit. And so then, you know, it takes one or two or three treatments to save the animal.
BRODIE: I would imagine that smell is not terribly pleasant.
AJA: It's one of the worst smells I've ever smelled in my life.
BRODIE: And how big are the worms?
AJA: The worms are about 3/8- to a half-inch.
BRODIE: Pretty small.
AJA: Yeah, they're small.
BRODIE: So, how big of a concern is it to you and and to your members that we could be seeing this again in American cows?
AJA: Livestock economists are predicting if it got into the United States like we once had it in the '50s, '60s, that it would cost $150 billion.
BRODIE: Wow. And given that cattle is a pretty big component of Arizona's economy, obviously it's still, a lot of ranchers here. It seems like a pretty big deal for Arizona, too.
AJA: Well, it is a big deal. Arizona's nearly $4 billion cattle industry would, it would hurt dramatically. And also, other countries, if you have an outbreak, there, there's some trade barriers once you're found to have screwworm, which is right now we have the border closed with Mexico because of screwworm.
BRODIE: Right. So that would mean that, for example, if there were screwworm in Arizona cattle, ranchers would not be able to sell the beef to other countries?
AJA: We might not be able to move our cattle to other states, and also other countries might forbid us from selling beef there.
BRODIE: How did it come to be that this is a thing that you have to worry about again?
AJA: Well, we walled off the screwworm at the Darien Gap in Central America in the early '70s, and then continued a program of releasing sterile flies. And so, I think people kind of got complacent. Different countries, not just the U.S. but all a lot of countries quit putting as many resources into it. And then, as the people in those countries were finding it difficult to live, that one of the ways they found they could live, they could start raising cattle. And so they started raising cattle in areas in Central America where they hadn't previously, and so it left a host for the fly and the worm to move up the isthmus.
BRODIE: Is closing the border with Mexico, at least as far as cattle is concerned, is that enough in your mind to stop the threat?
AJA: Oh no, no. They're releasing sterile flights seven days a week now. There's some hiccups, there's some problems with getting the flights out of Panama, where the sterile facility is, into Mexico. Some bureaucratic stuff.
And, and we need to release, well, what they say to really control it, we're gonna need to release 50 to 100 million flies a day, and we're doing about 100 to 150 a week. So it's not enough. Our fly facilities were shut down or converted to fruit fly, so because of the danger of the fruit fly for citrus. And so, we're trying to retool some of those back up.
BRODIE: And the idea with the sterile flies is that the screwworms try to reproduce with them and they're not able to and then the population just goes down.
AJA: Yes, the target is the male, sterilize the male, and then, and then there's no reproduction.
BRODIE: So, let's assume that you could get the quantity of flies to release that that you say we need to. Is that enough, or are there other measures you need to take as well?
AJA: Well, that's the main one to control it. And the narrowest part of Mexico, what they call the isthmus, and we have a line there now and there's only been one or two detections above it. But, you need to have about 50 million flies per square mile to really have effective control. And so if you get a real narrow area, you can do a lot of flies per square mile. If it starts getting farther north into Mexico, it takes more and more and more flies, plus it gets closer to Texas. That isthmus is only about 700 miles from Texas today.
BRODIE: Has screwworm been detected north of there so far?
AJA: Two incidents and, and they're not active now, but they were, and they caught them.
BRODIE: In the universe of things that keep you up at night, where does this one rank?
AJA: This one ranks up there, and, and especially as it goes forward, it, I wasn't really worried about screwworm. I heard about it in, you know, Panama and in Costa Rica. But, when they hit Guatemala, it got our attention and then when I got into Mexico, it was, you know, it was no holds barred now.
BRODIE: Are your members testing? Are they trying to be on the lookout for signs of it?
AJA: They're, they're always looking, we have bio plans for, for our ranches and feedlots and dairies and that, so we're always watching for stuff. And as you can see what is happening with HPAI, they're always on the lookout.
BRODIE: Do you see any parallels between this situation and what we've been seeing with avian flu in terms of how chicken producers are having to deal with that and whole flocks having to be wiped out and that kind of thing?
AJA: Yes and no, but mostly no, because HPAI is viral, right. With the screwworm, it's not that way. The short life span of the fly and, and, and it's not viral. It takes that physical contact and laying of the egg, but, but it is, you know, something that makes us look at our food production system, is very important to protect.
